button: Implement clip

This allows all widgets that implement clip to use box shadows.

docs/reference/gtk/gtk3-sections.txt

@@ -5475,6 +5475,8 @@ gtk_widget_get_allocated_height
 gtk_widget_get_allocation
 gtk_widget_set_allocation
 gtk_widget_get_allocated_baseline
+gtk_widget_get_clip
+gtk_widget_set_clip
 gtk_widget_get_app_paintable
 gtk_widget_get_can_default
 gtk_widget_set_can_default

gtk/gtkbox.c

@@ -791,6 +791,8 @@ gtk_box_size_allocate_no_center (GtkWidget     *widget,
 	  i++;
 	}
     }
+
+  _gtk_widget_set_simple_clip (widget);
 }
 
 static void
@@ -1158,6 +1160,8 @@ gtk_box_size_allocate_with_center (GtkWidget     *widget,
       child_allocation.height = center_size;
     }
   gtk_widget_size_allocate_with_baseline (priv->center->widget, &child_allocation, baseline);
+
+  _gtk_widget_set_simple_clip (widget);
 }
 
 static void

gtk/gtkbutton.c

@@ -1761,6 +1761,8 @@ gtk_button_size_allocate (GtkWidget     *widget,
 
       gtk_widget_size_allocate_with_baseline (child, &child_allocation, baseline);
     }
+
+  _gtk_widget_set_simple_clip (widget);
 }
 
 static gboolean

gtk/gtkcssstylepropertyimpl.c

@@ -1004,7 +1004,7 @@ _gtk_css_style_property_init_properties (void)
   gtk_css_style_property_register        ("-gtk-icon-transform",
                                           GTK_CSS_PROPERTY_ICON_TRANSFORM,
                                           G_TYPE_NONE,
-                                          GTK_STYLE_PROPERTY_ANIMATED | GTK_STYLE_PROPERTY_NO_RESIZE,
+                                          GTK_STYLE_PROPERTY_ANIMATED,
                                           transform_value_parse,
                                           NULL,
                                           NULL,
@@ -1013,7 +1013,7 @@ _gtk_css_style_property_init_properties (void)
   gtk_css_style_property_register        ("box-shadow",
                                           GTK_CSS_PROPERTY_BOX_SHADOW,
                                           G_TYPE_NONE,
-                                          GTK_STYLE_PROPERTY_ANIMATED | GTK_STYLE_PROPERTY_NO_RESIZE,
+                                          GTK_STYLE_PROPERTY_ANIMATED,
                                           shadow_value_parse,
                                           NULL,
                                           NULL,

gtk/gtkgrid.c

@@ -24,6 +24,7 @@
 
 #include "gtkorientableprivate.h"
 #include "gtksizerequest.h"
+#include "gtkwidgetprivate.h"
 #include "gtkprivate.h"
 #include "gtkintl.h"
 
@@ -1677,6 +1678,8 @@ gtk_grid_size_allocate (GtkWidget     *widget,
   gtk_grid_request_position (&request, 1);
 
   gtk_grid_request_allocate_children (&request);
+
+  _gtk_widget_set_simple_clip (widget);
 }
 
 static gboolean

gtk/gtkspinner.c

@@ -35,6 +35,7 @@
 #include "gtkintl.h"
 #include "gtkstylecontext.h"
 #include "gtkstylecontextprivate.h"
+#include "gtkwidgetprivate.h"
 #include "a11y/gtkspinneraccessible.h"
 
 
@@ -67,6 +68,8 @@ struct _GtkSpinnerPrivate
 
 static gboolean gtk_spinner_draw       (GtkWidget       *widget,
                                         cairo_t         *cr);
+static void gtk_spinner_size_allocate  (GtkWidget       *widget,
+                                        GtkAllocation   *allocation);
 static void gtk_spinner_get_property   (GObject         *object,
                                         guint            param_id,
                                         GValue          *value,
@@ -98,6 +101,7 @@ gtk_spinner_class_init (GtkSpinnerClass *klass)
   gobject_class->set_property = gtk_spinner_set_property;
 
   widget_class = GTK_WIDGET_CLASS(klass);
+  widget_class->size_allocate = gtk_spinner_size_allocate;
   widget_class->draw = gtk_spinner_draw;
   widget_class->get_preferred_width = gtk_spinner_get_preferred_width;
   widget_class->get_preferred_height = gtk_spinner_get_preferred_height;
@@ -186,6 +190,29 @@ gtk_spinner_get_preferred_height (GtkWidget *widget,
   *natural_size = SPINNER_SIZE;
 }
 
+static void
+gtk_spinner_size_allocate (GtkWidget     *widget,
+                           GtkAllocation *allocation)
+{
+  GtkStyleContext *context;
+  GtkAllocation clip;
+  gint size;
+
+  context = gtk_widget_get_style_context (widget);
+  size = MIN (allocation->width, allocation->height);
+
+  _gtk_style_context_get_icon_extents (context,
+                                       &clip,
+                                       allocation->x + (allocation->width - size) / 2,
+                                       allocation->y + (allocation->height - size) / 2,
+                                       size, size);
+
+  gdk_rectangle_union (&clip, allocation, &clip);
+
+  gtk_widget_set_allocation (widget, allocation);
+  gtk_widget_set_clip (widget, &clip);
+}
+
 static gboolean
 gtk_spinner_draw (GtkWidget *widget,
                   cairo_t   *cr)

gtk/gtkstylecontext.c

@@ -28,8 +28,11 @@
 #include "gtkcsscornervalueprivate.h"
 #include "gtkcssenginevalueprivate.h"
 #include "gtkcssenumvalueprivate.h"
+#include "gtkcssimagevalueprivate.h"
 #include "gtkcssnumbervalueprivate.h"
 #include "gtkcssrgbavalueprivate.h"
+#include "gtkcssshadowsvalueprivate.h"
+#include "gtkcsstransformvalueprivate.h"
 #include "gtkdebug.h"
 #include "gtkstylepropertiesprivate.h"
 #include "gtktypebuiltins.h"
@@ -4680,6 +4683,82 @@ _gtk_style_context_get_changes (GtkStyleContext *context)
   return context->priv->invalidating_context;
 }
 
+void
+gtk_cairo_rectangle_transform (cairo_rectangle_int_t       *dest,
+                               const cairo_rectangle_int_t *src,
+                               const cairo_matrix_t        *matrix)
+{
+  double x1, x2, x3, x4;
+  double y1, y2, y3, y4;
+
+  g_return_if_fail (dest != NULL);
+  g_return_if_fail (src != NULL);
+  g_return_if_fail (matrix != NULL);
+
+  x1 = src->x;
+  y1 = src->y;
+  x2 = src->x + src->width;
+  y2 = src->y;
+  x3 = src->x + src->width;
+  y3 = src->y + src->height;
+  x4 = src->x;
+  y4 = src->y + src->height;
+
+  cairo_matrix_transform_point (matrix, &x1, &y1);
+  cairo_matrix_transform_point (matrix, &x2, &y2);
+  cairo_matrix_transform_point (matrix, &x3, &y3);
+  cairo_matrix_transform_point (matrix, &x4, &y4);
+
+  dest->x = floor (MIN (MIN (x1, x2), MIN (x3, x4)));
+  dest->y = floor (MIN (MIN (y1, y2), MIN (y3, y4)));
+  dest->width = ceil (MAX (MAX (x1, x2), MAX (x3, x4))) - dest->x;
+  dest->height = ceil (MAX (MAX (y1, y2), MAX (y3, y4))) - dest->y;
+}
+void
+_gtk_style_context_get_icon_extents (GtkStyleContext *context,
+                                     GdkRectangle    *extents,
+                                     gint             x,
+                                     gint             y,
+                                     gint             width,
+                                     gint             height)
+{
+  cairo_matrix_t transform_matrix, matrix;
+  GtkBorder border;
+  GdkRectangle rect;
+
+  g_return_if_fail (GTK_IS_STYLE_CONTEXT (context));
+  g_return_if_fail (extents != NULL);
+
+  rect.x = x;
+  rect.y = y;
+  rect.width = width;
+  rect.height = height;
+
+  /* strictly speaking we should return an empty rect here,
+   * but most code still draws a fallback  in this case */
+  if (_gtk_css_image_value_get_image (_gtk_style_context_peek_property (context, GTK_CSS_PROPERTY_ICON_SOURCE)) == NULL)
+    return;
+
+  if (!_gtk_css_transform_value_get_matrix (_gtk_style_context_peek_property (context, GTK_CSS_PROPERTY_ICON_TRANSFORM), &transform_matrix))
+    return;
+  
+  cairo_matrix_init_translate (&matrix, x + width / 2.0, y + height / 2.0);
+  cairo_matrix_multiply (&matrix, &transform_matrix, &matrix);
+  /* need to round to full pixels */
+  rect.x = - (width + 1) / 2;
+  rect.y = - (height + 1) / 2;
+  rect.width = (width + 1) & ~1;
+  rect.height = (height + 1) & ~1;
+  gtk_cairo_rectangle_transform (extents, &rect, &matrix);
+
+  _gtk_css_shadows_value_get_extents (_gtk_style_context_peek_property (context, GTK_CSS_PROPERTY_ICON_SHADOW), &border);
+
+  extents->x -= border.left;
+  extents->y -= border.top;
+  extents->width += border.left + border.right;
+  extents->height += border.top + border.bottom;
+}
+
 GtkIconLookupFlags
 _gtk_style_context_get_icon_lookup_flags (GtkStyleContext *context)
 {

gtk/gtkstylecontextprivate.h

@@ -56,6 +56,12 @@ void           _gtk_style_context_get_cursor_color           (GtkStyleContext
 
 void           _gtk_style_context_update_animating           (GtkStyleContext    *context);
 
+void           _gtk_style_context_get_icon_extents           (GtkStyleContext    *context,
+                                                              GdkRectangle       *extents,
+                                                              gint                x,
+                                                              gint                y,
+                                                              gint                width,
+                                                              gint                height);
 GtkIconLookupFlags _gtk_style_context_get_icon_lookup_flags  (GtkStyleContext    *context);
 
 G_END_DECLS

gtk/gtkwidget.c

@@ -39,6 +39,7 @@
 #include "gtkclipboard.h"
 #include "gtkcssstylepropertyprivate.h"
 #include "gtkcssnumbervalueprivate.h"
+#include "gtkcssshadowsvalueprivate.h"
 #include "gtkintl.h"
 #include "gtkmarshalers.h"
 #include "gtkselectionprivate.h"
@@ -430,6 +431,7 @@ struct _GtkWidgetPrivate
   guint multidevice           : 1;
   guint has_shape_mask        : 1;
   guint in_reparent           : 1;
+  guint supports_clip         : 1;
 
   /* Queue-resize related flags */
   guint alloc_needed          : 1;
@@ -476,6 +478,7 @@ struct _GtkWidgetPrivate
   /* The widget's allocated size */
   GtkAllocation allocation;
   gint allocated_baseline;
+  GtkAllocation clip;
 
   /* The widget's requested sizes */
   SizeRequestCache requests;
@@ -4218,10 +4221,10 @@ gtk_widget_queue_draw_child (GtkWidget *widget)
   parent = priv->parent;
   if (parent && gtk_widget_is_drawable (parent))
     gtk_widget_queue_draw_area (parent,
-				priv->allocation.x,
+				priv->clip.x,
-				priv->allocation.y,
+				priv->clip.y,
-				priv->allocation.width,
+				priv->clip.width,
-				priv->allocation.height);
+				priv->clip.height);
 }
 
 /**
@@ -4628,7 +4631,7 @@ gtk_widget_map (GtkWidget *widget)
       g_signal_emit (widget, widget_signals[MAP], 0);
 
       if (!gtk_widget_get_has_window (widget))
-        gdk_window_invalidate_rect (priv->window, &priv->allocation, FALSE);
+        gdk_window_invalidate_rect (priv->window, &priv->clip, FALSE);
 
       if (widget->priv->context)
         _gtk_style_context_update_animating (widget->priv->context);
@@ -4658,7 +4661,7 @@ gtk_widget_unmap (GtkWidget *widget)
       gtk_widget_push_verify_invariants (widget);
 
       if (!gtk_widget_get_has_window (widget))
-	gdk_window_invalidate_rect (priv->window, &priv->allocation, FALSE);
+	gdk_window_invalidate_rect (priv->window, &priv->clip, FALSE);
       _gtk_tooltip_hide (widget);
 
       if (widget->priv->context)
@@ -5267,7 +5270,7 @@ gtk_widget_queue_draw (GtkWidget *widget)
 
   g_return_if_fail (GTK_IS_WIDGET (widget));
 
-  gtk_widget_get_allocation (widget, &rect);
+  gtk_widget_get_clip (widget, &rect);
 
   if (!gtk_widget_get_has_window (widget))
     gtk_widget_queue_draw_area (widget,
@@ -5504,7 +5507,7 @@ gtk_widget_size_allocate_with_baseline (GtkWidget     *widget,
 {
   GtkWidgetPrivate *priv;
   GdkRectangle real_allocation;
-  GdkRectangle old_allocation;
+  GdkRectangle old_allocation, old_clip;
   GdkRectangle adjusted_allocation;
   gboolean alloc_needed;
   gboolean size_changed;
@@ -5561,6 +5564,7 @@ gtk_widget_size_allocate_with_baseline (GtkWidget     *widget,
   priv->alloc_needed = FALSE;
 
   old_allocation = priv->allocation;
+  old_clip = priv->clip;
   old_baseline = priv->allocated_baseline;
   real_allocation = *allocation;
 
@@ -5652,20 +5656,35 @@ gtk_widget_size_allocate_with_baseline (GtkWidget     *widget,
   if (!alloc_needed && !size_changed && !position_changed && !baseline_changed)
     goto out;
 
+  memset (&priv->clip, 0, sizeof (priv->clip));
+  priv->supports_clip = FALSE;
+
   priv->allocated_baseline = baseline;
   g_signal_emit (widget, widget_signals[SIZE_ALLOCATE], 0, &real_allocation);
 
   /* Size allocation is god... after consulting god, no further requests or allocations are needed */
   priv->alloc_needed = FALSE;
 
+  if (priv->supports_clip)
+    {
+      size_changed |= (old_clip.width != priv->clip.width ||
+                       old_clip.height != priv->clip.height);
+      position_changed |= (old_clip.x != priv->clip.x ||
+                          old_clip.y != priv->clip.y);
+    }
+  else
+    {
+      priv->clip = priv->allocation;
+    }
+
   if (gtk_widget_get_mapped (widget) && priv->redraw_on_alloc)
     {
       if (!gtk_widget_get_has_window (widget) && position_changed)
 	{
-	  /* Invalidate union(old_allaction,priv->allocation) in priv->window
+	  /* Invalidate union(old_clip,priv->clip) in priv->window
 	   */
-	  cairo_region_t *invalidate = cairo_region_create_rectangle (&priv->allocation);
+	  cairo_region_t *invalidate = cairo_region_create_rectangle (&priv->clip);
-	  cairo_region_union_rectangle (invalidate, &old_allocation);
+	  cairo_region_union_rectangle (invalidate, &old_clip);
 
 	  gdk_window_invalidate_region (priv->window, invalidate, FALSE);
 	  cairo_region_destroy (invalidate);
@@ -5673,10 +5692,10 @@ gtk_widget_size_allocate_with_baseline (GtkWidget     *widget,
 
       if (size_changed || baseline_changed)
 	{
-          /* Invalidate union(old_allaction,priv->allocation) in priv->window and descendents owned by widget
+          /* Invalidate union(old_clip,priv->clip) in priv->window and descendents owned by widget
            */
-          cairo_region_t *invalidate = cairo_region_create_rectangle (&priv->allocation);
+          cairo_region_t *invalidate = cairo_region_create_rectangle (&priv->clip);
-          cairo_region_union_rectangle (invalidate, &old_allocation);
+          cairo_region_union_rectangle (invalidate, &old_clip);
 
           gtk_widget_invalidate_widget_windows (widget, invalidate);
           cairo_region_destroy (invalidate);
@@ -5686,7 +5705,7 @@ gtk_widget_size_allocate_with_baseline (GtkWidget     *widget,
   if ((size_changed || position_changed || baseline_changed) && priv->parent &&
       gtk_widget_get_realized (priv->parent) && _gtk_container_get_reallocate_redraws (GTK_CONTAINER (priv->parent)))
     {
-      cairo_region_t *invalidate = cairo_region_create_rectangle (&priv->parent->priv->allocation);
+      cairo_region_t *invalidate = cairo_region_create_rectangle (&priv->parent->priv->clip);
       gtk_widget_invalidate_widget_windows (priv->parent, invalidate);
       cairo_region_destroy (invalidate);
     }
@@ -6522,9 +6541,10 @@ _gtk_widget_draw_internal (GtkWidget *widget,
   if (clip_to_size)
     {
       cairo_rectangle (cr,
-                       0, 0,
+                       widget->priv->clip.x - widget->priv->allocation.x,
-                       widget->priv->allocation.width,
+                       widget->priv->clip.y - widget->priv->allocation.y,
-                       widget->priv->allocation.height);
+                       widget->priv->clip.width,
+                       widget->priv->clip.height);
       cairo_clip (cr);
     }
 
@@ -8466,6 +8486,7 @@ _gtk_widget_set_visible_flag (GtkWidget *widget,
       priv->allocation.y = -1;
       priv->allocation.width = 1;
       priv->allocation.height = 1;
+      memset (&priv->clip, 0, sizeof (priv->clip));
     }
 }
 
@@ -14880,6 +14901,148 @@ gtk_widget_get_has_tooltip (GtkWidget *widget)
   return has_tooltip;
 }
 
+/**
+ * gtk_widget_get_clip:
+ * @widget: a #GtkWidget
+ * @clip: (out): a pointer to a #GtkAllocation to copy to
+ *
+ * Retrieves the widget’s clip area.
+ *
+ * The clip area is the area in which all of @widget's drawing will
+ * happen. Other toolkits call it the bounding box.
+ *
+ * Historically, in GTK the clip area has been equal to the allocation 
+ * retrieved via gtk_widget_get_allocation().
+ *
+ * Since: 3.14
+ */
+void
+gtk_widget_get_clip (GtkWidget     *widget,
+                     GtkAllocation *clip)
+{
+  GtkWidgetPrivate *priv;
+
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+  g_return_if_fail (clip != NULL);
+
+  priv = widget->priv;
+
+  *clip = priv->clip;
+}
+
+/**
+ * gtk_widget_set_clip:
+ * @widget: a #GtkWidget
+ * @clip: a pointer to a #GtkAllocation to copy from
+ *
+ * Sets the widget’s clip.  This must not be used
+ * directly, but from within a widget’s size_allocate method.
+ *
+ * The clip set should be the area that @widget draws on. If @widget is a
+ * #GtkContainer, the area must contain all children's clips.
+ *
+ * If this function is not called by @widget during a size_allocate handler,
+ * it is assumed to be equal to the allocation. However, if the function is
+ * not called, certain features that might extend a widget's allocation will
+ * not be available:
+ *
+ *  * The GtkWidget::draw signal will be clipped to the widget's allocation
+ *    to avoid overdraw.
+ *  * Calling gtk_render_background() will not draw outset shadows.
+ *
+ * It is therefor suggested that you always call gtk_widget_set_clip() during
+ * a size_allocate handler.
+ *
+ * Since: 3.14
+ */
+void
+gtk_widget_set_clip (GtkWidget           *widget,
+                     const GtkAllocation *clip)
+{
+  GtkWidgetPrivate *priv;
+
+  g_return_if_fail (GTK_IS_WIDGET (widget));
+  g_return_if_fail (gtk_widget_get_visible (widget) || gtk_widget_is_toplevel (widget));
+  g_return_if_fail (clip != NULL);
+
+  priv = widget->priv;
+
+  priv->clip = *clip;
+  priv->supports_clip = TRUE;
+}
+
+/**
+ * _gtk_widget_supports_clip:
+ * @widget: The #GtkWidget to check
+ *
+ * Returns %TRUE if the widget called gtk_widget_set_clip() during
+ * size allocation. See that function for details.
+ *
+ * Returns: %TRUE if the widget handles a clip separate from its allocation.
+ **/
+gboolean
+_gtk_widget_supports_clip (GtkWidget *widget)
+{
+  g_return_val_if_fail (GTK_IS_WIDGET (widget), TRUE);
+
+  return widget->priv->supports_clip;
+}
+
+static void
+union_with_clip (GtkWidget *widget,
+                 gpointer   clip)
+{
+  GtkAllocation widget_clip;
+
+  if (!gtk_widget_is_drawable (widget))
+    return;
+
+  gtk_widget_get_clip (widget, &widget_clip);
+
+  gdk_rectangle_union (&widget_clip, clip, clip);
+}
+
+/**
+ * _gtk_widget_set_simple_clip:
+ * @widget: 
+ *
+ * This is a convenience function for gtk_widget_set_clip(), if you
+ * just want to set the clip for @widget based on its allocation,
+ * CSS properties and - if the widget is a #GtkContainer - its
+ * children. gtk_widget_set_allocation() must have been called
+ * and all children must have been allocated with
+ * gtk_widget_size_allocate() before calling this function. It is
+ * therefor a good idea to call this function last in your
+ * implementation of GtkWidget::size_allocate().
+ *
+ * If your widget overdraws its contents, you cannot use this
+ * function and must call gtk_widget_set_clip() yourself.
+ **/
+void
+_gtk_widget_set_simple_clip (GtkWidget *widget)
+{
+  GtkStyleContext *context;
+  GtkAllocation clip;
+  GtkBorder extents;
+
+  context = gtk_widget_get_style_context (widget);
+
+  gtk_widget_get_allocation (widget, &clip);
+
+  _gtk_css_shadows_value_get_extents (_gtk_style_context_peek_property (context,
+                                                                        GTK_CSS_PROPERTY_BOX_SHADOW),
+                                      &extents);
+  clip.x -= extents.left;
+  clip.y -= extents.top;
+  clip.width += extents.left + extents.right;
+  clip.height += extents.top + extents.bottom;
+
+  if (GTK_IS_CONTAINER (widget))
+    gtk_container_forall (GTK_CONTAINER (widget), union_with_clip, &clip);
+
+  gtk_widget_set_clip (widget, &clip);
+}
+
 /**
  * gtk_widget_get_allocation:
  * @widget: a #GtkWidget

gtk/gtkwidget.h

@@ -945,6 +945,12 @@ void                  gtk_widget_get_allocation         (GtkWidget     *widget,
 GDK_AVAILABLE_IN_ALL
 void                  gtk_widget_set_allocation         (GtkWidget     *widget,
                                                          const GtkAllocation *allocation);
+GDK_AVAILABLE_IN_3_14
+void                  gtk_widget_set_clip               (GtkWidget     *widget,
+                                                         const GtkAllocation *allocation);  
+GDK_AVAILABLE_IN_3_14
+void                  gtk_widget_get_clip               (GtkWidget     *widget,
+                                                         GtkAllocation *allocation);  
 
 GDK_DEPRECATED_IN_3_0_FOR(gtk_widget_get_preferred_width & gtk_widget_get_preferred_height)
 

gtk/gtkwidgetprivate.h

@@ -132,6 +132,8 @@ void              _gtk_widget_buildable_finish_accelerator (GtkWidget *widget,
 GtkStyle *        _gtk_widget_get_style                    (GtkWidget *widget);
 void              _gtk_widget_set_style                    (GtkWidget *widget,
                                                             GtkStyle  *style);
+gboolean          _gtk_widget_supports_clip                (GtkWidget *widget);
+void              _gtk_widget_set_simple_clip              (GtkWidget *widget);
 
 typedef gboolean (*GtkCapturedEventHandler) (GtkWidget *widget, GdkEvent *event);