gsk: Tweak GskGLShader long desc

Reformulate one paragraph, as suggested by Benjamin.

.gitlab-ci/test-msys2.sh

@@ -48,7 +48,7 @@ if ! pkg-config --atleast-version=2.65.0 glib-2.0; then
 fi
 pkg-config --modversion glib-2.0
 
-if ! pkg-config --atleast-version=1.45.4 pango; then
+if ! pkg-config --atleast-version=1.47.0 pango; then
     git clone https://gitlab.gnome.org/GNOME/pango.git _pango
     meson setup _pango_build _pango
     meson compile -C _pango_build

AUTHORS

@@ -1,5 +1,5 @@
-Please do not mail any of the authors listed here 
-asking questions about this version of GTK+. 
+Please do not mail any of the authors listed here
+asking questions about this version of GTK.
 
 Original Authors
 ----------------
@@ -7,8 +7,8 @@ Peter Mattis      <petm@xcf.berkeley.edu>
 Spencer Kimball   <spencer@xcf.berkeley.edu>
 Josh MacDonald    <jmacd@xcf.berkeley.edu>
 
-The GTK+ Team (in alphabetical order)
--------------------------------------
+The Team that build GTK 2 (in alphabetical order)
+-------------------------------------------------
 Shawn T. Amundson <amundson@gtk.org>
 Jerome Bolliet    <bolliet@gtk.org>
 Damon Chaplin     <damon@gtk.org>
@@ -28,11 +28,24 @@ Jay Painter       <jpaint@gtk.org>
 Manish Singh      <manish@gtk.org>
 Owen Taylor       <otaylor@gtk.org>
 
+The current team (GTK 3 and 4)
+------------------------------
+
+Jonas Ådahl       <jadahl@gmail.com>
+Tim Bäder         <mail@baedert.org>
+Emmanuele Bassi   <ebassi@gnome.org>
+Chun-wei Fan      <fanchunwei@src.gnome.org>
+Matthias Clasen   <mclasen@redhat.com>
+Carlos Garnacho   <mrgarnacho@gmail.com>
+Alexander Larsson <alexl@redhat.com>
+Benjamin Otte     <otte@gnome.org>
+
+
 There are many others who have contributed patches; we thank them,
-GTK+ is much better because of them.
+GTK is much better because of them.
 
 
-Over time, GTK+ has incorporated some pieces of software which 
+Over time, GTK has incorporated some pieces of software which
 started as independent projects. We list the original authors here:
 
 
@@ -63,3 +76,8 @@ DirectFB backend
 Denis Oliver Kropp
 Sven Neumann
 Mike Emmel
+
+
+gtkparasite
+-----------
+Christian Hammond

NEWS

@@ -1,3 +1,121 @@
+Overview of Changes in GTK 3.99.2
+=================================
+
+* GtkEntry:
+ - Fix issues with Emoji insertion
+ - Fix issues with dnd
+ - Set correct hotspot for dnd icon
+
+* GtkPasswordEntry:
+ - Use non-pageable memory
+
+* GtkSearchEntry:
+ - Don't handle forwarded events twice
+
+* GtkPasswordEntry:
+ - Add an ::activate signal
+
+* GtkTextView:
+ - Fix dnd
+ - Improve undo state tracking
+ - Speed rendering in the presence of selections
+ - Make clickable links work again
+ - Fix handling of anchored children
+
+* GtkRevealer:
+ - Fix clipping issues in the swing transitions
+
+* GtkColorChooser:
+ - Update the default palette
+
+* GtkFileChooser:
+ - Fix a crash
+ - Fix setting unlisted filters
+
+* GtkFontChooser:
+ - Determine sample text based on font coverage
+ - Allow filtering by language
+
+* GtkStack:
+ - Add gtk_stack_add_child
+
+* GtkVideo:
+ - Make autoplay work
+
+* CSS:
+ - Allow more than 64 selectors per rule
+
+* Adwaita:
+ - Improve gesture graphics
+ - Tweak DND highlight color
+ - Add spacing to .navigation-sidebar
+
+* GDK:
+ - Add gdk_frame_clock_get_fps
+
+* GSK:
+ - Add radial gradient nodes
+
+* GL renderer:
+ - Fix clipping with projective transforms
+ - Use linear interpolation for offscreen rendering
+   with non-axis-aligned transforms
+ - Fix texture caching to avoid size mismatches
+
+* Vulkan renderer:
+ - Fix swapchain creation
+
+* Windows:
+ - Fix display of CSD windows
+
+* Wayland
+ - Always ack configure to avoid jumping windows
+
+* API cleanups:
+ - Make filter and sorter constructors return exact types
+ - Rename GdkSurfaceState to GdkToplevelState
+ - Remove GdkWaylandSurface::committed
+ - Make Wayland backend api take GdkToplevel
+
+* Demos:
+ - Bug and crash fixes
+ - Cosmetic improvements for several demos
+ - Improve search in the sidebar
+ - Add a Shadertoy demo
+ - Add an Emblem demo
+ - Add a demo for input validation and error states
+ - Add a demo for context menus
+ - Make gtk-demo demo itself
+
+* Build:
+ - Fix Vulkan dependency checking
+ - Make sysprof truly optional
+
+* Translation updates:
+ Basque
+ British English
+ Catalan
+ Croatian
+ Czech
+ Danish
+ French
+ Galician
+ German
+ Hungarian
+ Indonesian
+ Italian
+ Kazakh
+ Latvian
+ Lithuanian
+ Persian
+ Polish
+ Slovak
+ Slovenian
+ Spanish
+ Turkish
+ Ukrainian
+
+
 Overview of Changes in GTK 3.99.1
 =================================
 

config.h.meson

@@ -69,6 +69,9 @@
 /* Define to 1 if you have the `mkstemp' function. */
 #mesondefine HAVE_MKSTEMP
 
+/* Define to 1 if you have the `mlock` function. */
+#mesondefine HAVE_MLOCK
+
 /* Define to 1 if you have a working `mmap' system call. */
 #mesondefine HAVE_MMAP
 

demos/constraint-editor/constraint-view.c

@@ -177,11 +177,11 @@ constraint_view_init (ConstraintView *self)
   guides = gtk_constraint_layout_observe_guides (GTK_CONSTRAINT_LAYOUT (manager));
 
   all_constraints = gtk_constraint_layout_observe_constraints (GTK_CONSTRAINT_LAYOUT (manager));
-  filter = gtk_custom_filter_new (omit_internal, NULL, NULL);
+  filter = GTK_FILTER (gtk_custom_filter_new (omit_internal, NULL, NULL));
   constraints = (GListModel *)gtk_filter_list_model_new (all_constraints, filter);
 
   all_children = gtk_widget_observe_children (GTK_WIDGET (self));
-  filter = gtk_custom_filter_new (omit_internal, NULL, NULL);
+  filter = GTK_FILTER (gtk_custom_filter_new (omit_internal, NULL, NULL));
   children = (GListModel *)gtk_filter_list_model_new (all_children, filter);
 
   list = g_list_store_new (G_TYPE_LIST_MODEL);

demos/gtk-demo/alienplanet.glsl

@@ -0,0 +1,345 @@
+// Originally from: https://www.shadertoy.com/view/wsjBD3
+// License CC0: A battered alien planet
+//  Been experimenting with space inspired shaders
+
+#define PI  3.141592654
+#define TAU (2.0*PI)
+
+#define TOLERANCE       0.00001
+#define MAX_ITER        65
+#define MIN_DISTANCE    0.01
+#define MAX_DISTANCE    9.0
+
+const vec3  skyCol1       = vec3(0.35, 0.45, 0.6);
+const vec3  skyCol2       = vec3(0.4, 0.7, 1.0);
+const vec3  skyCol3       = pow(skyCol1, vec3(0.25));
+const vec3  sunCol1       = vec3(1.0,0.6,0.4);
+const vec3  sunCol2       = vec3(1.0,0.9,0.7);
+const vec3  smallSunCol1  = vec3(1.0,0.5,0.25)*0.5;
+const vec3  smallSunCol2  = vec3(1.0,0.5,0.25)*0.5;
+const vec3  mountainColor = 1.0*sqrt(vec3(0.95, 0.65, 0.45));
+const float cellWidth     = 1.0;
+const vec4  planet        = vec4(80.0, -20.0, 100.0, 50.0)*1000.0;
+
+void rot(inout vec2 p, float a) {
+  float c = cos(a);
+  float s = sin(a);
+  p = vec2(p.x*c + p.y*s, -p.x*s + p.y*c);
+}
+
+vec2 mod2(inout vec2 p, vec2 size) {
+  vec2 c = floor((p + size*0.5)/size);
+  p = mod(p + size*0.5,size) - size*0.5;
+  return c;
+}
+
+float circle(vec2 p, float r) {
+  return length(p) - r;
+}
+
+float egg(vec2 p, float ra, float rb) {
+  const float k = sqrt(3.0);
+  p.x = abs(p.x);
+  float r = ra - rb;
+  return ((p.y<0.0)       ? length(vec2(p.x,  p.y    )) - r :
+          (k*(p.x+r)<p.y) ? length(vec2(p.x,  p.y-k*r)) :
+                              length(vec2(p.x+r,p.y    )) - 2.0*r) - rb;
+}
+
+vec2 hash(vec2 p) {
+  p = vec2(dot (p, vec2 (127.1, 311.7)), dot (p, vec2 (269.5, 183.3)));
+  return -1. + 2.*fract (sin (p)*43758.5453123);
+}
+
+vec2 raySphere(vec3 ro, vec3 rd, vec4 sphere) {
+  vec3 center = sphere.xyz;
+  float radius = sphere.w;
+  vec3 m = ro - center.xyz;
+  float b = dot(m, rd);
+  float c = dot(m, m) - radius*radius;
+  if(c > 0.0 && b > 0.0) return vec2(-1.0, -1.0);
+  float discr = b * b - c;
+  if(discr < 0.0) return vec2(-1.0);
+  float normalMultiplier = 1.0;
+  float s = sqrt(discr);
+  float t0 = -b - s;
+  float t1 = -b + s;;
+  return vec2(t0, t1);
+}
+
+float noise1(vec2 p) {
+  vec2 n = mod2(p, vec2(cellWidth));
+  vec2 hh = hash(sqrt(2.0)*(n+1000.0));
+  hh.x *= hh.y;
+
+  float r = 0.225*cellWidth;
+
+  float d = circle(p, 2.0*r);
+
+  float h = hh.x*smoothstep(0.0, r, -d);
+
+  return h*0.25;
+}
+
+float noise2(vec2 p) {
+  vec2 n = mod2(p, vec2(cellWidth));
+  vec2 hh = hash(sqrt(2.0)*(n+1000.0));
+  hh.x *= hh.y;
+
+  rot(p, TAU*hh.y);
+  float r = 0.45*cellWidth;
+
+//  float d = circle(p, 1.0*r);
+  float d = egg(p, 0.75*r, 0.5*r*abs(hh.y));
+
+  float h = (hh.x)*smoothstep(0.0, r, -2.0*d);
+
+  return h*0.275;
+}
+
+
+float height(vec2 p, float dd, int mx) {
+  const float aa   = 0.45;
+  const float ff   = 2.03;
+  const float tt   = 1.2;
+  const float oo   = 3.93;
+  const float near = 0.25;
+  const float far  = 0.65;
+
+  float a = 1.0;
+  float o = 0.2;
+  float s = 0.0;
+  float d = 0.0;
+
+  int i = 0;
+
+  for (; i < 4;++i) {
+    float nn = a*noise2(p);
+    s += nn;
+    d += abs(a);
+    p += o;
+    a *= aa;
+    p *= ff;
+    o *= oo;
+    rot(p, tt);
+  }
+
+  float lod = s/d;
+
+  float rdd = dd/MAX_DISTANCE;
+  mx = int(mix(float(4), float(mx), step(rdd, far)));
+
+  for (; i < mx; ++i) {
+    float nn = a*noise1(p);
+    s += nn;
+    d += abs(a);
+    p += o;
+    a *= aa;
+    p *= ff;
+    o *= oo;
+    rot(p, tt);
+  }
+
+  float hid = (s/d);
+
+  return mix(hid, lod, smoothstep(near, far, rdd));
+}
+
+float loheight(vec2 p, float d) {
+  return height(p, d, 0);
+}
+
+float height(vec2 p, float d) {
+  return height(p, d, 6);
+}
+
+float hiheight(vec2 p, float d) {
+  return height(p, d, 8);
+}
+
+vec3 normal(vec2 p, float d) {
+  vec2 eps = vec2(0.00125, 0.0);
+
+  vec3 n;
+
+  n.x = (hiheight(p - eps.xy, d) - hiheight(p + eps.xy, d));
+  n.y = 2.0*eps.x;
+  n.z = (hiheight(p - eps.yx, d) - hiheight(p + eps.yx, d));
+
+  return normalize(n);
+}
+
+const float stepLength[] = float[](0.9, 0.25);
+
+
+float march(vec3 ro, vec3 rd, out int max_iter) {
+  float dt = 0.1;
+  float d = MIN_DISTANCE;
+  int currentStep = 0;
+  float lastd = d;
+  for (int i = 0; i < MAX_ITER; ++i)
+  {
+    vec3 p = ro + d*rd;
+    float h = height(p.xz, d);
+
+    if (d > MAX_DISTANCE) {
+      max_iter = i;
+      return MAX_DISTANCE;
+    }
+
+    float hd = p.y - h;
+
+    if (hd < TOLERANCE) {
+      ++currentStep;
+      if (currentStep >= stepLength.length()) {
+        max_iter = i;
+        return d;
+      }
+
+      d = lastd;
+      continue;
+    }
+
+    float sl = stepLength[currentStep];
+
+    dt = max(hd, TOLERANCE)*sl + 0.0025*d;
+    lastd = d;
+    d += dt;
+  }
+
+  max_iter = MAX_ITER;
+  return MAX_DISTANCE;
+}
+
+vec3 sunDirection() {
+  return normalize(vec3(-0.5, 0.085, 1.0));
+}
+
+vec3 smallSunDirection() {
+  return normalize(vec3(-0.2, -0.05, 1.0));
+}
+
+float psin(float f) {
+  return 0.5 + 0.5*sin(f);
+}
+
+vec3 skyColor(vec3 ro, vec3 rd) {
+  vec3 sunDir = sunDirection();
+  vec3 smallSunDir = smallSunDirection();
+
+  float sunDot = max(dot(rd, sunDir), 0.0);
+  float smallSunDot = max(dot(rd, smallSunDir), 0.0);
+
+  float angle = atan(rd.y, length(rd.xz))*2.0/PI;
+
+  vec3 skyCol = mix(mix(skyCol1, skyCol2, max(0.0, angle)), skyCol3, clamp(-angle*2.0, 0.0, 1.0));
+
+  vec3 sunCol = 0.5*sunCol1*pow(sunDot, 20.0) + 8.0*sunCol2*pow(sunDot, 2000.0);
+  vec3 smallSunCol = 0.5*smallSunCol1*pow(smallSunDot, 200.0) + 8.0*smallSunCol2*pow(smallSunDot, 20000.0);
+
+  vec3 dust = pow(sunCol2*mountainColor, vec3(1.75))*smoothstep(0.05, -0.1, rd.y)*0.5;
+
+  vec2 si = raySphere(ro, rd, planet);
+
+  vec3 planetSurface = ro + si.x*rd;
+  vec3 planetNormal = normalize(planetSurface - planet.xyz);
+  float planetDiff = max(dot(planetNormal, sunDir), 0.0);
+  float planetBorder = max(dot(planetNormal, -rd), 0.0);
+  float planetLat = (planetSurface.x+planetSurface.y)*0.0005;
+  vec3 planetCol = mix(1.3*vec3(0.9, 0.8, 0.7), 0.3*vec3(0.9, 0.8, 0.7), pow(psin(planetLat+1.0)*psin(sqrt(2.0)*planetLat+2.0)*psin(sqrt(3.5)*planetLat+3.0), 0.5));
+
+  vec3 final = vec3(0.0);
+
+  final += step(0.0, si.x)*pow(planetDiff, 0.75)*planetCol*smoothstep(-0.075, 0.0, rd.y)*smoothstep(0.0, 0.1, planetBorder);
+
+  final += skyCol + sunCol + smallSunCol + dust;
+
+  return final;
+}
+
+vec3 getColor(vec3 ro, vec3 rd) {
+  int max_iter = 0;
+  vec3 skyCol = skyColor(ro, rd);
+  vec3 col = vec3(0);
+
+  float d = march(ro, rd, max_iter);
+
+  if (d < MAX_DISTANCE)   {
+    vec3 sunDir = sunDirection();
+    vec3 osunDir = sunDir*vec3(-1.0, .0, -1.0);
+    vec3 p = ro + d*rd;
+
+    vec3 normal = normal(p.xz, d);
+
+    float amb = 0.2;
+
+    float dif1 = max(0.0, dot(sunDir, normal));
+    vec3 shd1 = sunCol2*mix(amb, 1.0, pow(dif1, 0.75));
+
+    float dif2 = max(0.0, dot(osunDir, normal));
+    vec3 shd2 = sunCol1*mix(amb, 1.0, pow(dif2, 0.75));
+
+    vec3 ref = reflect(rd, normal);
+    vec3 rcol = skyColor(p, ref);
+
+    col = mountainColor*amb*skyCol3;
+    col += mix(shd1, shd2, -0.5)*mountainColor;
+    float fre = max(dot(normal, -rd), 0.0);
+    fre = pow(1.0 - fre, 5.0);
+    col += rcol*fre*0.5;
+    col += (1.0*p.y);
+    col = tanh(col);
+    col = mix(col, skyCol, smoothstep(0.5*MAX_DISTANCE, 1.0*MAX_DISTANCE, d));
+
+  } else {
+    col = skyCol;
+  }
+
+//  col += vec3(1.1, 0.0, 0.0)* smoothstep(0.25, 1.0,(float(max_iter)/float(MAX_ITER)));
+  return col;
+}
+
+vec3 getSample1(vec2 p, float time) {
+  float off = 0.5*iTime;
+
+  vec3 ro  = vec3(0.5, 1.0-0.25, -2.0 + off);
+  vec3 la  = ro + vec3(0.0, -0.30,  2.0);
+
+  vec3 ww = normalize(la - ro);
+  vec3 uu = normalize(cross(vec3(0.0,1.0,0.0), ww));
+  vec3 vv = normalize(cross(ww, uu));
+  vec3 rd = normalize(p.x*uu + p.y*vv + 2.0*ww);
+
+  vec3 col = getColor(ro, rd)  ;
+
+  return col;
+}
+
+vec3 getSample2(vec2 p, float time) {
+  p.y-=time*0.25;
+  float h = height(p, 0.0);
+  vec3 n = normal(p, 0.0);
+
+  vec3 lp = vec3(10.0, -1.2, 0.0);
+
+  vec3 ld = normalize(vec3(p.x, h, p.y)- lp);
+
+  float d = max(dot(ld, n), 0.0);
+
+  vec3 col = vec3(0.0);
+
+  col = vec3(1.0)*(h+0.1);
+  col += vec3(1.5)*pow(d, 0.75);
+
+  return col;
+}
+
+void mainImage(out vec4 fragColor, vec2 fragCoord) {
+  vec2 q = fragCoord.xy/iResolution.xy;
+  vec2 p = -1.0 + 2.0*q;
+  p.x *= iResolution.x/iResolution.y;
+
+  vec3 col = getSample1(p, iTime);
+
+  fragColor = vec4(col, 1.0);
+}

demos/gtk-demo/application.c

@@ -472,11 +472,11 @@ static void
 surface_state_changed (GtkWidget *widget)
 {
   DemoApplicationWindow *window = (DemoApplicationWindow *)widget;
-  GdkSurfaceState new_state;
+  GdkToplevelState new_state;
 
   new_state = gdk_toplevel_get_state (GDK_TOPLEVEL (gtk_native_get_surface (GTK_NATIVE (widget))));
-  window->maximized = (new_state & GDK_SURFACE_STATE_MAXIMIZED) != 0;
-  window->fullscreen = (new_state & GDK_SURFACE_STATE_FULLSCREEN) != 0;
+  window->maximized = (new_state & GDK_TOPLEVEL_STATE_MAXIMIZED) != 0;
+  window->fullscreen = (new_state & GDK_TOPLEVEL_STATE_FULLSCREEN) != 0;
 }
 
 static void

demos/gtk-demo/assistant.c

@@ -1,8 +1,8 @@
 /* Assistant
  *
- * Demonstrates a sample multi-step assistant. Assistants are used to divide
- * an operation into several simpler sequential steps, and to guide the user
- * through these steps.
+ * Demonstrates a sample multi-step assistant with GtkAssistant. Assistants
+ * are used to divide an operation into several simpler sequential steps,
+ * and to guide the user through these steps.
  */
 
 #include <gtk/gtk.h>

demos/gtk-demo/builder.c

@@ -1,6 +1,8 @@
 /* Builder
+ * #Keywords: GMenu, GtkPopoverMenuBar, GtkBuilder, GtkStatusBar, toolbar
  *
- * Demonstrates an interface loaded from a XML description.
+ * Demonstrates a traditional interface, loaded from a XML description,
+ * and shows how to connect actions to the menu items and toolbar buttons.
  */
 
 #include <gtk/gtk.h>
@@ -104,6 +106,7 @@ do_builder (GtkWidget *do_widget)
       GtkBuilder *builder;
       GtkWidget *about;
       GtkWidget *status;
+      GtkEventController *controller;
 
       builder = gtk_builder_new_from_resource ("/builder/demo.ui");
 
@@ -117,6 +120,41 @@ do_builder (GtkWidget *do_widget)
                                        window);
       gtk_widget_insert_action_group (window, "win", actions);
 
+      controller = gtk_shortcut_controller_new ();
+      gtk_shortcut_controller_set_scope (GTK_SHORTCUT_CONTROLLER (controller),
+                                         GTK_SHORTCUT_SCOPE_GLOBAL);
+      gtk_widget_add_controller (window, controller);
+      gtk_shortcut_controller_add_shortcut (GTK_SHORTCUT_CONTROLLER (controller),
+           gtk_shortcut_new (gtk_keyval_trigger_new (GDK_KEY_n, GDK_CONTROL_MASK),
+                             gtk_named_action_new ("win.new")));
+      gtk_shortcut_controller_add_shortcut (GTK_SHORTCUT_CONTROLLER (controller),
+           gtk_shortcut_new (gtk_keyval_trigger_new (GDK_KEY_o, GDK_CONTROL_MASK),
+                             gtk_named_action_new ("win.open")));
+      gtk_shortcut_controller_add_shortcut (GTK_SHORTCUT_CONTROLLER (controller),
+           gtk_shortcut_new (gtk_keyval_trigger_new (GDK_KEY_s, GDK_CONTROL_MASK),
+                             gtk_named_action_new ("win.save")));
+      gtk_shortcut_controller_add_shortcut (GTK_SHORTCUT_CONTROLLER (controller),
+           gtk_shortcut_new (gtk_keyval_trigger_new (GDK_KEY_s, GDK_CONTROL_MASK|GDK_SHIFT_MASK),
+                             gtk_named_action_new ("win.save-as")));
+      gtk_shortcut_controller_add_shortcut (GTK_SHORTCUT_CONTROLLER (controller),
+           gtk_shortcut_new (gtk_keyval_trigger_new (GDK_KEY_q, GDK_CONTROL_MASK),
+                             gtk_named_action_new ("win.quit")));
+      gtk_shortcut_controller_add_shortcut (GTK_SHORTCUT_CONTROLLER (controller),
+           gtk_shortcut_new (gtk_keyval_trigger_new (GDK_KEY_c, GDK_CONTROL_MASK),
+                             gtk_named_action_new ("win.copy")));
+      gtk_shortcut_controller_add_shortcut (GTK_SHORTCUT_CONTROLLER (controller),
+           gtk_shortcut_new (gtk_keyval_trigger_new (GDK_KEY_x, GDK_CONTROL_MASK),
+                             gtk_named_action_new ("win.cut")));
+      gtk_shortcut_controller_add_shortcut (GTK_SHORTCUT_CONTROLLER (controller),
+           gtk_shortcut_new (gtk_keyval_trigger_new (GDK_KEY_v, GDK_CONTROL_MASK),
+                             gtk_named_action_new ("win.paste")));
+      gtk_shortcut_controller_add_shortcut (GTK_SHORTCUT_CONTROLLER (controller),
+           gtk_shortcut_new (gtk_keyval_trigger_new (GDK_KEY_F1, 0),
+                             gtk_named_action_new ("win.help")));
+      gtk_shortcut_controller_add_shortcut (GTK_SHORTCUT_CONTROLLER (controller),
+           gtk_shortcut_new (gtk_keyval_trigger_new (GDK_KEY_F7, 0),
+                             gtk_named_action_new ("win.about")));
+
       about = GTK_WIDGET (gtk_builder_get_object (builder, "aboutdialog1"));
       gtk_window_set_transient_for (GTK_WINDOW (about), GTK_WINDOW (window));
       gtk_window_set_hide_on_close (GTK_WINDOW (about), TRUE);

demos/gtk-demo/cogs.glsl

@@ -0,0 +1,224 @@
+// Originally from: https://www.shadertoy.com/view/3ljyDD
+// License CC0: Hexagonal tiling + cog wheels
+//  Nothing fancy, just hexagonal tiling + cog wheels
+
+#define PI      3.141592654
+#define TAU     (2.0*PI)
+#define MROT(a) mat2(cos(a), sin(a), -sin(a), cos(a))
+
+float hash(in vec2 co) {
+  return fract(sin(dot(co.xy ,vec2(12.9898,58.233))) * 13758.5453);
+}
+
+float pcos(float a) {
+  return 0.5 + 0.5*cos(a);
+}
+
+void rot(inout vec2 p, float a) {
+  float c = cos(a);
+  float s = sin(a);
+  p = vec2(c*p.x + s*p.y, -s*p.x + c*p.y);
+}
+
+float modPolar(inout vec2 p, float repetitions) {
+  float angle = 2.0*PI/repetitions;
+  float a = atan(p.y, p.x) + angle/2.;
+  float r = length(p);
+  float c = floor(a/angle);
+  a = mod(a,angle) - angle/2.;
+  p = vec2(cos(a), sin(a))*r;
+  // For an odd number of repetitions, fix cell index of the cell in -x direction
+  // (cell index would be e.g. -5 and 5 in the two halves of the cell):
+  if (abs(c) >= (repetitions/2.0)) c = abs(c);
+  return c;
+}
+
+float pmin(float a, float b, float k) {
+  float h = clamp( 0.5+0.5*(b-a)/k, 0.0, 1.0 );
+  return mix( b, a, h ) - k*h*(1.0-h);
+}
+
+const vec2 sz       = vec2(1.0, sqrt(3.0));
+const vec2 hsz      = 0.5*sz;
+const float smallCount = 16.0;
+
+vec2 hextile(inout vec2 p) {
+  // See Art of Code: Hexagonal Tiling Explained!
+  // https://www.youtube.com/watch?v=VmrIDyYiJBA
+
+  vec2 p1 = mod(p, sz)-hsz;
+  vec2 p2 = mod(p - hsz*1.0, sz)-hsz;
+  vec2 p3 = mix(p2, p1, vec2(length(p1) < length(p2)));
+  vec2 n = p3 - p;
+  p = p3;
+
+  return n;
+}
+
+float circle(vec2 p, float r) {
+  return length(p) - r;
+}
+
+float box(vec2 p, vec2 b) {
+  vec2 d = abs(p)-b;
+  return length(max(d,0.0)) + min(max(d.x,d.y),0.0);
+}
+
+float unevenCapsule(vec2 p, float r1, float r2, float h) {
+  p.x = abs(p.x);
+  float b = (r1-r2)/h;
+  float a = sqrt(1.0-b*b);
+  float k = dot(p,vec2(-b,a));
+  if( k < 0.0 ) return length(p) - r1;
+  if( k > a*h ) return length(p-vec2(0.0,h)) - r2;
+  return dot(p, vec2(a,b) ) - r1;
+}
+
+float cogwheel(vec2 p, float innerRadius, float outerRadius, float cogs, float holes) {
+  float cogWidth  = 0.25*innerRadius*TAU/cogs;
+
+  float d0 = circle(p, innerRadius);
+
+  vec2 icp = p;
+  modPolar(icp, holes);
+  icp -= vec2(innerRadius*0.55, 0.0);
+  float d1 = circle(icp, innerRadius*0.25);
+
+  vec2 cp = p;
+  modPolar(cp, cogs);
+  cp -= vec2(innerRadius, 0.0);
+  float d2 = unevenCapsule(cp.yx, cogWidth, cogWidth*0.75, (outerRadius-innerRadius));
+
+  float d3 = circle(p, innerRadius*0.20);
+
+  float d = 1E6;
+  d = min(d, d0);
+  d = pmin(d, d2, 0.5*cogWidth);
+  d = min(d, d2);
+  d = max(d, -d1);
+  d = max(d, -d3);
+
+  return d;
+}
+
+float ccell1(vec2 p, float r) {
+  float d = 1E6;
+  const float bigCount = 60.0;
+
+  vec2 cp0 = p;
+  rot(cp0, -iTime*TAU/bigCount);
+  float d0 = cogwheel(cp0, 0.36, 0.38, bigCount, 5.0);
+
+  vec2 cp1 = p;
+  float nm = modPolar(cp1, 6.0);
+
+  cp1 -= vec2(0.5, 0.0);
+  rot(cp1, 0.2+TAU*nm/2.0 + iTime*TAU/smallCount);
+  float d1 = cogwheel(cp1, 0.11, 0.125, smallCount, 5.0);
+
+  d = min(d, d0);
+  d = min(d, d1);
+  return d;
+}
+
+float ccell2(vec2 p, float r) {
+  float d = 1E6;
+  vec2 cp0 = p;
+  float nm = modPolar(cp0, 6.0);
+  vec2 cp1 = cp0;
+  const float off = 0.275;
+  const float count = smallCount + 2.0;
+  cp0 -= vec2(off, 0.0);
+  rot(cp0, 0.+TAU*nm/2.0 - iTime*TAU/count);
+  float d0 = cogwheel(cp0, 0.09, 0.105, count, 5.0);
+
+
+  cp1 -= vec2(0.5, 0.0);
+  rot(cp1, 0.2+TAU*nm/2.0 + iTime*TAU/smallCount);
+  float d1 = cogwheel(cp1, 0.11, 0.125, smallCount, 5.0);
+
+  float l = length(p);
+  float d2 = l - (off+0.055);
+  float d3 = d2 + 0.020;;
+
+  vec2 tp0 = p;
+  modPolar(tp0, 60.0);
+  tp0.x -= off;
+  float d4 = box(tp0, vec2(0.0125, 0.005));
+
+  float ctime = -(iTime*0.05 + r)*TAU;
+
+  vec2 tp1 = p;
+  rot(tp1, ctime*12.0);
+  tp1.x -= 0.13;
+  float d5 = box(tp1, vec2(0.125, 0.005));
+
+  vec2 tp2 = p;
+  rot(tp2, ctime);
+  tp2.x -= 0.13*0.5;
+  float d6 = box(tp2, vec2(0.125*0.5, 0.0075));
+
+  float d7 = l - 0.025;
+  float d8 = l - 0.0125;
+
+  d = min(d, d0);
+  d = min(d, d1);
+  d = min(d, d2);
+  d = max(d, -d3);
+  d = min(d, d4);
+  d = min(d, d5);
+  d = min(d, d6);
+  d = min(d, d7);
+  d = max(d, -d8);
+
+  return d;
+}
+
+float df(vec2 p, float scale, inout vec2 nn) {
+  p /= scale;
+  nn = hextile(p);
+  nn = round(nn);
+  float r = hash(nn);
+
+  float d;;
+
+  if (r < 0.5) {
+    d = ccell1(p, r);
+  } else {
+    d = ccell2(p, r);
+  }
+
+  return d*scale;
+}
+
+vec3 postProcess(vec3 col, vec2 q)  {
+  //col = saturate(col);
+  col=pow(clamp(col,0.0,1.0),vec3(0.75));
+  col=col*0.6+0.4*col*col*(3.0-2.0*col);  // contrast
+  col=mix(col, vec3(dot(col, vec3(0.33))), -0.4);  // satuation
+  col*=0.5+0.5*pow(19.0*q.x*q.y*(1.0-q.x)*(1.0-q.y),0.7);  // vigneting
+  return col;
+}
+
+void mainImage(out vec4 fragColor, vec2 fragCoord) {
+  vec2 q = fragCoord/iResolution.xy;
+  vec2 p = -1.0 + 2.0*q;
+  p.x *= iResolution.x/iResolution.y;
+  float tm = iTime*0.1;
+  p += vec2(cos(tm), sin(tm*sqrt(0.5)));
+  float z = mix(0.5, 1.0, pcos(tm*sqrt(0.3)));
+  float aa = 4.0 / iResolution.y;
+
+  vec2 nn = vec2(0.0);
+  float d = df(p, z, nn);
+
+  vec3 col = vec3(160.0)/vec3(255.0);
+  vec3 baseCol = vec3(0.3);
+  vec4 logoCol = vec4(baseCol, 1.0)*smoothstep(-aa, 0.0, -d);
+  col = mix(col, logoCol.xyz, pow(logoCol.w, 8.0));
+  col += 0.4*pow(abs(sin(20.0*d)), 0.6);
+
+  col = postProcess(col, q);
+
+  fragColor = vec4(col, 1.0);
+}

demos/gtk-demo/cogs2.glsl

@@ -0,0 +1,226 @@
+uniform float iTime;
+
+// Originally from: https://www.shadertoy.com/view/3ljyDD
+// License CC0: Hexagonal tiling + cog wheels
+//  Nothing fancy, just hexagonal tiling + cog wheels
+
+#define PI      3.141592654
+#define TAU     (2.0*PI)
+#define MROT(a) mat2(cos(a), sin(a), -sin(a), cos(a))
+
+float hash(in vec2 co) {
+  return fract(sin(dot(co.xy ,vec2(12.9898,58.233))) * 13758.5453);
+}
+
+float pcos(float a) {
+  return 0.5 + 0.5*cos(a);
+}
+
+void rot(inout vec2 p, float a) {
+  float c = cos(a);
+  float s = sin(a);
+  p = vec2(c*p.x + s*p.y, -s*p.x + c*p.y);
+}
+
+float modPolar(inout vec2 p, float repetitions) {
+  float angle = 2.0*PI/repetitions;
+  float a = atan(p.y, p.x) + angle/2.;
+  float r = length(p);
+  float c = floor(a/angle);
+  a = mod(a,angle) - angle/2.;
+  p = vec2(cos(a), sin(a))*r;
+  // For an odd number of repetitions, fix cell index of the cell in -x direction
+  // (cell index would be e.g. -5 and 5 in the two halves of the cell):
+  if (abs(c) >= (repetitions/2.0)) c = abs(c);
+  return c;
+}
+
+float pmin(float a, float b, float k) {
+  float h = clamp( 0.5+0.5*(b-a)/k, 0.0, 1.0 );
+  return mix( b, a, h ) - k*h*(1.0-h);
+}
+
+const vec2 sz       = vec2(1.0, sqrt(3.0));
+const vec2 hsz      = 0.5*sz;
+const float smallCount = 16.0;
+
+vec2 hextile(inout vec2 p) {
+  // See Art of Code: Hexagonal Tiling Explained!
+  // https://www.youtube.com/watch?v=VmrIDyYiJBA
+
+  vec2 p1 = mod(p, sz)-hsz;
+  vec2 p2 = mod(p - hsz*1.0, sz)-hsz;
+  vec2 p3 = mix(p2, p1, vec2(length(p1) < length(p2)));
+  vec2 n = p3 - p;
+  p = p3;
+
+  return n;
+}
+
+float circle(vec2 p, float r) {
+  return length(p) - r;
+}
+
+float box(vec2 p, vec2 b) {
+  vec2 d = abs(p)-b;
+  return length(max(d,0.0)) + min(max(d.x,d.y),0.0);
+}
+
+float unevenCapsule(vec2 p, float r1, float r2, float h) {
+  p.x = abs(p.x);
+  float b = (r1-r2)/h;
+  float a = sqrt(1.0-b*b);
+  float k = dot(p,vec2(-b,a));
+  if( k < 0.0 ) return length(p) - r1;
+  if( k > a*h ) return length(p-vec2(0.0,h)) - r2;
+  return dot(p, vec2(a,b) ) - r1;
+}
+
+float cogwheel(vec2 p, float innerRadius, float outerRadius, float cogs, float holes) {
+  float cogWidth  = 0.25*innerRadius*TAU/cogs;
+
+  float d0 = circle(p, innerRadius);
+
+  vec2 icp = p;
+  modPolar(icp, holes);
+  icp -= vec2(innerRadius*0.55, 0.0);
+  float d1 = circle(icp, innerRadius*0.25);
+
+  vec2 cp = p;
+  modPolar(cp, cogs);
+  cp -= vec2(innerRadius, 0.0);
+  float d2 = unevenCapsule(cp.yx, cogWidth, cogWidth*0.75, (outerRadius-innerRadius));
+
+  float d3 = circle(p, innerRadius*0.20);
+
+  float d = 1E6;
+  d = min(d, d0);
+  d = pmin(d, d2, 0.5*cogWidth);
+  d = min(d, d2);
+  d = max(d, -d1);
+  d = max(d, -d3);
+
+  return d;
+}
+
+float ccell1(vec2 p, float r) {
+  float d = 1E6;
+  const float bigCount = 60.0;
+
+  vec2 cp0 = p;
+  rot(cp0, -iTime*TAU/bigCount);
+  float d0 = cogwheel(cp0, 0.36, 0.38, bigCount, 5.0);
+
+  vec2 cp1 = p;
+  float nm = modPolar(cp1, 6.0);
+
+  cp1 -= vec2(0.5, 0.0);
+  rot(cp1, 0.2+TAU*nm/2.0 + iTime*TAU/smallCount);
+  float d1 = cogwheel(cp1, 0.11, 0.125, smallCount, 5.0);
+
+  d = min(d, d0);
+  d = min(d, d1);
+  return d;
+}
+
+float ccell2(vec2 p, float r) {
+  float d = 1E6;
+  vec2 cp0 = p;
+  float nm = modPolar(cp0, 6.0);
+  vec2 cp1 = cp0;
+  const float off = 0.275;
+  const float count = smallCount + 2.0;
+  cp0 -= vec2(off, 0.0);
+  rot(cp0, 0.+TAU*nm/2.0 - iTime*TAU/count);
+  float d0 = cogwheel(cp0, 0.09, 0.105, count, 5.0);
+
+
+  cp1 -= vec2(0.5, 0.0);
+  rot(cp1, 0.2+TAU*nm/2.0 + iTime*TAU/smallCount);
+  float d1 = cogwheel(cp1, 0.11, 0.125, smallCount, 5.0);
+
+  float l = length(p);
+  float d2 = l - (off+0.055);
+  float d3 = d2 + 0.020;;
+
+  vec2 tp0 = p;
+  modPolar(tp0, 60.0);
+  tp0.x -= off;
+  float d4 = box(tp0, vec2(0.0125, 0.005));
+
+  float ctime = -(iTime*0.05 + r)*TAU;
+
+  vec2 tp1 = p;
+  rot(tp1, ctime*12.0);
+  tp1.x -= 0.13;
+  float d5 = box(tp1, vec2(0.125, 0.005));
+
+  vec2 tp2 = p;
+  rot(tp2, ctime);
+  tp2.x -= 0.13*0.5;
+  float d6 = box(tp2, vec2(0.125*0.5, 0.0075));
+
+  float d7 = l - 0.025;
+  float d8 = l - 0.0125;
+
+  d = min(d, d0);
+  d = min(d, d1);
+  d = min(d, d2);
+  d = max(d, -d3);
+  d = min(d, d4);
+  d = min(d, d5);
+  d = min(d, d6);
+  d = min(d, d7);
+  d = max(d, -d8);
+
+  return d;
+}
+
+float df(vec2 p, float scale, inout vec2 nn) {
+  p /= scale;
+  nn = hextile(p);
+  nn = round(nn);
+  float r = hash(nn);
+
+  float d;;
+
+  if (r < 0.5) {
+    d = ccell1(p, r);
+  } else {
+    d = ccell2(p, r);
+  }
+
+  return d*scale;
+}
+
+vec3 postProcess(vec3 col, vec2 q)  {
+  //col = saturate(col);
+  col=pow(clamp(col,0.0,1.0),vec3(0.75));
+  col=col*0.6+0.4*col*col*(3.0-2.0*col);  // contrast
+  col=mix(col, vec3(dot(col, vec3(0.33))), -0.4);  // satuation
+  col*=0.5+0.5*pow(19.0*q.x*q.y*(1.0-q.x)*(1.0-q.y),0.7);  // vigneting
+  return col;
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv) {
+  vec2 q = fragCoord/resolution.xy;
+  vec2 p = -1.0 + 2.0*q;
+  p.x *= resolution.x/resolution.y;
+  float tm = iTime*0.1;
+  p += vec2(cos(tm), sin(tm*sqrt(0.5)));
+  float z = mix(0.5, 1.0, pcos(tm*sqrt(0.3)));
+  float aa = 4.0 / resolution.y;
+
+  vec2 nn = vec2(0.0);
+  float d = df(p, z, nn);
+
+  vec3 col = vec3(160.0)/vec3(255.0);
+  vec3 baseCol = vec3(0.3);
+  vec4 logoCol = vec4(baseCol, 1.0)*smoothstep(-aa, 0.0, -d);
+  col = mix(col, logoCol.xyz, pow(logoCol.w, 8.0));
+  col += 0.4*pow(abs(sin(20.0*d)), 0.6);
+
+  col = postProcess(col, q);
+
+  fragColor = vec4(col, 1.0);
+}

demos/gtk-demo/combobox.c

@@ -1,4 +1,5 @@
 /* Combo Boxes
+ * #Keywords: GtkCellRenderer
  *
  * The GtkComboBox widget allows to select one option out of a list.
  * The GtkComboBoxEntry additionally allows the user to enter a value

demos/gtk-demo/constraints.c

@@ -1,4 +1,5 @@
 /* Constraints/Simple
+ * #Keywords: GtkLayoutManager
  *
  * GtkConstraintLayout provides a layout manager that uses relations
  * between widgets (also known as "constraints") to compute the position

demos/gtk-demo/constraints2.c

@@ -1,4 +1,5 @@
 /* Constraints/Interactive
+ * #Keywords: GtkConstraintLayout
  *
  * Demonstrate how constraints can be updates during user interaction.
  * The vertical edge between the buttons can be dragged with the mouse.

demos/gtk-demo/css_accordion.c

@@ -1,7 +1,6 @@
 /* Theming/CSS Accordion
  *
  * A simple accordion demo written using CSS transitions and multiple backgrounds
- *
  */
 
 #include <gtk/gtk.h>

demos/gtk-demo/css_basics.c

@@ -1,8 +1,7 @@
 /* Theming/CSS Basics
  *
- * Gtk themes are written using CSS. Every widget is build of multiple items
+ * GTK themes are written using CSS. Every widget is build of multiple items
  * that you can style very similarly to a regular website.
- *
  */
 
 #include <gtk/gtk.h>

demos/gtk-demo/css_multiplebgs.c

@@ -1,8 +1,7 @@
 /* Theming/Multiple Backgrounds
  *
- * Gtk themes are written using CSS. Every widget is build of multiple items
+ * GTK themes are written using CSS. Every widget is build of multiple items
  * that you can style very similarly to a regular website.
- *
  */
 
 #include <gtk/gtk.h>

demos/gtk-demo/css_pixbufs.c

@@ -1,6 +1,7 @@
 /* Theming/Animated Backgrounds
  *
- * This demo is done in honour of the Pixbufs demo further down.
+ * This demo is in honour of a classic Pixbufs demo.
+ *
  * It is done exclusively with CSS as the background of the window.
  */
 

demos/gtk-demo/demo.gresource.xml

@@ -112,6 +112,9 @@
   <gresource prefix="/dnd">
     <file>dnd.css</file>
   </gresource>
+  <gresource prefix="/errorstates">
+    <file>errorstates.ui</file>
+  </gresource>
   <gresource prefix="/fishbowl">
     <file>fishbowl.ui</file>
     <file>gtkfishbowl.c</file>
@@ -121,6 +124,27 @@
     <file>gtkgears.c</file>
     <file>gtkgears.h</file>
   </gresource>
+  <gresource prefix="/shadertoy">
+    <file>gtkshadertoy.c</file>
+    <file>gtkshadertoy.h</file>
+    <file>alienplanet.glsl</file>
+    <file>mandelbrot.glsl</file>
+    <file>neon.glsl</file>
+    <file>cogs.glsl</file>
+    <file>glowingstars.glsl</file>
+  </gresource>
+  <gresource prefix="/gltransition">
+    <file>gtkshaderstack.c</file>
+    <file>gtkshaderstack.h</file>
+    <file>gtkshaderbin.h</file>
+    <file>gtkshaderbin.c</file>
+    <file>fire.glsl</file>
+    <file>transition1.glsl</file>
+    <file>transition2.glsl</file>
+    <file>transition3.glsl</file>
+    <file>transition4.glsl</file>
+    <file>cogs2.glsl</file>
+  </gresource>
   <gresource prefix="/iconscroll">
     <file>iconscroll.ui</file>
   </gresource>
@@ -164,6 +188,16 @@
     <file compressed="true">color.names.txt</file>
     <file>listview_colors.css</file>
   </gresource>
+  <gresource prefix="/main">
+    <file>fontify.c</file>
+    <file>fontify.h</file>
+    <file>main.ui</file>
+  </gresource>
+  <gresource prefix="/menu">
+    <file>demo3widget.c</file>
+    <file>demo3widget.h</file>
+    <file>demo3widget.ui</file>
+  </gresource>
   <gresource prefix="/shortcuts">
     <file>shortcuts.ui</file>
     <file>shortcuts-builder.ui</file>
@@ -187,6 +221,9 @@
     <file>floppybuddy.gif</file>
     <file>gtk-logo.webm</file>
   </gresource>
+  <gresource prefix="/video-player">
+    <file>bbb.png</file>
+  </gresource>
   <gresource prefix="/sources">
     <file>application_demo.c</file>
     <file>assistant.c</file>
@@ -210,6 +247,7 @@
     <file>editable_cells.c</file>
     <file>entry_completion.c</file>
     <file>entry_undo.c</file>
+    <file>errorstates.c</file>
     <file>expander.c</file>
     <file>filtermodel.c</file>
     <file>fishbowl.c</file>
@@ -221,6 +259,7 @@
     <file>gears.c</file>
     <file>gestures.c</file>
     <file>glarea.c</file>
+    <file>gltransition.c</file>
     <file>headerbar.c</file>
     <file>hypertext.c</file>
     <file>iconscroll.c</file>
@@ -242,13 +281,16 @@
     <file>listview_weather.c</file>
     <file>listview_words.c</file>
     <file>list_store.c</file>
+    <file>main.c</file>
     <file>markup.c</file>
+    <file>menu.c</file>
     <file>overlay.c</file>
     <file>overlay2.c</file>
     <file>paint.c</file>
     <file>pagesetup.c</file>
     <file>paintable.c</file>
     <file>paintable_animated.c</file>
+    <file>paintable_emblem.c</file>
     <file>paintable_mediastream.c</file>
     <file>panes.c</file>
     <file>password_entry.c</file>
@@ -260,6 +302,7 @@
     <file>scale.c</file>
     <file>search_entry.c</file>
     <file>search_entry2.c</file>
+    <file>shadertoy.c</file>
     <file>shortcuts.c</file>
     <file>shortcut_triggers.c</file>
     <file>sizegroup.c</file>

demos/gtk-demo/demo.ui

@@ -29,29 +29,24 @@
         <item>
           <attribute name="label" translatable="yes">_New</attribute>
           <attribute name="action">win.new</attribute>
-          <attribute name="accel">&lt;Control&gt;n</attribute>
         </item>
         <item>
           <attribute name="label" translatable="yes">_Open</attribute>
           <attribute name="action">win.open</attribute>
-          <attribute name="accel">&lt;Control&gt;o</attribute>
         </item>
         <item>
           <attribute name="label" translatable="yes">_Save</attribute>
           <attribute name="action">win.save</attribute>
-          <attribute name="accel">&lt;Control&gt;s</attribute>
         </item>
         <item>
           <attribute name="label" translatable="yes">Save _As</attribute>
           <attribute name="action">win.save-as</attribute>
-          <attribute name="accel">&lt;Control&gt;q</attribute>
         </item>
       </section>
       <section>
         <item>
           <attribute name="label" translatable="yes">_Quit</attribute>
           <attribute name="action">win.quit</attribute>
-          <attribute name="accel">&lt;Control&gt;&lt;Shift&gt;s</attribute>
         </item>
       </section>
     </submenu>
@@ -61,17 +56,14 @@
         <item>
           <attribute name="label" translatable="yes">_Copy</attribute>
           <attribute name="action">win.copy</attribute>
-          <attribute name="accel">&lt;Control&gt;c</attribute>
         </item>
         <item>
           <attribute name="label" translatable="yes">_Cut</attribute>
           <attribute name="action">win.cut</attribute>
-          <attribute name="accel">&lt;Control&gt;x</attribute>
         </item>
         <item>
           <attribute name="label" translatable="yes">_Paste</attribute>
           <attribute name="action">win.paste</attribute>
-          <attribute name="accel">&lt;Control&gt;v</attribute>
         </item>
       </section>
     </submenu>
@@ -81,12 +73,10 @@
         <item>
           <attribute name="label" translatable="yes">_Help</attribute>
           <attribute name="action">win.help</attribute>
-          <attribute name="accel">F1</attribute>
         </item>
         <item>
           <attribute name="label" translatable="yes">_About</attribute>
           <attribute name="action">win.about</attribute>
-          <attribute name="accel">F7</attribute>
         </item>
       </section>
     </submenu>
@@ -110,11 +100,15 @@
         </child>
         <child>
           <object class="GtkBox" id="toolbar1">
+            <style>
+              <class name="toolbar"/>
+            </style>
             <child>
               <object class="GtkButton">
                 <property name="label" translatable="yes">New</property>
                 <property name="tooltip-text" translatable="yes">Create a new file</property>
                 <property name="icon-name">document-new</property>
+                <property name="action-name">win.new</property>
               </object>
             </child>
             <child>
@@ -122,6 +116,7 @@
                 <property name="label" translatable="yes">Open</property>
                 <property name="tooltip-text" translatable="yes">Open a file</property>
                 <property name="icon-name">document-open</property>
+                <property name="action-name">win.open</property>
               </object>
             </child>
             <child>
@@ -129,6 +124,7 @@
                 <property name="label" translatable="yes">Save</property>
                 <property name="tooltip-text" translatable="yes">Save a file</property>
                 <property name="icon-name">document-save</property>
+                <property name="action-name">win.save</property>
               </object>
             </child>
             <child>
@@ -139,6 +135,7 @@
                 <property name="label" translatable="yes">Copy</property>
                 <property name="tooltip-text" translatable="yes">Copy selected object into the clipboard</property>
                 <property name="icon-name">edit-copy</property>
+                <property name="action-name">win.copy</property>
               </object>
             </child>
             <child>
@@ -146,6 +143,7 @@
                 <property name="label" translatable="yes">Cut</property>
                 <property name="tooltip-text" translatable="yes">Cut selected object into the clipboard</property>
                 <property name="icon-name">edit-cut</property>
+                <property name="action-name">win.cut</property>
               </object>
             </child>
             <child>
@@ -153,6 +151,7 @@
                 <property name="label" translatable="yes">Paste</property>
                 <property name="tooltip-text" translatable="yes">Paste object from the clipboard</property>
                 <property name="icon-name">edit-paste</property>
+                <property name="action-name">win.paste</property>
               </object>
             </child>
           </object>

demos/gtk-demo/demo3widget.c

@@ -0,0 +1,243 @@
+#include <math.h>
+#include "demo3widget.h"
+
+enum
+{
+  PROP_PAINTABLE = 1,
+  PROP_SCALE
+};
+
+struct _Demo3Widget
+{
+  GtkWidget parent_instance;
+
+  GdkPaintable *paintable;
+  float scale;
+
+  GtkWidget *menu;
+};
+
+struct _Demo3WidgetClass
+{
+  GtkWidgetClass parent_class;
+};
+
+G_DEFINE_TYPE (Demo3Widget, demo3_widget, GTK_TYPE_WIDGET)
+
+static void
+demo3_widget_init (Demo3Widget *self)
+{
+  self->scale = 1.f;
+  gtk_widget_init_template (GTK_WIDGET (self));
+}
+
+static void
+demo3_widget_dispose (GObject *object)
+{
+  Demo3Widget *self = DEMO3_WIDGET (object);
+
+  g_clear_object (&self->paintable);
+  g_clear_pointer (&self->menu, gtk_widget_unparent);
+
+  G_OBJECT_CLASS (demo3_widget_parent_class)->dispose (object);
+}
+
+static void
+demo3_widget_snapshot (GtkWidget   *widget,
+                       GtkSnapshot *snapshot)
+{
+  Demo3Widget *self = DEMO3_WIDGET (widget);
+  int x, y, width, height;
+  double w, h;
+
+  width = gtk_widget_get_width (widget);
+  height = gtk_widget_get_height (widget);
+
+  w = self->scale * gdk_paintable_get_intrinsic_width (self->paintable);
+  h = self->scale * gdk_paintable_get_intrinsic_height (self->paintable);
+
+  x = MAX (0, (width - ceil (w)) / 2);
+  y = MAX (0, (height - ceil (h)) / 2);
+
+  gtk_snapshot_push_clip (snapshot, &GRAPHENE_RECT_INIT (0, 0, width, height));
+  gtk_snapshot_save (snapshot);
+  gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (x, y));
+  gdk_paintable_snapshot (self->paintable, snapshot, w, h);
+  gtk_snapshot_restore (snapshot);
+  gtk_snapshot_pop (snapshot);
+}
+
+static void
+demo3_widget_measure (GtkWidget      *widget,
+                      GtkOrientation  orientation,
+                      int             for_size,
+                      int            *minimum,
+                      int            *natural,
+                      int            *minimum_baseline,
+                      int            *natural_baseline)
+{
+  Demo3Widget *self = DEMO3_WIDGET (widget);
+  int size;
+
+  if (orientation == GTK_ORIENTATION_HORIZONTAL)
+    size = gdk_paintable_get_intrinsic_width (self->paintable);
+  else
+    size = gdk_paintable_get_intrinsic_height (self->paintable);
+
+  *minimum = *natural = self->scale * size;
+}
+
+static void
+demo3_widget_size_allocate (GtkWidget *widget,
+                            int        width,
+                            int        height,
+                            int        baseline)
+{
+  Demo3Widget *self = DEMO3_WIDGET (widget);
+
+  /* Since we are not using a layout manager (who would do this
+   * for us), we need to allocate a size for our menu by calling
+   * gtk_native_check_resize().
+   */
+  gtk_native_check_resize (GTK_NATIVE (self->menu));
+}
+
+static void
+demo3_widget_set_property (GObject      *object,
+                           guint         prop_id,
+                           const GValue *value,
+                           GParamSpec   *pspec)
+{
+  Demo3Widget *self = DEMO3_WIDGET (object);
+
+  switch (prop_id)
+    {
+    case PROP_PAINTABLE:
+      g_clear_object (&self->paintable);
+      self->paintable = g_value_dup_object (value);
+      gtk_widget_queue_resize (GTK_WIDGET (object));
+      break;
+
+    case PROP_SCALE:
+      self->scale = g_value_get_float (value);
+      gtk_widget_queue_resize (GTK_WIDGET (object));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+demo3_widget_get_property (GObject     *object,
+                           guint        prop_id,
+                           GValue      *value,
+                           GParamSpec  *pspec)
+{
+  Demo3Widget *self = DEMO3_WIDGET (object);
+
+  switch (prop_id)
+    {
+    case PROP_PAINTABLE:
+      g_value_set_object (value, self->paintable);
+      break;
+
+    case PROP_SCALE:
+      g_value_set_float (value, self->scale);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+pressed_cb (GtkGestureClick *gesture,
+            guint            n_press,
+            double           x,
+            double           y,
+            Demo3Widget     *self)
+{
+  /* We are placing our menu at the point where
+   * the click happened, before popping it up.
+   */
+  gtk_popover_set_pointing_to (GTK_POPOVER (self->menu),
+                               &(const GdkRectangle){ x, y, 1, 1 });
+  gtk_popover_popup (GTK_POPOVER (self->menu));
+}
+
+static void
+zoom_cb (GtkWidget  *widget,
+         const char *action_name,
+         GVariant   *parameter)
+{
+  Demo3Widget *self = DEMO3_WIDGET (widget);
+  float scale;
+
+  if (g_str_equal (action_name, "zoom.in"))
+    scale = MIN (10, self->scale * M_SQRT2);
+  else if (g_str_equal (action_name, "zoom.out"))
+    scale = MAX (0.01, self->scale / M_SQRT2);
+  else
+    scale = 1.0;
+
+  gtk_widget_action_set_enabled (widget, "zoom.in", scale < 10);
+  gtk_widget_action_set_enabled (widget, "zoom.out", scale > 0.01);
+  gtk_widget_action_set_enabled (widget, "zoom.reset", scale != 1);
+
+  g_object_set (widget, "scale", scale, NULL);
+}
+
+static void
+demo3_widget_class_init (Demo3WidgetClass *class)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+
+  object_class->dispose = demo3_widget_dispose;
+  object_class->set_property = demo3_widget_set_property;
+  object_class->get_property = demo3_widget_get_property;
+
+  widget_class->snapshot = demo3_widget_snapshot;
+  widget_class->measure = demo3_widget_measure;
+  widget_class->size_allocate = demo3_widget_size_allocate;
+
+  g_object_class_install_property (object_class, PROP_PAINTABLE,
+      g_param_spec_object ("paintable", "Paintable", "Paintable",
+                           GDK_TYPE_PAINTABLE,
+                           G_PARAM_READWRITE));
+
+  g_object_class_install_property (object_class, PROP_SCALE,
+      g_param_spec_float ("scale", "Scale", "Scale",
+                          0.0, 10.0, 1.0,
+                          G_PARAM_READWRITE));
+
+  /* These are the actions that we are using in the menu */
+  gtk_widget_class_install_action (widget_class, "zoom.in", NULL, zoom_cb);
+  gtk_widget_class_install_action (widget_class, "zoom.out", NULL, zoom_cb);
+  gtk_widget_class_install_action (widget_class, "zoom.reset", NULL, zoom_cb);
+
+  gtk_widget_class_set_template_from_resource (widget_class, "/menu/demo3widget.ui");
+  gtk_widget_class_bind_template_child (widget_class, Demo3Widget, menu);
+  gtk_widget_class_bind_template_callback (widget_class, pressed_cb);
+}
+
+GtkWidget *
+demo3_widget_new (const char *resource)
+{
+  Demo3Widget *self;
+  GdkPixbuf *pixbuf;
+  GdkPaintable *paintable;
+
+  pixbuf = gdk_pixbuf_new_from_resource (resource, NULL);
+  paintable = GDK_PAINTABLE (gdk_texture_new_for_pixbuf (pixbuf));
+
+  self = g_object_new (DEMO3_TYPE_WIDGET, "paintable", paintable, NULL);
+
+  g_object_unref (pixbuf);
+  g_object_unref (paintable);
+
+  return GTK_WIDGET (self);
+}

demos/gtk-demo/demo3widget.h

@@ -0,0 +1,8 @@
+#pragma once
+
+#include <gtk/gtk.h>
+
+#define DEMO3_TYPE_WIDGET (demo3_widget_get_type ())
+G_DECLARE_FINAL_TYPE (Demo3Widget, demo3_widget, DEMO3, WIDGET, GtkWidget)
+
+GtkWidget * demo3_widget_new (const char *resource);

demos/gtk-demo/demo3widget.ui

@@ -0,0 +1,30 @@
+<interface>
+  <menu id="model">
+    <item>
+      <attribute name="label">Zoom Out</attribute>
+      <attribute name="action">zoom.out</attribute>
+    </item>
+    <item>
+      <attribute name="label">Zoom In</attribute>
+      <attribute name="action">zoom.in</attribute>
+    </item>
+    <item>
+      <attribute name="label">1∶1</attribute>
+      <attribute name="action">zoom.reset</attribute>
+    </item>
+  </menu>
+  <template class="Demo3Widget">
+    <child>
+      <object class="GtkPopoverMenu" id="menu">
+        <property name="has-arrow">0</property>
+        <property name="menu-model">model</property>
+      </object>
+    </child>
+    <child>
+      <object class="GtkGestureClick">
+        <property name="button">3</property>
+        <signal name="pressed" handler="pressed_cb"/>
+      </object>
+    </child>
+  </template>
+</interface>

demos/gtk-demo/dialog.c

@@ -1,4 +1,5 @@
 /* Dialogs
+ * #Keywords: GtkMessageDialog
  *
  * Dialogs are used to pop up transient windows for information
  * and user feedback.

demos/gtk-demo/dnd.c

@@ -1,8 +1,12 @@
 /* Drag-and-Drop
+ * #Keywords: dnd, menu, popover, gesture
  *
  * This demo shows dragging colors and widgets.
  * The items in this demo can be moved, recolored
  * and rotated.
+ *
+ * The demo also has an example for creating a
+ * menu-like popover without using a menu model.
  */
 
 #include <gtk/gtk.h>

demos/gtk-demo/drawingarea.c

@@ -1,4 +1,5 @@
 /* Drawing Area
+ * #Keywords: GtkDrawingArea
  *
  * GtkDrawingArea is a blank area where you can draw custom displays
  * of various kinds.

demos/gtk-demo/errorstates.c

@@ -0,0 +1,124 @@
+/* Error states
+ *
+ * GtkLabel and GtkEntry can indicate errors if you set the .error
+ * style class on them.
+ *
+ * This examples shows how this can be used in a dialog for input validation.
+ *
+ * It also shows how pass callbacks and objects to GtkBuilder with
+ * GtkBuilderScope and gtk_builder_expose_object().
+ */
+
+#include <glib/gi18n.h>
+#include <gtk/gtk.h>
+
+static void
+validate_more_details (GtkEntry   *entry,
+                       GParamSpec *pspec,
+                       GtkEntry   *details)
+{
+  if (strlen (gtk_editable_get_text (GTK_EDITABLE (entry))) > 0 &&
+      strlen (gtk_editable_get_text (GTK_EDITABLE (details))) == 0)
+    {
+      gtk_widget_set_tooltip_text (GTK_WIDGET (entry), "Must have details first");
+      gtk_widget_add_css_class (GTK_WIDGET (entry), "error");
+    }
+  else
+    {
+      gtk_widget_set_tooltip_text (GTK_WIDGET (entry), "");
+      gtk_widget_remove_css_class (GTK_WIDGET (entry), "error");
+    }
+}
+
+static gboolean
+mode_switch_state_set (GtkSwitch *sw,
+                       gboolean   state,
+                       GtkWidget *scale)
+{
+  GtkWidget *label;
+
+  label = GTK_WIDGET (g_object_get_data (G_OBJECT (sw), "error_label"));
+
+  if (!state ||
+      (gtk_range_get_value (GTK_RANGE (scale)) > 50))
+    {
+      gtk_widget_hide (label);
+      gtk_switch_set_state (sw, state);
+    }
+  else
+    {
+      gtk_widget_show (label);
+    }
+
+  return TRUE;
+}
+
+static void
+level_scale_value_changed (GtkRange *range,
+                           GtkWidget *sw)
+{
+  GtkWidget *label;
+
+  label = GTK_WIDGET (g_object_get_data (G_OBJECT (sw), "error_label"));
+
+  if (gtk_switch_get_active (GTK_SWITCH (sw)) &&
+      !gtk_switch_get_state (GTK_SWITCH (sw)) &&
+      (gtk_range_get_value (range) > 50))
+    {
+      gtk_widget_hide (label);
+      gtk_switch_set_state (GTK_SWITCH (sw), TRUE);
+    }
+  else if (gtk_switch_get_state (GTK_SWITCH (sw)) &&
+          (gtk_range_get_value (range) <= 50))
+    {
+      gtk_switch_set_state (GTK_SWITCH (sw), FALSE);
+    }
+}
+
+GtkWidget *
+do_errorstates (GtkWidget *do_widget)
+{
+  static GtkWidget *window = NULL;
+
+  if (!window)
+    {
+      GtkWidget *toplevel;
+      GtkBuilder *builder;
+      GtkBuilderScope *scope;
+      GtkWidget *sw, *label;
+
+      toplevel = GTK_WIDGET (gtk_widget_get_root (do_widget));
+
+      scope = gtk_builder_cscope_new ();
+      gtk_builder_cscope_add_callback_symbols (GTK_BUILDER_CSCOPE (scope),
+              "validate_more_details", G_CALLBACK (validate_more_details),
+              "mode_switch_state_set", G_CALLBACK (mode_switch_state_set),
+              "level_scale_value_changed", G_CALLBACK (level_scale_value_changed),
+              NULL);
+
+      builder = gtk_builder_new ();
+      gtk_builder_set_scope (builder, scope);
+      gtk_builder_expose_object (builder, "toplevel", G_OBJECT (toplevel));
+      gtk_builder_add_from_resource (builder, "/errorstates/errorstates.ui", NULL);
+
+      window = GTK_WIDGET (gtk_builder_get_object (builder, "dialog"));
+
+      gtk_window_set_display (GTK_WINDOW (window),
+                              gtk_widget_get_display (do_widget));
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
+
+      sw = GTK_WIDGET (gtk_builder_get_object (builder, "mode_switch"));
+      label = GTK_WIDGET (gtk_builder_get_object (builder, "error_label"));
+      g_object_set_data (G_OBJECT (sw), "error_label", label);
+
+      g_object_unref (builder);
+      g_object_unref (scope);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_widget_show (window);
+  else
+    gtk_window_destroy (GTK_WINDOW (window));
+
+  return window;
+}

demos/gtk-demo/errorstates.ui

@@ -0,0 +1,158 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<interface>
+  <object class="GtkDialog" id="dialog">
+    <property name="transient-for">toplevel</property>
+    <property name="modal">1</property>
+    <property name="resizable">0</property>
+    <property name="use-header-bar">1</property>
+    <property name="title" translatable="yes">Settings</property>
+    <property name="hide-on-close">1</property>
+    <child internal-child="content_area">
+      <object class="GtkBox">
+        <child>
+          <object class="GtkGrid">
+            <property name="row-spacing">10</property>
+            <property name="column-spacing">10</property>
+            <property name="margin-start">20</property>
+            <property name="margin-end">20</property>
+            <property name="margin-top">20</property>
+            <property name="margin-bottom">20</property>
+            <child>
+              <object class="GtkLabel">
+                <property name="halign">end</property>
+                <property name="valign">baseline</property>
+                <property name="label">_Details</property>
+                <property name="use-underline">1</property>
+                <property name="mnemonic-widget">details_entry</property>
+                <style>
+                  <class name="dim-label"/>
+                </style>
+                <layout>
+                  <property name="column">0</property>
+                  <property name="row">0</property>
+                </layout>
+              </object>
+            </child>
+            <child>
+              <object class="GtkEntry" id="details_entry">
+                <property name="valign">baseline</property>
+                <signal name="notify::text" handler="validate_more_details" object="more_details_entry" swapped="yes"/>
+                <layout>
+                  <property name="column">1</property>
+                  <property name="row">0</property>
+                  <property name="column-span">2</property>
+                </layout>
+              </object>
+            </child>
+            <child>
+              <object class="GtkLabel">
+                <property name="halign">end</property>
+                <property name="valign">baseline</property>
+                <property name="label">More D_etails</property>
+                <property name="use-underline">1</property>
+                <property name="mnemonic-widget">more_details_entry</property>
+                <style>
+                  <class name="dim-label"/>
+                </style>
+                <layout>
+                  <property name="column">0</property>
+                  <property name="row">1</property>
+                </layout>
+              </object>
+            </child>
+            <child>
+              <object class="GtkEntry" id="more_details_entry">
+                <property name="valign">baseline</property>
+                <signal name="notify::text" handler="validate_more_details" object="details_entry" swapped="no"/>
+                <layout>
+                  <property name="column">1</property>
+                  <property name="row">1</property>
+                  <property name="column-span">2</property>
+                </layout>
+              </object>
+            </child>
+            <child>
+              <object class="GtkLabel">
+                <property name="halign">end</property>
+                <property name="valign">baseline</property>
+                <property name="label">_Level</property>
+                <property name="use-underline">1</property>
+                <property name="mnemonic-widget">level_scale</property>
+                <style>
+                  <class name="dim-label"/>
+                </style>
+                <layout>
+                  <property name="column">0</property>
+                  <property name="row">2</property>
+                </layout>
+              </object>
+            </child>
+            <child>
+              <object class="GtkScale" id="level_scale">
+                <property name="valign">baseline</property>
+                <property name="draw-value">0</property>
+                <property name="adjustment">
+                  <object class="GtkAdjustment">
+                    <property name="upper">100</property>
+                    <property name="lower">0</property>
+                    <property name="value">50</property>
+                    <property name="step-increment">1</property>
+                    <property name="page-increment">10</property>
+                  </object>
+                </property>
+                <signal name="value-changed" handler="level_scale_value_changed" object="mode_switch" swapped="no"/>
+                <layout>
+                  <property name="column">1</property>
+                  <property name="row">2</property>
+                  <property name="column-span">2</property>
+                </layout>
+              </object>
+            </child>
+            <child>
+              <object class="GtkLabel">
+                <property name="halign">end</property>
+                <property name="valign">baseline</property>
+                <property name="label">_Mode</property>
+                <property name="use-underline">1</property>
+                <property name="mnemonic-widget">mode_switch</property>
+                <style>
+                  <class name="dim-label"/>
+                </style>
+                <layout>
+                  <property name="column">0</property>
+                  <property name="row">3</property>
+                </layout>
+              </object>
+            </child>
+            <child>
+              <object class="GtkSwitch" id="mode_switch">
+                <property name="halign">start</property>
+                <property name="valign">baseline</property>
+                <signal name="state-set" handler="mode_switch_state_set" object="level_scale" swapped="no"/>
+                <layout>
+                  <property name="column">1</property>
+                  <property name="row">3</property>
+                </layout>
+              </object>
+            </child>
+            <child>
+              <object class="GtkLabel" id="error_label">
+                <property name="visible">0</property>
+                <property name="halign">start</property>
+                <property name="valign">baseline</property>
+                <property name="label">Level too low</property>
+                <style>
+                  <class name="error"/>
+                </style>
+                <layout>
+                  <property name="column">2</property>
+                  <property name="row">3</property>
+                </layout>
+              </object>
+            </child>
+          </object>
+        </child>
+      </object>
+    </child>
+  </object>
+</interface>

demos/gtk-demo/filtermodel.c

@@ -1,4 +1,5 @@
 /* Tree View/Filter Model
+ * #Keywords: GtkTreeView
  *
  * This example demonstrates how GtkTreeModelFilter can be used not
  * just to show a subset of the rows, but also to compute columns

demos/gtk-demo/fire.glsl

@@ -0,0 +1,72 @@
+uniform float u_time;
+uniform sampler2D u_texture1;
+
+/* 2D -> [0..1] random number generator */
+float random(vec2 st) {
+  return fract(sin(dot(st.xy,
+                       vec2(12.9898,78.233))) *
+               43758.5453123);
+}
+
+/* Generate a smoothed 2d noise based on random() */
+float noise(vec2 v) {
+  /* Round point v to integer grid grid */
+  vec2 grid_point = floor(v);
+  /* Randomize in grid corners */
+  float corner1 = random(grid_point);
+  float corner2 = random(grid_point + vec2(1, 0));
+  float corner3 = random(grid_point + vec2(0, 1));
+  float corner4 = random(grid_point + vec2(1, 1));
+  /* Interpolate smoothly between grid points */
+  vec2 fraction = smoothstep(vec2(0.0), vec2(1.0), fract(v));
+  return mix(mix(corner1, corner2, fraction.x),
+             mix(corner3, corner4, fraction.x),
+             fraction.y);
+}
+
+/* fractal brownian motion noice, see https://www.iquilezles.org/www/articles/fbm/fbm.htm */
+float fbm(in vec2 x)
+{
+  const float octaveScale = 1.9;
+  const float G = 0.5;
+  float f = 1.0;
+  float a = 1.0;
+  float t = 0.0;
+  int numOctaves = 5;
+  for (int i = 0; i < numOctaves; i++) {
+    t += a*noise(f*x);
+    f *= octaveScale;
+    a *= G;
+  }
+
+  return t;
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv)
+{
+  vec2 xy = fragCoord / resolution;
+
+  float zoom = 3.0 - sin(u_time*0.5)*0.3;
+
+  // Normalize coord to height of widget
+  vec2 p = (vec2 (-resolution.x/2.0 + fragCoord.x, resolution.y - fragCoord.y) / resolution.yy)* zoom;
+
+    // Use recursive incantations of fbm
+  float q1 = fbm(p - vec2(0.8, 0.3) * u_time);
+  float q2 = fbm(p - vec2(0.5, 1.3) * u_time);
+  float r = fbm(2.0*p + vec2(q1,q2) - vec2(0.0, 1.0)*u_time*10.0 *0.4);
+
+  // Compute intensity, mostly on the bottom
+  float w = 2.0 * r * p.y;
+
+  // Smooth out left/right side and fade in at start
+  w /= smoothstep(0.0,0.1, xy.x)* smoothstep(0.0,0.1, 1.0-xy.x) *  smoothstep(0.0,0.4, u_time);
+
+  // Compute colors
+  vec3 c = vec3(1.0,.2,.05);
+  vec3 color = 1.0 / (w*w/c + 1.0);
+
+  // Mix in widget
+  vec4 widget = GskTexture(u_texture1,uv);
+  fragColor = mix(vec4(color,1), widget, 1.0-color.x);
+}

demos/gtk-demo/fishbowl.c

@@ -9,6 +9,7 @@
 
 #include "gtkfishbowl.h"
 #include "gtkgears.h"
+#include "gskshaderpaintable.h"
 
 const char *const css =
 ".blurred-button {"
@@ -149,6 +150,38 @@ create_switch (void)
   return w;
 }
 
+static gboolean
+update_paintable (GtkWidget     *widget,
+                  GdkFrameClock *frame_clock,
+                  gpointer       user_data)
+{
+  GskShaderPaintable *paintable;
+  gint64 frame_time;
+
+  paintable = GSK_SHADER_PAINTABLE (gtk_picture_get_paintable (GTK_PICTURE (widget)));
+  frame_time = gdk_frame_clock_get_frame_time (frame_clock);
+  gsk_shader_paintable_update_time (paintable, 0, frame_time);
+
+  return G_SOURCE_CONTINUE;
+}
+
+static GtkWidget *
+create_cogs (void)
+{
+  GtkWidget *picture;
+  static GskGLShader *cog_shader = NULL;
+  GdkPaintable *paintable;
+
+ if (cog_shader == NULL)
+    cog_shader = gsk_gl_shader_new_from_resource ("/gltransition/cogs2.glsl");
+  paintable = gsk_shader_paintable_new (g_object_ref (cog_shader), NULL);
+  picture = gtk_picture_new_for_paintable (paintable);
+  gtk_widget_set_size_request (picture, 150, 75);
+  gtk_widget_add_tick_callback (picture, update_paintable, NULL, NULL);
+
+  return picture;
+}
+
 static void
 mapped (GtkWidget *w)
 {
@@ -185,6 +218,7 @@ static const struct {
   { "Gears",      create_gears          },
   { "Switch",     create_switch         },
   { "Menubutton", create_menu_button    },
+  { "Shader",     create_cogs           },
 };
 
 static int selected_widget_type = -1;

demos/gtk-demo/fishbowl.ui

@@ -33,6 +33,9 @@
                 <lookup name="framerate">bowl</lookup>
               </closure>
             </binding>
+            <attributes>
+              <attribute name="font-features" value="tnum=1"/>
+            </attributes>
           </object>
         </child>
         <child type="end">

demos/gtk-demo/fixed.c

@@ -1,4 +1,5 @@
 /* Fixed Layout
+ * #Keywords: GtkLayoutManager
  *
  * GtkFixed is a container that allows placing and transforming
  * widgets manually.

demos/gtk-demo/fontify.c

@@ -24,15 +24,29 @@ insert_tags_for_attributes (GtkTextBuffer     *buffer,
                             GtkTextIter       *end)
 {
   GtkTextTagTable *table;
-  PangoAttribute *attr;
+  GSList *attrs, *l;
   GtkTextTag *tag;
   char name[256];
+  float fg_alpha, bg_alpha;
 
   table = gtk_text_buffer_get_tag_table (buffer);
 
-#define STRING_ATTR(pango_attr_name, attr_name) \
-  attr = pango_attr_iterator_get (iter, pango_attr_name); \
-  if (attr) \
+#define LANGUAGE_ATTR(attr_name) \
+    { \
+      const char *language = pango_language_to_string (((PangoAttrLanguage*)attr)->value); \
+      g_snprintf (name, 256, "language=%s", language); \
+      tag = gtk_text_tag_table_lookup (table, name); \
+      if (!tag) \
+        { \
+          tag = gtk_text_tag_new (name); \
+          g_object_set (tag, #attr_name, language, NULL); \
+          gtk_text_tag_table_add (table, tag); \
+          g_object_unref (tag); \
+        } \
+      gtk_text_buffer_apply_tag (buffer, tag, start, end); \
+    }
+
+#define STRING_ATTR(attr_name) \
     { \
       const char *string = ((PangoAttrString*)attr)->value; \
       g_snprintf (name, 256, #attr_name "=%s", string); \
@@ -47,9 +61,7 @@ insert_tags_for_attributes (GtkTextBuffer     *buffer,
       gtk_text_buffer_apply_tag (buffer, tag, start, end); \
     }
 
-#define INT_ATTR(pango_attr_name, attr_name) \
-  attr = pango_attr_iterator_get (iter, pango_attr_name); \
-  if (attr) \
+#define INT_ATTR(attr_name) \
     { \
       int value = ((PangoAttrInt*)attr)->value; \
       g_snprintf (name, 256, #attr_name "=%d", value); \
@@ -64,9 +76,24 @@ insert_tags_for_attributes (GtkTextBuffer     *buffer,
       gtk_text_buffer_apply_tag (buffer, tag, start, end); \
     }
 
-#define FLOAT_ATTR(pango_attr_name, attr_name) \
-  attr = pango_attr_iterator_get (iter, pango_attr_name); \
-  if (attr) \
+#define FONT_ATTR(attr_name) \
+    { \
+      PangoFontDescription *desc = ((PangoAttrFontDesc*)attr)->desc; \
+      char *str = pango_font_description_to_string (desc); \
+      g_snprintf (name, 256, "font-desc=%s", str); \
+      g_free (str); \
+      tag = gtk_text_tag_table_lookup (table, name); \
+      if (!tag) \
+        { \
+          tag = gtk_text_tag_new (name); \
+          g_object_set (tag, #attr_name, desc, NULL); \
+          gtk_text_tag_table_add (table, tag); \
+          g_object_unref (tag); \
+        } \
+      gtk_text_buffer_apply_tag (buffer, tag, start, end); \
+    }
+
+#define FLOAT_ATTR(attr_name) \
     { \
       float value = ((PangoAttrFloat*)attr)->value; \
       g_snprintf (name, 256, #attr_name "=%g", value); \
@@ -81,9 +108,7 @@ insert_tags_for_attributes (GtkTextBuffer     *buffer,
       gtk_text_buffer_apply_tag (buffer, tag, start, end); \
     }
 
-#define RGBA_ATTR(pango_attr_name, attr_name) \
-  attr = pango_attr_iterator_get (iter, pango_attr_name); \
-  if (attr) \
+#define RGBA_ATTR(attr_name, alpha_value) \
     { \
       PangoColor *color; \
       GdkRGBA rgba; \
@@ -91,7 +116,7 @@ insert_tags_for_attributes (GtkTextBuffer     *buffer,
       rgba.red = color->red / 65535.; \
       rgba.green = color->green / 65535.; \
       rgba.blue = color->blue / 65535.; \
-      rgba.alpha = 1.; \
+      rgba.alpha = alpha_value; \
       char *str = gdk_rgba_to_string (&rgba); \
       g_snprintf (name, 256, #attr_name "=%s", str); \
       g_free (str); \
@@ -106,63 +131,153 @@ insert_tags_for_attributes (GtkTextBuffer     *buffer,
       gtk_text_buffer_apply_tag (buffer, tag, start, end); \
     }
 
-  attr = pango_attr_iterator_get (iter, PANGO_ATTR_LANGUAGE);
-  if (attr)
+  fg_alpha = bg_alpha = 1.;
+
+  attrs = pango_attr_iterator_get_attrs (iter);
+  for (l = attrs; l; l = l->next)
     {
-      const char *language = pango_language_to_string (((PangoAttrLanguage*)attr)->value);
-      g_snprintf (name, 256, "language=%s", language);
-      tag = gtk_text_tag_table_lookup (table, name);
-      if (!tag)
+      PangoAttribute *attr = l->data;
+
+      switch ((int)attr->klass->type)
         {
-          tag = gtk_text_tag_new (name);
-          g_object_set (tag, "language", language, NULL);
-          gtk_text_tag_table_add (table, tag);
-          g_object_unref (tag);
+        case PANGO_ATTR_FOREGROUND_ALPHA:
+          fg_alpha = ((PangoAttrInt*)attr)->value / 65535.;
+          break;
+
+        case PANGO_ATTR_BACKGROUND_ALPHA:
+          bg_alpha = ((PangoAttrInt*)attr)->value / 65535.;
+          break;
+
+        default:
+          break;
         }
-      gtk_text_buffer_apply_tag (buffer, tag, start, end);
     }
 
-  STRING_ATTR (PANGO_ATTR_FAMILY, family)
-  INT_ATTR    (PANGO_ATTR_STYLE, style)
-  INT_ATTR    (PANGO_ATTR_WEIGHT, weight)
-  INT_ATTR    (PANGO_ATTR_VARIANT, variant)
-  INT_ATTR    (PANGO_ATTR_STRETCH, stretch)
-  INT_ATTR    (PANGO_ATTR_SIZE, size)
-
-  attr = pango_attr_iterator_get (iter, PANGO_ATTR_FONT_DESC);
-  if (attr)
+  for (l = attrs; l; l = l->next)
     {
-      PangoFontDescription *desc = ((PangoAttrFontDesc*)attr)->desc;
-      char *str = pango_font_description_to_string (desc);
-      g_snprintf (name, 256, "font-desc=%s", str);
-      g_free (str);
-      tag = gtk_text_tag_table_lookup (table, name);
-      if (!tag)
+      PangoAttribute *attr = l->data;
+
+      switch (attr->klass->type)
         {
-          tag = gtk_text_tag_new (name);
-          g_object_set (tag, "font-desc", desc, NULL);
-          gtk_text_tag_table_add (table, tag);
-          g_object_unref (tag);
+        case PANGO_ATTR_LANGUAGE:
+          LANGUAGE_ATTR (language);
+          break;
+
+        case PANGO_ATTR_FAMILY:
+          STRING_ATTR (family);
+          break;
+
+        case PANGO_ATTR_STYLE:
+          INT_ATTR (style);
+          break;
+
+        case PANGO_ATTR_WEIGHT:
+          INT_ATTR (weight);
+          break;
+
+        case PANGO_ATTR_VARIANT:
+          INT_ATTR (variant);
+          break;
+
+        case PANGO_ATTR_STRETCH:
+          INT_ATTR (stretch);
+          break;
+
+        case PANGO_ATTR_SIZE:
+          INT_ATTR (size);
+          break;
+
+        case PANGO_ATTR_FONT_DESC:
+          FONT_ATTR (font-desc);
+          break;
+
+        case PANGO_ATTR_FOREGROUND:
+          RGBA_ATTR (foreground_rgba, fg_alpha);
+          break;
+
+        case PANGO_ATTR_BACKGROUND:
+          RGBA_ATTR (background_rgba, bg_alpha);
+          break;
+
+        case PANGO_ATTR_UNDERLINE:
+          INT_ATTR (underline);
+          break;
+
+        case PANGO_ATTR_UNDERLINE_COLOR:
+          RGBA_ATTR (underline_rgba, fg_alpha);
+          break;
+
+        case PANGO_ATTR_OVERLINE:
+          INT_ATTR (overline);
+          break;
+
+        case PANGO_ATTR_OVERLINE_COLOR:
+          RGBA_ATTR (overline_rgba, fg_alpha);
+          break;
+
+        case PANGO_ATTR_STRIKETHROUGH:
+          INT_ATTR (strikethrough);
+          break;
+
+        case PANGO_ATTR_STRIKETHROUGH_COLOR:
+          RGBA_ATTR (strikethrough_rgba, fg_alpha);
+          break;
+
+        case PANGO_ATTR_RISE:
+          INT_ATTR (rise);
+          break;
+
+        case PANGO_ATTR_SCALE:
+          FLOAT_ATTR (scale);
+          break;
+
+        case PANGO_ATTR_FALLBACK:
+          INT_ATTR (fallback);
+          break;
+
+        case PANGO_ATTR_LETTER_SPACING:
+          INT_ATTR (letter_spacing);
+          break;
+
+        case PANGO_ATTR_FONT_FEATURES:
+          STRING_ATTR (font_features);
+          break;
+
+        case PANGO_ATTR_ALLOW_BREAKS:
+          INT_ATTR (allow_breaks);
+          break;
+
+        case PANGO_ATTR_SHOW:
+          INT_ATTR (show_spaces);
+          break;
+
+        case PANGO_ATTR_INSERT_HYPHENS:
+          INT_ATTR (insert_hyphens);
+          break;
+
+        case PANGO_ATTR_SHAPE:
+        case PANGO_ATTR_ABSOLUTE_SIZE:
+        case PANGO_ATTR_GRAVITY:
+        case PANGO_ATTR_GRAVITY_HINT:
+        case PANGO_ATTR_FOREGROUND_ALPHA:
+        case PANGO_ATTR_BACKGROUND_ALPHA:
+          break;
+
+        case PANGO_ATTR_INVALID:
+        default:
+          g_assert_not_reached ();
+          break;
         }
-      gtk_text_buffer_apply_tag (buffer, tag, start, end);
     }
 
-  RGBA_ATTR   (PANGO_ATTR_FOREGROUND, foreground_rgba)
-  RGBA_ATTR   (PANGO_ATTR_BACKGROUND, background_rgba)
-  INT_ATTR    (PANGO_ATTR_UNDERLINE, underline)
-  RGBA_ATTR   (PANGO_ATTR_UNDERLINE_COLOR, underline_rgba)
-  INT_ATTR    (PANGO_ATTR_OVERLINE, overline)
-  RGBA_ATTR   (PANGO_ATTR_OVERLINE_COLOR, overline_rgba)
-  INT_ATTR    (PANGO_ATTR_STRIKETHROUGH, strikethrough)
-  RGBA_ATTR   (PANGO_ATTR_STRIKETHROUGH_COLOR, strikethrough_rgba)
-  INT_ATTR    (PANGO_ATTR_RISE, rise)
-  FLOAT_ATTR  (PANGO_ATTR_SCALE, scale)
-  INT_ATTR    (PANGO_ATTR_FALLBACK, fallback)
-  INT_ATTR    (PANGO_ATTR_LETTER_SPACING, letter_spacing)
-  STRING_ATTR (PANGO_ATTR_FONT_FEATURES, font_features)
-  INT_ATTR    (PANGO_ATTR_ALLOW_BREAKS, allow_breaks)
-  INT_ATTR    (PANGO_ATTR_SHOW, show_spaces)
-  INT_ATTR    (PANGO_ATTR_INSERT_HYPHENS, insert_hyphens)
+  g_slist_free_full (attrs, (GDestroyNotify)pango_attribute_destroy);
+
+#undef LANGUAGE_ATTR
+#undef STRING_ATTR
+#undef INT_ATTR
+#undef FONT_ATTR
+#undef FLOAT_ATTR
+#undef RGBA_ATTR
 }
 
 typedef struct

demos/gtk-demo/geninclude.py

@@ -6,6 +6,22 @@ import re
 import os
 from collections import *
 
+def add_quotes(s):
+    return "\"" + s.lower() + "\""
+
+def wordify(s):
+    return s.strip().rstrip(".,;:")
+
+def is_keyword(s):
+    if s == "GTK":
+      return False
+    elif s.startswith(("Gtk", "Gdk", "Pango")):
+        return True
+    elif s.startswith("G") and s[1].isupper():
+        return True
+    else:
+        return False
+
 out_file = sys.argv[1]
 in_files = sys.argv[2:]
 
@@ -19,13 +35,14 @@ struct _DemoData
 {
   const char *name;
   const char *title;
+  const char **keywords;
   const char *filename;
   GDoDemoFunc func;
   DemoData *children;
 };
 """
 
-# Demo = namedtuple('Demo', ['name', 'title', 'file', 'func'])
+# Demo = namedtuple('Demo', ['name', 'title', 'keywords', 'file', 'func'])
 
 demos = []
 
@@ -34,14 +51,17 @@ for demo_file in in_files:
     demo_name = filename.replace(".c", "")
     with open(demo_file, 'r', encoding='utf-8') as f:
         title = f.readline().replace("/*", "").strip()
-
+        keywords = set()
+        line = f.readline().strip();
+        while not line.endswith('*/'):
+            if line.startswith("* #Keywords:"):
+                keywords = keywords.union(set(map(wordify, line.replace ("* #Keywords:", "").strip().split(","))))
+            else:
+                keywords = keywords.union(set(filter(is_keyword, map(wordify, line.replace ("* ", "").split()))))
+            line = f.readline().strip()
 
     file_output += "GtkWidget *do_" + demo_name + " (GtkWidget *do_widget);\n"
-    # demos += Demo(name = demo_name,
-                  # title = title,
-                  # file = demo_file,
-                  # func = "do_" + title)
-    demos.append((demo_name, title, filename, "do_" + demo_name, -1))
+    demos.append((demo_name, title, keywords, filename, "do_" + demo_name, -1))
 
 # Generate a List of "Parent names"
 parents = []
@@ -57,7 +77,7 @@ for demo in demos:
         if not parent_name in parents:
             parents.append(parent_name)
             parent_ids.append(parent_index)
-            demos.append(("NULL", parent_name, "NULL", "NULL", parent_index))
+            demos.append(("NULL", parent_name, set(), "NULL", "NULL", parent_index))
 
         parent_index = parent_index + 1
 
@@ -71,8 +91,7 @@ for parent in parents:
     for child in demos:
         if child[1].startswith(parent + "/"):
             title = child[1][child[1].rfind('/') + 1:]
-            file_output += "  { \"" + child[0] + "\", \"" + title + "\", \"" + child[2] + "\", " + child[3] + ", NULL },\n"
-
+            file_output += "  { \"" + child[0] + "\", \"" + title + "\", " + "(const char*[]) {" + ", ".join(list(map(add_quotes, child[2])) + ["NULL"]) + " }, \"" + child[3] + "\", " + child[4] + ", NULL },\n"
 
     file_output += "  { NULL }\n};\n"
     i = i + 1
@@ -86,9 +105,10 @@ for demo in demos:
     # Do not generate one of these for demos with a parent demo
     if "/" not in demo[1]:
         child_array = "NULL"
-        name = demo[0];
-        title = demo[1];
-        file = demo[2]
+        name = demo[0]
+        title = demo[1]
+        keywords = demo[2]
+        file = demo[3]
         if name != "NULL":
             name = "\"" + name + "\""
         if title != "NULL":
@@ -96,9 +116,9 @@ for demo in demos:
         if file != "NULL":
             file = "\"" + file + "\""
 
-        if demo[4] != -1:
-            child_array = "child" + str(demo[4])
-        file_output += "  { " + name + ", " + title + ", " + file + ", " + demo[3] + ", " + child_array + " },\n"
+        if demo[5] != -1:
+            child_array = "child" + str(demo[5])
+        file_output += "  { " + name + ", " + title + ", " + "(const char*[]) {" + ", ".join(list(map(add_quotes, keywords)) + ["NULL"]) + " }, " + file + ", " + demo[4] + ", " + child_array + " },\n"
 
 file_output += "  { NULL }\n};\n"
 

demos/gtk-demo/gestures.c

@@ -1,4 +1,5 @@
 /* Gestures
+ * #Keywords: GtkGesture
  *
  * Perform gestures on touchscreens and other input devices. This
  * demo reacts to long presses and swipes from all devices, plus

demos/gtk-demo/glowingstars.glsl

@@ -0,0 +1,174 @@
+// Originally from: https://www.shadertoy.com/view/ttBcRV
+// License CC0: Flying through glowing stars
+//  The result of playing around trying to improve an old shader
+
+#define PI              3.141592654
+#define TAU             (2.0*PI)
+#define TIME            iTime
+#define RESOLUTION      iResolution
+
+#define LESS(a,b,c)     mix(a,b,step(0.,c))
+#define SABS(x,k)       LESS((.5/(k))*(x)*(x)+(k)*.5,abs(x),abs(x)-(k))
+
+#define MROT(a) mat2(cos(a), sin(a), -sin(a), cos(a))
+
+vec3 hsv2rgb(vec3 c) {
+  const vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+  vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
+  return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
+}
+
+float hash(in vec3 co) {
+  return fract(sin(dot(co, vec3(12.9898,58.233, 12.9898+58.233))) * 13758.5453);
+}
+
+float starn(vec2 p, float r, int n, float m) {
+  // From IQ: https://www.shadertoy.com/view/3tSGDy
+  // https://iquilezles.org/www/articles/distfunctions2d/distfunctions2d.htm
+
+  // Minor tweak to use SABS over abs to smooth inner corners
+  // SABS: https://www.shadertoy.com/view/Ws2SDK
+
+  // next 4 lines can be precomputed for a given shape
+  float an = 3.141593/float(n);
+  float en = 3.141593/m;  // m is between 2 and n
+  vec2  acs = vec2(cos(an),sin(an));
+  vec2  ecs = vec2(cos(en),sin(en)); // ecs=vec2(0,1) for regular polygon,
+
+  float bn = mod(atan(p.x,p.y),2.0*an) - an;
+  p = length(p)*vec2(cos(bn),SABS(sin(bn), 0.15));
+  p -= r*acs;
+  p += ecs*clamp( -dot(p,ecs), 0.0, r*acs.y/ecs.y);
+  return length(p)*sign(p.x);
+}
+
+vec4 alphaBlend(vec4 back, vec4 front) {
+  vec3 xyz = mix(back.xyz*back.w, front.xyz, front.w);
+  float w = mix(back.w, 1.0, front.w);
+  return vec4(xyz, w);
+}
+
+void rot(inout vec2 p, float a) {
+  float c = cos(a);
+  float s = sin(a);
+  p = vec2(c*p.x + s*p.y, -s*p.x + c*p.y);
+}
+
+vec3 offset(float z) {
+  float a = z;
+  vec2 p = -0.075*(vec2(cos(a), sin(a*sqrt(2.0))) + vec2(cos(a*sqrt(0.75)), sin(a*sqrt(0.5))));
+  return vec3(p, z);
+}
+
+vec3 doffset(float z) {
+  float eps = 0.05;
+  return 0.5*(offset(z + eps) - offset(z - eps))/eps;
+}
+
+vec3 ddoffset(float z) {
+  float eps = 0.05;
+  return 0.5*(doffset(z + eps) - doffset(z - eps))/eps;
+}
+
+vec4 planeCol(vec3 ro, vec3 rd, float n, vec3 pp) {
+  const float s = 0.5;
+
+  vec2 p = pp.xy;
+  float z = pp.z;
+  vec2 dpy = dFdy(p);
+  float aa = length(dpy);
+
+  p -= (1.0+5.0*(pp.z - ro.z))*offset(z).xy;
+
+  p *= s;
+  float r = hash(vec3(floor(p+0.5), n));
+  p = fract(p+0.5)-0.5;
+  rot(p, ((TAU*r+n)*0.25));
+  float d = starn(p, 0.20, 3 + 2*int(3.0*r), 3.0);
+  d -= 0.06;
+  d/=s;
+
+  float ds = -d+0.03;
+  vec3 cols = hsv2rgb(vec3(337.0/360.0+0.1*sin(n*0.3), 0.8, 0.54+0.2*sin(n*0.3)));
+  float ts = 1.0 - smoothstep(-aa, 0.0, ds);
+  vec4 cs =  vec4(cols, ts*0.93);
+
+  float db = abs(d) - (0.06);
+  db = abs(db) - 0.03;
+  db = abs(db) - 0.00;
+  db = max(db, -d+0.03);
+    vec3 colb = vec3(1.0, 0.7, 0.5);
+  float tb = exp(-(db)*30.0*(1.0 - 10.0*aa));
+  vec4 cb = vec4(1.5*colb, tb);
+
+  vec4 ct = alphaBlend(cs, cb);
+
+  return ct;
+}
+
+vec3 color(vec3 ww, vec3 uu, vec3 vv, vec3 ro, vec2 p) {
+  vec3 rd = normalize(p.x*uu + p.y*vv + (2.0-tanh(length(p)))*ww);
+
+  vec4 col = vec4(vec3(0.0), 1.0);
+
+  const float planeDist = 1.0;
+  const int furthest = 6;
+  const int fadeFrom = furthest-3;
+
+  float nz = floor(ro.z / planeDist);
+
+  for (int i = furthest; i >= 1; --i) {
+    float pz = planeDist*nz + planeDist*float(i);
+
+    float pd = (pz - ro.z)/rd.z;
+
+    if (pd > 0.0) {
+      vec3 pp = ro + rd*pd;
+
+      vec4 pcol = planeCol(ro, rd, nz+float(i), pp);
+      float fadeIn = 1.0-smoothstep(planeDist*float(fadeFrom), planeDist*float(furthest), pp.z-ro.z);
+      pcol.xyz *= sqrt(fadeIn);
+
+      col = alphaBlend(col, pcol);
+    }
+  }
+
+  return col.xyz*col.w;
+}
+
+vec3 postProcess(vec3 col, vec2 q)  {
+  col=pow(clamp(col,0.0,1.0),vec3(0.75));
+  col=col*0.6+0.4*col*col*(3.0-2.0*col);
+  col=mix(col, vec3(dot(col, vec3(0.33))), -0.4);
+  col*=0.5+0.5*pow(19.0*q.x*q.y*(1.0-q.x)*(1.0-q.y),0.7);
+  return col;
+}
+
+vec3 effect(vec2 p, vec2 q) {
+  float tm = TIME*0.65;
+
+  vec3 ro   = offset(tm);
+  vec3 dro  = doffset(tm);
+  vec3 ddro = ddoffset(tm);
+
+  vec3 ww = normalize(dro);
+  vec3 uu = normalize(cross(vec3(0.0,1.0,0.0)+1.5*ddro, ww));
+  vec3 vv = normalize(cross(ww, uu));
+
+  vec3 col = color(ww, uu, vv, ro, p);
+  col = postProcess(col, q);
+
+  const float fadeIn = 2.0;
+
+  return col*smoothstep(0.0, fadeIn, TIME);
+}
+
+void mainImage(out vec4 fragColor, vec2 fragCoord) {
+  vec2 q = fragCoord/RESOLUTION.xy;
+  vec2 p = -1. + 2. * q;
+  p.x *= RESOLUTION.x/RESOLUTION.y;
+
+  vec3 col = effect(p, q);
+
+  fragColor = vec4(col, 1.0);
+}

demos/gtk-demo/gltransition.c

@@ -0,0 +1,329 @@
+/* OpenGL/Transitions
+ * #Keywords: OpenGL, shader
+ *
+ * Create transitions between pages using a custom fragment shader.
+ *
+ * The example transitions here are taken from gl-transitions.com, and you
+ * can edit the shader code itself on the last page of the stack.
+ *
+ * The transitions work with arbitrary content. We use images, shaders
+ * GL areas and plain old widgets to demonstrate this.
+ *
+ * The demo also shows some sample fire effects on the buttons.
+ */
+
+#include <math.h>
+#include <gtk/gtk.h>
+#include "gtkshaderstack.h"
+#include "gtkshaderbin.h"
+#include "gtkshadertoy.h"
+#include "gskshaderpaintable.h"
+
+static GtkWidget *demo_window = NULL;
+
+static void
+close_window (GtkWidget *widget)
+{
+  /* Reset the state */
+  demo_window = NULL;
+}
+
+static void
+text_changed (GtkTextBuffer *buffer,
+              GtkWidget     *button)
+{
+  gtk_widget_show (button);
+}
+
+static void
+apply_text (GtkWidget     *button,
+            GtkTextBuffer *buffer)
+{
+  GtkWidget *stack;
+  GskGLShader *shader;
+  GtkTextIter start, end;
+  char *text;
+
+  stack = g_object_get_data (G_OBJECT (button), "the-stack");
+
+  gtk_text_buffer_get_bounds (buffer, &start, &end);
+  text = gtk_text_buffer_get_text (buffer, &start, &end, TRUE);
+
+  GBytes *bytes = g_bytes_new_take (text, strlen (text));
+  shader = gsk_gl_shader_new_from_bytes (bytes);
+
+  gtk_shader_stack_set_shader (GTK_SHADER_STACK (stack), shader);
+
+  g_object_unref (shader);
+  g_bytes_unref (bytes);
+
+  gtk_widget_hide (button);
+}
+
+static void
+go_back (GtkWidget     *button,
+         GtkWidget     *stack)
+{
+  gtk_shader_stack_transition (GTK_SHADER_STACK (stack), FALSE);
+}
+
+static void
+go_forward (GtkWidget     *button,
+            GtkWidget     *stack)
+{
+  gtk_shader_stack_transition (GTK_SHADER_STACK (stack), TRUE);
+}
+
+static void
+clicked_cb (GtkGestureClick *gesture,
+            guint            n_pressed,
+            double           x,
+            double           y,
+            gpointer         data)
+{
+  gtk_gesture_set_state (GTK_GESTURE (gesture), GTK_EVENT_SEQUENCE_CLAIMED);
+}
+
+static GtkWidget *
+fire_bin_new (void)
+{
+  GtkWidget *bin = gtk_shader_bin_new ();
+  static GskGLShader *shader = NULL;
+
+  if (shader == NULL)
+    shader = gsk_gl_shader_new_from_resource ("/gltransition/fire.glsl");
+
+  gtk_shader_bin_add_shader (GTK_SHADER_BIN (bin), shader, GTK_STATE_FLAG_PRELIGHT, GTK_STATE_FLAG_PRELIGHT);
+
+  return bin;
+}
+
+static GtkWidget *
+new_shadertoy (const char *path)
+{
+  GBytes *shader;
+  GtkWidget *toy;
+
+  toy = gtk_shadertoy_new ();
+  shader = g_resources_lookup_data (path, 0, NULL);
+  gtk_shadertoy_set_image_shader (GTK_SHADERTOY (toy),
+                                  g_bytes_get_data (shader, NULL));
+  g_bytes_unref (shader);
+
+  return toy;
+}
+
+static gboolean
+update_paintable (GtkWidget     *widget,
+                  GdkFrameClock *frame_clock,
+                  gpointer       user_data)
+{
+  GskShaderPaintable *paintable;
+  gint64 frame_time;
+
+  paintable = GSK_SHADER_PAINTABLE (gtk_picture_get_paintable (GTK_PICTURE (widget)));
+  frame_time = gdk_frame_clock_get_frame_time (frame_clock);
+  gsk_shader_paintable_update_time (paintable, 0, frame_time);
+
+  return G_SOURCE_CONTINUE;
+}
+
+static GtkWidget *
+make_shader_stack (const char *name,
+                   const char *resource_path,
+                   GtkWidget  *scale)
+{
+  GtkWidget *stack, *child, *widget, *vbox, *hbox, *bin;
+  GtkWidget *label, *button, *tv;
+  GskGLShader *shader;
+  GObjectClass *class;
+  GParamSpecFloat *pspec;
+  GtkAdjustment *adjustment;
+  GtkTextBuffer *buffer;
+  GBytes *bytes;
+  GtkEventController *controller;
+  GtkCssProvider *provider;
+  GdkPaintable *paintable;
+
+  stack = gtk_shader_stack_new ();
+  shader = gsk_gl_shader_new_from_resource (resource_path);
+  gtk_shader_stack_set_shader (GTK_SHADER_STACK (stack), shader);
+  g_object_unref (shader);
+
+  child = gtk_picture_new_for_resource ("/css_pixbufs/background.jpg");
+  gtk_picture_set_can_shrink (GTK_PICTURE (child), TRUE);
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  shader = gsk_gl_shader_new_from_resource ("/gltransition/cogs2.glsl");
+  paintable = gsk_shader_paintable_new (shader, NULL);
+
+  child = gtk_picture_new_for_paintable (paintable);
+  gtk_widget_add_tick_callback (child, update_paintable, NULL, NULL);
+  gtk_picture_set_can_shrink (GTK_PICTURE (child), TRUE);
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  child = gtk_picture_new_for_resource ("/transparent/portland-rose.jpg");
+  gtk_picture_set_can_shrink (GTK_PICTURE (child), TRUE);
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  child = new_shadertoy ("/shadertoy/neon.glsl");
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  child = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
+
+  class = g_type_class_ref (GTK_TYPE_SHADER_STACK);
+  pspec = G_PARAM_SPEC_FLOAT (g_object_class_find_property (class, "duration"));
+
+  adjustment = gtk_range_get_adjustment (GTK_RANGE (scale));
+  if (gtk_adjustment_get_lower (adjustment) == 0.0 &&
+      gtk_adjustment_get_upper (adjustment) == 0.0)
+    {
+      gtk_adjustment_configure (adjustment,
+                                pspec->default_value,
+                                pspec->minimum,
+                                pspec->maximum,
+                                0.1, 0.5, 0);
+    }
+
+  g_type_class_unref (class);
+
+  g_object_bind_property (adjustment, "value",
+                          stack, "duration",
+                          G_BINDING_DEFAULT);
+
+  widget = gtk_scrolled_window_new ();
+  gtk_scrolled_window_set_has_frame (GTK_SCROLLED_WINDOW (widget), TRUE);
+  gtk_widget_set_hexpand (widget, TRUE);
+  gtk_widget_set_vexpand (widget, TRUE);
+
+  controller = GTK_EVENT_CONTROLLER (gtk_gesture_click_new ());
+  gtk_gesture_single_set_button (GTK_GESTURE_SINGLE (controller), 0);
+  g_signal_connect (controller, "released", G_CALLBACK (clicked_cb), NULL);
+  gtk_event_controller_set_propagation_phase (controller, GTK_PHASE_BUBBLE);
+  gtk_widget_add_controller (GTK_WIDGET (widget), controller);
+
+  tv = gtk_text_view_new ();
+  gtk_text_view_set_left_margin (GTK_TEXT_VIEW (tv), 4);
+  gtk_text_view_set_right_margin (GTK_TEXT_VIEW (tv), 4);
+  gtk_text_view_set_top_margin (GTK_TEXT_VIEW (tv), 4);
+  gtk_text_view_set_bottom_margin (GTK_TEXT_VIEW (tv), 4);
+  buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (tv));
+  bytes = g_resources_lookup_data (resource_path, 0, NULL);
+  gtk_text_buffer_set_text (buffer,
+                            (const char *)g_bytes_get_data (bytes, NULL),
+                            g_bytes_get_size (bytes));
+  g_bytes_unref (bytes);
+  gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (widget), tv);
+
+  gtk_box_append (GTK_BOX (child), widget);
+
+  gtk_shader_stack_add_child (GTK_SHADER_STACK (stack), child);
+
+  vbox = gtk_box_new (GTK_ORIENTATION_VERTICAL, 6);
+
+  widget = gtk_center_box_new ();
+  label = gtk_label_new (name);
+  gtk_widget_add_css_class (label, "title-4");
+  gtk_widget_set_size_request (label, -1, 26);
+  gtk_center_box_set_center_widget (GTK_CENTER_BOX (widget), label);
+
+  button = gtk_button_new_from_icon_name ("view-refresh-symbolic");
+  g_signal_connect (buffer, "changed", G_CALLBACK (text_changed), button);
+  g_object_set_data (G_OBJECT (button), "the-stack", stack);
+  g_signal_connect (button, "clicked", G_CALLBACK (apply_text), buffer);
+  provider = gtk_css_provider_new ();
+  gtk_css_provider_load_from_data (provider, "button.small { padding: 0; }", -1);
+  gtk_style_context_add_provider (gtk_widget_get_style_context (button),
+                                  GTK_STYLE_PROVIDER (provider),
+                                  GTK_STYLE_PROVIDER_PRIORITY_APPLICATION);
+  g_object_unref (provider);
+  gtk_widget_set_halign (button, GTK_ALIGN_CENTER);
+  gtk_widget_set_valign (button, GTK_ALIGN_CENTER);
+  gtk_widget_add_css_class (button, "small");
+  gtk_widget_hide (button);
+  gtk_center_box_set_end_widget (GTK_CENTER_BOX (widget), button);
+
+  gtk_box_append (GTK_BOX (vbox), widget);
+
+  gtk_box_append (GTK_BOX (vbox), stack);
+
+  hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, 6);
+  gtk_widget_set_halign (hbox, GTK_ALIGN_CENTER);
+
+  gtk_box_append (GTK_BOX (vbox), hbox);
+
+  button = gtk_button_new_from_icon_name ("go-previous");
+  g_signal_connect (button, "clicked", G_CALLBACK (go_back), stack);
+  bin = fire_bin_new ();
+  gtk_shader_bin_set_child (GTK_SHADER_BIN (bin), button);
+  gtk_box_append (GTK_BOX (hbox), bin);
+
+  button = gtk_button_new_from_icon_name ("go-next");
+  g_signal_connect (button, "clicked", G_CALLBACK (go_forward), stack);
+  bin = fire_bin_new ();
+  gtk_shader_bin_set_child (GTK_SHADER_BIN (bin), button);
+  gtk_box_append (GTK_BOX (hbox), bin);
+
+  return vbox;
+}
+
+static GtkWidget *
+create_gltransition_window (GtkWidget *do_widget)
+{
+  GtkWidget *window, *headerbar, *scale, *grid;
+
+  window = gtk_window_new ();
+  gtk_window_set_display (GTK_WINDOW (window),  gtk_widget_get_display (do_widget));
+  gtk_window_set_title (GTK_WINDOW (window), "Transitions");
+  headerbar = gtk_header_bar_new ();
+  scale = gtk_scale_new (GTK_ORIENTATION_HORIZONTAL, NULL);
+  gtk_scale_set_draw_value (GTK_SCALE (scale), FALSE);
+  gtk_widget_set_size_request (scale, 100, -1);
+  gtk_header_bar_pack_end (GTK_HEADER_BAR (headerbar), scale);
+  gtk_window_set_titlebar (GTK_WINDOW (window), headerbar);
+  gtk_window_set_default_size (GTK_WINDOW (window), 800, 600);
+  g_signal_connect (window, "destroy", G_CALLBACK (close_window), NULL);
+
+  grid = gtk_grid_new ();
+  gtk_window_set_child (GTK_WINDOW (window), grid);
+
+  gtk_widget_set_halign (grid, GTK_ALIGN_CENTER);
+  gtk_widget_set_valign (grid, GTK_ALIGN_CENTER);
+  gtk_widget_set_margin_start (grid, 12);
+  gtk_widget_set_margin_end (grid, 12);
+  gtk_widget_set_margin_top (grid, 12);
+  gtk_widget_set_margin_bottom (grid, 12);
+  gtk_grid_set_row_spacing (GTK_GRID (grid), 6);
+  gtk_grid_set_column_spacing (GTK_GRID (grid), 6);
+  gtk_grid_set_row_homogeneous (GTK_GRID (grid), TRUE);
+  gtk_grid_set_column_homogeneous (GTK_GRID (grid), TRUE);
+
+  gtk_grid_attach (GTK_GRID (grid),
+                   make_shader_stack ("Wind", "/gltransition/transition1.glsl", scale),
+                   0, 0, 1, 1);
+  gtk_grid_attach (GTK_GRID (grid),
+                   make_shader_stack ("Radial", "/gltransition/transition2.glsl", scale),
+                   1, 0, 1, 1);
+  gtk_grid_attach (GTK_GRID (grid),
+                   make_shader_stack ("Crosswarp", "/gltransition/transition3.glsl", scale),
+                   0, 1, 1, 1);
+  gtk_grid_attach (GTK_GRID (grid),
+                   make_shader_stack ("Kaleidoscope", "/gltransition/transition4.glsl", scale),
+                   1, 1, 1, 1);
+
+  return window;
+}
+
+GtkWidget *
+do_gltransition (GtkWidget *do_widget)
+{
+  if (!demo_window)
+    demo_window = create_gltransition_window (do_widget);
+
+  if (!gtk_widget_get_visible (demo_window))
+    gtk_widget_show (demo_window);
+  else
+    gtk_window_destroy (GTK_WINDOW (demo_window));
+
+  return demo_window;
+}

demos/gtk-demo/gskshaderpaintable.c

@@ -0,0 +1,344 @@
+/*
+ * Copyright © 2020 Red Hat, Inc
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen <mclasen@redhat.com>
+ */
+
+#include "config.h"
+
+#include <gtk/gtk.h>
+#include "gskshaderpaintable.h"
+
+/**
+ * SECTION:gskshaderpaintable
+ * @Short_description: Drawing with shaders
+ * @Title: GskShaderPaintable
+ * @see_also: #GdkPaintable
+ *
+ * GskShaderPaintable is an implementation of the #GdkPaintable interface
+ * that uses a #GskGLShader to create pixels.
+ *
+ * You can set the uniform data that the shader needs for rendering
+ * using gsk_shader_paintable_set_uniform_data(). This function can
+ * be called repeatedly to change the uniform data for the next
+ * snapshot.
+ *
+ * Commonly, time is passed to shaders as a float uniform containing
+ * the elapsed time in seconds. The convenience API
+ * gsk_shader_paintable_update_time() can be called from a #GtkTickCallback
+ * to update the time based on the frame time of the frame clock.
+ */
+
+
+struct _GskShaderPaintable
+{
+  GObject parent_instance;
+
+  GskGLShader *shader;
+  GBytes *uniform_data;
+
+  gint64 start_time;
+};
+
+struct _GskShaderPaintableClass
+{
+  GObjectClass parent_class;
+};
+
+enum {
+  PROP_0,
+  PROP_SHADER,
+  PROP_UNIFORM_DATA,
+
+  N_PROPS,
+};
+
+static GParamSpec *properties[N_PROPS] = { NULL, };
+
+static void
+gsk_shader_paintable_paintable_snapshot (GdkPaintable *paintable,
+                                         GdkSnapshot  *snapshot,
+                                         double        width,
+                                         double        height)
+{
+  GskShaderPaintable *self = GSK_SHADER_PAINTABLE (paintable);
+
+  gtk_snapshot_push_gl_shader (snapshot, self->shader, &GRAPHENE_RECT_INIT(0, 0, width, height), g_bytes_ref (self->uniform_data));
+  gtk_snapshot_pop (snapshot);
+}
+
+static void
+gsk_shader_paintable_paintable_init (GdkPaintableInterface *iface)
+{
+  iface->snapshot = gsk_shader_paintable_paintable_snapshot;
+}
+
+G_DEFINE_TYPE_EXTENDED (GskShaderPaintable, gsk_shader_paintable, G_TYPE_OBJECT, 0,
+                        G_IMPLEMENT_INTERFACE (GDK_TYPE_PAINTABLE,
+                                               gsk_shader_paintable_paintable_init))
+
+static void
+gsk_shader_paintable_set_property (GObject      *object,
+                                   guint         prop_id,
+                                   const GValue *value,
+                                   GParamSpec   *pspec)
+
+{
+  GskShaderPaintable *self = GSK_SHADER_PAINTABLE (object);
+
+  switch (prop_id)
+    {
+    case PROP_SHADER:
+      gsk_shader_paintable_set_shader (self, g_value_get_object (value));
+      break;
+
+    case PROP_UNIFORM_DATA:
+      gsk_shader_paintable_set_uniform_data (self, g_value_get_boxed (value));
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gsk_shader_paintable_get_property (GObject    *object,
+                                   guint       prop_id,
+                                   GValue     *value,
+                                   GParamSpec *pspec)
+{
+  GskShaderPaintable *self = GSK_SHADER_PAINTABLE (object);
+
+  switch (prop_id)
+    {
+    case PROP_SHADER:
+      g_value_set_object (value, self->shader);
+      break;
+
+    case PROP_UNIFORM_DATA:
+      g_value_set_boxed (value, self->uniform_data);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gsk_shader_paintable_finalize (GObject *object)
+{
+  GskShaderPaintable *self = GSK_SHADER_PAINTABLE (object);
+
+  g_clear_pointer (&self->uniform_data, g_bytes_unref);
+  g_clear_object (&self->shader);
+
+  G_OBJECT_CLASS (gsk_shader_paintable_parent_class)->finalize (object);
+}
+
+static void
+gsk_shader_paintable_class_init (GskShaderPaintableClass *klass)
+{
+  GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
+
+  gobject_class->get_property = gsk_shader_paintable_get_property;
+  gobject_class->set_property = gsk_shader_paintable_set_property;
+  gobject_class->finalize = gsk_shader_paintable_finalize;
+
+  properties[PROP_SHADER] =
+    g_param_spec_object ("shader", "Shader", "The shader",
+                         GSK_TYPE_GL_SHADER,
+                         G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  properties[PROP_UNIFORM_DATA] =
+    g_param_spec_boxed ("uniform-data", "Uniform data", "The uniform data",
+                        G_TYPE_BYTES,
+                        G_PARAM_READWRITE | G_PARAM_EXPLICIT_NOTIFY | G_PARAM_STATIC_STRINGS);
+
+  g_object_class_install_properties (gobject_class, N_PROPS, properties);
+}
+
+static void
+gsk_shader_paintable_init (GskShaderPaintable *self)
+{
+}
+
+/**
+ * gsk_shader_paintable_new:
+ * @shader: (transfer full) (nullable): the shader to use
+ * @data: (transfer full) (nullable): uniform data
+ *
+ * Creates a paintable that uses the @shader to create
+ * pixels. The shader must not require input textures.
+ * If @data is %NULL, all uniform values are set to zero.
+ *
+ * Returns: (transfer full): a new #GskShaderPaintable
+ */
+GdkPaintable *
+gsk_shader_paintable_new (GskGLShader *shader,
+                          GBytes      *data)
+{
+  GdkPaintable *ret;
+
+  g_return_val_if_fail (shader == NULL || GSK_IS_GL_SHADER (shader), NULL);
+
+  if (shader && !data)
+    {
+      int size = gsk_gl_shader_get_args_size (shader);
+      data = g_bytes_new_take (g_new0 (guchar, size), size);
+    }
+
+  ret = g_object_new (GSK_TYPE_SHADER_PAINTABLE,
+                      "shader", shader,
+                      "uniform-data", data,
+                      NULL);
+
+  g_clear_object (&shader);
+  g_clear_pointer (&data, g_bytes_unref);
+
+  return ret;
+}
+
+/**
+ * gsk_shader_paintable_set_shader:
+ * @self: a #GskShaderPaintable
+ * @shader: the #GskGLShader to use
+ *
+ * Sets the shader that the paintable will use
+ * to create pixels. The shader must not require
+ * input textures.
+ */
+void
+gsk_shader_paintable_set_shader (GskShaderPaintable *self,
+                                 GskGLShader        *shader)
+{
+  g_return_if_fail (GSK_IS_SHADER_PAINTABLE (self));
+  g_return_if_fail (shader == NULL || GSK_IS_GL_SHADER (shader));
+  g_return_if_fail (shader == NULL || gsk_gl_shader_get_n_required_textures (shader) == 0);
+
+  if (!g_set_object (&self->shader, shader))
+    return;
+
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_SHADER]);
+  gdk_paintable_invalidate_contents (GDK_PAINTABLE (self));
+
+  g_clear_pointer (&self->uniform_data, g_bytes_unref);
+}
+
+/**
+ * gsk_shader_paintable_get_shader:
+ * @self: a #GskShaderPaintable
+ *
+ * Returns the shader that the paintable is using.
+ *
+ * Returns: (transfer none): the #GskGLShader that is used
+ */
+GskGLShader *
+gsk_shader_paintable_get_shader (GskShaderPaintable *self)
+{
+  g_return_val_if_fail (GSK_IS_SHADER_PAINTABLE (self), NULL);
+
+  return self->shader;
+}
+
+/**
+ * gsk_shader_paintable_set_uniform_data:
+ * @self: a #GskShaderPaintable
+ * @data: Data block with uniform data for the shader
+ *
+ * Sets the uniform data that will be passed to the
+ * shader when rendering. The @data will typically
+ * be produced by a #GskUniformDataBuilder.
+ *
+ * Note that the @data should be considered immutable
+ * after it has been passed to this function.
+ */
+void
+gsk_shader_paintable_set_uniform_data (GskShaderPaintable *self,
+                                       GBytes             *data)
+{
+  g_return_if_fail (GSK_IS_SHADER_PAINTABLE (self));
+  g_return_if_fail (data == NULL || g_bytes_get_size (data) == gsk_gl_shader_get_args_size (self->shader));
+
+  g_clear_pointer (&self->uniform_data, g_bytes_unref);
+  if (data)
+    self->uniform_data = g_bytes_ref (data);
+
+  g_object_notify_by_pspec (G_OBJECT (self), properties[PROP_UNIFORM_DATA]);
+  gdk_paintable_invalidate_contents (GDK_PAINTABLE (self));
+}
+
+/**
+ * gsk_shader_paintable_get_uniform_data:
+ * @self: a #GskShaderPaintable
+ *
+ * Returns the uniform data set with
+ * gsk_shader_paintable_get_uniform_data().
+ *
+ * Returns: (transfer none): the uniform data
+ */
+GBytes *
+gsk_shader_paintable_get_uniform_data (GskShaderPaintable *self)
+{
+  g_return_val_if_fail (GSK_IS_SHADER_PAINTABLE (self), NULL);
+
+  return self->uniform_data;
+}
+
+/**
+ * gsk_shader_paintable_update_time:
+ * @self: a #GskShaderPaintable
+ * @time_idx: the index of the uniform for time in seconds as float
+ * @frame_time: the current frame time, as returned by #GdkFrameClock
+ *
+ * This function is a convenience wrapper for
+ * gsk_shader_paintable_set_uniform_data() that leaves all
+ * uniform values unchanged, except for the uniform with
+ * index @time_idx, which will be set to the elapsed time
+ * in seconds, since the first call to this function.
+ *
+ * This function is usually called from a #GtkTickCallback.
+ */
+void
+gsk_shader_paintable_update_time (GskShaderPaintable *self,
+                                  int                 time_idx,
+                                  gint64              frame_time)
+{
+  int size;
+  int offset;
+  guchar *data;
+  float time;
+  GBytes *uniform_data;
+
+  size = gsk_gl_shader_get_args_size (self->shader);
+  offset = gsk_gl_shader_get_uniform_offset (self->shader, time_idx);
+
+  data = g_new0 (guchar, size);
+  memcpy (data, g_bytes_get_data (self->uniform_data, NULL), size);
+
+  if (self->start_time == 0)
+    self->start_time = frame_time;
+
+  time = (frame_time - self->start_time) / (float)G_TIME_SPAN_SECOND;
+  *(float*)(data + offset) = time;
+
+  uniform_data = g_bytes_new_take (data, size);
+
+  gsk_shader_paintable_set_uniform_data (self, uniform_data);
+
+  g_bytes_unref (uniform_data);
+}

demos/gtk-demo/gskshaderpaintable.h

@@ -0,0 +1,53 @@
+/*
+ * Copyright © 2020 Red Hat, Inc.
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library. If not, see <http://www.gnu.org/licenses/>.
+ *
+ * Authors: Matthias Clasen <mclasen@redhat.com>
+ */
+
+#ifndef __GSK_SHADER_PAINTABLE_H__
+#define __GSK_SHADER_PAINTABLE_H__
+
+#include <gdk/gdk.h>
+#include <gsk/gsk.h>
+
+G_BEGIN_DECLS
+
+#define GSK_TYPE_SHADER_PAINTABLE (gsk_shader_paintable_get_type ())
+
+GDK_AVAILABLE_IN_ALL
+G_DECLARE_FINAL_TYPE (GskShaderPaintable, gsk_shader_paintable, GSK, SHADER_PAINTABLE, GObject)
+
+GDK_AVAILABLE_IN_ALL
+GdkPaintable *   gsk_shader_paintable_new              (GskGLShader        *shader,
+                                                        GBytes             *data);
+
+GDK_AVAILABLE_IN_ALL
+GskGLShader *    gsk_shader_paintable_get_shader       (GskShaderPaintable *self);
+GDK_AVAILABLE_IN_ALL
+void             gsk_shader_paintable_set_shader       (GskShaderPaintable *self,
+                                                        GskGLShader        *shader);
+GDK_AVAILABLE_IN_ALL
+GBytes *         gsk_shader_paintable_get_uniform_data (GskShaderPaintable *self);
+GDK_AVAILABLE_IN_ALL
+void             gsk_shader_paintable_set_uniform_data (GskShaderPaintable *self,
+                                                        GBytes             *data);
+GDK_AVAILABLE_IN_ALL
+void             gsk_shader_paintable_update_time      (GskShaderPaintable *self,
+                                                        int                 time_idx,
+                                                        gint64              frame_time);
+G_END_DECLS
+
+#endif /* __GSK_SHADER_PAINTABLE_H__ */

demos/gtk-demo/gtkshaderbin.c

@@ -0,0 +1,241 @@
+#include "gtkshaderbin.h"
+
+typedef struct {
+  GskGLShader *shader;
+  GtkStateFlags state;
+  GtkStateFlags state_mask;
+  gboolean compiled;
+  gboolean compiled_ok;
+} ShaderInfo;
+
+struct _GtkShaderBin
+{
+  GtkWidget parent_instance;
+  GtkWidget *child;
+  ShaderInfo *active_shader;
+  GPtrArray *shaders;
+  guint tick_id;
+  float time;
+  gint64 first_frame_time;
+};
+
+struct _GtkShaderBinClass
+{
+  GtkWidgetClass parent_class;
+};
+
+G_DEFINE_TYPE (GtkShaderBin, gtk_shader_bin, GTK_TYPE_WIDGET)
+
+static void
+shader_info_free (ShaderInfo *info)
+{
+  g_object_unref (info->shader);
+  g_free (info);
+}
+
+static void
+gtk_shader_bin_finalize (GObject *object)
+{
+  GtkShaderBin *self = GTK_SHADER_BIN (object);
+
+  g_ptr_array_free (self->shaders, TRUE);
+
+  G_OBJECT_CLASS (gtk_shader_bin_parent_class)->finalize (object);
+}
+
+static void
+gtk_shader_bin_dispose (GObject *object)
+{
+  GtkShaderBin *self = GTK_SHADER_BIN (object);
+
+  g_clear_pointer (&self->child, gtk_widget_unparent);
+
+  G_OBJECT_CLASS (gtk_shader_bin_parent_class)->dispose (object);
+}
+
+static gboolean
+gtk_shader_bin_tick (GtkWidget     *widget,
+                     GdkFrameClock *frame_clock,
+                     gpointer       unused)
+{
+  GtkShaderBin *self = GTK_SHADER_BIN (widget);
+  gint64 frame_time;
+
+  frame_time = gdk_frame_clock_get_frame_time (frame_clock);
+  if (self->first_frame_time == 0)
+    self->first_frame_time = frame_time;
+  self->time = (frame_time - self->first_frame_time) / (float)G_USEC_PER_SEC;
+
+  gtk_widget_queue_draw (widget);
+
+  return G_SOURCE_CONTINUE;
+}
+
+static void
+gtk_shader_bin_init (GtkShaderBin *self)
+{
+  self->shaders = g_ptr_array_new_with_free_func ((GDestroyNotify)shader_info_free);
+}
+
+void
+gtk_shader_bin_update_active_shader (GtkShaderBin *self)
+{
+  GtkStateFlags new_state = gtk_widget_get_state_flags (GTK_WIDGET (self));
+  ShaderInfo *new_shader = NULL;
+
+  for (int i = 0; i < self->shaders->len; i++)
+    {
+      ShaderInfo *info = g_ptr_array_index (self->shaders, i);
+
+      if ((info->state_mask & new_state) == info->state)
+        {
+          new_shader = info;
+          break;
+        }
+    }
+
+  if (self->active_shader == new_shader)
+    return;
+
+  self->active_shader = new_shader;
+  self->first_frame_time = 0;
+
+  if (self->active_shader)
+    {
+      if (self->tick_id == 0)
+        self->tick_id = gtk_widget_add_tick_callback (GTK_WIDGET (self),
+                                                      gtk_shader_bin_tick,
+                                                      NULL, NULL);
+    }
+  else
+    {
+      if (self->tick_id != 0)
+        {
+          gtk_widget_remove_tick_callback (GTK_WIDGET (self), self->tick_id);
+          self->tick_id = 0;
+        }
+    }
+
+  gtk_widget_queue_draw (GTK_WIDGET (self));
+}
+
+static void
+gtk_shader_bin_state_flags_changed (GtkWidget        *widget,
+                                    GtkStateFlags     previous_state_flags)
+{
+  GtkShaderBin *self = GTK_SHADER_BIN (widget);
+
+  gtk_shader_bin_update_active_shader (self);
+}
+
+void
+gtk_shader_bin_add_shader (GtkShaderBin *self,
+                           GskGLShader  *shader,
+                           GtkStateFlags state,
+                           GtkStateFlags state_mask)
+{
+  ShaderInfo *info = g_new0 (ShaderInfo, 1);
+  info->shader = g_object_ref (shader);
+  info->state = state;
+  info->state_mask = state_mask;
+
+  g_ptr_array_add (self->shaders, info);
+
+  gtk_shader_bin_update_active_shader (self);
+}
+
+void
+gtk_shader_bin_set_child (GtkShaderBin *self,
+                          GtkWidget    *child)
+{
+
+  if (self->child == child)
+    return;
+
+  g_clear_pointer (&self->child, gtk_widget_unparent);
+
+  if (child)
+    {
+      self->child = child;
+      gtk_widget_set_parent (child, GTK_WIDGET (self));
+    }
+}
+
+GtkWidget *
+gtk_shader_bin_get_child   (GtkShaderBin *self)
+{
+  return self->child;
+}
+
+static void
+gtk_shader_bin_snapshot (GtkWidget   *widget,
+                         GtkSnapshot *snapshot)
+{
+  GtkShaderBin *self = GTK_SHADER_BIN (widget);
+  int width, height;
+
+  width = gtk_widget_get_width (widget);
+  height = gtk_widget_get_height (widget);
+
+  if (self->active_shader)
+    {
+      if (!self->active_shader->compiled)
+        {
+          GtkNative *native = gtk_widget_get_native (widget);
+          GskRenderer *renderer = gtk_native_get_renderer (native);
+          GError *error = NULL;
+
+          self->active_shader->compiled = TRUE;
+          self->active_shader->compiled_ok =
+            gsk_gl_shader_try_compile_for (self->active_shader->shader,
+                                           renderer, &error);
+          if (!self->active_shader->compiled_ok)
+            {
+              g_warning ("GtkShaderBin failed to compile shader: %s", error->message);
+              g_error_free (error);
+            }
+        }
+
+      if (self->active_shader->compiled_ok)
+        {
+          gtk_snapshot_push_gl_shader (snapshot, self->active_shader->shader,
+                                       &GRAPHENE_RECT_INIT(0, 0, width, height),
+                                       gsk_gl_shader_format_args (self->active_shader->shader,
+                                                                  "u_time", self->time,
+                                                                  NULL));
+          gtk_widget_snapshot_child (widget, self->child, snapshot);
+          gtk_snapshot_gl_shader_pop_texture (snapshot);
+          gtk_snapshot_pop (snapshot);
+
+          return;
+        }
+    }
+
+  /* Non-shader fallback */
+  gtk_widget_snapshot_child (widget, self->child, snapshot);
+}
+
+static void
+gtk_shader_bin_class_init (GtkShaderBinClass *class)
+{
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+
+  object_class->finalize = gtk_shader_bin_finalize;
+  object_class->dispose = gtk_shader_bin_dispose;
+
+  gtk_widget_class_set_layout_manager_type (widget_class, GTK_TYPE_BIN_LAYOUT);
+
+  widget_class->snapshot = gtk_shader_bin_snapshot;
+  widget_class->state_flags_changed = gtk_shader_bin_state_flags_changed;
+}
+
+GtkWidget *
+gtk_shader_bin_new (void)
+{
+  GtkShaderBin *self;
+
+  self = g_object_new (GTK_TYPE_SHADER_BIN, NULL);
+
+  return GTK_WIDGET (self);
+}

demos/gtk-demo/gtkshaderbin.h

@@ -0,0 +1,22 @@
+#ifndef __GTK_SHADER_BIN_H__
+#define __GTK_SHADER_BIN_H__
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+#define GTK_TYPE_SHADER_BIN      (gtk_shader_bin_get_type ())
+G_DECLARE_FINAL_TYPE (GtkShaderBin, gtk_shader_bin, GTK, SHADER_BIN, GtkWidget)
+
+GtkWidget  *gtk_shader_bin_new        (void);
+void        gtk_shader_bin_add_shader (GtkShaderBin *self,
+                                       GskGLShader  *shader,
+                                       GtkStateFlags state,
+                                       GtkStateFlags state_mask);
+void       gtk_shader_bin_set_child   (GtkShaderBin *self,
+                                       GtkWidget    *child);
+GtkWidget *gtk_shader_bin_get_child   (GtkShaderBin *self);
+
+G_END_DECLS
+
+#endif /* __GTK_SHADER_BIN_H__ */

demos/gtk-demo/gtkshaderstack.c

@@ -0,0 +1,353 @@
+#include "gtkshaderstack.h"
+
+struct _GtkShaderStack
+{
+  GtkWidget parent_instance;
+
+  GskGLShader *shader;
+  GPtrArray *children;
+  int current;
+  int next;
+  gboolean backwards;
+
+  guint tick_id;
+  float time;
+  float duration;
+  gint64 start_time;
+};
+
+struct _GtkShaderStackClass
+{
+  GtkWidgetClass parent_class;
+};
+
+
+enum {
+  PROP_DURATION = 1,
+  NUM_PROPERTIES
+};
+
+static GParamSpec *properties[NUM_PROPERTIES] = { NULL };
+
+G_DEFINE_TYPE (GtkShaderStack, gtk_shader_stack, GTK_TYPE_WIDGET)
+
+static void
+gtk_shader_stack_finalize (GObject *object)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (object);
+
+  g_object_unref (self->shader);
+
+  G_OBJECT_CLASS (gtk_shader_stack_parent_class)->finalize (object);
+}
+
+static void
+update_child_visible (GtkShaderStack *self)
+{
+  int i;
+
+  for (i = 0; i < self->children->len; i++)
+    {
+      GtkWidget *child = g_ptr_array_index (self->children, i);
+
+      gtk_widget_set_child_visible (child,
+                                    i == self->current || i == self->next);
+    }
+}
+
+static gboolean
+transition_cb (GtkWidget     *widget,
+               GdkFrameClock *clock,
+               gpointer       unused)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (widget);
+  gint64 frame_time;
+
+  frame_time = gdk_frame_clock_get_frame_time (clock);
+
+  if (self->start_time == 0)
+    self->start_time = frame_time;
+
+  self->time = (frame_time - self->start_time) / (float)G_USEC_PER_SEC;
+
+  gtk_widget_queue_draw (widget);
+
+  if (self->time >= self->duration)
+    {
+      self->current = self->next;
+      self->next = -1;
+
+      update_child_visible (self);
+
+      return G_SOURCE_REMOVE;
+    }
+  else
+    return G_SOURCE_CONTINUE;
+}
+
+static void
+start_transition (GtkShaderStack *self)
+{
+  self->start_time = 0;
+  self->tick_id = gtk_widget_add_tick_callback (GTK_WIDGET (self),
+                                                transition_cb,
+                                                NULL, NULL);
+}
+
+static void
+stop_transition (GtkShaderStack *self)
+{
+  if (self->tick_id != 0)
+    {
+      gtk_widget_remove_tick_callback (GTK_WIDGET (self), self->tick_id);
+      self->tick_id = 0;
+    }
+
+  if (self->next != -1)
+    self->current = self->next;
+  self->next = -1;
+
+  update_child_visible (self);
+}
+
+static void
+gtk_shader_stack_dispose (GObject *object)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (object);
+
+  stop_transition (self);
+
+  g_clear_pointer (&self->children, g_ptr_array_unref);
+
+  G_OBJECT_CLASS (gtk_shader_stack_parent_class)->dispose (object);
+}
+
+void
+gtk_shader_stack_transition (GtkShaderStack *self,
+                             gboolean forward)
+{
+  stop_transition (self);
+
+  self->backwards = !forward;
+  if (self->backwards)
+    self->next = (self->current + self->children->len - 1) % self->children->len;
+  else
+    self->next = (self->current + 1) % self->children->len;
+
+  update_child_visible (self);
+
+  start_transition (self);
+}
+
+static void
+gtk_shader_stack_init (GtkShaderStack *self)
+{
+  self->children = g_ptr_array_new_with_free_func ((GDestroyNotify)gtk_widget_unparent);
+  self->current = -1;
+  self->next = -1;
+  self->backwards = FALSE;
+  self->duration = 1.0;
+}
+
+static void
+gtk_shader_stack_measure (GtkWidget      *widget,
+                          GtkOrientation  orientation,
+                          int             for_size,
+                          int            *minimum,
+                          int            *natural,
+                          int            *minimum_baseline,
+                          int            *natural_baseline)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (widget);
+  int i;
+
+  *minimum = 0;
+  *natural = 0;
+
+  for (i = 0; i < self->children->len; i++)
+    {
+      GtkWidget *child = g_ptr_array_index (self->children, i);
+      int child_min, child_nat;
+
+      if (gtk_widget_get_visible (child))
+        {
+          gtk_widget_measure (child, orientation, for_size, &child_min, &child_nat, NULL, NULL);
+
+          *minimum = MAX (*minimum, child_min);
+          *natural = MAX (*natural, child_nat);
+        }
+    }
+}
+
+static void
+gtk_shader_stack_size_allocate (GtkWidget *widget,
+                                int        width,
+                                int        height,
+                                int        baseline)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (widget);
+  GtkAllocation child_allocation;
+  GtkWidget *child;
+  int i;
+
+  child_allocation.x = 0;
+  child_allocation.y = 0;
+  child_allocation.width = width;
+  child_allocation.height = height;
+
+  for (i = 0; i < self->children->len; i++)
+    {
+      child = g_ptr_array_index (self->children, i);
+      if (gtk_widget_get_visible (child))
+        gtk_widget_size_allocate (child, &child_allocation, -1);
+    }
+}
+
+static void
+gtk_shader_stack_snapshot (GtkWidget   *widget,
+                           GtkSnapshot *snapshot)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (widget);
+  int width, height;
+  GtkWidget *current, *next;
+
+  width = gtk_widget_get_width (widget);
+  height = gtk_widget_get_height (widget);
+
+  current = g_ptr_array_index (self->children, self->current);
+
+  if (self->next == -1)
+    {
+      gtk_widget_snapshot_child (widget, current, snapshot);
+    }
+  else
+    {
+      GtkNative *native = gtk_widget_get_native (widget);
+      GskRenderer *renderer = gtk_native_get_renderer (native);
+      float progress;
+
+      next = g_ptr_array_index (self->children, self->next);
+
+      progress = self->time / self->duration;
+
+      if (self->backwards)
+        {
+          GtkWidget *tmp = next;
+          next = current;
+          current = tmp;
+          progress = 1. - progress;
+        }
+
+      if (gsk_gl_shader_try_compile_for (self->shader,
+                                         renderer, NULL))
+        {
+          gtk_snapshot_push_gl_shader (snapshot,
+                                       self->shader,
+                                       &GRAPHENE_RECT_INIT(0, 0, width, height),
+                                       gsk_gl_shader_format_args (self->shader,
+                                                                  "progress", progress,
+                                                                  NULL));
+
+          gtk_widget_snapshot_child (widget, current, snapshot);
+          gtk_snapshot_gl_shader_pop_texture (snapshot); /* current child */
+          gtk_widget_snapshot_child (widget, next, snapshot);
+          gtk_snapshot_gl_shader_pop_texture (snapshot); /* next child */
+          gtk_snapshot_pop (snapshot);
+        }
+      else
+        {
+          /* Non-shader fallback */
+          gtk_widget_snapshot_child (widget, current, snapshot);
+        }
+    }
+}
+
+static void
+gtk_shader_stack_get_property (GObject      *object,
+                               guint         prop_id,
+                               GValue       *value,
+                               GParamSpec   *pspec)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (object);
+
+  switch (prop_id)
+    {
+    case PROP_DURATION:
+      g_value_set_float (value, self->duration);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_shader_stack_set_property (GObject      *object,
+                               guint         prop_id,
+                               const GValue *value,
+                               GParamSpec   *pspec)
+{
+  GtkShaderStack *self = GTK_SHADER_STACK (object);
+
+  switch (prop_id)
+    {
+    case PROP_DURATION:
+      self->duration = g_value_get_float (value);
+      break;
+
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gtk_shader_stack_class_init (GtkShaderStackClass *class)
+{
+  GtkWidgetClass *widget_class = GTK_WIDGET_CLASS (class);
+  GObjectClass *object_class = G_OBJECT_CLASS (class);
+
+  object_class->finalize = gtk_shader_stack_finalize;
+  object_class->dispose = gtk_shader_stack_dispose;
+  object_class->get_property = gtk_shader_stack_get_property;
+  object_class->set_property = gtk_shader_stack_set_property;
+
+  widget_class->snapshot = gtk_shader_stack_snapshot;
+  widget_class->measure = gtk_shader_stack_measure;
+  widget_class->size_allocate = gtk_shader_stack_size_allocate;
+
+  properties[PROP_DURATION] =
+      g_param_spec_float ("duration", "Duration", "Duration",
+                          0.1, 3.0, 1.0,
+                          G_PARAM_READWRITE);
+
+  g_object_class_install_properties (object_class, NUM_PROPERTIES, properties);
+}
+
+GtkWidget *
+gtk_shader_stack_new (void)
+{
+  return g_object_new (GTK_TYPE_SHADER_STACK, NULL);
+}
+
+void
+gtk_shader_stack_set_shader (GtkShaderStack *self,
+                             GskGLShader    *shader)
+{
+  g_set_object (&self->shader, shader);
+}
+
+void
+gtk_shader_stack_add_child (GtkShaderStack *self,
+                            GtkWidget      *child)
+{
+  g_ptr_array_add (self->children, child);
+  gtk_widget_set_parent (child, GTK_WIDGET (self));
+  gtk_widget_queue_resize (GTK_WIDGET (self));
+
+  if (self->current == -1)
+    self->current = 0;
+  else
+    gtk_widget_set_child_visible (child, FALSE);
+}

demos/gtk-demo/gtkshaderstack.h

@@ -0,0 +1,21 @@
+#ifndef __GTK_SHADER_STACK_H__
+#define __GTK_SHADER_STACK_H__
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+#define GTK_TYPE_SHADER_STACK     (gtk_shader_stack_get_type ())
+G_DECLARE_FINAL_TYPE (GtkShaderStack, gtk_shader_stack, GTK, SHADER_STACK, GtkWidget)
+
+GtkWidget * gtk_shader_stack_new          (void);
+void        gtk_shader_stack_set_shader   (GtkShaderStack *self,
+                                           GskGLShader    *shader);
+void        gtk_shader_stack_add_child    (GtkShaderStack *self,
+                                           GtkWidget      *child);
+void        gtk_shader_stack_transition   (GtkShaderStack *self,
+                                           gboolean       forward);
+
+G_END_DECLS
+
+#endif /* __GTK_SHADER_STACK_H__ */

demos/gtk-demo/gtkshadertoy.c

@@ -0,0 +1,526 @@
+#include <math.h>
+#include <stdlib.h>
+#include <string.h>
+#include <epoxy/gl.h>
+
+#include "gtkshadertoy.h"
+
+const char *default_image_shader =
+  "void mainImage(out vec4 fragColor, in vec2 fragCoord) {\n"
+  "    // Normalized pixel coordinates (from 0 to 1)\n"
+  "    vec2 uv = fragCoord/iResolution.xy;\n"
+  "\n"
+  "   // Time varying pixel color\n"
+  "    vec3 col = 0.5 + 0.5*cos(iTime+uv.xyx+vec3(0,2,4));\n"
+  "\n"
+  "    if (distance(iMouse.xy, fragCoord.xy) <= 10.0) {\n"
+  "        col = vec3(0.0);\n"
+  "    }\n"
+  "\n"
+  "    // Output to screen\n"
+  "    fragColor = vec4(col,1.0);\n"
+  "}\n";
+
+const char *shadertoy_vertex_shader =
+  "#version 150 core\n"
+  "\n"
+  "uniform vec3 iResolution;\n"
+  "\n"
+  "in vec2 position;\n"
+  "out vec2 fragCoord;\n"
+  "\n"
+  "void main() {\n"
+  "    gl_Position = vec4(position, 0.0, 1.0);\n"
+  "\n"
+  "    // Convert from OpenGL coordinate system (with origin in center\n"
+  "    // of screen) to Shadertoy/texture coordinate system (with origin\n"
+  "    // in lower left corner)\n"
+  "    fragCoord = (gl_Position.xy + vec2(1.0)) / vec2(2.0) * iResolution.xy;\n"
+  "}\n";
+
+const char *fragment_prefix =
+  "#version 150 core\n"
+  "\n"
+  "uniform vec3      iResolution;           // viewport resolution (in pixels)\n"
+  "uniform float     iTime;                 // shader playback time (in seconds)\n"
+  "uniform float     iTimeDelta;            // render time (in seconds)\n"
+  "uniform int       iFrame;                // shader playback frame\n"
+  "uniform float     iChannelTime[4];       // channel playback time (in seconds)\n"
+  "uniform vec3      iChannelResolution[4]; // channel resolution (in pixels)\n"
+  "uniform vec4      iMouse;                // mouse pixel coords. xy: current (if MLB down), zw: click\n"
+  "uniform sampler2D iChannel0;\n"
+  "uniform sampler2D iChannel1;\n"
+  "uniform sampler2D iChannel2;\n"
+  "uniform sampler2D iChannel3;\n"
+  "uniform vec4      iDate;                 // (year, month, day, time in seconds)\n"
+  "uniform float     iSampleRate;           // sound sample rate (i.e., 44100)\n"
+  "\n"
+  "in vec2 fragCoord;\n"
+  "out vec4 vFragColor;\n";
+
+
+// Fragment shader suffix
+const char *fragment_suffix =
+  "    void main() {\n"
+  "        vec4 c;\n"
+  "        mainImage(c, fragCoord);\n"
+  "         vFragColor = c;\n"
+  "    }\n";
+
+typedef struct {
+  char *image_shader;
+  gboolean image_shader_dirty;
+
+  gboolean error_set;
+
+  /* Vertex buffers */
+  GLuint vao;
+  GLuint buffer;
+
+  /* Active program */
+  GLuint program;
+
+  /* Location of uniforms for program */
+  GLuint resolution_location;
+  GLuint time_location;
+  GLuint timedelta_location;
+  GLuint frame_location;
+  GLuint mouse_location;
+
+  /* Current uniform values */
+  float resolution[3];
+  float time;
+  float timedelta;
+  float mouse[4];
+  int frame;
+
+  /* Animation data */
+  gint64 first_frame_time;
+  gint64 first_frame;
+  guint tick;
+} GtkShadertoyPrivate;
+
+G_DEFINE_TYPE_WITH_PRIVATE (GtkShadertoy, gtk_shadertoy, GTK_TYPE_GL_AREA)
+
+static gboolean gtk_shadertoy_render        (GtkGLArea     *area,
+                                             GdkGLContext  *context);
+static void     gtk_shadertoy_reshape       (GtkGLArea     *area,
+                                             int            width,
+                                             int            height);
+static void     gtk_shadertoy_realize       (GtkWidget     *widget);
+static void     gtk_shadertoy_unrealize     (GtkWidget     *widget);
+static gboolean gtk_shadertoy_tick          (GtkWidget     *widget,
+                                             GdkFrameClock *frame_clock,
+                                             gpointer       user_data);
+
+GtkWidget *
+gtk_shadertoy_new (void)
+{
+  return g_object_new (gtk_shadertoy_get_type (), NULL);
+}
+
+static void
+drag_begin_cb (GtkGestureDrag *drag,
+               double          x,
+               double          y,
+               gpointer        user_data)
+{
+  GtkShadertoy *shadertoy = GTK_SHADERTOY (user_data);
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
+  int height = gtk_widget_get_height (GTK_WIDGET (shadertoy));
+  int scale = gtk_widget_get_scale_factor (GTK_WIDGET (shadertoy));
+
+ priv->mouse[0] = x * scale;
+ priv->mouse[1] = (height - y) * scale;
+ priv->mouse[2] = priv->mouse[0];
+ priv->mouse[3] = priv->mouse[1];
+}
+
+static void
+drag_update_cb (GtkGestureDrag *drag,
+                double          dx,
+                double          dy,
+                gpointer        user_data)
+{
+  GtkShadertoy *shadertoy = GTK_SHADERTOY (user_data);
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
+  int width = gtk_widget_get_width (GTK_WIDGET (shadertoy));
+  int height = gtk_widget_get_height (GTK_WIDGET (shadertoy));
+  int scale = gtk_widget_get_scale_factor (GTK_WIDGET (shadertoy));
+  double x, y;
+
+  gtk_gesture_drag_get_start_point (drag, &x, &y);
+  x += dx;
+  y += dy;
+
+  if (x >= 0 && x < width &&
+      y >= 0 && y < height)
+    {
+      priv->mouse[0] = x * scale;
+      priv->mouse[1] = (height - y) * scale;
+    }
+}
+
+static void
+drag_end_cb (GtkGestureDrag *drag,
+             gdouble         dx,
+             gdouble         dy,
+             gpointer        user_data)
+{
+  GtkShadertoy *shadertoy = GTK_SHADERTOY (user_data);
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
+
+  priv->mouse[2] = -priv->mouse[2];
+  priv->mouse[3] = -priv->mouse[3];
+}
+
+static void
+gtk_shadertoy_init (GtkShadertoy *shadertoy)
+{
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
+  GtkGesture *drag;
+
+  priv->image_shader = g_strdup (default_image_shader);
+  priv->tick = gtk_widget_add_tick_callback (GTK_WIDGET (shadertoy), gtk_shadertoy_tick, shadertoy, NULL);
+
+  drag = gtk_gesture_drag_new ();
+  gtk_widget_add_controller (GTK_WIDGET (shadertoy), GTK_EVENT_CONTROLLER (drag));
+  g_signal_connect (drag, "drag-begin", (GCallback)drag_begin_cb, shadertoy);
+  g_signal_connect (drag, "drag-update", (GCallback)drag_update_cb, shadertoy);
+  g_signal_connect (drag, "drag-end", (GCallback)drag_end_cb, shadertoy);
+}
+
+static void
+gtk_shadertoy_finalize (GObject *obj)
+{
+  GtkShadertoy *shadertoy = GTK_SHADERTOY (obj);
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
+
+  gtk_widget_remove_tick_callback (GTK_WIDGET (shadertoy), priv->tick);
+  g_free (priv->image_shader);
+
+  G_OBJECT_CLASS (gtk_shadertoy_parent_class)->finalize (obj);
+}
+
+static void
+gtk_shadertoy_class_init (GtkShadertoyClass *klass)
+{
+  GTK_GL_AREA_CLASS (klass)->render = gtk_shadertoy_render;
+  GTK_GL_AREA_CLASS (klass)->resize = gtk_shadertoy_reshape;
+
+  GTK_WIDGET_CLASS (klass)->realize = gtk_shadertoy_realize;
+  GTK_WIDGET_CLASS (klass)->unrealize = gtk_shadertoy_unrealize;
+
+  G_OBJECT_CLASS (klass)->finalize = gtk_shadertoy_finalize;
+}
+
+/* new window size or exposure */
+static void
+gtk_shadertoy_reshape (GtkGLArea *area, int width, int height)
+{
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private ((GtkShadertoy *) area);
+
+  priv->resolution[0] = width;
+  priv->resolution[1] = height;
+  priv->resolution[2] = 1.0; /* screen aspect ratio */
+
+  /* Set the viewport */
+  glViewport (0, 0, (GLint) width, (GLint) height);
+}
+
+static GLuint
+create_shader (int         type,
+               const char *src,
+               GError    **error)
+{
+  GLuint shader;
+  int status;
+
+  shader = glCreateShader (type);
+  glShaderSource (shader, 1, &src, NULL);
+  glCompileShader (shader);
+
+  glGetShaderiv (shader, GL_COMPILE_STATUS, &status);
+  if (status == GL_FALSE)
+    {
+      int log_len;
+      char *buffer;
+
+      glGetShaderiv (shader, GL_INFO_LOG_LENGTH, &log_len);
+
+      buffer = g_malloc (log_len + 1);
+      glGetShaderInfoLog (shader, log_len, NULL, buffer);
+
+      g_set_error (error, GDK_GL_ERROR, GDK_GL_ERROR_COMPILATION_FAILED,
+                   "Compile failure in %s shader:\n%s",
+                   type == GL_VERTEX_SHADER ? "vertex" : "fragment",
+                   buffer);
+
+      g_free (buffer);
+
+      glDeleteShader (shader);
+
+      return 0;
+    }
+
+  return shader;
+}
+
+static gboolean
+init_shaders (GtkShadertoy *shadertoy,
+              const char *vertex_source,
+              const char *fragment_source,
+              GError **error)
+{
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
+  GLuint vertex, fragment;
+  GLuint program = 0;
+  int status;
+  gboolean res = TRUE;
+
+  vertex = create_shader (GL_VERTEX_SHADER, vertex_source, error);
+  if (vertex == 0)
+    return FALSE;
+
+  fragment = create_shader (GL_FRAGMENT_SHADER, fragment_source, error);
+  if (fragment == 0)
+    {
+      glDeleteShader (vertex);
+      return FALSE;
+    }
+
+  program = glCreateProgram ();
+  glAttachShader (program, vertex);
+  glAttachShader (program, fragment);
+
+  glLinkProgram (program);
+
+  glGetProgramiv (program, GL_LINK_STATUS, &status);
+  if (status == GL_FALSE)
+    {
+      int log_len;
+      char *buffer;
+
+      glGetProgramiv (program, GL_INFO_LOG_LENGTH, &log_len);
+
+      buffer = g_malloc (log_len + 1);
+      glGetProgramInfoLog (program, log_len, NULL, buffer);
+
+      g_set_error (error, GDK_GL_ERROR, GDK_GL_ERROR_LINK_FAILED,
+                   "Linking failure:\n%s", buffer);
+      res = FALSE;
+
+      g_free (buffer);
+
+      glDeleteProgram (program);
+
+      goto out;
+    }
+
+  if (priv->program != 0)
+    glDeleteProgram (priv->program);
+
+  priv->program = program;
+  priv->resolution_location = glGetUniformLocation (program, "iResolution");
+  priv->time_location = glGetUniformLocation (program, "iTime");
+  priv->timedelta_location = glGetUniformLocation (program, "iTimeDelta");
+  priv->frame_location = glGetUniformLocation (program, "iFrame");
+  priv->mouse_location = glGetUniformLocation (program, "iMouse");
+
+  glDetachShader (program, vertex);
+  glDetachShader (program, fragment);
+
+out:
+  /* These are now owned by the program and can be deleted */
+  glDeleteShader (vertex);
+  glDeleteShader (fragment);
+
+  return res;
+}
+
+static void
+gtk_shadertoy_realize_shader (GtkShadertoy *shadertoy)
+{
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
+  char *fragment_shader;
+  GError *error = NULL;
+
+  fragment_shader = g_strconcat (fragment_prefix, priv->image_shader, fragment_suffix, NULL);
+  if (!init_shaders (shadertoy, shadertoy_vertex_shader, fragment_shader, &error))
+    {
+      priv->error_set = TRUE;
+      gtk_gl_area_set_error (GTK_GL_AREA (shadertoy), error);
+      g_error_free (error);
+    }
+  g_free (fragment_shader);
+
+  /* Start new shader at time zero */
+  priv->first_frame_time = 0;
+  priv->first_frame = 0;
+
+  priv->image_shader_dirty = FALSE;
+}
+
+static gboolean
+gtk_shadertoy_render (GtkGLArea    *area,
+                      GdkGLContext *context)
+{
+  GtkShadertoy *shadertoy = GTK_SHADERTOY (area);
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
+
+  if (gtk_gl_area_get_error (area) != NULL)
+    return FALSE;
+
+  if (priv->image_shader_dirty)
+    gtk_shadertoy_realize_shader (shadertoy);
+
+  /* Clear the viewport */
+  glClearColor (0.0, 0.0, 0.0, 1.0);
+  glClear (GL_COLOR_BUFFER_BIT);
+
+  glUseProgram (priv->program);
+
+  /* Update uniforms */
+  if (priv->resolution_location != -1)
+    glUniform3fv (priv->resolution_location, 1, priv->resolution);
+  if (priv->time_location != -1)
+    glUniform1f (priv->time_location, priv->time);
+  if (priv->timedelta_location != -1)
+    glUniform1f (priv->timedelta_location, priv->timedelta);
+  if (priv->frame_location != -1)
+    glUniform1i (priv->frame_location, priv->frame);
+  if (priv->mouse_location != -1)
+    glUniform4fv (priv->mouse_location, 1, priv->mouse);
+
+  /* Use the vertices in our buffer */
+  glBindBuffer (GL_ARRAY_BUFFER, priv->buffer);
+  glEnableVertexAttribArray (0);
+  glVertexAttribPointer (0, 4, GL_FLOAT, GL_FALSE, 0, 0);
+
+  glDrawArrays (GL_TRIANGLES, 0, 6);
+
+  /* We finished using the buffers and program */
+  glDisableVertexAttribArray (0);
+  glBindBuffer (GL_ARRAY_BUFFER, 0);
+  glUseProgram (0);
+
+  /* Flush the contents of the pipeline */
+  glFlush ();
+
+  return TRUE;
+}
+
+const char *
+gtk_shadertoy_get_image_shader (GtkShadertoy *shadertoy)
+{
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
+
+  return priv->image_shader;
+}
+
+void
+gtk_shadertoy_set_image_shader (GtkShadertoy *shadertoy,
+                                const char   *shader)
+{
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
+
+  g_free (priv->image_shader);
+  priv->image_shader = g_strdup (shader);
+
+  /* Don't override error we didn't set it ourselves */
+  if (priv->error_set)
+    {
+      gtk_gl_area_set_error (GTK_GL_AREA (shadertoy), NULL);
+      priv->error_set = FALSE;
+    }
+  priv->image_shader_dirty = TRUE;
+}
+
+static void
+gtk_shadertoy_realize (GtkWidget *widget)
+{
+  GtkGLArea *glarea = GTK_GL_AREA (widget);
+  GtkShadertoy *shadertoy = GTK_SHADERTOY (widget);
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
+
+  /* Draw two triangles across whole screen */
+  const GLfloat vertex_data[] = {
+    -1.0f, -1.0f, 0.f, 1.f,
+    -1.0f,  1.0f, 0.f, 1.f,
+    1.0f,  1.0f, 0.f, 1.f,
+
+    -1.0f, -1.0f, 0.f, 1.f,
+    1.0f,  1.0f, 0.f, 1.f,
+    1.0f, -1.0f, 0.f, 1.f,
+  };
+
+  GTK_WIDGET_CLASS (gtk_shadertoy_parent_class)->realize (widget);
+
+  gtk_gl_area_make_current (glarea);
+  if (gtk_gl_area_get_error (glarea) != NULL)
+    return;
+
+  glGenVertexArrays (1, &priv->vao);
+  glBindVertexArray (priv->vao);
+
+  glGenBuffers (1, &priv->buffer);
+  glBindBuffer (GL_ARRAY_BUFFER, priv->buffer);
+  glBufferData (GL_ARRAY_BUFFER, sizeof (vertex_data), vertex_data, GL_STATIC_DRAW);
+  glBindBuffer (GL_ARRAY_BUFFER, 0);
+
+  gtk_shadertoy_realize_shader (shadertoy);
+}
+
+static void
+gtk_shadertoy_unrealize (GtkWidget *widget)
+{
+  GtkGLArea *glarea = GTK_GL_AREA (widget);
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private ((GtkShadertoy *) widget);
+
+  gtk_gl_area_make_current (glarea);
+  if (gtk_gl_area_get_error (glarea) == NULL)
+    {
+      if (priv->buffer != 0)
+        glDeleteBuffers (1, &priv->buffer);
+
+      if (priv->vao != 0)
+        glDeleteVertexArrays (1, &priv->vao);
+
+      if (priv->program != 0)
+        glDeleteProgram (priv->program);
+    }
+
+  GTK_WIDGET_CLASS (gtk_shadertoy_parent_class)->unrealize (widget);
+}
+
+static gboolean
+gtk_shadertoy_tick (GtkWidget     *widget,
+                    GdkFrameClock *frame_clock,
+                    gpointer       user_data)
+{
+  GtkShadertoy *shadertoy = GTK_SHADERTOY (widget);
+  GtkShadertoyPrivate *priv = gtk_shadertoy_get_instance_private (shadertoy);
+  gint64 frame_time;
+  gint64 frame;
+  float previous_time;
+
+  frame = gdk_frame_clock_get_frame_counter (frame_clock);
+  frame_time = gdk_frame_clock_get_frame_time (frame_clock);
+
+  if (priv->first_frame_time == 0)
+    {
+      priv->first_frame_time = frame_time;
+      priv->first_frame = frame;
+      previous_time = 0;
+    }
+  else
+    previous_time = priv->time;
+
+  priv->time = (frame_time - priv->first_frame_time) / 1000000.0f;
+  priv->frame = frame - priv->first_frame;
+  priv->timedelta = priv->time - previous_time;
+
+  gtk_widget_queue_draw (widget);
+
+  return G_SOURCE_CONTINUE;
+}

demos/gtk-demo/gtkshadertoy.h

@@ -0,0 +1,34 @@
+#ifndef __GTK_SHADERTOY_H__
+#define __GTK_SHADERTOY_H__
+
+#include <gtk/gtk.h>
+
+G_BEGIN_DECLS
+
+#define GTK_TYPE_SHADERTOY      (gtk_shadertoy_get_type ())
+#define GTK_SHADERTOY(inst)     (G_TYPE_CHECK_INSTANCE_CAST ((inst), \
+                                 GTK_TYPE_SHADERTOY,                 \
+                                 GtkShadertoy))
+#define GTK_IS_SHADERTOY(inst)  (G_TYPE_CHECK_INSTANCE_TYPE ((inst), \
+                                 GTK_TYPE_SHADERTOY))
+
+typedef struct _GtkShadertoy GtkShadertoy;
+typedef struct _GtkShadertoyClass GtkShadertoyClass;
+
+struct _GtkShadertoy {
+  GtkGLArea parent;
+};
+
+struct _GtkShadertoyClass {
+  GtkGLAreaClass parent_class;
+};
+
+GType       gtk_shadertoy_get_type         (void) G_GNUC_CONST;
+GtkWidget  *gtk_shadertoy_new              (void);
+const char *gtk_shadertoy_get_image_shader (GtkShadertoy *shadertoy);
+void        gtk_shadertoy_set_image_shader (GtkShadertoy *shadertoy,
+                                            const char   *shader);
+
+G_END_DECLS
+
+#endif /* __GTK_SHADERTOY_H__ */

demos/gtk-demo/headerbar.c

@@ -1,4 +1,5 @@
 /* Header Bar
+ * #Keywords: GtkWindowHandle, GtkWindowControls
  *
  * GtkHeaderBar is a container that is suitable for implementing
  * window titlebars. One of its features is that it can position
@@ -48,6 +49,7 @@ do_headerbar (GtkWidget *do_widget)
       gtk_box_append (GTK_BOX (box), button);
 
       gtk_header_bar_pack_start (GTK_HEADER_BAR (header), box);
+      gtk_header_bar_pack_start (GTK_HEADER_BAR (header), gtk_switch_new ());
 
       gtk_window_set_titlebar (GTK_WINDOW (window), header);
 

demos/gtk-demo/hypertext.c

@@ -1,9 +1,13 @@
 /* Text View/Hypertext
+ * #Keywords: GtkTextView, GtkTextBuffer
  *
  * Usually, tags modify the appearance of text in the view, e.g. making it
  * bold or colored or underlined. But tags are not restricted to appearance.
  * They can also affect the behavior of mouse and key presses, as this demo
  * shows.
+ *
+ * We also demonstrate adding other things to a text view, such as
+ * clickable icons.
  */
 
 #include <gtk/gtk.h>
@@ -30,35 +34,103 @@ insert_link (GtkTextBuffer *buffer,
   gtk_text_buffer_insert_with_tags (buffer, iter, text, -1, tag, NULL);
 }
 
+/* Quick-and-dirty text-to-speech for a single word. If you don't hear
+ * anything, you are missing espeak-ng on your system.
+ */
+static void
+say_word (GtkGestureClick *gesture,
+          guint            n_press,
+          double           x,
+          double           y,
+          const char      *word)
+{
+  const char *argv[3];
+
+  argv[0] = "espeak-ng";
+  argv[1] = word;
+  argv[2] = NULL;
+
+  g_spawn_async (NULL, (char **)argv, NULL, G_SPAWN_SEARCH_PATH, NULL, NULL, NULL, NULL);
+}
+
 /* Fills the buffer with text and interspersed links. In any real
  * hypertext app, this method would parse a file to identify the links.
  */
 static void
-show_page (GtkTextBuffer *buffer,
-           int            page)
+show_page (GtkTextView *text_view,
+           int          page)
 {
+  GtkTextBuffer *buffer;
   GtkTextIter iter;
+  GtkWidget *child;
+  GtkTextChildAnchor *anchor;
+  GtkEventController *controller;
 
+  buffer = gtk_text_view_get_buffer (text_view);
   gtk_text_buffer_set_text (buffer, "", 0);
   gtk_text_buffer_get_iter_at_offset (buffer, &iter, 0);
   gtk_text_buffer_begin_irreversible_action (buffer);
   if (page == 1)
     {
+      GtkIconPaintable *icon;
+      GtkIconTheme *theme;
+
       gtk_text_buffer_insert (buffer, &iter, "Some text to show that simple ", -1);
-      insert_link (buffer, &iter, "hyper text", 3);
+      insert_link (buffer, &iter, "hypertext", 3);
       gtk_text_buffer_insert (buffer, &iter, " can easily be realized with ", -1);
       insert_link (buffer, &iter, "tags", 2);
+      gtk_text_buffer_insert (buffer, &iter, ".\n", -1);
+      gtk_text_buffer_insert (buffer, &iter,
+          "Of course you can also embed Emoji 😋, "
+          "icons ", -1);
+
+      theme = gtk_icon_theme_get_for_display (gtk_widget_get_display (GTK_WIDGET (text_view)));
+      icon = gtk_icon_theme_lookup_icon (theme,
+                                         "microphone-sensitivity-high-symbolic",
+                                         NULL,
+                                         16,
+                                         1,
+                                         GTK_TEXT_DIR_LTR,
+                                         0);
+      gtk_text_buffer_insert_paintable (buffer, &iter, GDK_PAINTABLE (icon));
+      g_object_unref (icon);
+      gtk_text_buffer_insert (buffer, &iter, ", or even widgets ", -1);
+      anchor = gtk_text_buffer_create_child_anchor (buffer, &iter);
+      child = gtk_level_bar_new_for_interval (0, 100);
+      gtk_level_bar_set_value (GTK_LEVEL_BAR (child), 50);
+      gtk_widget_set_size_request (child, 100, -1);
+      gtk_text_view_add_child_at_anchor (text_view, child, anchor);
       gtk_text_buffer_insert (buffer, &iter, ".", -1);
     }
   else if (page == 2)
     {
-      gtk_text_buffer_insert (buffer, &iter,
-                              "A tag is an attribute that can be applied to some range of text. "
-                              "For example, a tag might be called \"bold\" and make the text inside "
-                              "the tag bold. However, the tag concept is more general than that; "
-                              "tags don't have to affect appearance. They can instead affect the "
-                              "behavior of mouse and key presses, \"lock\" a range of text so the "
-                              "user can't edit it, or countless other things.\n", -1);
+      GtkTextTag *tag;
+
+      tag = gtk_text_buffer_create_tag (buffer, NULL,
+                                        "weight", PANGO_WEIGHT_BOLD,
+                                        "scale", PANGO_SCALE_X_LARGE,
+                                        NULL);
+      gtk_text_buffer_insert_with_tags (buffer, &iter, "tag", -1, tag, NULL);
+      tag = gtk_text_buffer_create_tag (buffer, NULL,
+                                        "family", "monospace",
+                                        NULL);
+      gtk_text_buffer_insert_with_tags (buffer, &iter, " / tag / ", -1, tag, NULL);
+
+      anchor = gtk_text_buffer_create_child_anchor (buffer, &iter);
+      child = gtk_image_new_from_icon_name ("audio-volume-high-symbolic");
+      gtk_widget_set_cursor_from_name (child, "pointer");
+      controller = GTK_EVENT_CONTROLLER (gtk_gesture_click_new ());
+      g_signal_connect (controller, "pressed", G_CALLBACK (say_word), (gpointer)"tag");
+      gtk_widget_add_controller (child, controller);
+      gtk_text_view_add_child_at_anchor (text_view, child, anchor);
+
+      gtk_text_buffer_insert (buffer, &iter, "\n"
+          "An attribute that can be applied to some range of text. For example, "
+          "a tag might be called “bold” and make the text inside the tag bold.\n"
+          "However, the tag concept is more general than that; "
+          "tags don't have to affect appearance. They can instead affect the "
+          "behavior of mouse and key presses, “lock” a range of text so the "
+          "user can't edit it, or countless other things.\n", -1);
       insert_link (buffer, &iter, "Go back", 1);
     }
   else if (page == 3)
@@ -67,11 +139,25 @@ show_page (GtkTextBuffer *buffer,
 
       tag = gtk_text_buffer_create_tag (buffer, NULL,
                                         "weight", PANGO_WEIGHT_BOLD,
+                                        "scale", PANGO_SCALE_X_LARGE,
                                         NULL);
-      gtk_text_buffer_insert_with_tags (buffer, &iter, "hypertext:\n", -1, tag, NULL);
-      gtk_text_buffer_insert (buffer, &iter,
-                              "machine-readable text that is not sequential but is organized "
-                              "so that related items of information are connected.\n", -1);
+      gtk_text_buffer_insert_with_tags (buffer, &iter, "hypertext", -1, tag, NULL);
+      tag = gtk_text_buffer_create_tag (buffer, NULL,
+                                        "family", "monospace",
+                                        NULL);
+      gtk_text_buffer_insert_with_tags (buffer, &iter, " / ˈhaɪ pərˌtɛkst / ", -1, tag, NULL);
+
+      anchor = gtk_text_buffer_create_child_anchor (buffer, &iter);
+      child = gtk_image_new_from_icon_name ("audio-volume-high-symbolic");
+      gtk_widget_set_cursor_from_name (child, "pointer");
+      controller = GTK_EVENT_CONTROLLER (gtk_gesture_click_new ());
+      g_signal_connect (controller, "pressed", G_CALLBACK (say_word), (gpointer)"hypertext");
+      gtk_widget_add_controller (child, controller);
+      gtk_text_view_add_child_at_anchor (text_view, child, anchor);
+
+      gtk_text_buffer_insert (buffer, &iter, "\n"
+          "Machine-readable text that is not sequential but is organized "
+          "so that related items of information are connected.\n", -1);
       insert_link (buffer, &iter, "Go back", 1);
     }
   gtk_text_buffer_end_irreversible_action (buffer);
@@ -95,7 +181,7 @@ follow_if_link (GtkWidget   *text_view,
 
       if (page != 0)
         {
-          show_page (gtk_text_view_get_buffer (GTK_TEXT_VIEW (text_view)), page);
+          show_page (GTK_TEXT_VIEW (text_view), page);
           break;
         }
     }
@@ -162,7 +248,7 @@ released_cb (GtkGestureClick *gesture,
   if (gtk_text_iter_get_offset (&start) != gtk_text_iter_get_offset (&end))
     return;
 
-  if (gtk_text_view_get_iter_at_location (GTK_TEXT_VIEW (text_view), &iter, x, y))
+  if (gtk_text_view_get_iter_at_location (GTK_TEXT_VIEW (text_view), &iter, tx, ty))
     follow_if_link (text_view, &iter);
 }
 
@@ -172,7 +258,13 @@ motion_cb (GtkEventControllerMotion *controller,
            double                    y,
            GtkTextView              *text_view)
 {
-  set_cursor_if_appropriate (text_view, x, y);
+  int tx, ty;
+
+  gtk_text_view_window_to_buffer_coords (text_view,
+                                         GTK_TEXT_WINDOW_WIDGET,
+                                         x, y, &tx, &ty);
+
+  set_cursor_if_appropriate (text_view, tx, ty);
 }
 
 static gboolean hovering_over_link = FALSE;
@@ -182,9 +274,9 @@ static gboolean hovering_over_link = FALSE;
  * typically used by web browsers.
  */
 static void
-set_cursor_if_appropriate (GtkTextView    *text_view,
-                           int             x,
-                           int             y)
+set_cursor_if_appropriate (GtkTextView *text_view,
+                           int          x,
+                           int          y)
 {
   GSList *tags = NULL, *tagp = NULL;
   GtkTextIter iter;
@@ -236,13 +328,17 @@ do_hypertext (GtkWidget *do_widget)
       gtk_window_set_title (GTK_WINDOW (window), "Hypertext");
       gtk_window_set_display (GTK_WINDOW (window),
                               gtk_widget_get_display (do_widget));
-      gtk_window_set_default_size (GTK_WINDOW (window), 450, 450);
+      gtk_window_set_default_size (GTK_WINDOW (window), 330, 330);
+      gtk_window_set_resizable (GTK_WINDOW (window), FALSE);
       g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
 
       view = gtk_text_view_new ();
       gtk_text_view_set_wrap_mode (GTK_TEXT_VIEW (view), GTK_WRAP_WORD);
+      gtk_text_view_set_top_margin (GTK_TEXT_VIEW (view), 20);
+      gtk_text_view_set_bottom_margin (GTK_TEXT_VIEW (view), 20);
       gtk_text_view_set_left_margin (GTK_TEXT_VIEW (view), 20);
       gtk_text_view_set_right_margin (GTK_TEXT_VIEW (view), 20);
+      gtk_text_view_set_pixels_below_lines (GTK_TEXT_VIEW (view), 10);
       controller = gtk_event_controller_key_new ();
       g_signal_connect (controller, "key-pressed", G_CALLBACK (key_pressed), view);
       gtk_widget_add_controller (view, controller);
@@ -267,7 +363,7 @@ do_hypertext (GtkWidget *do_widget)
       gtk_window_set_child (GTK_WINDOW (window), sw);
       gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), view);
 
-      show_page (buffer, 1);
+      show_page (GTK_TEXT_VIEW (view), 1);
     }
 
   if (!gtk_widget_get_visible (window))

demos/gtk-demo/iconscroll.c

@@ -1,4 +1,5 @@
 /* Benchmark/Scrolling
+ * #Keywords: GtkScrolledWindow
  *
  * This demo scrolls a view with various content.
  */
@@ -255,12 +256,38 @@ iconscroll_prev_clicked_cb (GtkButton *source,
   set_widget_type (new_index);
 }
 
+static gboolean
+update_fps (gpointer data)
+{
+  GtkWidget *label = data;
+  GdkFrameClock *frame_clock;
+  double fps;
+  char *str;
+
+  frame_clock = gtk_widget_get_frame_clock (label);
+
+  fps = gdk_frame_clock_get_fps (frame_clock);
+  str = g_strdup_printf ("%.2f fps", fps);
+  gtk_label_set_label (GTK_LABEL (label), str);
+  g_free (str);
+
+  return G_SOURCE_CONTINUE;
+}
+
+static void
+remove_timeout (gpointer data)
+{
+  g_source_remove (GPOINTER_TO_UINT (data));
+}
+
 G_MODULE_EXPORT GtkWidget *
 do_iconscroll (GtkWidget *do_widget)
 {
   if (!window)
     {
       GtkBuilder *builder;
+      GtkWidget *label;
+      guint id;
 
       builder = gtk_builder_new_from_resource ("/iconscroll/iconscroll.ui");
       window = GTK_WIDGET (gtk_builder_get_object (builder, "window"));
@@ -274,6 +301,11 @@ do_iconscroll (GtkWidget *do_widget)
       vadjustment = GTK_ADJUSTMENT (gtk_builder_get_object (builder, "vadjustment"));
       set_widget_type (0);
 
+      label = GTK_WIDGET (gtk_builder_get_object (builder, "fps_label"));
+      id = g_timeout_add (500, update_fps, label);
+      g_object_set_data_full (G_OBJECT (label), "timeout",
+                              GUINT_TO_POINTER (id), remove_timeout);
+
       g_object_unref (builder);
     }
 

demos/gtk-demo/iconscroll.ui

@@ -25,6 +25,13 @@
             </child>
           </object>
         </child>
+        <child type="end">
+          <object class="GtkLabel" id="fps_label">
+            <attributes>
+              <attribute name="font-features" value="tnum=1"/>
+            </attributes>
+          </object>
+        </child>
       </object>
     </child>
     <child>

demos/gtk-demo/images.c

@@ -1,4 +1,5 @@
 /* Images
+ * #Keywords: GdkPaintable, GtkWidgetPaintable
  *
  * GtkImage and GtkPicture are used to display an image; the image can be
  * in a number of formats.

demos/gtk-demo/infobar.c

@@ -1,4 +1,5 @@
 /* Info Bars
+ * #Keywords: GtkInfoBar
  *
  * Info bar widgets are used to report important messages to the user.
  */

demos/gtk-demo/layoutmanager.c

@@ -1,4 +1,5 @@
 /* Layout Manager/Transition
+ * #Keywords: GtkLayoutManager
  *
  * This demo shows a simple example of a custom layout manager
  * and a widget using it. The layout manager places the children

demos/gtk-demo/layoutmanager2.c

@@ -1,4 +1,5 @@
 /* Layout Manager/Transformation
+ * #Keywords: GtkLayoutManager, GskTransform
  *
  * This demo shows how to use transforms in a nontrivial
  * way with a custom layout manager. The layout manager places

demos/gtk-demo/list_store.c

@@ -3,7 +3,6 @@
  * The GtkListStore is used to store data in list form, to be used
  * later on by a GtkTreeView to display it. This demo builds a
  * simple GtkListStore and displays it.
- *
  */
 
 #include <gtk/gtk.h>

demos/gtk-demo/listbox.c

@@ -2,7 +2,6 @@
  *
  * GtkListBox allows lists with complicated layouts, using
  * regular widgets supporting sorting and filtering.
- *
  */
 
 #include <gtk/gtk.h>

demos/gtk-demo/listview_applauncher.c

@@ -1,4 +1,5 @@
 /* Lists/Application launcher
+ * #Keywords: GtkListItemFactory, GListModel
  *
  * This demo uses the GtkListView widget as a fancy application launcher.
  *

demos/gtk-demo/listview_clocks.c

@@ -1,10 +1,11 @@
 /* Lists/Clocks
+ * #Keywords: GtkGridView, GtkListItemFactory, GListModel
  *
  * This demo displays the time in different timezones.
  *
  * The goal is to show how to set up expressions that track changes
  * in objects and make them update widgets. For that, we create a
- * GtkClock object that updates its time every second and then use
+ * clock object that updates its time every second and then use
  * various ways to display that time.
  *
  * Typically, this will be done using GtkBuilder .ui files with the

demos/gtk-demo/listview_colors.c

@@ -1,4 +1,5 @@
 /* Lists/Colors
+ * #Keywords: GtkSortListModel, GtkMultiSelection
  *
  * This demo displays a grid of colors.
  *
@@ -1022,31 +1023,31 @@ do_listview_colors (GtkWidget *do_widget)
       /* An empty multisorter doesn't do any sorting and the sortmodel is
        * smart enough to know that.
        */
-      sorter = gtk_multi_sorter_new ();
+      sorter = GTK_SORTER (gtk_multi_sorter_new ());
       set_title (sorter, "Unsorted");
       g_list_store_append (sorters, sorter);
       g_object_unref (sorter);
 
-      sorter = gtk_string_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "name"));
+      sorter = GTK_SORTER (gtk_string_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "name")));
       set_title (sorter, "Name");
       g_list_store_append (sorters, sorter);
       g_object_unref (sorter);
 
-      multi_sorter = gtk_multi_sorter_new ();
+      multi_sorter = GTK_SORTER (gtk_multi_sorter_new ());
 
-      sorter = gtk_numeric_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "red"));
+      sorter = GTK_SORTER (gtk_numeric_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "red")));
       gtk_numeric_sorter_set_sort_order (GTK_NUMERIC_SORTER (sorter), GTK_SORT_DESCENDING);
       set_title (sorter, "Red");
       g_list_store_append (sorters, sorter);
       gtk_multi_sorter_append (GTK_MULTI_SORTER (multi_sorter), sorter);
 
-      sorter = gtk_numeric_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "green"));
+      sorter = GTK_SORTER (gtk_numeric_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "green")));
       gtk_numeric_sorter_set_sort_order (GTK_NUMERIC_SORTER (sorter), GTK_SORT_DESCENDING);
       set_title (sorter, "Green");
       g_list_store_append (sorters, sorter);
       gtk_multi_sorter_append (GTK_MULTI_SORTER (multi_sorter), sorter);
 
-      sorter = gtk_numeric_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "blue"));
+      sorter = GTK_SORTER (gtk_numeric_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "blue")));
       gtk_numeric_sorter_set_sort_order (GTK_NUMERIC_SORTER (sorter), GTK_SORT_DESCENDING);
       set_title (sorter, "Blue");
       g_list_store_append (sorters, sorter);
@@ -1056,21 +1057,21 @@ do_listview_colors (GtkWidget *do_widget)
       g_list_store_append (sorters, multi_sorter);
       g_object_unref (multi_sorter);
 
-      multi_sorter = gtk_multi_sorter_new ();
+      multi_sorter = GTK_SORTER (gtk_multi_sorter_new ());
 
-      sorter = gtk_numeric_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "hue"));
+      sorter = GTK_SORTER (gtk_numeric_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "hue")));
       gtk_numeric_sorter_set_sort_order (GTK_NUMERIC_SORTER (sorter), GTK_SORT_DESCENDING);
       set_title (sorter, "Hue");
       g_list_store_append (sorters, sorter);
       gtk_multi_sorter_append (GTK_MULTI_SORTER (multi_sorter), sorter);
 
-      sorter = gtk_numeric_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "saturation"));
+      sorter = GTK_SORTER (gtk_numeric_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "saturation")));
       gtk_numeric_sorter_set_sort_order (GTK_NUMERIC_SORTER (sorter), GTK_SORT_DESCENDING);
       set_title (sorter, "Saturation");
       g_list_store_append (sorters, sorter);
       gtk_multi_sorter_append (GTK_MULTI_SORTER (multi_sorter), sorter);
 
-      sorter = gtk_numeric_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "value"));
+      sorter = GTK_SORTER (gtk_numeric_sorter_new (gtk_property_expression_new (GTK_TYPE_COLOR, NULL, "value")));
       gtk_numeric_sorter_set_sort_order (GTK_NUMERIC_SORTER (sorter), GTK_SORT_DESCENDING);
       set_title (sorter, "Value");
       g_list_store_append (sorters, sorter);

demos/gtk-demo/listview_filebrowser.c

@@ -1,4 +1,5 @@
 /* Lists/File browser
+ * #Keywords: GListModel
  *
  * This demo shows off the different layouts that are quickly achievable
  * with GtkListview and GtkGridView by implementing a file browser with

demos/gtk-demo/listview_minesweeper.c

@@ -1,7 +1,8 @@
 /* Lists/Minesweeper
+ * #Keywords: GtkGridView, GListModel, game
  *
  * This demo shows how to develop a user interface for small game using a
- * gridview.
+ * grid view.
  *
  * It demonstrates how to use the activate signal and single-press behavior
  * to implement rather different interaction behavior to a typical list.
@@ -428,7 +429,7 @@ sweeper_game_reveal_cell (SweeperGame *self,
   sweeper_game_check_finished (self);
 }
 
-void
+G_MODULE_EXPORT void
 minesweeper_cell_clicked_cb (GtkGridView *gridview,
                              guint        pos,
                              SweeperGame *game)
@@ -436,7 +437,7 @@ minesweeper_cell_clicked_cb (GtkGridView *gridview,
   sweeper_game_reveal_cell (game, pos);
 }
 
-void
+G_MODULE_EXPORT void
 minesweeper_new_game_cb (GtkButton   *button,
                          SweeperGame *game)
 {

demos/gtk-demo/listview_settings.c

@@ -1,4 +1,5 @@
 /* Lists/Settings
+ * #Keywords: GtkListItemFactory, GListModel
  *
  * This demo shows a settings viewer for GSettings.
  *
@@ -247,7 +248,7 @@ transform_settings_to_keys (GBinding     *binding,
   sort_model = gtk_sort_list_model_new (G_LIST_MODEL (store),
                                         g_object_ref (gtk_column_view_get_sorter (GTK_COLUMN_VIEW (data))));
 
-  filter = gtk_string_filter_new (gtk_property_expression_new (SETTINGS_TYPE_KEY, NULL, "name"));
+  filter = GTK_FILTER (gtk_string_filter_new (gtk_property_expression_new (SETTINGS_TYPE_KEY, NULL, "name")));
   g_set_object (&current_filter, filter);
   filter_model = gtk_filter_list_model_new (G_LIST_MODEL (sort_model), filter);
 
@@ -417,7 +418,7 @@ do_listview_settings (GtkWidget *do_widget)
       g_object_unref (selection);
 
       name_column = GTK_COLUMN_VIEW_COLUMN (gtk_builder_get_object (builder, "name_column"));
-      sorter = gtk_string_sorter_new (gtk_property_expression_new (SETTINGS_TYPE_KEY, NULL, "name"));
+      sorter = GTK_SORTER (gtk_string_sorter_new (gtk_property_expression_new (SETTINGS_TYPE_KEY, NULL, "name")));
       gtk_column_view_column_set_sorter (name_column, sorter);
       g_object_unref (sorter);
 

demos/gtk-demo/listview_words.c

@@ -1,4 +1,5 @@
 /* Lists/Words
+ * #Keywords: GtkListView, GtkFilterListModel
  *
  * This demo shows filtering a long list - of words.
  *
@@ -179,7 +180,7 @@ do_listview_words (GtkWidget *do_widget)
         }
       g_object_unref (file);
 
-      filter = gtk_string_filter_new (gtk_property_expression_new (GTK_TYPE_STRING_OBJECT, NULL, "string"));
+      filter = GTK_FILTER (gtk_string_filter_new (gtk_property_expression_new (GTK_TYPE_STRING_OBJECT, NULL, "string")));
       filter_model = gtk_filter_list_model_new (G_LIST_MODEL (stringlist), filter);
       gtk_filter_list_model_set_incremental (filter_model, TRUE);
 

demos/gtk-demo/main.c

@@ -1,3 +1,17 @@
+/* GTK Demo
+ *
+ * GTK Demo is a collection of useful examples to demonstrate
+ * GTK widgets and features. It is a useful example in itself.
+ *
+ * You can select examples in the sidebar or search for them by
+ * typing a search term. Double-clicking or hitting the “Run” button
+ * will run the demo. The source code and other resources used in the
+ * demo are shown in this area.
+ *
+ * You can also use the GTK Inspector, available from the menu on the
+ * top right, to poke at the running demos, and see how they are put
+ * together.
+ */
 #include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -28,6 +42,7 @@ struct _GtkDemo
 
   const char *name;
   const char *title;
+  const char **keywords;
   const char *filename;
   GDoDemoFunc func;
   GListModel *children_model;
@@ -38,6 +53,7 @@ enum {
   PROP_FILENAME,
   PROP_NAME,
   PROP_TITLE,
+  PROP_KEYWORDS,
 
   N_PROPS
 };
@@ -70,6 +86,10 @@ gtk_demo_get_property (GObject    *object,
       g_value_set_string (value, self->title);
       break;
 
+    case PROP_KEYWORDS:
+      g_value_set_boxed (value, self->keywords);
+      break;
+
     default:
       G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
       break;
@@ -100,6 +120,12 @@ static void gtk_demo_class_init (GtkDemoClass *klass)
                          "title",
                          NULL,
                          G_PARAM_READABLE);
+  properties[PROP_KEYWORDS] =
+    g_param_spec_string ("keywords",
+                         "keywords",
+                         "keywords",
+                         NULL,
+                         G_PARAM_READABLE);
 
   g_object_class_install_properties (gobject_class, N_PROPS, properties);
 }
@@ -315,12 +341,10 @@ display_text (const char  *format,
   g_assert (g_utf8_validate (g_bytes_get_data (bytes, NULL), g_bytes_get_size (bytes), NULL));
 
   textview = gtk_text_view_new ();
-  g_object_set (textview,
-                "left-margin", 20,
-                "right-margin", 20,
-                "top-margin", 20,
-                "bottom-margin", 20,
-                NULL);
+  gtk_text_view_set_left_margin (GTK_TEXT_VIEW (textview), 20);
+  gtk_text_view_set_right_margin (GTK_TEXT_VIEW (textview), 20);
+  gtk_text_view_set_top_margin (GTK_TEXT_VIEW (textview), 20);
+  gtk_text_view_set_bottom_margin (GTK_TEXT_VIEW (textview), 20);
   gtk_text_view_set_editable (GTK_TEXT_VIEW (textview), FALSE);
   gtk_text_view_set_cursor_visible (GTK_TEXT_VIEW (textview), FALSE);
   /* Make it a bit nicer for text. */
@@ -581,6 +605,9 @@ load_file (const char *demoname,
               while (g_ascii_isspace (*(p + len - 1)))
                 len--;
 
+              if (*p == '#')
+                break;
+
               if (len > 0)
                 {
                   if (in_para)
@@ -656,6 +683,7 @@ selection_cb (GtkSingleSelection *sel,
 {
   GtkTreeListRow *row = gtk_single_selection_get_selected_item (sel);
   GtkDemo *demo;
+  GAction *action;
 
   gtk_widget_set_sensitive (GTK_WIDGET (notebook), !!row);
 
@@ -671,6 +699,9 @@ selection_cb (GtkSingleSelection *sel,
   if (demo->filename)
     load_file (demo->name, demo->filename);
 
+  action = g_action_map_lookup_action (G_ACTION_MAP (toplevel), "run");
+  g_simple_action_set_enabled (G_SIMPLE_ACTION (action), demo->func != NULL);
+
   gtk_window_set_title (GTK_WINDOW (toplevel), demo->title);
 }
 
@@ -688,6 +719,21 @@ filter_demo (GtkDemo *demo)
       if (g_str_match_string (search_needle[i], demo->title, TRUE))
         continue;
 
+      if (demo->keywords)
+        {
+          int j;
+          gboolean found = FALSE;
+
+          for (j = 0; !found && demo->keywords[j]; j++)
+            {
+              if (strstr (demo->keywords[j], search_needle[i]))
+                found = TRUE;
+            }
+
+          if (found)
+            continue;
+        }
+
       return FALSE;
     }
 
@@ -695,9 +741,11 @@ filter_demo (GtkDemo *demo)
 }
 
 static gboolean
-demo_filter_by_name (GtkTreeListRow     *row,
-                     GtkFilterListModel *model)
+demo_filter_by_name (gpointer item,
+                     gpointer user_data)
 {
+  GtkTreeListRow *row = item;
+  GtkFilterListModel *model = user_data;
   GListModel *children;
   GtkDemo *demo;
   guint i, n;
@@ -756,7 +804,7 @@ demo_search_changed_cb (GtkSearchEntry *entry,
   g_clear_pointer (&search_needle, g_strfreev);
 
   if (text && *text)
-    search_needle = g_strsplit (text, " ", 0);
+    search_needle = g_str_tokenize_and_fold (text, NULL, NULL);
 
   gtk_filter_changed (filter, GTK_FILTER_CHANGE_DIFFERENT);
 }
@@ -766,14 +814,25 @@ create_demo_model (void)
 {
   GListStore *store = g_list_store_new (GTK_TYPE_DEMO);
   DemoData *demo = gtk_demos;
+  GtkDemo *d;
+
+  d = GTK_DEMO (g_object_new (GTK_TYPE_DEMO, NULL));
+  d->name = "main";
+  d->title = "GTK Demo";
+  d->keywords = NULL;
+  d->filename = "main.c";
+  d->func = NULL;
+
+  g_list_store_append (store, d);
 
   while (demo->title)
     {
-      GtkDemo *d = GTK_DEMO (g_object_new (GTK_TYPE_DEMO, NULL));
+      d = GTK_DEMO (g_object_new (GTK_TYPE_DEMO, NULL));
       DemoData *children = demo->children;
 
       d->name = demo->name;
       d->title = demo->title;
+      d->keywords = demo->keywords;
       d->filename = demo->filename;
       d->func = demo->func;
 
@@ -789,6 +848,7 @@ create_demo_model (void)
 
               child->name = children->name;
               child->title = children->title;
+              child->keywords = children->keywords;
               child->filename = children->filename;
               child->func = children->func;
 
@@ -834,18 +894,16 @@ activate (GApplication *app)
   GtkWidget *window, *listview, *search_entry, *search_bar;
   GtkFilterListModel *filter_model;
   GtkFilter *filter;
-
-  static GActionEntry win_entries[] = {
-    { "run", activate_run, NULL, NULL, NULL }
-  };
+  GSimpleAction *action;
 
   builder = gtk_builder_new_from_resource ("/ui/main.ui");
 
   window = (GtkWidget *)gtk_builder_get_object (builder, "window");
   gtk_application_add_window (GTK_APPLICATION (app), GTK_WINDOW (window));
-  g_action_map_add_action_entries (G_ACTION_MAP (window),
-                                   win_entries, G_N_ELEMENTS (win_entries),
-                                   window);
+
+  action = g_simple_action_new ("run", NULL);
+  g_signal_connect (action, "activate", G_CALLBACK (activate_run), window);
+  g_action_map_add_action (G_ACTION_MAP (window), G_ACTION (action));
 
   notebook = GTK_WIDGET (gtk_builder_get_object (builder, "notebook"));
 
@@ -865,9 +923,10 @@ activate (GApplication *app)
                                        NULL,
                                        NULL);
   filter_model = gtk_filter_list_model_new (G_LIST_MODEL (treemodel), NULL);
-  filter = gtk_custom_filter_new ((GtkCustomFilterFunc)demo_filter_by_name, filter_model, NULL);
+  filter = GTK_FILTER (gtk_custom_filter_new (demo_filter_by_name, filter_model, NULL));
   gtk_filter_list_model_set_filter (filter_model, filter);
   g_object_unref (filter);
+
   search_entry = GTK_WIDGET (gtk_builder_get_object (builder, "search-entry"));
   g_signal_connect (search_entry, "search-changed", G_CALLBACK (demo_search_changed_cb), filter);
 

demos/gtk-demo/main.ui

@@ -106,8 +106,9 @@
                         <property name="right-margin">20</property>
                         <property name="top-margin">20</property>
                         <property name="bottom-margin">20</property>
-                        <property name="pixels-above-lines">2</property>
-                        <property name="pixels-below-lines">2</property>
+                        <property name="pixels-above-lines">6</property>
+                        <property name="pixels-below-lines">6</property>
+                        <property name="monospace">0</property>
                         <property name="editable">0</property>
                         <property name="wrap-mode">word</property>
                         <property name="cursor-visible">0</property>

demos/gtk-demo/mandelbrot.glsl

@@ -0,0 +1,95 @@
+// Originally from: https://www.shadertoy.com/view/wdBfDK
+// License: CC0
+
+#define MANDELBROT_ZOOM_START 0.0
+#define MANDELBROT_ITER       240
+
+void pR(inout vec2 p, in float a) {
+  p = cos(a)*p + sin(a)*vec2(p.y, -p.x);
+}
+
+vec2 pMod2(inout vec2 p, in vec2 size) {
+  vec2 c = floor((p + size*0.5)/size);
+  p = mod(p + size*0.5,size) - size*0.5;
+  return c;
+}
+
+
+vec3 mandelbrot(float time, vec2 p, out float ii) {
+  vec3 col = vec3(0.0);
+
+  float ztime = (time - MANDELBROT_ZOOM_START)*step(MANDELBROT_ZOOM_START, time);
+
+  float zoo = 0.64 + 0.36*cos(.07*ztime);
+  float coa = cos(0.15*(1.0-zoo)*ztime);
+  float sia = sin(0.15*(1.0-zoo)*ztime);
+  zoo = pow(zoo,8.0);
+  vec2 xy = vec2( p.x*coa-p.y*sia, p.x*sia+p.y*coa);
+  vec2 c = vec2(-.745,.186) + xy*zoo;
+
+  const float B = 10.0;
+  float l = 0.0;
+  vec2 z  = vec2(0.0);
+
+  vec2 zc = vec2(1.0);
+
+  pR(zc, ztime);
+
+  float d = 1e20;
+
+  int i = 0;
+
+  for(int j = 0; j < MANDELBROT_ITER; ++j) {
+    float re2 = z.x*z.x;
+    float im2 = z.y*z.y;
+    float reim= z.x*z.y;
+
+    if(re2 + im2 > (B*B)) break;
+
+    z = vec2(re2 - im2, 2.0*reim) + c;
+
+    vec2 zm = z;
+    vec2 n = pMod2(zm, vec2(4));
+    vec2 pp = zm - zc;
+    float dd = dot(pp, pp);
+
+    d = min(d, dd);
+
+    l += 1.0;
+
+    i = j;
+  }
+
+  ii = float(i)/float(MANDELBROT_ITER);
+
+  float sl = l - log2(log2(dot(z,z))) + 4.0;
+
+  vec3 dc = vec3(pow(max(1.0 - d, 0.0), 20.0));
+  vec3 gc = 0.5 + 0.5*cos(3.0 + sl*0.15 + vec3(0.1,0.5,0.9));
+  return gc + dc*smoothstep(28.8, 29.0, ztime);
+}
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord) {
+  float s = 2.0/iResolution.y;
+
+  vec2 o1 = vec2(1.0/8.0, 3.0/8.0)*s;
+  vec2 o2 = vec2(-3.0/8.0, 1.0/8.0)*s;
+
+  vec2 p = (-iResolution.xy + 2.0*fragCoord.xy)/iResolution.y;
+  float ii = 0.0;
+  vec3 col = mandelbrot(iTime, p+o1, ii);
+
+  // "smart" AA? Is that a good idea?
+  vec2 dii2 = vec2(dFdx(ii), dFdy(ii));
+  float dii = length(dii2);
+
+  if(abs(dii) > 0.01) {
+    col += mandelbrot(iTime, p-o1, ii);
+    col += mandelbrot(iTime, p+o2, ii);
+    col += mandelbrot(iTime, p-o2, ii);
+    col *=0.25;
+//    col = vec3(1.0, 0.0, 0.0);
+  }
+
+  fragColor = vec4(col, 1.0);
+}

demos/gtk-demo/markup.c

@@ -1,4 +1,5 @@
 /* Text View/Markup
+ * #Keywords: GtkTextView
  *
  * GtkTextBuffer lets you define your own tags that can influence
  * text formatting in a variety of ways. In this example, we show
@@ -13,9 +14,9 @@ static GtkWidget *view;
 static GtkWidget *view2;
 
 static void
-source_toggled (GtkToggleButton *button)
+source_toggled (GtkCheckButton *button)
 {
-  if (gtk_toggle_button_get_active (button))
+  if (gtk_check_button_get_active (button))
     gtk_stack_set_visible_child_name (GTK_STACK (stack), "source");
   else
     {

demos/gtk-demo/menu.c

@@ -0,0 +1,47 @@
+/* Menu
+ * #Keywords: action, zoom
+ *
+ * Demonstrates how to add a context menu to a custom widget
+ * and connect it with widget actions.
+ *
+ * The custom widget we create here is similar to a GtkPicture,
+ * but allows setting a zoom level for the displayed paintable.
+ *
+ * Our context menu has items to change the zoom level.
+ */
+
+#include <gtk/gtk.h>
+#include "demo3widget.h"
+
+
+GtkWidget *
+do_menu (GtkWidget *do_widget)
+{
+  static GtkWidget *window = NULL;
+
+  if (!window)
+    {
+      GtkWidget *sw;
+      GtkWidget *widget;
+
+      window = gtk_window_new ();
+      gtk_window_set_title (GTK_WINDOW (window), "Menu");
+      gtk_window_set_default_size (GTK_WINDOW (window), 600, 400);
+      gtk_window_set_display (GTK_WINDOW (window),
+                              gtk_widget_get_display (do_widget));
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
+
+      sw = gtk_scrolled_window_new ();
+      gtk_window_set_child (GTK_WINDOW (window), sw);
+
+      widget = demo3_widget_new ("/transparent/portland-rose.jpg");
+      gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), widget);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_widget_show (window);
+  else
+    gtk_window_destroy (GTK_WINDOW (window));
+
+  return window;
+}

demos/gtk-demo/meson.build

@@ -23,6 +23,7 @@ demos = files([
   'editable_cells.c',
   'entry_completion.c',
   'entry_undo.c',
+  'errorstates.c',
   'expander.c',
   'filtermodel.c',
   'fishbowl.c',
@@ -31,6 +32,7 @@ demos = files([
   'gears.c',
   'gestures.c',
   'glarea.c',
+  'gltransition.c',
   'headerbar.c',
   'hypertext.c',
   'iconscroll.c',
@@ -43,6 +45,7 @@ demos = files([
   'links.c',
   'listbox.c',
   'listbox2.c',
+  'menu.c',
   'flowbox.c',
   'list_store.c',
   'listview_applauncher.c',
@@ -59,6 +62,7 @@ demos = files([
   'paint.c',
   'paintable.c',
   'paintable_animated.c',
+  'paintable_emblem.c',
   'paintable_mediastream.c',
   'panes.c',
   'password_entry.c',
@@ -70,6 +74,7 @@ demos = files([
   'scale.c',
   'search_entry.c',
   'search_entry2.c',
+  'shadertoy.c',
   'shortcuts.c',
   'shortcut_triggers.c',
   'sidebar.c',
@@ -98,6 +103,10 @@ extra_demo_sources = files(['main.c',
                             'gtkfishbowl.c',
                             'fontplane.c',
                             'gtkgears.c',
+                            'gtkshaderbin.c',
+                            'gtkshadertoy.c',
+                            'gtkshaderstack.c',
+                            'gskshaderpaintable.c',
                             'puzzlepiece.c',
                             'bluroverlay.c',
                             'demoimage.c',
@@ -108,7 +117,8 @@ extra_demo_sources = files(['main.c',
                             'demo2layout.c',
                             'singular_value_decomposition.c',
                             'four_point_transform.c',
-                            'demo2widget.c'])
+                            'demo2widget.c',
+                            'demo3widget.c'])
 
 if harfbuzz_dep.found() and pangoft_dep.found()
   demos += files('font_features.c')

demos/gtk-demo/neon.glsl

@@ -0,0 +1,220 @@
+// Originally from: https://www.shadertoy.com/view/WlByzy
+// License CC0: Neonwave style road, sun and city
+//  The result of a bit of experimenting with neonwave style colors.
+
+#define PI          3.141592654
+#define TAU         (2.0*PI)
+
+#define TIME        iTime
+#define RESOLUTION  iResolution
+
+vec3 hsv2rgb(vec3 c) {
+  const vec4 K = vec4(1.0, 2.0 / 3.0, 1.0 / 3.0, 3.0);
+  vec3 p = abs(fract(c.xxx + K.xyz) * 6.0 - K.www);
+  return c.z * mix(K.xxx, clamp(p - K.xxx, 0.0, 1.0), c.y);
+}
+
+float hash(in float co) {
+  return fract(sin(co*12.9898) * 13758.5453);
+}
+
+float hash(in vec2 co) {
+  return fract(sin(dot(co.xy ,vec2(12.9898,58.233))) * 13758.5453);
+}
+
+float psin(float a) {
+  return 0.5 + 0.5*sin(a);
+}
+
+float mod1(inout float p, float size) {
+  float halfsize = size*0.5;
+  float c = floor((p + halfsize)/size);
+  p = mod(p + halfsize, size) - halfsize;
+  return c;
+}
+
+float circle(vec2 p, float r) {
+  return length(p) - r;
+}
+
+float box(vec2 p, vec2 b) {
+  vec2 d = abs(p)-b;
+  return length(max(d,0.0)) + min(max(d.x,d.y),0.0);
+}
+
+float planex(vec2 p, float w) {
+  return abs(p.y) - w;
+}
+
+float planey(vec2 p, float w) {
+  return abs(p.x) - w;
+}
+
+float pmin(float a, float b, float k) {
+  float h = clamp( 0.5+0.5*(b-a)/k, 0.0, 1.0 );
+  return mix( b, a, h ) - k*h*(1.0-h);
+}
+
+float pmax(float a, float b, float k) {
+  return -pmin(-a, -b, k);
+}
+
+float sun(vec2 p) {
+  const float ch = 0.0125;
+  vec2 sp = p;
+  vec2 cp = p;
+  mod1(cp.y, ch*6.0);
+
+  float d0 = circle(sp, 0.5);
+  float d1 = planex(cp, ch);
+  float d2 = p.y+ch*3.0;
+
+  float d = d0;
+  d = pmax(d, -max(d1, d2), ch*2.0);
+
+  return d;
+}
+
+float city(vec2 p) {
+  float sd = circle(p, 0.5);
+  float cd = 1E6;
+
+  const float count = 5.0;
+  const float width = 0.1;
+
+  for (float i = 0.0; i < count; ++i) {
+    vec2 pp = p;
+    pp.x += i*width/count;
+    float nn = mod1(pp.x, width);
+    float rr = hash(nn+sqrt(3.0)*i);
+    float dd = box(pp-vec2(0.0, -0.5), vec2(0.02, 0.35*(1.0-smoothstep(0.0, 5.0, abs(nn)))*rr+0.1));
+    cd = min(cd, dd);
+  }
+
+  return max(sd,cd);
+}
+vec3 sunEffect(vec2 p) {
+  float aa = 4.0 / RESOLUTION.y;
+
+  vec3 col = vec3(0.1);
+  vec3 skyCol1 = hsv2rgb(vec3(283.0/360.0, 0.83, 0.16));
+  vec3 skyCol2 = hsv2rgb(vec3(297.0/360.0, 0.79, 0.43));
+  col = mix(skyCol1, skyCol2, pow(clamp(0.5*(1.0+p.y+0.1*sin(4.0*p.x+TIME*0.5)), 0.0, 1.0), 4.0));
+
+  p.y -= 0.375;
+  float ds = sun(p);
+  float dc = city(p);
+
+  float dd = circle(p, 0.5);
+
+  vec3 sunCol = mix(vec3(1.0, 1.0, 0.0), vec3(1.0, 0.0, 1.0), clamp(0.5 - 1.0*p.y, 0.0, 1.0));
+  vec3 glareCol = sqrt(sunCol);
+  vec3 cityCol = sunCol*sunCol;
+
+  col += glareCol*(exp(-30.0*ds))*step(0.0, ds);
+
+
+  float t1 = smoothstep(0.0, 0.075, -dd);
+  float t2 = smoothstep(0.0, 0.3, -dd);
+  col = mix(col, sunCol, smoothstep(-aa, 0.0, -ds));
+  col = mix(col, glareCol, smoothstep(-aa, 0.0, -dc)*t1);
+  col += vec3(0.0, 0.25, 0.0)*(exp(-90.0*dc))*step(0.0, dc)*t2;
+
+//  col += 0.3*psin(d*400);
+
+  return col;
+}
+
+float ground(vec2 p) {
+  p.y += TIME*80.0;
+  p *= 0.075;
+  vec2 gp = p;
+  gp = fract(gp) - vec2(0.5);
+  float d0 = abs(gp.x);
+  float d1 = abs(gp.y);
+  float d2 = circle(gp, 0.05);
+
+  const float rw = 2.5;
+  const float sw = 0.0125;
+
+  vec2 rp = p;
+  mod1(rp.y, 12.0);
+  float d3 = abs(rp.x) - rw;
+  float d4 = abs(d3) - sw*2.0;
+  float d5 = box(rp, vec2(sw*2.0, 2.0));
+  vec2 sp = p;
+  mod1(sp.y, 4.0);
+  sp.x = abs(sp.x);
+  sp -= vec2(rw - 0.125, 0.0);
+  float d6 = box(sp, vec2(sw, 1.0));
+
+  float d = d0;
+  d = pmin(d, d1, 0.1);
+  d = max(d, -d3);
+  d = min(d, d4);
+  d = min(d, d5);
+  d = min(d, d6);
+
+  return d;
+}
+
+vec3 groundEffect(vec2 p) {
+  vec3 ro = vec3(0.0, 20.0, 0.0);
+  vec3 ww = normalize(vec3(0.0, -0.025, 1.0));
+  vec3 uu = normalize(cross(vec3(0.0,1.0,0.0), ww));
+  vec3 vv = normalize(cross(ww,uu));
+  vec3 rd = normalize(p.x*uu + p.y*vv + 2.5*ww);
+
+  float distg = (-9.0 - ro.y)/rd.y;
+
+  const vec3 shineCol = 0.75*vec3(0.5, 0.75, 1.0);
+  const vec3 gridCol = vec3(1.0);
+
+  vec3 col = vec3(0.0);
+  if (distg > 0.0) {
+    vec3 pg = ro + rd*distg;
+    float aa = length(dFdx(pg))*0.0002*RESOLUTION.x;
+
+    float dg = ground(pg.xz);
+
+    col = mix(col, gridCol, smoothstep(-aa, 0.0, -(dg+0.0175)));
+    col += shineCol*(exp(-10.0*clamp(dg, 0.0, 1.0)));
+    col = clamp(col, 0.0, 1.0);
+
+//    col += 0.3*psin(dg*100);
+    col *= pow(1.0-smoothstep(ro.y*3.0, 220.0+ro.y*2.0, distg), 2.0);
+  }
+
+  return col;
+}
+
+vec3 postProcess(vec3 col, vec2 q)  {
+  col = clamp(col,0.0,1.0);
+//  col=pow(col,vec3(0.75));
+  col=col*0.6+0.4*col*col*(3.0-2.0*col);
+  col=mix(col, vec3(dot(col, vec3(0.33))), -0.4);
+  col*=0.5+0.5*pow(19.0*q.x*q.y*(1.0-q.x)*(1.0-q.y),0.7);
+  return col;
+}
+
+vec3 effect(vec2 p, vec2 q) {
+  vec3 col = vec3(0.0);
+
+  vec2 off = vec2(0.0, 0.0);
+
+  col += sunEffect(p+off);
+  col += groundEffect(p+off);
+
+  col = postProcess(col, q);
+  return col;
+}
+
+void mainImage(out vec4 fragColor, vec2 fragCoord) {
+  vec2 q = fragCoord/iResolution.xy;
+  vec2 p = -1. + 2. * q;
+  p.x *= RESOLUTION.x / RESOLUTION.y;
+
+  vec3 col = effect(p, q);
+
+  fragColor = vec4(col, 1.0);
+}

demos/gtk-demo/overlay.c

@@ -1,4 +1,5 @@
 /* Overlay/Interactive Overlay
+ * #Keywords: GtkOverlay
  *
  * Shows widgets in static positions over a main widget.
  *

demos/gtk-demo/overlay2.c

@@ -1,4 +1,5 @@
 /* Overlay/Decorative Overlay
+ * #Keywords: GtkOverlay
  *
  * Another example of an overlay with some decorative
  * and some interactive controls.

demos/gtk-demo/pagesetup.c

@@ -1,4 +1,5 @@
 /* Printing/Page Setup
+ * #Keywords: GtkPageSetup
  *
  * GtkPageSetupUnixDialog can be used if page setup is needed
  * independent of a full printing dialog.

demos/gtk-demo/paint.c

@@ -1,4 +1,5 @@
 /* Paint
+ * #Keywords: GdkDrawingArea, GtkGesture
  *
  * Demonstrates practical handling of drawing tablets in a real world
  * usecase.

demos/gtk-demo/paintable.c

@@ -48,15 +48,17 @@ void
 gtk_nuclear_snapshot (GtkSnapshot *snapshot,
                       double       width,
                       double       height,
-                      double       rotation)
+                      double       rotation,
+                      gboolean     draw_background)
 {
 #define RADIUS 0.3
   cairo_t *cr;
   double size;
 
-  gtk_snapshot_append_color (snapshot,
-                             &(GdkRGBA) { 0.9, 0.75, 0.15, 1.0 },
-                             &GRAPHENE_RECT_INIT (0, 0, width, height));
+  if (draw_background)
+    gtk_snapshot_append_color (snapshot,
+                               &(GdkRGBA) { 0.9, 0.75, 0.15, 1.0 },
+                               &GRAPHENE_RECT_INIT (0, 0, width, height));
 
   size = MIN (width, height);
   cr = gtk_snapshot_append_cairo (snapshot,
@@ -93,7 +95,8 @@ gtk_nuclear_icon_snapshot (GdkPaintable *paintable,
 
   gtk_nuclear_snapshot (snapshot,
                         width, height,
-                        nuclear->rotation);
+                        nuclear->rotation,
+                        TRUE);
 }
 
 static GdkPaintableFlags
@@ -161,6 +164,7 @@ do_paintable (GtkWidget *do_widget)
                               gtk_widget_get_display (do_widget));
       gtk_window_set_title (GTK_WINDOW (window), "Nuclear Icon");
       gtk_window_set_default_size (GTK_WINDOW (window), 300, 200);
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
 
       nuclear = gtk_nuclear_icon_new (0.0);
       image = gtk_image_new_from_paintable (nuclear);

demos/gtk-demo/paintable.h

@@ -6,10 +6,11 @@
 void            gtk_nuclear_snapshot           (GtkSnapshot     *snapshot,
                                                 double           width,
                                                 double           height,
-                                                double           rotation);
+                                                double           rotation,
+                                                gboolean         draw_background);
 
 GdkPaintable *  gtk_nuclear_icon_new            (double          rotation);
-GdkPaintable *  gtk_nuclear_animation_new       (void);
+GdkPaintable *  gtk_nuclear_animation_new       (gboolean        draw_background);
 GtkMediaStream *gtk_nuclear_media_stream_new    (void);
 
 #endif /* __PAINTABLE_H__ */

demos/gtk-demo/paintable_animated.c

@@ -33,6 +33,8 @@ struct _GtkNuclearAnimation
 {
   GObject parent_instance;
 
+  gboolean draw_background;
+
   /* This variable stores the progress of our animation.
    * We just count upwards until we hit MAX_PROGRESS and
    * then start from scratch.
@@ -64,7 +66,8 @@ gtk_nuclear_animation_snapshot (GdkPaintable *paintable,
   /* We call the function from the previous example here. */
   gtk_nuclear_snapshot (snapshot,
                         width, height,
-                        2 * G_PI * nuclear->progress / MAX_PROGRESS);
+                        2 * G_PI * nuclear->progress / MAX_PROGRESS,
+                        nuclear->draw_background);
 }
 
 static GdkPaintable *
@@ -175,9 +178,15 @@ gtk_nuclear_animation_init (GtkNuclearAnimation *nuclear)
 
 /* And finally, we add the simple constructor we declared in the header. */
 GdkPaintable *
-gtk_nuclear_animation_new (void)
+gtk_nuclear_animation_new (gboolean draw_background)
 {
-  return g_object_new (GTK_TYPE_NUCLEAR_ANIMATION, NULL);
+  GtkNuclearAnimation *nuclear;
+
+  nuclear = g_object_new (GTK_TYPE_NUCLEAR_ANIMATION, NULL);
+
+  nuclear->draw_background = draw_background;
+
+  return GDK_PAINTABLE (nuclear);
 }
 
 GtkWidget *
@@ -193,8 +202,9 @@ do_paintable_animated (GtkWidget *do_widget)
                               gtk_widget_get_display (do_widget));
       gtk_window_set_title (GTK_WINDOW (window), "Nuclear Animation");
       gtk_window_set_default_size (GTK_WINDOW (window), 300, 200);
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
 
-      nuclear = gtk_nuclear_animation_new ();
+      nuclear = gtk_nuclear_animation_new (TRUE);
       image = gtk_image_new_from_paintable (nuclear);
       gtk_window_set_child (GTK_WINDOW (window), image);
       g_object_unref (nuclear);

demos/gtk-demo/paintable_emblem.c

@@ -0,0 +1,186 @@
+/* Paintable/Emblems
+ *
+ * This demo shows how GdkPaintable can be used to
+ * overlay an emblem on top of an icon. The emblem
+ * can either be another icon, or an arbitrary
+ * paintable.
+ */
+
+#include <gtk/gtk.h>
+
+#include "paintable.h"
+
+static GtkWidget *window = NULL;
+
+#define DEMO_TYPE_ICON (demo_icon_get_type ())
+G_DECLARE_FINAL_TYPE (DemoIcon, demo_icon, DEMO, ICON, GObject)
+
+struct _DemoIcon
+{
+  GObject parent_instance;
+
+  GdkPaintable *icon;
+  GdkPaintable *emblem;
+  GdkPaintableFlags flags;
+};
+
+struct _DemoIconClass
+{
+  GObjectClass parent_class;
+};
+
+void
+demo_icon_snapshot (GdkPaintable *paintable,
+                    GtkSnapshot  *snapshot,
+                    double        width,
+                    double        height)
+{
+  DemoIcon *self = DEMO_ICON (paintable);
+
+  gdk_paintable_snapshot (self->icon, snapshot, width, height);
+  gtk_snapshot_save (snapshot);
+  gtk_snapshot_translate (snapshot, &GRAPHENE_POINT_INIT (0.5 * width, 0));
+  gdk_paintable_snapshot (self->emblem, snapshot, 0.5 * width, 0.5 * height);
+  gtk_snapshot_restore (snapshot);
+}
+
+static GdkPaintableFlags
+demo_icon_get_flags (GdkPaintable *paintable)
+{
+  DemoIcon *self = DEMO_ICON (paintable);
+
+  return self->flags;
+}
+
+static void
+demo_icon_paintable_init (GdkPaintableInterface *iface)
+{
+  iface->snapshot = demo_icon_snapshot;
+  iface->get_flags = demo_icon_get_flags;
+}
+
+G_DEFINE_TYPE_WITH_CODE (DemoIcon, demo_icon, G_TYPE_OBJECT,
+                         G_IMPLEMENT_INTERFACE (GDK_TYPE_PAINTABLE,
+                                                demo_icon_paintable_init))
+
+static void
+demo_icon_dispose (GObject *object)
+{
+  DemoIcon *self = DEMO_ICON (object);
+
+  g_signal_handlers_disconnect_by_func (self->emblem,
+                                        gdk_paintable_invalidate_contents,
+                                        self);
+
+  g_clear_object (&self->icon);
+  g_clear_object (&self->emblem);
+
+  G_OBJECT_CLASS (demo_icon_parent_class)->dispose (object);
+}
+
+static void
+demo_icon_class_init (DemoIconClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = demo_icon_dispose;
+}
+
+static void
+demo_icon_init (DemoIcon *self)
+{
+  self->flags = GDK_PAINTABLE_STATIC_SIZE | GDK_PAINTABLE_STATIC_CONTENTS;
+}
+
+GdkPaintable *
+demo_icon_new_with_paintable (const char   *icon_name,
+                              GdkPaintable *emblem)
+{
+  GtkIconTheme *theme;
+  GtkIconPaintable *icon;
+  DemoIcon *self;
+
+  theme = gtk_icon_theme_get_for_display (gdk_display_get_default ());
+
+  icon = gtk_icon_theme_lookup_icon (theme,
+                                     icon_name, NULL,
+                                     128, 1,
+                                     GTK_TEXT_DIR_LTR, 0);
+
+  self = g_object_new (DEMO_TYPE_ICON, NULL);
+
+  self->icon = GDK_PAINTABLE (icon);
+  self->emblem = emblem;
+
+  if ((gdk_paintable_get_flags (emblem) & GDK_PAINTABLE_STATIC_CONTENTS) == 0)
+    {
+      self->flags &= ~GDK_PAINTABLE_STATIC_CONTENTS;
+
+      g_signal_connect_swapped (emblem, "invalidate-contents",
+                                G_CALLBACK (gdk_paintable_invalidate_contents), self);
+    }
+
+  return GDK_PAINTABLE (self);
+}
+
+GdkPaintable *
+demo_icon_new (const char *icon_name,
+               const char *emblem_name)
+{
+  GtkIconTheme *theme;
+  GtkIconPaintable *emblem;
+
+  theme = gtk_icon_theme_get_for_display (gdk_display_get_default ());
+
+  emblem = gtk_icon_theme_lookup_icon (theme,
+                                       emblem_name, NULL,
+                                       128, 1,
+                                       GTK_TEXT_DIR_LTR, 0);
+
+  return GDK_PAINTABLE (demo_icon_new_with_paintable (icon_name,
+                                                      GDK_PAINTABLE (emblem)));
+}
+
+GtkWidget *
+do_paintable_emblem (GtkWidget *do_widget)
+{
+  GdkPaintable *icon;
+  GtkWidget *grid;
+  GtkWidget *image;
+
+  if (!window)
+    {
+      window = gtk_window_new ();
+      gtk_window_set_display (GTK_WINDOW (window),
+                              gtk_widget_get_display (do_widget));
+      gtk_window_set_title (GTK_WINDOW (window), "Emblems");
+      gtk_window_set_default_size (GTK_WINDOW (window), 300, 200);
+      g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
+
+      grid = gtk_grid_new ();
+
+      icon = demo_icon_new ("folder", "starred");
+      image = gtk_image_new_from_paintable (icon);
+      gtk_widget_set_hexpand (image, TRUE);
+      gtk_widget_set_vexpand (image, TRUE);
+      gtk_grid_attach (GTK_GRID (grid), image, 0, 0, 1, 1);
+
+      icon = demo_icon_new_with_paintable ("drive-multidisk",
+                                           gtk_nuclear_animation_new (FALSE));
+      image = gtk_image_new_from_paintable (icon);
+      gtk_widget_set_hexpand (image, TRUE);
+      gtk_widget_set_vexpand (image, TRUE);
+      gtk_grid_attach (GTK_GRID (grid), image, 1, 0, 1, 1);
+
+      gtk_window_set_child (GTK_WINDOW (window), grid);
+      g_object_unref (icon);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_widget_show (window);
+  else
+    gtk_window_destroy (GTK_WINDOW (window));
+
+  return window;
+}
+

demos/gtk-demo/paintable_mediastream.c

@@ -74,7 +74,8 @@ gtk_nuclear_media_stream_snapshot (GdkPaintable *paintable,
   /* We call the function from the previous example here. */
   gtk_nuclear_snapshot (snapshot,
                         width, height,
-                        2 * G_PI * nuclear->progress / DURATION);
+                        2 * G_PI * nuclear->progress / DURATION,
+                        TRUE);
 }
 
 static GdkPaintable *

demos/gtk-demo/peg_solitaire.c

@@ -1,4 +1,5 @@
 /* Peg Solitaire
+ * #Keywords: GtkGridView, game
  *
  * This demo demonstrates how to use drag'n'drop to implement peg solitaire.
  *

demos/gtk-demo/pickers.c

@@ -1,11 +1,37 @@
 /* Pickers
+ * #Keywords: GtkColorChooser, GtkFontChooser, GtkFileChooser,
+ * #Keywords: GtkApplicationChooser
  *
  * These widgets are mainly intended for use in preference dialogs.
  * They allow to select colors, fonts, files, directories and applications.
+ *
+ * This demo shows both the default appearance for these dialogs,
+ * as well as some of the customizations that are possible.
  */
 
 #include <gtk/gtk.h>
 
+static gboolean
+filter_font_cb (const PangoFontFamily *family,
+                const PangoFontFace   *face,
+                gpointer               data)
+{
+  const char *alias_families[] = {
+    "Cursive",
+    "Fantasy",
+    "Monospace",
+    "Sans",
+    "Serif",
+    "System-ui",
+    NULL
+  };
+  const char *family_name;
+
+  family_name = pango_font_family_get_name (PANGO_FONT_FAMILY (family));
+
+  return g_strv_contains (alias_families, family_name);
+}
+
 #define COLOR(r,g,b) { r/255., g/255., b/255., 1.0 }
 
 GtkWidget *
@@ -37,6 +63,9 @@ do_pickers (GtkWidget *do_widget)
 
   if (!window)
   {
+    char *dir;
+    GFile *file;
+
     window = gtk_window_new ();
     gtk_window_set_display (GTK_WINDOW (window),
                             gtk_widget_get_display (do_widget));
@@ -52,10 +81,22 @@ do_pickers (GtkWidget *do_widget)
     gtk_grid_set_column_spacing (GTK_GRID (table), 10);
     gtk_window_set_child (GTK_WINDOW (window), table);
 
+    label = gtk_label_new ("Standard");
+    gtk_widget_add_css_class (label, "title-4");
+    gtk_grid_attach (GTK_GRID (table), label, 1, -1, 1, 1);
+    label = gtk_label_new ("Custom");
+    gtk_widget_add_css_class (label, "title-4");
+    gtk_grid_attach (GTK_GRID (table), label, 2, -1, 1, 1);
+
     label = gtk_label_new ("Color:");
     gtk_widget_set_halign (label, GTK_ALIGN_START);
     gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
     gtk_widget_set_hexpand (label, TRUE);
+    gtk_grid_attach (GTK_GRID (table), label, 0, 0, 1, 1);
+
+    picker = gtk_color_button_new ();
+    gtk_grid_attach (GTK_GRID (table), picker, 1, 0, 1, 1);
+
     picker = gtk_color_button_new ();
     gtk_color_button_set_title (GTK_COLOR_BUTTON (picker), "Solarized colors");
     gtk_color_chooser_add_palette (GTK_COLOR_CHOOSER (picker),
@@ -63,27 +104,58 @@ do_pickers (GtkWidget *do_widget)
                                    9,
                                    18,
                                    solarized);
-
-    gtk_grid_attach (GTK_GRID (table), label, 0, 0, 1, 1);
-    gtk_grid_attach (GTK_GRID (table), picker, 1, 0, 1, 1);
+    gtk_grid_attach (GTK_GRID (table), picker, 2, 0, 1, 1);
 
     label = gtk_label_new ("Font:");
     gtk_widget_set_halign (label, GTK_ALIGN_START);
     gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
     gtk_widget_set_hexpand (label, TRUE);
-    picker = gtk_font_button_new ();
     gtk_grid_attach (GTK_GRID (table), label, 0, 1, 1, 1);
+
+    picker = gtk_font_button_new ();
     gtk_grid_attach (GTK_GRID (table), picker, 1, 1, 1, 1);
 
+    picker = gtk_font_button_new ();
+    gtk_font_chooser_set_level (GTK_FONT_CHOOSER (picker),
+                                GTK_FONT_CHOOSER_LEVEL_FAMILY |
+                                GTK_FONT_CHOOSER_LEVEL_SIZE);
+    gtk_font_chooser_set_filter_func (GTK_FONT_CHOOSER (picker), filter_font_cb, NULL, NULL);
+
+    gtk_grid_attach (GTK_GRID (table), picker, 2, 1, 1, 1);
+
     label = gtk_label_new ("File:");
     gtk_widget_set_halign (label, GTK_ALIGN_START);
     gtk_widget_set_valign (label, GTK_ALIGN_CENTER);
     gtk_widget_set_hexpand (label, TRUE);
+    gtk_grid_attach (GTK_GRID (table), label, 0, 2, 1, 1);
+
     picker = gtk_file_chooser_button_new ("Pick a File",
                                           GTK_FILE_CHOOSER_ACTION_OPEN);
-    gtk_grid_attach (GTK_GRID (table), label, 0, 2, 1, 1);
     gtk_grid_attach (GTK_GRID (table), picker, 1, 2, 1, 1);
 
+    picker = gtk_file_chooser_button_new ("Pick a File",
+                                          GTK_FILE_CHOOSER_ACTION_OPEN);
+
+    dir = g_get_current_dir ();
+    file = g_file_new_for_path (dir);
+    gtk_file_chooser_add_shortcut_folder (GTK_FILE_CHOOSER (picker), file, NULL);
+    g_object_unref (file);
+    g_free (dir);
+
+    gtk_file_chooser_add_choice (GTK_FILE_CHOOSER (picker),
+                                 "choice",
+                                 "Encoding",
+                                 (const char *[]) { "option1", "option2", NULL },
+                                 (const char *[]) { "UTF-8", "Other Encoding", NULL });
+    gtk_file_chooser_set_choice (GTK_FILE_CHOOSER (picker), "choice", "option1");
+    gtk_file_chooser_add_choice (GTK_FILE_CHOOSER (picker),
+                                 "check",
+                                 "Read backwards",
+                                 NULL, NULL);
+    gtk_file_chooser_set_choice (GTK_FILE_CHOOSER (picker), "check", "false");
+
+    gtk_grid_attach (GTK_GRID (table), picker, 2, 2, 1, 1);
+
     label = gtk_label_new ("Folder:");
     gtk_widget_set_halign (label, GTK_ALIGN_START);
     gtk_widget_set_valign (label, GTK_ALIGN_CENTER);

demos/gtk-demo/printing.c

@@ -2,7 +2,6 @@
  *
  * GtkPrintOperation offers a simple API to support printing
  * in a cross-platform way.
- *
  */
 
 #include <math.h>

demos/gtk-demo/rotated_text.c

@@ -1,10 +1,10 @@
 /* Pango/Rotated Text
  *
  * This demo shows how to use PangoCairo to draw rotated and transformed
- * text.  The right pane shows a rotated GtkLabel widget.
+ * text. The right pane shows a rotated GtkLabel widget.
  *
  * In both cases, a custom PangoCairo shape renderer is installed to draw
- * a red heard using cairo drawing operations instead of the Unicode heart
+ * a red heart using cairo drawing operations instead of the Unicode heart
  * character.
  */
 

demos/gtk-demo/search_entry2.c

@@ -1,9 +1,13 @@
 /* Entry/Delayed Search Entry
  *
- * GtkSearchEntry sets up GtkEntries ready for search. Search entries
- * have their "changed" signal delayed and should be used
- * when the searched operation is slow such as loads of entries
- * to search, or online searches.
+ * GtkSearchEntry provides an entry that is ready for search.
+ *
+ * Search entries have their "changed" signal delayed and should
+ * be used when the searched operation is slow such as loads of
+ * entries to search, or online searches.
+ *
+ * GtkSearchBar allows have a hidden search entry that 'springs
+ * into action' upon keyboard input.
  */
 
 #include <gtk/gtk.h>

demos/gtk-demo/shadertoy.c

@@ -0,0 +1,202 @@
+/* OpenGL/Shadertoy
+ * #Keywords: GtkGLArea
+ *
+ * Generate pixels using a custom fragment shader.
+ *
+ * The names of the uniforms are compatible with the shaders on shadertoy.com, so
+ * many of the shaders there work here too.
+ */
+#include <math.h>
+#include <gtk/gtk.h>
+#include <epoxy/gl.h>
+#include "gtkshadertoy.h"
+
+static GtkWidget *demo_window = NULL;
+static GtkWidget *shadertoy = NULL;
+static GtkTextBuffer *textbuffer = NULL;
+
+static void
+run (void)
+{
+  GtkTextIter start, end;
+  char *text;
+
+  gtk_text_buffer_get_bounds (textbuffer, &start, &end);
+  text = gtk_text_buffer_get_text (textbuffer, &start, &end, FALSE);
+
+  gtk_shadertoy_set_image_shader (GTK_SHADERTOY (shadertoy), text);
+  g_free (text);
+}
+
+static void
+run_clicked_cb (GtkWidget *button,
+                gpointer   user_data)
+{
+  run ();
+}
+
+static void
+load_clicked_cb (GtkWidget *button,
+                 gpointer   user_data)
+{
+  const char *path = user_data;
+  GBytes *initial_shader;
+
+  initial_shader = g_resources_lookup_data (path, 0, NULL);
+  gtk_text_buffer_set_text (textbuffer, g_bytes_get_data (initial_shader, NULL), -1);
+  g_bytes_unref (initial_shader);
+
+  run ();
+}
+
+static void
+clear_clicked_cb (GtkWidget *button,
+                  gpointer   user_data)
+{
+  gtk_text_buffer_set_text (textbuffer, "", 0);
+}
+
+static void
+close_window (GtkWidget *widget)
+{
+  /* Reset the state */
+  demo_window = NULL;
+  shadertoy = NULL;
+  textbuffer = NULL;
+}
+
+static GtkWidget *
+new_shadertoy (const char *path)
+{
+  GBytes *shader;
+  GtkWidget *toy;
+
+  toy = gtk_shadertoy_new ();
+  shader = g_resources_lookup_data (path, 0, NULL);
+  gtk_shadertoy_set_image_shader (GTK_SHADERTOY (toy),
+                                  g_bytes_get_data (shader, NULL));
+  g_bytes_unref (shader);
+
+  return toy;
+}
+
+static GtkWidget *
+new_button (const char *path)
+{
+  GtkWidget *button, *toy;
+
+  button = gtk_button_new ();
+  g_signal_connect (button, "clicked", G_CALLBACK (load_clicked_cb), (char *)path);
+
+  toy = new_shadertoy (path);
+  gtk_widget_set_size_request (toy, 64, 36);
+  gtk_button_set_child (GTK_BUTTON (button),  toy);
+
+  return button;
+}
+
+static GtkWidget *
+create_shadertoy_window (GtkWidget *do_widget)
+{
+  GtkWidget *window, *box, *hbox, *button, *textview, *sw, *aspect, *centerbox;
+
+  window = gtk_window_new ();
+  gtk_window_set_display (GTK_WINDOW (window),  gtk_widget_get_display (do_widget));
+  gtk_window_set_title (GTK_WINDOW (window), "Shadertoy");
+  gtk_window_set_default_size (GTK_WINDOW (window), 690, 740);
+  g_signal_connect (window, "destroy", G_CALLBACK (close_window), NULL);
+
+  box = gtk_box_new (GTK_ORIENTATION_VERTICAL, FALSE);
+  gtk_widget_set_margin_start (box, 12);
+  gtk_widget_set_margin_end (box, 12);
+  gtk_widget_set_margin_top (box, 12);
+  gtk_widget_set_margin_bottom (box, 12);
+  gtk_box_set_spacing (GTK_BOX (box), 6);
+  gtk_window_set_child (GTK_WINDOW (window), box);
+
+  aspect = gtk_aspect_frame_new (0.5, 0.5, 1.77777, FALSE);
+  gtk_widget_set_hexpand (aspect, TRUE);
+  gtk_widget_set_vexpand (aspect, TRUE);
+  gtk_box_append (GTK_BOX (box), aspect);
+
+  shadertoy = new_shadertoy ("/shadertoy/alienplanet.glsl");
+  gtk_aspect_frame_set_child (GTK_ASPECT_FRAME (aspect), shadertoy);
+
+  sw = gtk_scrolled_window_new ();
+  gtk_scrolled_window_set_min_content_height (GTK_SCROLLED_WINDOW (sw), 250);
+  gtk_scrolled_window_set_has_frame (GTK_SCROLLED_WINDOW (sw), TRUE);
+  gtk_scrolled_window_set_policy (GTK_SCROLLED_WINDOW (sw),
+                                  GTK_POLICY_AUTOMATIC,
+                                  GTK_POLICY_AUTOMATIC);
+  gtk_widget_set_hexpand (sw, TRUE);
+  gtk_box_append (GTK_BOX (box), sw);
+
+  textview = gtk_text_view_new ();
+  gtk_text_view_set_monospace (GTK_TEXT_VIEW (textview), TRUE);
+  g_object_set (textview,
+                "left-margin", 20,
+                "right-margin", 20,
+                "top-margin", 20,
+                "bottom-margin", 20,
+                NULL);
+  gtk_scrolled_window_set_child (GTK_SCROLLED_WINDOW (sw), textview);
+
+  textbuffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (textview));
+  gtk_text_buffer_set_text (textbuffer,
+                            gtk_shadertoy_get_image_shader (GTK_SHADERTOY (shadertoy)),
+                            -1);
+
+  centerbox = gtk_center_box_new ();
+  gtk_box_append (GTK_BOX (box), centerbox);
+
+  hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, FALSE);
+  gtk_box_set_spacing (GTK_BOX (hbox), 6);
+  gtk_center_box_set_start_widget (GTK_CENTER_BOX (centerbox), hbox);
+
+  button = gtk_button_new_from_icon_name ("view-refresh-symbolic");
+  gtk_widget_set_tooltip_text (button, "Restart the demo");
+  gtk_widget_set_valign (button, GTK_ALIGN_CENTER);
+  g_signal_connect (button, "clicked", G_CALLBACK (run_clicked_cb), NULL);
+  gtk_box_append (GTK_BOX (hbox), button);
+
+  button = gtk_button_new_from_icon_name ("edit-clear-all-symbolic");
+  gtk_widget_set_tooltip_text (button, "Clear the text view");
+  gtk_widget_set_valign (button, GTK_ALIGN_CENTER);
+  g_signal_connect (button, "clicked", G_CALLBACK (clear_clicked_cb), NULL);
+  gtk_box_append (GTK_BOX (hbox), button);
+
+  hbox = gtk_box_new (GTK_ORIENTATION_HORIZONTAL, FALSE);
+  gtk_box_set_spacing (GTK_BOX (hbox), 6);
+  gtk_center_box_set_end_widget (GTK_CENTER_BOX (centerbox), hbox);
+
+  button = new_button ("/shadertoy/alienplanet.glsl");
+  gtk_box_append (GTK_BOX (hbox), button);
+
+  button = new_button ("/shadertoy/mandelbrot.glsl");
+  gtk_box_append (GTK_BOX (hbox), button);
+
+  button = new_button ("/shadertoy/neon.glsl");
+  gtk_box_append (GTK_BOX (hbox), button);
+
+  button = new_button ("/shadertoy/cogs.glsl");
+  gtk_box_append (GTK_BOX (hbox), button);
+
+  button = new_button ("/shadertoy/glowingstars.glsl");
+  gtk_box_append (GTK_BOX (hbox), button);
+
+  return window;
+}
+
+GtkWidget *
+do_shadertoy (GtkWidget *do_widget)
+{
+  if (!demo_window)
+    demo_window = create_shadertoy_window (do_widget);
+
+  if (!gtk_widget_get_visible (demo_window))
+    gtk_widget_show (demo_window);
+  else
+    gtk_window_destroy (GTK_WINDOW (demo_window));
+
+  return demo_window;
+}

demos/gtk-demo/shortcut_triggers.c

@@ -1,4 +1,5 @@
 /* Shortcuts
+ * #Keywords: GtkShortcutController
  *
  * GtkShortcut is the abstraction used by GTK to handle shortcuts from
  * keyboard or other input devices.

demos/gtk-demo/sidebar.c

@@ -1,9 +1,9 @@
 /* Stack Sidebar
  *
  * GtkStackSidebar provides an automatic sidebar widget to control
- * navigation of a GtkStack object. This widget automatically updates it
- * content based on what is presently available in the GtkStack object,
- * and using the "title" child property to set the display labels.
+ * navigation of a GtkStack object. This widget automatically updates
+ * its content based on what is presently available in the GtkStack
+ * object, and using the "title" child property to set the display labels.
  */
 
 #include <glib/gi18n.h>
@@ -37,7 +37,6 @@ do_sidebar (GtkWidget *do_widget)
     {
       window = gtk_window_new ();
       gtk_window_set_resizable (GTK_WINDOW (window), TRUE);
-      gtk_widget_set_size_request (window, 500, 350);
 
       header = gtk_header_bar_new ();
       gtk_window_set_titlebar (GTK_WINDOW(window), header);

demos/gtk-demo/sizegroup.c

@@ -59,8 +59,8 @@ add_row (GtkGrid      *table,
 }
 
 static void
-toggle_grouping (GtkToggleButton *check_button,
-                 GtkSizeGroup    *size_group)
+toggle_grouping (GtkCheckButton *check_button,
+                 GtkSizeGroup   *size_group)
 {
   GtkSizeGroupMode new_mode;
 
@@ -68,7 +68,7 @@ toggle_grouping (GtkToggleButton *check_button,
    * here to show the effect of GTK_SIZE_GROUP_HORIZONTAL by
    * contrast.
    */
-  if (gtk_toggle_button_get_active (check_button))
+  if (gtk_check_button_get_active (check_button))
     new_mode = GTK_SIZE_GROUP_HORIZONTAL;
   else
     new_mode = GTK_SIZE_GROUP_NONE;

demos/gtk-demo/sliding_puzzle.c

@@ -1,8 +1,8 @@
 /* Sliding Puzzle
+ * #Keywords: GdkPaintable, GdkGesture, game
  *
  * This demo demonstrates how to use gestures and paintables to create a
  * small sliding puzzle game.
- *
  */
 
 #include <gtk/gtk.h>
@@ -437,7 +437,7 @@ do_sliding_puzzle (GtkWidget *do_widget)
       choices = gtk_flow_box_new ();
       gtk_widget_add_css_class (choices, "view");
       add_choice (choices, puzzle);
-      add_choice (choices, gtk_nuclear_animation_new ());
+      add_choice (choices, gtk_nuclear_animation_new (TRUE));
       media = gtk_media_file_new_for_resource ("/images/gtk-logo.webm");
       gtk_media_stream_set_loop (media, TRUE);
       gtk_media_stream_set_muted (media, TRUE);

demos/gtk-demo/spinbutton.c

@@ -1,4 +1,5 @@
 /* Spin Buttons
+ * #Keywords: GtkEntry
  *
  * GtkSpinButton provides convenient ways to input data
  * that can be seen as a value in a range. The examples

demos/gtk-demo/spinner.c

@@ -1,7 +1,6 @@
 /* Spinner
  *
  * GtkSpinner allows to show that background activity is on-going.
- *
  */
 
 #include <glib/gi18n.h>

demos/gtk-demo/tabs.c

@@ -22,18 +22,21 @@ do_tabs (GtkWidget *do_widget)
       gtk_window_set_title (GTK_WINDOW (window), "Tabs");
       gtk_window_set_display (GTK_WINDOW (window),
                               gtk_widget_get_display (do_widget));
-      gtk_window_set_default_size (GTK_WINDOW (window), 450, 450);
+      gtk_window_set_default_size (GTK_WINDOW (window), 330, 330);
+      gtk_window_set_resizable (GTK_WINDOW (window), FALSE);
       g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
 
       view = gtk_text_view_new ();
       gtk_text_view_set_wrap_mode (GTK_TEXT_VIEW (view), GTK_WRAP_WORD);
+      gtk_text_view_set_top_margin (GTK_TEXT_VIEW (view), 20);
+      gtk_text_view_set_bottom_margin (GTK_TEXT_VIEW (view), 20);
       gtk_text_view_set_left_margin (GTK_TEXT_VIEW (view), 20);
       gtk_text_view_set_right_margin (GTK_TEXT_VIEW (view), 20);
 
       tabs = pango_tab_array_new (3, TRUE);
       pango_tab_array_set_tab (tabs, 0, PANGO_TAB_LEFT, 0);
-      pango_tab_array_set_tab (tabs, 1, PANGO_TAB_LEFT, 150);
-      pango_tab_array_set_tab (tabs, 2, PANGO_TAB_LEFT, 300);
+      pango_tab_array_set_tab (tabs, 1, PANGO_TAB_LEFT, 100);
+      pango_tab_array_set_tab (tabs, 2, PANGO_TAB_LEFT, 200);
       gtk_text_view_set_tabs (GTK_TEXT_VIEW (view), tabs);
       pango_tab_array_free (tabs);
 

demos/gtk-demo/textscroll.c

@@ -1,4 +1,5 @@
 /* Text View/Automatic Scrolling
+ * #Keywords: GtkTextView, GtkScrolledWindow
  *
  * This example demonstrates how to use the gravity of
  * GtkTextMarks to keep a text view scrolled to the bottom

demos/gtk-demo/textundo.c

@@ -26,13 +26,20 @@ do_textundo (GtkWidget *do_widget)
       window = gtk_window_new ();
       gtk_window_set_display (GTK_WINDOW (window),
                               gtk_widget_get_display (do_widget));
-      gtk_window_set_default_size (GTK_WINDOW (window), 450, 450);
+      gtk_window_set_default_size (GTK_WINDOW (window), 330, 330);
+      gtk_window_set_resizable (GTK_WINDOW (window), FALSE);
       g_object_add_weak_pointer (G_OBJECT (window), (gpointer *)&window);
 
       gtk_window_set_title (GTK_WINDOW (window), "Undo and Redo");
 
       view = gtk_text_view_new ();
       gtk_text_view_set_wrap_mode (GTK_TEXT_VIEW (view), GTK_WRAP_WORD);
+      gtk_text_view_set_pixels_below_lines (GTK_TEXT_VIEW (view), 10);
+      gtk_text_view_set_left_margin (GTK_TEXT_VIEW (view), 20);
+      gtk_text_view_set_right_margin (GTK_TEXT_VIEW (view), 20);
+      gtk_text_view_set_top_margin (GTK_TEXT_VIEW (view), 20);
+      gtk_text_view_set_bottom_margin (GTK_TEXT_VIEW (view), 20);
+
       buffer = gtk_text_view_get_buffer (GTK_TEXT_VIEW (view));
       gtk_text_buffer_set_enable_undo (buffer, TRUE);
 
@@ -40,10 +47,13 @@ do_textundo (GtkWidget *do_widget)
       gtk_text_buffer_begin_irreversible_action (buffer);
       gtk_text_buffer_get_start_iter (buffer, &iter);
       gtk_text_buffer_insert (buffer, &iter,
-                              "Type to add more text.\n"
-                              "Use Primary+Z to undo and Primary+Shift+Z to redo a previously undone action.\n"
-                              "\n",
-                              -1);
+          "The GtkTextView supports undo and redo through the use of a "
+          "GtkTextBuffer. You can enable or disable undo support using "
+          "gtk_text_buffer_set_enable_undo().\n"
+          "Type to add more text.\n"
+          "Use Control+z to undo and Control+Shift+z or Control+y to "
+          "redo previously undone operations.",
+          -1);
       gtk_text_buffer_end_irreversible_action (buffer);
 
       sw = gtk_scrolled_window_new ();

demos/gtk-demo/textview.c

@@ -142,7 +142,7 @@ insert_text (GtkTextView *view)
                                      32, 1,
                                      gtk_widget_get_direction (widget),
                                      0);
-  nuclear = gtk_nuclear_animation_new ();
+  nuclear = gtk_nuclear_animation_new (TRUE);
 
   /* get start of buffer; each insertion will revalidate the
    * iterator to point to just after the inserted text.

demos/gtk-demo/themes.c

@@ -10,76 +10,6 @@
 
 static guint tick_cb;
 
-static gint64
-guess_refresh_interval (GdkFrameClock *frame_clock)
-{
-  gint64 interval;
-  gint64 i;
-
-  interval = G_MAXINT64;
-
-  for (i = gdk_frame_clock_get_history_start (frame_clock);
-       i < gdk_frame_clock_get_frame_counter (frame_clock);
-       i++)
-    {
-      GdkFrameTimings *t, *before;
-      gint64 ts, before_ts;
-
-      t = gdk_frame_clock_get_timings (frame_clock, i);
-      before = gdk_frame_clock_get_timings (frame_clock, i - 1);
-      if (t == NULL || before == NULL)
-        continue;
-
-      ts = gdk_frame_timings_get_frame_time (t);
-      before_ts = gdk_frame_timings_get_frame_time (before);
-      if (ts == 0 || before_ts == 0)
-        continue;
-
-      interval = MIN (interval, ts - before_ts);
-    }
-
-  if (interval == G_MAXINT64)
-    return 0;
-
-  return interval;
-}
-
-static double
-frame_clock_get_fps (GdkFrameClock *frame_clock)
-{
-  GdkFrameTimings *start, *end;
-  gint64 start_counter, end_counter;
-  gint64 start_timestamp, end_timestamp;
-  gint64 interval;
-
-  start_counter = gdk_frame_clock_get_history_start (frame_clock);
-  end_counter = gdk_frame_clock_get_frame_counter (frame_clock);
-  start = gdk_frame_clock_get_timings (frame_clock, start_counter);
-  for (end = gdk_frame_clock_get_timings (frame_clock, end_counter);
-       end_counter > start_counter && end != NULL && !gdk_frame_timings_get_complete (end);
-       end = gdk_frame_clock_get_timings (frame_clock, end_counter))
-    end_counter--;
-  if (end_counter - start_counter < 4)
-    return 0.0;
-
-  start_timestamp = gdk_frame_timings_get_presentation_time (start);
-  end_timestamp = gdk_frame_timings_get_presentation_time (end);
-  if (start_timestamp == 0 || end_timestamp == 0)
-    {
-      start_timestamp = gdk_frame_timings_get_frame_time (start);
-      end_timestamp = gdk_frame_timings_get_frame_time (end);
-    }
-  interval = gdk_frame_timings_get_refresh_interval (end);
-  if (interval == 0)
-    {
-      interval = guess_refresh_interval (frame_clock);
-      if (interval == 0)
-        return 0.0;
-    }
-
-  return ((double) end_counter - start_counter) * G_USEC_PER_SEC / (end_timestamp - start_timestamp);
-}
-
 typedef struct {
   const char *name;
   gboolean dark;
@@ -116,7 +46,7 @@ change_theme (GtkWidget     *widget,
     {
       char *fps;
 
-      fps = g_strdup_printf ("%.2f fps", frame_clock_get_fps (frame_clock));
+      fps = g_strdup_printf ("%.2f fps", gdk_frame_clock_get_fps (frame_clock));
       gtk_label_set_label (GTK_LABEL (label), fps);
       g_free (fps);
     }

demos/gtk-demo/themes.ui

@@ -19,7 +19,11 @@
           </object>
         </child>
         <child type="end">
-          <object class="GtkLabel" id="fps"/>
+          <object class="GtkLabel" id="fps">
+            <attributes>
+              <attribute name="font-features" value="tnum=1"/>
+            </attributes>
+          </object>
         </child>
       </object>
     </child>

demos/gtk-demo/transition1.glsl

@@ -0,0 +1,33 @@
+uniform float progress;
+uniform sampler2D u_texture1;
+uniform sampler2D u_texture2;
+
+vec4 getFromColor (vec2 uv) {
+  return GskTexture(u_texture1, uv);
+}
+
+vec4 getToColor (vec2 uv) {
+  return GskTexture(u_texture2, uv);
+}
+
+// Source: https://gl-transitions.com/editor/wind
+// Author: gre
+// License: MIT
+
+const float size = 0.2;
+
+float rand(vec2 co) {
+  return fract(sin(dot(co.xy ,vec2(12.9898,78.233))) * 43758.5453);
+}
+
+vec4 transition(vec2 p) {
+  float r = rand(vec2(0, p.y));
+  float m = smoothstep(0.0, -size, p.x*(1.0-size) + size*r - (progress * (1.0 + size)));
+  return mix(getFromColor(p), getToColor(p), m);
+}
+
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv)
+{
+  fragColor = transition(uv);
+}

demos/gtk-demo/transition2.glsl

@@ -0,0 +1,34 @@
+uniform float progress;
+uniform sampler2D u_texture1;
+uniform sampler2D u_texture2;
+
+vec4 getFromColor (vec2 uv) {
+  return GskTexture(u_texture1, uv);
+}
+
+vec4 getToColor (vec2 uv) {
+  return GskTexture(u_texture2, uv);
+}
+
+// Source: https://gl-transitions.com/editor/Radial
+// License: MIT
+// Author: Xaychru
+
+const float smoothness = 1.0;
+
+const float PI = 3.141592653589;
+
+vec4 transition(vec2 p) {
+  vec2 rp = p*2.-1.;
+  return mix(
+    getToColor(p),
+    getFromColor(p),
+    smoothstep(0., smoothness, atan(rp.y,rp.x) - (progress-.5) * PI * 2.5)
+  );
+}
+
+
+void mainImage(out vec4 fragColor, in vec2 fragCoord, in vec2 resolution, in vec2 uv)
+{
+  fragColor = transition(uv);
+}