gtk-demo: Add multitouch demo

Pretty much ignores pointer events currently, so you're out
of luck to see anything happening at all if you don't have
a multitouch device...

configure.ac

@@ -1078,6 +1078,10 @@ if test "x$enable_x11_backend" == xyes; then
                     AC_DEFINE(XINPUT_2, 1, [Define to 1 if XInput 2.0 is available]),
                     X_EXTENSIONS="$X_EXTENSIONS XInput")
 
+    gtk_save_LIBS="$LIBS"
+    LIBS="$LIBS -lXi"
+    AC_CHECK_FUNC(XIAllowTouchEvents, AC_DEFINE(XINPUT_2_1, 1, [Define to 1 if XInput 2.1 is available]))
+    LIBS="$gtk_save_LIBS"
   else
     AC_DEFINE(XINPUT_NONE, 1,
               [Define to 1 if no XInput should be used])

demos/gtk-demo/Makefile.am

@@ -28,6 +28,7 @@ demos =						\
 	links.c					\
 	list_store.c				\
 	menus.c					\
+	multitouch.c				\
 	offscreen_window.c			\
 	offscreen_window2.c			\
 	panes.c					\

demos/gtk-demo/multitouch.c

@@ -0,0 +1,514 @@
+/* Multitouch
+ *
+ * Demonstrates some general multitouch event handling,
+ * using GdkTouchCluster in order to get grouped motion
+ * events for the touches within a cluster.
+ */
+
+#include <math.h>
+#include <gtk/gtk.h>
+#include "demo-common.h"
+
+static GtkWidget *window = NULL;
+static GList *shapes = NULL;
+
+typedef struct {
+  GdkTouchCluster *cluster;
+  GdkRGBA color;
+
+  gdouble angle;
+  gdouble zoom;
+
+  gdouble center_x;
+  gdouble center_y;
+
+  gdouble x;
+  gdouble y;
+  gdouble width;
+  gdouble height;
+
+  gdouble base_zoom;
+  gdouble base_angle;
+  gdouble initial_distance;
+  gdouble initial_angle;
+
+  GdkPoint points[4];
+} ShapeInfo;
+
+static void
+calculate_rotated_point (gdouble  angle,
+                         gdouble  zoom,
+                         gdouble  center_x,
+                         gdouble  center_y,
+                         gdouble  point_x,
+                         gdouble  point_y,
+                         gdouble *ret_x,
+                         gdouble *ret_y)
+{
+  gdouble distance, xd, yd, ang;
+
+  if (angle == 0)
+    {
+      *ret_x = point_x;
+      *ret_y = point_y;
+      return;
+    }
+
+  xd = center_x - point_x;
+  yd = center_y - point_y;
+
+  if (xd == 0 && yd == 0)
+    {
+      *ret_x = center_x;
+      *ret_y = center_y;
+      return;
+    }
+
+  distance = sqrt ((xd * xd) + (yd * yd));
+  distance *= zoom;
+
+  ang = atan2 (xd, yd);
+
+  /* Invert angle */
+  ang = (2 * G_PI) - ang;
+
+  /* Shift it 270° */
+  ang += 3 * (G_PI / 2);
+
+  /* And constraint it to 0°-360° */
+  ang = fmod (ang, 2 * G_PI);
+  ang += angle;
+
+  *ret_x = center_x + (distance * cos (ang));
+  *ret_y = center_y + (distance * sin (ang));
+}
+
+static void
+shape_info_allocate_input_rect (ShapeInfo *info)
+{
+  gint width, height, i;
+
+  width = info->width;
+  height = info->height;
+
+  /* Top/left */
+  info->points[0].x = info->x - info->center_x;
+  info->points[0].y = info->y - info->center_y;
+
+  /* Top/right */
+  info->points[1].x = info->x - info->center_x + width;
+  info->points[1].y = info->y - info->center_y;
+
+  /* Bottom/right */
+  info->points[2].x = info->x - info->center_x + width;
+  info->points[2].y = info->y - info->center_y + height;
+
+  /* Bottom/left */
+  info->points[3].x = info->x - info->center_x;
+  info->points[3].y = info->y - info->center_y + height;
+
+  for (i = 0; i < 4; i++)
+    {
+      gdouble ret_x, ret_y;
+
+      calculate_rotated_point (info->angle,
+                               info->zoom,
+                               info->x,
+                               info->y,
+                               (gdouble) info->points[i].x,
+                               (gdouble) info->points[i].y,
+                               &ret_x,
+                               &ret_y);
+
+      info->points[i].x = (gint) ret_x;
+      info->points[i].y = (gint) ret_y;
+    }
+}
+
+static void
+shape_info_bounding_rect (ShapeInfo    *info,
+                          GdkRectangle *rect)
+{
+  gint i, left, right, top, bottom;
+
+  left = top = G_MAXINT;
+  right = bottom = 0;
+
+  for (i = 0; i < 4; i++)
+    {
+      if (info->points[i].x < left)
+        left = info->points[i].x;
+
+      if (info->points[i].x > right)
+        right = info->points[i].x;
+
+      if (info->points[i].y < top)
+        top = info->points[i].y;
+
+      if (info->points[i].y > bottom)
+        bottom = info->points[i].y;
+    }
+
+  rect->x = left - 20;
+  rect->y = top - 20;
+  rect->width = right - left + 40;
+  rect->height = bottom - top + 40;
+}
+
+static gboolean
+shape_info_point_in (ShapeInfo *info,
+                     gint       x,
+                     gint       y)
+{
+  GdkPoint *left, *right, *top, *bottom;
+  gint i;
+
+  left = right = top = bottom = NULL;
+
+  for (i = 0; i < 4; i++)
+    {
+      GdkPoint *p = &info->points[i];
+
+      if (!left ||
+          p->x < left->x ||
+          (p->x == left->x && p->y > left->y))
+        left = p;
+
+      if (!right ||
+          p->x > right->x ||
+          (p->x == right->x && p->y < right->y))
+        right = p;
+    }
+
+  for (i = 0; i < 4; i++)
+    {
+      GdkPoint *p = &info->points[i];
+
+      if (p == left || p == right)
+        continue;
+
+      if (!top ||
+          p->y < top->y)
+        top = p;
+
+      if (!bottom ||
+          p->y > bottom->y)
+        bottom = p;
+    }
+
+  g_assert (left && right && top && bottom);
+
+  if (x < left->x ||
+      x > right->x ||
+      y < top->y ||
+      y > bottom->y)
+    return FALSE;
+
+  /* Check whether point is above the sides
+   * between leftmost and topmost, and
+   * topmost and rightmost corners.
+   */
+  if (x <= top->x)
+    {
+      if (left->y - ((left->y - top->y) * (((gdouble) x - left->x) / (top->x - left->x))) > y)
+        return FALSE;
+    }
+  else
+    {
+      if (top->y + ((right->y - top->y) * (((gdouble) x - top->x) / (right->x - top->x))) > y)
+        return FALSE;
+    }
+
+  /* Check whether point is below the sides
+   * between leftmost and bottom, and
+   * bottom and rightmost corners.
+   */
+  if (x <= bottom->x)
+    {
+      if (left->y + ((bottom->y - left->y) * (((gdouble) x - left->x) / (bottom->x - left->x))) < y)
+        return FALSE;
+    }
+  else
+    {
+      if (bottom->y - ((bottom->y - right->y) * (((gdouble) x - bottom->x) / (right->x - bottom->x))) < y)
+        return FALSE;
+    }
+
+  return TRUE;
+}
+
+static ShapeInfo *
+shape_info_new (gdouble  x,
+                gdouble  y,
+                gdouble  width,
+                gdouble  height,
+                GdkRGBA *color)
+{
+  ShapeInfo *info;
+
+  info = g_slice_new0 (ShapeInfo);
+  info->cluster = NULL;
+  info->color = *color;
+
+  info->x = x;
+  info->y = y;
+  info->width = width;
+  info->height = height;
+
+  info->angle = 0;
+  info->zoom = 1;
+
+  info->base_zoom = 1;
+  info->base_angle = 0;
+  info->initial_distance = 0;
+  info->initial_angle = 0;
+
+  shape_info_allocate_input_rect (info);
+
+  shapes = g_list_prepend (shapes, info);
+
+  return info;
+}
+
+static void
+shape_info_free (ShapeInfo *info)
+{
+  g_slice_free (ShapeInfo, info);
+}
+
+static void
+shape_info_draw (cairo_t   *cr,
+                 ShapeInfo *info)
+{
+  cairo_save (cr);
+
+  cairo_translate (cr, info->points[0].x, info->points[0].y);
+  cairo_scale (cr, info->zoom, info->zoom);
+  cairo_rotate (cr, info->angle);
+
+  cairo_rectangle (cr, 0, 0, info->width, info->height);
+  gdk_cairo_set_source_rgba (cr, &info->color);
+  cairo_fill_preserve (cr);
+
+  cairo_set_line_width (cr, 6);
+  cairo_set_source_rgb (cr, 0, 0, 0);
+  cairo_stroke (cr);
+
+  cairo_restore (cr);
+}
+
+static gboolean
+draw_cb (GtkWidget *widget,
+         cairo_t   *cr,
+         gpointer   user_data)
+{
+  GList *l;
+
+  for (l = shapes; l; l = l->next)
+    shape_info_draw (cr, l->data);
+
+  return FALSE;
+}
+
+static gboolean
+button_press_cb (GtkWidget *widget,
+                 GdkEvent  *event,
+                 gpointer   user_data)
+{
+  ShapeInfo *shape = NULL;
+  guint touch_id;
+
+  if (gdk_event_get_touch_id (event, &touch_id))
+    {
+      GList *l;
+
+      for (l = shapes; l; l = l->next)
+        {
+          ShapeInfo *info = l->data;
+
+          if (shape_info_point_in (info,
+                                   (gint) event->button.x,
+                                   (gint) event->button.y))
+            shape = info;
+        }
+
+      if (!shape)
+        return FALSE;
+
+      if (!shape->cluster)
+        shape->cluster = gdk_window_create_touch_cluster (gtk_widget_get_window (widget));
+
+      /* Only change cluster device if there were no touches or no device */
+      if (!gdk_touch_cluster_get_device (shape->cluster) ||
+          !gdk_touch_cluster_get_touches (shape->cluster))
+        gdk_touch_cluster_set_device (shape->cluster,
+                                      gdk_event_get_source_device (event));
+
+      gdk_touch_cluster_add_touch (shape->cluster, touch_id);
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
+static gboolean
+multitouch_cb (GtkWidget *widget,
+               GdkEvent  *event,
+               gpointer   user_data)
+{
+  ShapeInfo *info = NULL;
+  gboolean new_center = FALSE;
+  gboolean new_position = FALSE;
+  gdouble event_x, event_y;
+  cairo_region_t *region;
+  GdkRectangle rect;
+  GList *l;
+
+  for (l = shapes; l; l = l->next)
+    {
+      ShapeInfo *shape = l->data;
+
+      if (event->multitouch.group == shape->cluster)
+        {
+          info = shape;
+          break;
+        }
+    }
+
+  if (!info)
+    return FALSE;
+
+  shape_info_bounding_rect (info, &rect);
+  region = cairo_region_create_rectangle ((cairo_rectangle_int_t *) &rect);
+
+  if (event->multitouch.n_events == 1)
+    {
+      /* Update center if we just got to
+       * this situation from either way */
+      if (event->type == GDK_MULTITOUCH_ADDED ||
+          event->type == GDK_MULTITOUCH_REMOVED)
+        new_center = TRUE;
+
+      event_x = event->multitouch.events[0]->x;
+      event_y = event->multitouch.events[0]->y;
+      new_position = TRUE;
+    }
+  else if (event->multitouch.n_events == 2)
+    {
+      gdouble distance, angle;
+
+      gdk_events_get_center ((GdkEvent *) event->multitouch.events[0],
+                             (GdkEvent *) event->multitouch.events[1],
+                             &event_x, &event_y);
+
+      gdk_events_get_distance ((GdkEvent *) event->multitouch.events[0],
+                               (GdkEvent *) event->multitouch.events[1],
+                               &distance);
+
+      gdk_events_get_angle ((GdkEvent *) event->multitouch.events[0],
+                            (GdkEvent *) event->multitouch.events[1],
+                            &angle);
+
+      if (event->type == GDK_MULTITOUCH_ADDED)
+        {
+          /* Second touch was just added, update base zoom/angle */
+          info->base_zoom = info->zoom;
+          info->base_angle = info->angle;
+          info->initial_angle = angle;
+          info->initial_distance = distance;
+          new_center = TRUE;
+        }
+
+      info->zoom = MAX (info->base_zoom * (distance / info->initial_distance), 1.0);
+      info->angle = info->base_angle + (angle - info->initial_angle);
+      new_position = TRUE;
+    }
+
+  if (new_center)
+    {
+      gdouble origin_x, origin_y;
+
+      origin_x = info->x - info->center_x;
+      origin_y = info->y - info->center_y;
+
+      calculate_rotated_point (- info->angle,
+                               1 / info->zoom,
+                               info->x - origin_x,
+                               info->y - origin_y,
+                               event_x - origin_x,
+                               event_y - origin_y,
+                               &info->center_x,
+                               &info->center_y);
+    }
+
+  if (new_position)
+    {
+      info->x = event_x;
+      info->y = event_y;
+    }
+
+  shape_info_allocate_input_rect (info);
+
+  shape_info_bounding_rect (info, &rect);
+  cairo_region_union_rectangle (region, (cairo_rectangle_int_t *) &rect);
+  gdk_window_invalidate_region (gtk_widget_get_window (widget), region, FALSE);
+
+  return TRUE;
+}
+
+GtkWidget *
+do_multitouch (GtkWidget *do_widget)
+{
+  if (!window)
+    {
+      GdkRGBA color;
+
+      window = gtk_window_new (GTK_WINDOW_TOPLEVEL);
+      gtk_window_set_title (GTK_WINDOW (window), "Multitouch demo");
+      gtk_window_set_default_size (GTK_WINDOW (window), 600, 600);
+
+      gtk_window_set_screen (GTK_WINDOW (window),
+			     gtk_widget_get_screen (do_widget));
+
+      gtk_widget_add_events (window,
+                             GDK_TOUCH_MASK |
+                             GDK_POINTER_MOTION_MASK |
+                             GDK_BUTTON_PRESS_MASK |
+                             GDK_BUTTON_RELEASE_MASK);
+
+      gtk_widget_set_app_paintable (window, TRUE);
+
+      g_signal_connect (window, "draw",
+                        G_CALLBACK (draw_cb), NULL);
+      g_signal_connect (window, "button-press-event",
+                        G_CALLBACK (button_press_cb), NULL);
+      g_signal_connect (window, "multitouch-event",
+                        G_CALLBACK (multitouch_cb), NULL);
+
+      gdk_rgba_parse (&color, "red");
+      color.alpha = 0.5;
+      shape_info_new (100, 50, 100, 140, &color);
+
+      gdk_rgba_parse (&color, "green");
+      color.alpha = 0.5;
+      shape_info_new (200, 100, 120, 90, &color);
+
+      gdk_rgba_parse (&color, "blue");
+      color.alpha = 0.5;
+      shape_info_new (150, 190, 140, 90, &color);
+    }
+
+  if (!gtk_widget_get_visible (window))
+    gtk_widget_show (window);
+  else
+    {
+      gtk_widget_destroy (window);
+      window = NULL;
+
+      g_list_foreach (shapes, (GFunc) shape_info_free, NULL);
+      g_list_free (shapes);
+      shapes = NULL;
+    }
+
+  return window;
+}

docs/reference/gdk/gdk-docs.sgml

@@ -33,6 +33,7 @@
     <xi:include href="xml/windows.xml" />
     <xi:include href="xml/events.xml" />
     <xi:include href="xml/event_structs.xml" />
+    <xi:include href="xml/touchcluster.xml" />
     <xi:include href="xml/keys.xml" />
     <xi:include href="xml/selections.xml" />
     <xi:include href="xml/dnd.xml" />

docs/reference/gdk/gdk3-sections.txt

@@ -770,6 +770,7 @@ gdk_event_request_motions
 gdk_events_get_angle
 gdk_events_get_center
 gdk_events_get_distance
+gdk_event_get_touch_id
 
 <SUBSECTION>
 gdk_event_handler_set
@@ -817,6 +818,7 @@ GdkEventWindowState
 GdkEventSetting
 GdkEventOwnerChange
 GdkEventGrabBroken
+GdkEventMultiTouch
 
 <SUBSECTION>
 GdkScrollDirection
@@ -844,6 +846,29 @@ gdk_event_get_type
 gdk_owner_change_get_type
 </SECTION>
 
+<SECTION>
+<TITLE>Multitouch</TITLE>
+<FILE>touchcluster</FILE>
+GdkTouchCluster
+gdk_touch_cluster_add_touch
+gdk_touch_cluster_remove_touch
+gdk_touch_cluster_remove_all
+gdk_touch_cluster_set_device
+gdk_touch_cluster_get_device
+gdk_touch_cluster_get_touches
+
+<SUBSECTION>
+gdk_window_create_touch_cluster
+gdk_window_remove_touch_cluster
+
+<SUBSECTION Standard>
+GDK_TYPE_TOUCH_CLUSTER
+
+<SUBSECTION Private>
+gdk_touch_cluster_get_type
+</SECTION>
+
+
 <SECTION>
 <TITLE>Cursors</TITLE>
 <FILE>cursors</FILE>

docs/reference/gdk/gdk3.types

@@ -9,5 +9,6 @@ gdk_display_manager_get_type
 gdk_drag_context_get_type
 gdk_keymap_get_type
 gdk_screen_get_type
+gdk_touch_cluster_get_type
 gdk_visual_get_type
 gdk_window_get_type

gdk/Makefile.am

@@ -88,6 +88,7 @@ gdk_public_h_sources = 				\
 	gdkselection.h				\
 	gdktestutils.h				\
 	gdkthreads.h				\
+	gdktouchcluster.h			\
 	gdktypes.h				\
 	gdkvisual.h				\
 	gdkwindow.h
@@ -129,6 +130,7 @@ gdk_c_sources = 				\
 	gdkrgba.c				\
 	gdkscreen.c				\
 	gdkselection.c				\
+	gdktouchcluster.c			\
 	gdkvisual.c				\
 	gdkwindow.c				\
 	gdkwindowimpl.c

gdk/gdk.h

@@ -53,6 +53,7 @@
 #include <gdk/gdkselection.h>
 #include <gdk/gdktestutils.h>
 #include <gdk/gdkthreads.h>
+#include <gdk/gdktouchcluster.h>
 #include <gdk/gdktypes.h>
 #include <gdk/gdkvisual.h>
 #include <gdk/gdkwindow.h>

gdk/gdk.symbols

@@ -163,6 +163,7 @@ gdk_event_get_screen
 gdk_event_get_source_device
 gdk_event_get_state
 gdk_event_get_time
+gdk_event_get_touch_id
 gdk_event_get_type G_GNUC_CONST
 gdk_event_handler_set
 gdk_event_mask_get_type G_GNUC_CONST
@@ -318,6 +319,11 @@ gdk_threads_enter
 gdk_threads_init
 gdk_threads_leave
 gdk_threads_set_lock_functions
+gdk_touch_cluster_add_touch
+gdk_touch_cluster_get_device
+gdk_touch_cluster_get_type G_GNUC_CONST
+gdk_touch_cluster_list_touches
+gdk_touch_cluster_remove_touch
 gdk_unicode_to_keyval G_GNUC_CONST
 gdk_utf8_to_string_target
 gdk_visibility_state_get_type G_GNUC_CONST

gdk/gdkdevice.h

@@ -61,6 +61,7 @@ typedef enum
  *                     of a stylus on a graphics tablet.
  * @GDK_SOURCE_CURSOR: the device is a graphics tablet "puck" or similar device.
  * @GDK_SOURCE_KEYBOARD: the device is a keyboard.
+ * @GDK_SOURCE_TOUCH: the device is a touch capable device.
  *
  * An enumeration describing the type of an input device in general terms.
  */
@@ -70,7 +71,8 @@ typedef enum
   GDK_SOURCE_PEN,
   GDK_SOURCE_ERASER,
   GDK_SOURCE_CURSOR,
-  GDK_SOURCE_KEYBOARD
+  GDK_SOURCE_KEYBOARD,
+  GDK_SOURCE_TOUCH
 } GdkInputSource;
 
 /**

gdk/gdkevents.c

@@ -445,6 +445,7 @@ gdk_event_new (GdkEventType type)
   switch (type)
     {
     case GDK_MOTION_NOTIFY:
+    case GDK_TOUCH_MOTION:
       new_event->motion.x = 0.;
       new_event->motion.y = 0.;
       new_event->motion.x_root = 0.;
@@ -454,6 +455,8 @@ gdk_event_new (GdkEventType type)
     case GDK_2BUTTON_PRESS:
     case GDK_3BUTTON_PRESS:
     case GDK_BUTTON_RELEASE:
+    case GDK_TOUCH_PRESS:
+    case GDK_TOUCH_RELEASE:
       new_event->button.x = 0.;
       new_event->button.y = 0.;
       new_event->button.x_root = 0.;
@@ -558,12 +561,15 @@ gdk_event_copy (const GdkEvent *event)
     case GDK_2BUTTON_PRESS:
     case GDK_3BUTTON_PRESS:
     case GDK_BUTTON_RELEASE:
+    case GDK_TOUCH_PRESS:
+    case GDK_TOUCH_RELEASE:
       if (event->button.axes)
         new_event->button.axes = g_memdup (event->button.axes,
                                            sizeof (gdouble) * gdk_device_get_n_axes (event->button.device));
       break;
 
     case GDK_MOTION_NOTIFY:
+    case GDK_TOUCH_MOTION:
       if (event->motion.axes)
         new_event->motion.axes = g_memdup (event->motion.axes,
                                            sizeof (gdouble) * gdk_device_get_n_axes (event->motion.device));
@@ -583,6 +589,22 @@ gdk_event_copy (const GdkEvent *event)
         g_object_unref (new_event->selection.requestor);
       break;
 
+    case GDK_MULTITOUCH_ADDED:
+    case GDK_MULTITOUCH_REMOVED:
+    case GDK_MULTITOUCH_UPDATED:
+      {
+        GdkEventMotion **motion_events;
+        guint i;
+
+        motion_events = g_new0 (GdkEventMotion*, event->multitouch.n_events);
+
+        for (i = 0; i < event->multitouch.n_events; i++)
+          motion_events[i] = (GdkEventMotion *) gdk_event_copy ((GdkEvent *) event->multitouch.events[i]);
+
+        new_event->multitouch.events = motion_events;
+      }
+      break;
+
     default:
       break;
     }
@@ -637,6 +659,8 @@ gdk_event_free (GdkEvent *event)
     case GDK_2BUTTON_PRESS:
     case GDK_3BUTTON_PRESS:
     case GDK_BUTTON_RELEASE:
+    case GDK_TOUCH_PRESS:
+    case GDK_TOUCH_RELEASE:
       g_free (event->button.axes);
       break;
       
@@ -647,6 +671,7 @@ gdk_event_free (GdkEvent *event)
       break;
       
     case GDK_MOTION_NOTIFY:
+    case GDK_TOUCH_MOTION:
       g_free (event->motion.axes);
       break;
       
@@ -666,6 +691,20 @@ gdk_event_free (GdkEvent *event)
         g_object_unref (event->selection.requestor);
       break;
 
+    case GDK_MULTITOUCH_ADDED:
+    case GDK_MULTITOUCH_REMOVED:
+    case GDK_MULTITOUCH_UPDATED:
+      if (event->multitouch.events)
+        {
+          guint i;
+
+          for (i = 0; i < event->multitouch.n_events; i++)
+            gdk_event_free ((GdkEvent *) event->multitouch.events[i]);
+
+          g_free (event->multitouch.events);
+        }
+      break;
+
     default:
       break;
     }
@@ -692,11 +731,14 @@ gdk_event_get_time (const GdkEvent *event)
     switch (event->type)
       {
       case GDK_MOTION_NOTIFY:
+      case GDK_TOUCH_MOTION:
 	return event->motion.time;
       case GDK_BUTTON_PRESS:
       case GDK_2BUTTON_PRESS:
       case GDK_3BUTTON_PRESS:
       case GDK_BUTTON_RELEASE:
+      case GDK_TOUCH_PRESS:
+      case GDK_TOUCH_RELEASE:
 	return event->button.time;
       case GDK_SCROLL:
         return event->scroll.time;
@@ -722,6 +764,10 @@ gdk_event_get_time (const GdkEvent *event)
       case GDK_DROP_START:
       case GDK_DROP_FINISHED:
 	return event->dnd.time;
+      case GDK_MULTITOUCH_ADDED:
+      case GDK_MULTITOUCH_REMOVED:
+      case GDK_MULTITOUCH_UPDATED:
+        return event->multitouch.time;
       case GDK_CLIENT_EVENT:
       case GDK_VISIBILITY_NOTIFY:
       case GDK_CONFIGURE:
@@ -767,12 +813,15 @@ gdk_event_get_state (const GdkEvent        *event,
     switch (event->type)
       {
       case GDK_MOTION_NOTIFY:
+      case GDK_TOUCH_MOTION:
 	*state = event->motion.state;
         return TRUE;
       case GDK_BUTTON_PRESS:
       case GDK_2BUTTON_PRESS:
       case GDK_3BUTTON_PRESS:
       case GDK_BUTTON_RELEASE:
+      case GDK_TOUCH_PRESS:
+      case GDK_TOUCH_RELEASE:
         *state =  event->button.state;
         return TRUE;
       case GDK_SCROLL:
@@ -786,6 +835,11 @@ gdk_event_get_state (const GdkEvent        *event,
       case GDK_LEAVE_NOTIFY:
 	*state =  event->crossing.state;
         return TRUE;
+      case GDK_MULTITOUCH_ADDED:
+      case GDK_MULTITOUCH_REMOVED:
+      case GDK_MULTITOUCH_UPDATED:
+        *state = event->multitouch.state;
+        return TRUE;
       case GDK_PROPERTY_NOTIFY:
       case GDK_VISIBILITY_NOTIFY:
       case GDK_CLIENT_EVENT:
@@ -861,10 +915,13 @@ gdk_event_get_coords (const GdkEvent *event,
     case GDK_2BUTTON_PRESS:
     case GDK_3BUTTON_PRESS:
     case GDK_BUTTON_RELEASE:
+    case GDK_TOUCH_PRESS:
+    case GDK_TOUCH_RELEASE:
       x = event->button.x;
       y = event->button.y;
       break;
     case GDK_MOTION_NOTIFY:
+    case GDK_TOUCH_MOTION:
       x = event->motion.x;
       y = event->motion.y;
       break;
@@ -904,6 +961,7 @@ gdk_event_get_root_coords (const GdkEvent *event,
   switch (event->type)
     {
     case GDK_MOTION_NOTIFY:
+    case GDK_TOUCH_MOTION:
       x = event->motion.x_root;
       y = event->motion.y_root;
       break;
@@ -915,6 +973,8 @@ gdk_event_get_root_coords (const GdkEvent *event,
     case GDK_2BUTTON_PRESS:
     case GDK_3BUTTON_PRESS:
     case GDK_BUTTON_RELEASE:
+    case GDK_TOUCH_PRESS:
+    case GDK_TOUCH_RELEASE:
       x = event->button.x_root;
       y = event->button.y_root;
       break;
@@ -972,7 +1032,8 @@ gdk_event_get_axis (const GdkEvent *event,
       
       switch (event->type)
 	{
-	case GDK_MOTION_NOTIFY:
+        case GDK_MOTION_NOTIFY:
+        case GDK_TOUCH_MOTION:
 	  x = event->motion.x;
 	  y = event->motion.y;
 	  break;
@@ -982,6 +1043,8 @@ gdk_event_get_axis (const GdkEvent *event,
 	  break;
 	case GDK_BUTTON_PRESS:
 	case GDK_BUTTON_RELEASE:
+        case GDK_TOUCH_PRESS:
+        case GDK_TOUCH_RELEASE:
 	  x = event->button.x;
 	  y = event->button.y;
 	  break;
@@ -1003,12 +1066,15 @@ gdk_event_get_axis (const GdkEvent *event,
       return TRUE;
     }
   else if (event->type == GDK_BUTTON_PRESS ||
-	   event->type == GDK_BUTTON_RELEASE)
+	   event->type == GDK_BUTTON_RELEASE ||
+           event->type == GDK_TOUCH_PRESS ||
+           event->type == GDK_TOUCH_RELEASE)
     {
       device = event->button.device;
       axes = event->button.axes;
     }
-  else if (event->type == GDK_MOTION_NOTIFY)
+  else if (event->type == GDK_MOTION_NOTIFY ||
+           event->type == GDK_TOUCH_MOTION)
     {
       device = event->motion.device;
       axes = event->motion.axes;
@@ -1045,12 +1111,15 @@ gdk_event_set_device (GdkEvent  *event,
   switch (event->type)
     {
     case GDK_MOTION_NOTIFY:
+    case GDK_TOUCH_MOTION:
       event->motion.device = device;
       break;
     case GDK_BUTTON_PRESS:
     case GDK_2BUTTON_PRESS:
     case GDK_3BUTTON_PRESS:
     case GDK_BUTTON_RELEASE:
+    case GDK_TOUCH_PRESS:
+    case GDK_TOUCH_RELEASE:
       event->button.device = device;
       break;
     case GDK_SCROLL:
@@ -1060,6 +1129,10 @@ gdk_event_set_device (GdkEvent  *event,
     case GDK_PROXIMITY_OUT:
       event->proximity.device = device;
       break;
+    case GDK_MULTITOUCH_ADDED:
+    case GDK_MULTITOUCH_REMOVED:
+    case GDK_MULTITOUCH_UPDATED:
+      event->multitouch.device = device;
     default:
       break;
     }
@@ -1092,17 +1165,24 @@ gdk_event_get_device (const GdkEvent *event)
   switch (event->type)
     {
     case GDK_MOTION_NOTIFY:
+    case GDK_TOUCH_MOTION:
       return event->motion.device;
     case GDK_BUTTON_PRESS:
     case GDK_2BUTTON_PRESS:
     case GDK_3BUTTON_PRESS:
     case GDK_BUTTON_RELEASE:
+    case GDK_TOUCH_PRESS:
+    case GDK_TOUCH_RELEASE:
       return event->button.device;
     case GDK_SCROLL:
       return event->scroll.device;
     case GDK_PROXIMITY_IN:
     case GDK_PROXIMITY_OUT:
       return event->proximity.device;
+    case GDK_MULTITOUCH_ADDED:
+    case GDK_MULTITOUCH_REMOVED:
+    case GDK_MULTITOUCH_UPDATED:
+      return event->multitouch.device;
     default:
       break;
     }
@@ -1111,10 +1191,13 @@ gdk_event_get_device (const GdkEvent *event)
   switch (event->type)
     {
     case GDK_MOTION_NOTIFY:
+    case GDK_TOUCH_MOTION:
     case GDK_BUTTON_PRESS:
     case GDK_2BUTTON_PRESS:
     case GDK_3BUTTON_PRESS:
     case GDK_BUTTON_RELEASE:
+    case GDK_TOUCH_PRESS:
+    case GDK_TOUCH_RELEASE:
     case GDK_ENTER_NOTIFY:
     case GDK_LEAVE_NOTIFY:
     case GDK_FOCUS_CHANGE:
@@ -1130,6 +1213,9 @@ gdk_event_get_device (const GdkEvent *event)
     case GDK_GRAB_BROKEN:
     case GDK_KEY_PRESS:
     case GDK_KEY_RELEASE:
+    case GDK_MULTITOUCH_ADDED:
+    case GDK_MULTITOUCH_REMOVED:
+    case GDK_MULTITOUCH_UPDATED:
       {
         GdkDisplay *display;
         GdkDeviceManager *device_manager;
@@ -1446,6 +1532,45 @@ gdk_event_get_screen (const GdkEvent *event)
   return NULL;
 }
 
+/**
+ * gdk_event_get_touch_id:
+ * @event: a #GdkEvent
+ * @touch_id: return location of the touch ID of a touch event
+ *
+ * If @event if of type %GDK_TOUCH_MOTION, %GDK_TOUCH_PRESS or
+ * %GDK_TOUCH_RELEASE, fills in @touch_id and returns %TRUE,
+ * else it returns %FALSE.
+ *
+ * Returns: %TRUE if the touch ID can be extracted from @event.
+ **/
+gboolean
+gdk_event_get_touch_id (const GdkEvent *event,
+                        guint          *touch_id)
+{
+  if (!event)
+    return FALSE;
+
+  if (event->type == GDK_TOUCH_MOTION)
+    {
+      if (touch_id)
+        *touch_id = event->motion.touch_id;
+      return TRUE;
+    }
+  else if (event->type == GDK_TOUCH_PRESS ||
+           event->type == GDK_TOUCH_RELEASE)
+    {
+      if (touch_id)
+        *touch_id = event->button.touch_id;
+      return TRUE;
+    }
+  else
+    {
+      if (touch_id)
+        *touch_id = 0;
+      return FALSE;
+    }
+}
+
 /**
  * gdk_set_show_events:
  * @show_events:  %TRUE to output event debugging information.

gdk/gdkevents.h

@@ -35,6 +35,7 @@
 #include <gdk/gdktypes.h>
 #include <gdk/gdkdnd.h>
 #include <gdk/gdkdevice.h>
+#include <gdk/gdktouchcluster.h>
 
 G_BEGIN_DECLS
 
@@ -93,6 +94,7 @@ typedef struct _GdkEventDND         GdkEventDND;
 typedef struct _GdkEventWindowState GdkEventWindowState;
 typedef struct _GdkEventSetting     GdkEventSetting;
 typedef struct _GdkEventGrabBroken  GdkEventGrabBroken;
+typedef struct _GdkEventMultiTouch  GdkEventMultiTouch;
 
 typedef union  _GdkEvent	    GdkEvent;
 
@@ -213,6 +215,12 @@ typedef GdkFilterReturn (*GdkFilterFunc) (GdkXEvent *xevent,
  *   was added in 2.8.
  * @GDK_DAMAGE: the content of the window has been changed. This event type
  *   was added in 2.14.
+ * @GDK_TOUCH_MOTION: A touch device has been updated.
+ * @GDK_TOUCH_PRESS: A new touch stream has just started.
+ * @GDK_TOUCH_RELEASE: A touch stream has finished.
+ * @GDK_MULTITOUCH_ADDED: A touch ID was added to a #GdkTouchCluster
+ * @GDK_MULTITOUCH_UPDATED: A touch within a #GdkTouchCluster has been updated.
+ * @GDK_MULTITOUCH_REMOVED: A touch ID was removed from a #GdkTouchCluster.
  * @GDK_EVENT_LAST: marks the end of the GdkEventType enumeration. Added in 2.18
  *
  * Specifies the type of the event.
@@ -260,6 +268,12 @@ typedef enum
   GDK_OWNER_CHANGE      = 34,
   GDK_GRAB_BROKEN       = 35,
   GDK_DAMAGE            = 36,
+  GDK_TOUCH_MOTION      = 37,
+  GDK_TOUCH_PRESS       = 38,
+  GDK_TOUCH_RELEASE     = 39,
+  GDK_MULTITOUCH_ADDED  = 40,
+  GDK_MULTITOUCH_UPDATED = 41,
+  GDK_MULTITOUCH_REMOVED = 42,
   GDK_EVENT_LAST        /* helper variable for decls */
 } GdkEventType;
 
@@ -500,8 +514,9 @@ struct _GdkEventVisibility
  *   screen.
  * @y_root: the y coordinate of the pointer relative to the root of the
  *   screen.
+ * @touch_id: touch ID, only meaningful if event is of type %GDK_TOUCH_MOTION.
  *
- * Generated when the pointer moves.
+ * Generated when the pointer/touch moves.
  */
 struct _GdkEventMotion
 {
@@ -516,6 +531,56 @@ struct _GdkEventMotion
   gint16 is_hint;
   GdkDevice *device;
   gdouble x_root, y_root;
+  guint touch_id;
+};
+
+/**
+ * GdkEventMultiTouch:
+ * @type: the type of the event (%GDK_MULTITOUCH_ADDED, %GDK_MULTITOUCH_UPDATED
+ *   or %GDK_MULTITOUCH_REMOVED).
+ * @window: the window which received the event.
+ * @send_event: %TRUE if the event was sent explicitly (e.g. using
+ *   <function>XSendEvent</function>).
+ * @time: the time of the event in milliseconds.
+ * @state: (type GdkModifierType): a bit-mask representing the state of
+ *   the modifier keys (e.g. Control, Shift and Alt) and the pointer
+ *   buttons. See #GdkModifierType.
+ * @device: the device where the event originated.
+ * @group: the #GdkTouchCluster containing the touches that generated this event
+ * @events: an array of events of type %GDK_TOUCH_MOTION for the touches in @group
+ * @updated_touch_id: the touch ID that caused this event to be generated
+ * @n_events: the number of events in @events
+ * @n_updated_event: the index in @events of the event corresponding to
+ *   @updated_touch_id, or -1 for %GDK_MULTITOUCH_REMOVED events.
+ *
+ * Used for multitouch events. The @type field will be one of
+ * %GDK_MULTITOUCH_ADDED, %GDK_MULTITOUCH_UPDATED or
+ * %GDK_MULTITOUCH_REMOVED.
+ *
+ * Multitouch events group the events from the touches in a
+ * #GdkTouchCluster, so one of these events is generated
+ * whenever a touch ID generates a new event, or a touch ID
+ * is added or removed.
+ *
+ * For any given touch ID, %GDK_MULTITOUCH_ADDED and
+ * %GDK_MULTITOUCH_REMOVED events are always paired,
+ * with any number of %GDK_MULTITOUCH_UPDATED
+ * events in between. The minimum event stream is an
+ * added/removed pair.
+ */
+struct _GdkEventMultiTouch
+{
+  GdkEventType type;
+  GdkWindow *window;
+  gint8 send_event;
+  guint32 time;
+  guint state;
+  GdkDevice *device;
+  GdkTouchCluster *group;
+  GdkEventMotion **events;
+  guint updated_touch_id;
+  gint8 n_events;
+  gint8 n_updated_event;
 };
 
 /**
@@ -542,6 +607,8 @@ struct _GdkEventMotion
  *   screen.
  * @y_root: the y coordinate of the pointer relative to the root of the
  *   screen.
+ * @touch_id: touch ID, only meaningful if event is of type %GDK_TOUCH_PRESS
+ *   or %GDK_TOUCH_RELEASE.
  *
  * Used for button press and button release events. The
  * @type field will be one of %GDK_BUTTON_PRESS,
@@ -591,6 +658,7 @@ struct _GdkEventButton
   guint button;
   GdkDevice *device;
   gdouble x_root, y_root;
+  guint touch_id;
 };
 
 /**
@@ -1034,6 +1102,7 @@ union _GdkEvent
   GdkEventWindowState       window_state;
   GdkEventSetting           setting;
   GdkEventGrabBroken        grab_broken;
+  GdkEventMultiTouch        multitouch;
 };
 
 GType     gdk_event_get_type            (void) G_GNUC_CONST;
@@ -1087,6 +1156,9 @@ void       gdk_event_set_screen         (GdkEvent        *event,
                                          GdkScreen       *screen);
 GdkScreen *gdk_event_get_screen         (const GdkEvent  *event);
 
+gboolean   gdk_event_get_touch_id       (const GdkEvent  *event,
+                                         guint           *touch_id);
+
 void	  gdk_set_show_events		(gboolean	 show_events);
 gboolean  gdk_get_show_events		(void);
 

gdk/gdkinternals.h

@@ -248,6 +248,12 @@ struct _GdkWindow
   GHashTable *source_event_masks;
   gulong device_added_handler_id;
   gulong device_changed_handler_id;
+
+  /* Store of latest per-touch events, keys are
+   * GdkDevices, values are hashtables of touchID/info
+   */
+  GHashTable *touch_event_tracker;
+  GList *touch_clusters;
 };
 
 #define GDK_WINDOW_TYPE(d) (((GDK_WINDOW (d)))->window_type)

gdk/gdktouchcluster.c

@@ -0,0 +1,350 @@
+/* GDK - The GIMP Drawing Kit
+ * Copyright (C) 2011 Carlos Garnacho <carlosg@gnome.org>
+ *
+ * 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 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, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#include "config.h"
+
+#include "gdktouchcluster.h"
+#include "gdkintl.h"
+
+/**
+ * SECTION:touchcluster
+ * @Short_description: Multitouch handling
+ * @Title: Multitouch
+ * @See_also: #GdkEventMultiTouch
+ *
+ * #GdkTouchCluster is an object that gathers touch IDs from a
+ * touch-enabled slave #GdkDevice, in order to send
+ * #GdkEventMultiTouch<!-- --> events whenever a contained touch ID
+ * is updated.
+ *
+ * #GdkTouchCluster<!-- -->s are always associated to a window,
+ * you need to create them through gdk_window_create_touch_cluster(),
+ * and free them through gdk_window_remove_touch_cluster().
+ *
+ * Touch IDs from devices can be obtained from %GDK_TOUCH_PRESS,
+ * %GDK_TOUCH_MOTION or %GDK_TOUCH_RELEASE events through
+ * gdk_event_get_touch_id(), and then be added via
+ * gdk_touch_cluster_add_touch(). Note that touch IDs are
+ * highly transitive, even be an incrementable number only
+ * identifying the current touch event stream, so touch IDs
+ * should always be gotten from these events.
+ *
+ * Anytime a touch ID is within a cluster, no %GDK_TOUCH_PRESS,
+ * %GDK_TOUCH_MOTION or %GDK_TOUCH_RELEASE events will happen
+ * for the individual touch. The event will be available instead
+ * as part of the #GdkMultitouchEvent that will be emitted. This
+ * will hold true until gdk_touch_cluster_remove_touch() is
+ * called for it. Note that GTK+ will automatically take a
+ * touch ID out of any cluster if %GDK_TOUCH_RELEASE is gotten
+ * internally.
+ */
+
+typedef struct GdkTouchClusterPrivate GdkTouchClusterPrivate;
+
+struct GdkTouchClusterPrivate
+{
+  GdkDevice *device;
+  GList *touches;
+};
+
+enum {
+  PROP_0,
+  PROP_DEVICE
+};
+
+enum {
+  TOUCH_ADDED,
+  TOUCH_REMOVED,
+  LAST_SIGNAL
+};
+
+static guint signals [LAST_SIGNAL] = { 0 };
+
+static void   gdk_touch_cluster_finalize     (GObject      *object);
+static void   gdk_touch_cluster_set_property (GObject      *object,
+                                              guint         prop_id,
+                                              const GValue *value,
+                                              GParamSpec   *pspec);
+static void   gdk_touch_cluster_get_property (GObject      *object,
+                                              guint         prop_id,
+                                              GValue       *value,
+                                              GParamSpec   *pspec);
+
+
+G_DEFINE_TYPE (GdkTouchCluster, gdk_touch_cluster, G_TYPE_OBJECT)
+
+static void
+gdk_touch_cluster_class_init (GdkTouchClusterClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->finalize = gdk_touch_cluster_finalize;
+  object_class->get_property = gdk_touch_cluster_get_property;
+  object_class->set_property = gdk_touch_cluster_set_property;
+
+  g_object_class_install_property (object_class,
+                                   PROP_DEVICE,
+                                   g_param_spec_object ("device",
+                                                        P_("Device"),
+                                                        P_("Device attached to the cluster"),
+                                                        GDK_TYPE_DEVICE,
+                                                        G_PARAM_READWRITE | G_PARAM_CONSTRUCT_ONLY |
+                                                        G_PARAM_STATIC_STRINGS));
+
+  signals[TOUCH_ADDED] =
+    g_signal_new (g_intern_static_string ("touch-added"),
+                  G_TYPE_FROM_CLASS (object_class),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (GdkTouchClusterClass, touch_added),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__UINT,
+                  G_TYPE_NONE, 1, G_TYPE_UINT);
+  signals[TOUCH_REMOVED] =
+    g_signal_new (g_intern_static_string ("touch-removed"),
+                  G_TYPE_FROM_CLASS (object_class),
+                  G_SIGNAL_RUN_LAST,
+                  G_STRUCT_OFFSET (GdkTouchClusterClass, touch_removed),
+                  NULL, NULL,
+                  g_cclosure_marshal_VOID__UINT,
+                  G_TYPE_NONE, 1, G_TYPE_UINT);
+
+  g_type_class_add_private (object_class, sizeof (GdkTouchClusterPrivate));
+}
+
+static void
+gdk_touch_cluster_init (GdkTouchCluster *cluster)
+{
+  cluster->priv = G_TYPE_INSTANCE_GET_PRIVATE (cluster,
+                                               GDK_TYPE_TOUCH_CLUSTER,
+                                               GdkTouchClusterPrivate);
+}
+
+static void
+gdk_touch_cluster_finalize (GObject *object)
+{
+  GdkTouchClusterPrivate *priv;
+
+  priv = GDK_TOUCH_CLUSTER (object)->priv;
+  g_list_free (priv->touches);
+
+  G_OBJECT_CLASS (gdk_touch_cluster_parent_class)->finalize (object);
+}
+
+static void
+gdk_touch_cluster_set_property (GObject      *object,
+                                guint         prop_id,
+                                const GValue *value,
+                                GParamSpec   *pspec)
+{
+  GdkTouchClusterPrivate *priv;
+
+  priv = GDK_TOUCH_CLUSTER (object)->priv;
+
+  switch (prop_id)
+    {
+    case PROP_DEVICE:
+      gdk_touch_cluster_set_device (GDK_TOUCH_CLUSTER (object),
+                                    g_value_get_object (value));
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+static void
+gdk_touch_cluster_get_property (GObject      *object,
+                                guint         prop_id,
+                                GValue       *value,
+                                GParamSpec   *pspec)
+{
+  GdkTouchClusterPrivate *priv;
+
+  priv = GDK_TOUCH_CLUSTER (object)->priv;
+
+  switch (prop_id)
+    {
+    case PROP_DEVICE:
+      g_value_set_object (value, priv->device);
+      break;
+    default:
+      G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
+      break;
+    }
+}
+
+/**
+ * gdk_touch_cluster_add_touch:
+ * @cluster: a #GdkTouchCluster
+ * @touch_id: a touch ID from a touch event
+ *
+ * Adds a touch ID to @cluster, so it will generate a
+ * %GDK_MULTITOUCH_ADDED event, followed by %GDK_MULTITOUCH_UPDATED
+ * events whenever this touch ID is updated.
+ *
+ * If @touch_id already pertained to another #GdkTouchCluster, it
+ * will be removed from it, generating a %GDK_MULTITOUCH_REMOVED
+ * for that another cluster.
+ **/
+void
+gdk_touch_cluster_add_touch (GdkTouchCluster *cluster,
+                             guint            touch_id)
+{
+  GdkTouchClusterPrivate *priv;
+
+  g_return_if_fail (GDK_IS_TOUCH_CLUSTER (cluster));
+
+  priv = cluster->priv;
+
+  if (!g_list_find (priv->touches, GUINT_TO_POINTER (touch_id)))
+    {
+      priv->touches = g_list_prepend (priv->touches, GUINT_TO_POINTER (touch_id));
+      g_signal_emit (cluster, signals [TOUCH_ADDED], 0, touch_id);
+    }
+}
+
+/**
+ * gdk_touch_cluster_remove_touch:
+ * @cluster: a #GdkTouchCluster
+ * @touch_id: a touch ID from a touch event
+ *
+ * Removes a touch ID from @cluster, generating a %GDK_MULTITOUCH_REMOVED
+ * event for @cluster, and causing any further input from @touch_id
+ * to be reported trough %GDK_TOUCH_MOTION events.
+ *
+ * <note><para>
+ * Note that GTK+ automatically removes a touch ID from any cluster
+ * if a %GDK_TOUCH_RELEASE event is gotten internally.
+ * </para></note>
+ **/
+void
+gdk_touch_cluster_remove_touch (GdkTouchCluster *cluster,
+                                guint            touch_id)
+{
+  GdkTouchClusterPrivate *priv;
+  GList *link;
+
+  g_return_if_fail (GDK_IS_TOUCH_CLUSTER (cluster));
+
+  priv = cluster->priv;
+
+  link = g_list_find (priv->touches, GUINT_TO_POINTER (touch_id));
+
+  if (link)
+    {
+      priv->touches = g_list_remove_link (priv->touches, link);
+      g_signal_emit (cluster, signals [TOUCH_REMOVED], 0, touch_id);
+      g_list_free1 (link);
+    }
+}
+
+/**
+ * gdk_touch_cluster_remove_all:
+ * @cluster: a #GdkTouchCluster
+ *
+ * Removes all touch IDs from @cluster.
+ **/
+void
+gdk_touch_cluster_remove_all (GdkTouchCluster *cluster)
+{
+  GdkTouchClusterPrivate *priv;
+  GList *link;
+
+  g_return_if_fail (GDK_IS_TOUCH_CLUSTER (cluster));
+
+  priv = cluster->priv;
+  link = priv->touches;
+
+  while (link)
+    {
+      priv->touches = g_list_remove_link (priv->touches, link);
+      g_signal_emit (cluster, signals [TOUCH_REMOVED], 0, link->data);
+    }
+
+  g_list_free (priv->touches);
+  priv->touches = NULL;
+}
+
+
+/**
+ * gdk_touch_cluster_get_touches:
+ * @cluster: a #GdkTouchCluster
+ *
+ * Returns a const list of touch IDs as #guint.
+ *
+ * Returns: (transfer none): A list of touch IDs.
+ **/
+GList *
+gdk_touch_cluster_get_touches (GdkTouchCluster *cluster)
+{
+  GdkTouchClusterPrivate *priv;
+
+  g_return_val_if_fail (GDK_IS_TOUCH_CLUSTER (cluster), NULL);
+
+  priv = cluster->priv;
+  return priv->touches;
+}
+
+/**
+ * gdk_touch_cluster_set_device:
+ * @cluster: a #GdkTouchCluster
+ * @device: a #GdkDevice
+ *
+ * Sets the current device associated to @cluster, all contained
+ * touch IDs must pertain to this device. As a consequence,
+ * gdk_touch_cluster_remove_all() will be called on @cluster
+ * if the current device changes.
+ **/
+void
+gdk_touch_cluster_set_device (GdkTouchCluster *cluster,
+                              GdkDevice       *device)
+{
+  GdkTouchClusterPrivate *priv;
+
+  g_return_if_fail (GDK_IS_TOUCH_CLUSTER (cluster));
+  g_return_if_fail (!device || GDK_IS_DEVICE (device));
+
+  priv = cluster->priv;
+
+  if (priv->device != device)
+    gdk_touch_cluster_remove_all (cluster);
+
+  priv->device = device;
+}
+
+/**
+ * gdk_touch_cluster_get_device:
+ * @cluster: a #GdkTouchCluster
+ *
+ * Returns the slave/floating device this touch cluster pertains to,
+ * only touch IDs from this device can be included in @cluster.
+ * the #GdkDevice will typically have the %GDK_SOURCE_TOUCH input source.
+ *
+ * Returns: (transfer none): The #GdkDevice generating the contained touch IDs
+ **/
+GdkDevice *
+gdk_touch_cluster_get_device (GdkTouchCluster *cluster)
+{
+  GdkTouchClusterPrivate *priv;
+
+  g_return_val_if_fail (GDK_IS_TOUCH_CLUSTER (cluster), NULL);
+
+  priv = cluster->priv;
+  return priv->device;
+}

gdk/gdktouchcluster.h

@@ -0,0 +1,69 @@
+/* GDK - The GIMP Drawing Kit
+ * Copyright (C) 2011 Carlos Garnacho <carlosg@gnome.org>
+ *
+ * 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 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, write to the
+ * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
+ * Boston, MA 02111-1307, USA.
+ */
+
+#ifndef __GDK_TOUCH_CLUSTER_H__
+#define __GDK_TOUCH_CLUSTER_H__
+
+#include <glib-object.h>
+#include <gdk/gdkdevice.h>
+
+G_BEGIN_DECLS
+
+#define GDK_TYPE_TOUCH_CLUSTER         (gdk_touch_cluster_get_type ())
+#define GDK_TOUCH_CLUSTER(o)           (G_TYPE_CHECK_INSTANCE_CAST ((o), GDK_TYPE_TOUCH_CLUSTER, GdkTouchCluster))
+#define GDK_IS_TOUCH_CLUSTER(o)        (G_TYPE_CHECK_INSTANCE_TYPE ((o), GDK_TYPE_TOUCH_CLUSTER))
+
+typedef struct _GdkTouchCluster GdkTouchCluster;
+typedef struct _GdkTouchClusterClass GdkTouchClusterClass;
+
+struct _GdkTouchCluster
+{
+  GObject parent_instance;
+  gpointer priv;
+};
+
+struct _GdkTouchClusterClass
+{
+  GObjectClass parent_class;
+
+  void (* touch_added)   (GdkTouchCluster *cluster,
+                          guint            touch_id);
+  void (* touch_removed) (GdkTouchCluster *cluster,
+                          guint            touch_id);
+
+  gpointer padding[16];
+};
+
+GType       gdk_touch_cluster_get_type     (void) G_GNUC_CONST;
+
+void        gdk_touch_cluster_add_touch    (GdkTouchCluster *cluster,
+                                            guint            touch_id);
+void        gdk_touch_cluster_remove_touch (GdkTouchCluster *cluster,
+                                            guint            touch_id);
+void        gdk_touch_cluster_remove_all   (GdkTouchCluster *cluster);
+
+GList *     gdk_touch_cluster_get_touches  (GdkTouchCluster *cluster);
+
+void        gdk_touch_cluster_set_device   (GdkTouchCluster *cluster,
+                                            GdkDevice       *device);
+GdkDevice * gdk_touch_cluster_get_device   (GdkTouchCluster *cluster);
+
+G_END_DECLS
+
+#endif /* __GDK_TOUCH_CLUSTER_H__ */

gdk/gdktypes.h

@@ -288,6 +288,7 @@ typedef enum
  * @GDK_SUBSTRUCTURE_MASK: receive events about window configuration changes of
  *   child windows
  * @GDK_SCROLL_MASK: receive scroll events
+ * @GDK_TOUCH_MASK: receive (multi)touch events
  * @GDK_ALL_EVENTS_MASK: the combination of all the above event masks.
  *
  * A set of bit-flags to indicate which events a window is to receive.
@@ -327,7 +328,8 @@ typedef enum
   GDK_PROXIMITY_OUT_MASK        = 1 << 19,
   GDK_SUBSTRUCTURE_MASK         = 1 << 20,
   GDK_SCROLL_MASK               = 1 << 21,
-  GDK_ALL_EVENTS_MASK           = 0x3FFFFE
+  GDK_TOUCH_MASK                = 1 << 22,
+  GDK_ALL_EVENTS_MASK           = 0x3FFFFF
 } GdkEventMask;
 
 /**

gdk/gdkwindow.c

@@ -213,6 +213,11 @@ typedef struct {
   int dx, dy; /* The amount that the source was moved to reach dest_region */
 } GdkWindowRegionMove;
 
+typedef struct {
+  GdkEvent *event;          /* latest event for touch */
+  GdkTouchCluster *cluster; /* touch cluster the ID currently pertains to */
+} TouchEventInfo;
+
 /* Global info */
 
 static void             gdk_window_drop_cairo_surface (GdkWindow *private);
@@ -567,6 +572,12 @@ gdk_window_finalize (GObject *object)
   if (window->devices_inside)
     g_list_free (window->devices_inside);
 
+  if (window->touch_event_tracker)
+    g_hash_table_destroy (window->touch_event_tracker);
+
+  g_list_foreach (window->touch_clusters, (GFunc) g_object_unref, NULL);
+  g_list_free (window->touch_clusters);
+
   G_OBJECT_CLASS (parent_class)->finalize (object);
 }
 
@@ -8066,6 +8077,12 @@ static const guint type_masks[] = {
   0, /* GDK_OWNER_CHANGE = 34 */
   0, /* GDK_GRAB_BROKEN = 35 */
   0, /* GDK_DAMAGE = 36 */
+  GDK_TOUCH_MASK, /* GDK_TOUCH_MOTION                  = 37 */
+  GDK_TOUCH_MASK, /* GDK_TOUCH_PRESS                   = 38 */
+  GDK_TOUCH_MASK, /* GDK_TOUCH_RELEASE                 = 39 */
+  GDK_TOUCH_MASK, /* GDK_MULTITOUCH_ADDED              = 40 */
+  GDK_TOUCH_MASK, /* GDK_MULTITOUCH_REMOVED            = 41 */
+  GDK_TOUCH_MASK  /* GDK_MULTITOUCH_UPDATED            = 42 */
 };
 G_STATIC_ASSERT (G_N_ELEMENTS (type_masks) == GDK_EVENT_LAST);
 
@@ -8097,6 +8114,8 @@ is_button_type (GdkEventType type)
 	 type == GDK_2BUTTON_PRESS ||
 	 type == GDK_3BUTTON_PRESS ||
 	 type == GDK_BUTTON_RELEASE ||
+         type == GDK_TOUCH_PRESS ||
+         type == GDK_TOUCH_RELEASE ||
 	 type == GDK_SCROLL;
 }
 
@@ -8104,6 +8123,7 @@ static gboolean
 is_motion_type (GdkEventType type)
 {
   return type == GDK_MOTION_NOTIFY ||
+         type == GDK_TOUCH_MOTION ||
 	 type == GDK_ENTER_NOTIFY ||
 	 type == GDK_LEAVE_NOTIFY;
 }
@@ -8166,6 +8186,7 @@ _gdk_make_event (GdkWindow    *window,
   switch (type)
     {
     case GDK_MOTION_NOTIFY:
+    case GDK_TOUCH_MOTION:
       event->motion.time = the_time;
       event->motion.axes = NULL;
       event->motion.state = the_state;
@@ -8248,6 +8269,79 @@ _gdk_make_event (GdkWindow    *window,
   return event;
 }
 
+GdkEvent *
+gdk_make_multitouch_event (GdkWindow        *window,
+                           GdkEventType      type,
+                           GdkTouchCluster  *cluster,
+                           GdkDevice        *device,
+                           guint             touch_id,
+                           GdkEvent         *event_in_queue)
+{
+  GdkEvent *mt_event, *event = NULL;
+  gint i, n_touches, n_updated = -1;
+  GdkEventMotion **subevents;
+  TouchEventInfo *info;
+  GHashTable *by_touch;
+  GList *touches;
+
+  if (!window->touch_event_tracker)
+    return NULL;
+
+  by_touch = g_hash_table_lookup (window->touch_event_tracker, device);
+
+  if (by_touch)
+    {
+      info = g_hash_table_lookup (by_touch, GUINT_TO_POINTER (touch_id));
+      if (info)
+        event = info->event;
+    }
+
+  if (!event)
+    {
+      g_warning ("Creating a multitouch event but no input was pre-recorded");
+      return NULL;
+    }
+
+  /* Generate multitouch event */
+  mt_event = _gdk_make_event (window, type, event_in_queue, FALSE);
+  mt_event->multitouch.time = event->motion.time;
+  mt_event->multitouch.state = event->motion.state;
+  gdk_event_set_device (mt_event, gdk_event_get_device (event));
+  gdk_event_set_source_device (mt_event, gdk_event_get_source_device (event));
+
+  mt_event->multitouch.group = cluster;
+
+  /* Fill in individual motion sub-events */
+  touches = gdk_touch_cluster_get_touches (cluster);
+  n_touches = g_list_length (touches);
+  i = 0;
+
+  subevents = g_new0 (GdkEventMotion *, n_touches);
+
+  while (touches)
+    {
+      TouchEventInfo *subevent_info;
+      GdkEvent *subevent;
+
+      subevent_info = g_hash_table_lookup (by_touch, touches->data);
+      subevent = gdk_event_copy (subevent_info->event);
+      subevents[i] = (GdkEventMotion *) subevent;
+
+      if (subevent->motion.touch_id == touch_id)
+        n_updated = i;
+
+      touches = touches->next;
+      i++;
+    }
+
+  mt_event->multitouch.events = subevents;
+  mt_event->multitouch.n_updated_event = n_updated;
+  mt_event->multitouch.n_events = n_touches;
+  mt_event->multitouch.updated_touch_id = touch_id;
+
+  return mt_event;
+}
+
 static void
 send_crossing_event (GdkDisplay                 *display,
 		     GdkWindow                  *toplevel,
@@ -9092,6 +9186,127 @@ get_event_window (GdkDisplay                 *display,
   return NULL;
 }
 
+static TouchEventInfo *
+touch_event_info_new (void)
+{
+  return g_slice_new0 (TouchEventInfo);
+}
+
+static void
+touch_event_info_free (TouchEventInfo *info)
+{
+  if (info->event)
+    gdk_event_free (info->event);
+  g_slice_free (TouchEventInfo, info);
+}
+
+static TouchEventInfo *
+touch_event_info_lookup (GdkWindow *window,
+                         GdkDevice *device,
+                         guint      touch_id,
+                         gboolean   create)
+{
+  TouchEventInfo *info;
+  GHashTable *by_touch;
+
+  if (G_UNLIKELY (!window->touch_event_tracker))
+    window->touch_event_tracker = g_hash_table_new_full (NULL, NULL, NULL,
+                                                         (GDestroyNotify) g_hash_table_destroy);
+
+  by_touch = g_hash_table_lookup (window->touch_event_tracker, device);
+
+  if (!by_touch)
+    {
+      by_touch = g_hash_table_new_full (NULL, NULL, NULL,
+                                        (GDestroyNotify) touch_event_info_free);
+      g_hash_table_insert (window->touch_event_tracker, device, by_touch);
+    }
+
+  info = g_hash_table_lookup (by_touch, GUINT_TO_POINTER (touch_id));
+
+  if (create && !info)
+    {
+      info = touch_event_info_new ();
+      g_hash_table_insert (by_touch, GUINT_TO_POINTER (touch_id), info);
+    }
+
+  return info;
+}
+
+/* Stores touch event for posterior multitouch
+ * events generation, takes ownership of event
+ */
+static void
+store_touch_event (GdkWindow *window,
+                   GdkEvent  *event,
+                   guint      touch_id)
+{
+  GdkDevice *device, *source_device;
+  TouchEventInfo *info;
+
+  if (event->type != GDK_TOUCH_PRESS &&
+      event->type != GDK_TOUCH_RELEASE &&
+      event->type != GDK_TOUCH_MOTION)
+    return;
+
+  device = gdk_event_get_device (event);
+  source_device = gdk_event_get_source_device (event);
+
+  if (event->type == GDK_TOUCH_PRESS ||
+      event->type == GDK_TOUCH_RELEASE)
+    {
+      GdkEvent *new_event;
+
+      /* Create GDK_TOUCH_MOTION event from the available data */
+      new_event = gdk_event_new (GDK_TOUCH_MOTION);
+
+      if (event->button.window)
+        new_event->motion.window = g_object_ref (event->button.window);
+
+      new_event->motion.send_event = event->button.send_event;
+      new_event->motion.time = event->button.time;
+      new_event->motion.x = event->button.x;
+      new_event->motion.y = event->button.y;
+      new_event->motion.x_root = event->button.x_root;
+      new_event->motion.y_root = event->button.y_root;
+      new_event->motion.state = event->button.state;
+      new_event->motion.touch_id = event->button.touch_id;
+      new_event->motion.is_hint = FALSE;
+
+      gdk_event_set_device (new_event, device);
+      gdk_event_set_source_device (new_event, source_device);
+
+      new_event->motion.axes = g_memdup (event->button.axes,
+                                         sizeof (gdouble) * gdk_device_get_n_axes (device));
+
+      gdk_event_free (event);
+      event = new_event;
+    }
+
+  info = touch_event_info_lookup (window, source_device, touch_id, TRUE);
+  info->event = event;
+}
+
+static GdkTouchCluster *
+_gdk_window_lookup_touch_cluster (GdkWindow *window,
+                                  GdkEvent  *event)
+{
+  TouchEventInfo *info;
+  GdkDevice *device;
+  guint touch_id;
+
+  if (!gdk_event_get_touch_id (event, &touch_id))
+    return NULL;
+
+  device = gdk_event_get_source_device (event);
+  info = touch_event_info_lookup (window, device, touch_id, FALSE);
+
+  if (!info)
+    return NULL;
+
+  return info->cluster;
+}
+
 static gboolean
 proxy_pointer_event (GdkDisplay                 *display,
 		     GdkEvent                   *source_event,
@@ -9229,7 +9444,8 @@ proxy_pointer_event (GdkDisplay                 *display,
 				       serial, non_linear);
       _gdk_display_set_window_under_pointer (display, device, pointer_window);
     }
-  else if (source_event->type == GDK_MOTION_NOTIFY)
+  else if (source_event->type == GDK_MOTION_NOTIFY ||
+           source_event->type == GDK_TOUCH_MOTION)
     {
       GdkWindow *event_win;
       guint evmask;
@@ -9248,6 +9464,15 @@ proxy_pointer_event (GdkDisplay                 *display,
           gdk_window_get_device_events (event_win, device) == 0)
         return TRUE;
 
+      /* Block motion events coming from touch devices, only if
+       * the event mask allows both motion and touch events, since
+       * the latter will come right after.
+       */
+      if ((evmask & GDK_TOUCH_MASK) &&
+          gdk_device_get_source (source_device) == GDK_SOURCE_TOUCH &&
+          source_event->type == GDK_MOTION_NOTIFY)
+        return TRUE;
+
       is_hint = FALSE;
 
       if (event_win &&
@@ -9268,21 +9493,60 @@ proxy_pointer_event (GdkDisplay                 *display,
 	    }
 	}
 
-      if (event_win && !display->ignore_core_events)
-	{
-	  event = _gdk_make_event (event_win, GDK_MOTION_NOTIFY, source_event, FALSE);
-	  event->motion.time = time_;
-	  convert_toplevel_coords_to_window (event_win,
-					     toplevel_x, toplevel_y,
-					     &event->motion.x, &event->motion.y);
-	  event->motion.x_root = source_event->motion.x_root;
-	  event->motion.y_root = source_event->motion.y_root;
-	  event->motion.state = state;
-	  event->motion.is_hint = is_hint;
-	  event->motion.device = source_event->motion.device;
+      if (!event_win)
+        return TRUE;
+
+      if (!display->ignore_core_events)
+        {
+          GdkTouchCluster *cluster = NULL;
+          GdkEventType event_type;
+          guint touch_id;
+
+          if (gdk_event_get_touch_id (source_event, &touch_id))
+            cluster = _gdk_window_lookup_touch_cluster (event_win, source_event);
+
+          if (cluster)
+            event_type = GDK_TOUCH_MOTION;
+          else
+            event_type = source_event->type;
+
+          event = gdk_event_new (event_type);
+          event->any.window = g_object_ref (event_win);
+          event->any.send_event = source_event->any.send_event;
+          event->motion.time = time_;
+          convert_toplevel_coords_to_window (event_win,
+                                             toplevel_x, toplevel_y,
+                                             &event->motion.x, &event->motion.y);
+          event->motion.x_root = source_event->motion.x_root;
+          event->motion.y_root = source_event->motion.y_root;
+          event->motion.state = state;
+          event->motion.is_hint = is_hint;
+          event->motion.device = source_event->motion.device;
           event->motion.axes = g_memdup (source_event->motion.axes,
                                          sizeof (gdouble) * gdk_device_get_n_axes (source_event->motion.device));
+          event->motion.touch_id = touch_id;
           gdk_event_set_source_device (event, source_device);
+
+          if (cluster)
+            {
+              store_touch_event (event_win, event, touch_id);
+
+              /* Event is not added to the queue, instead it's stored
+               * in order to generate a multitouch event for the touch
+               * ID's cluster.
+               */
+              gdk_make_multitouch_event (event_win, GDK_MULTITOUCH_UPDATED,
+                                         cluster, source_device, touch_id,
+                                         source_event);
+            }
+          else
+            {
+              store_touch_event (event_win, gdk_event_copy (event), touch_id);
+
+              /* Just insert the event */
+              _gdk_event_queue_insert_after (gdk_window_get_display (event_win),
+                                             source_event, event);
+            }
 	}
     }
 
@@ -9299,7 +9563,8 @@ proxy_pointer_event (GdkDisplay                 *display,
 
 static gboolean
 proxy_button_event (GdkEvent *source_event,
-		    gulong serial)
+                    gulong    serial,
+                    gboolean *handle_ungrab)
 {
   GdkWindow *toplevel_window, *event_window;
   GdkWindow *event_win;
@@ -9313,6 +9578,7 @@ proxy_button_event (GdkEvent *source_event,
   GdkDisplay *display;
   GdkWindow *w;
   GdkDevice *device, *source_device;
+  GdkEventMask evmask;
 
   type = source_event->any.type;
   event_window = source_event->any.window;
@@ -9325,6 +9591,7 @@ proxy_button_event (GdkEvent *source_event,
   toplevel_window = convert_native_coords_to_toplevel (event_window,
 						       toplevel_x, toplevel_y,
 						       &toplevel_x, &toplevel_y);
+  *handle_ungrab = TRUE;
 
   if (type == GDK_BUTTON_PRESS &&
       !source_event->any.send_event &&
@@ -9368,7 +9635,20 @@ proxy_button_event (GdkEvent *source_event,
                                 device,
 				pointer_window,
 				type, state,
-				NULL, serial);
+				&evmask, serial);
+
+  /* Block button press/release events coming from touch devices, only if
+   * the event mask allows both normal and touch events, since
+   * the latter will come right after.
+   */
+  if ((evmask & GDK_TOUCH_MASK) &&
+      gdk_device_get_source (source_device) == GDK_SOURCE_TOUCH &&
+      source_event->type != GDK_TOUCH_PRESS &&
+      source_event->type != GDK_TOUCH_RELEASE)
+    {
+      *handle_ungrab = FALSE;
+      return TRUE;
+    }
 
   if (event_win == NULL || display->ignore_core_events)
     return TRUE;
@@ -9383,6 +9663,8 @@ proxy_button_event (GdkEvent *source_event,
     {
     case GDK_BUTTON_PRESS:
     case GDK_BUTTON_RELEASE:
+    case GDK_TOUCH_PRESS:
+    case GDK_TOUCH_RELEASE:
       event->button.button = source_event->button.button;
       convert_toplevel_coords_to_window (event_win,
 					 toplevel_x, toplevel_y,
@@ -9393,12 +9675,13 @@ proxy_button_event (GdkEvent *source_event,
       event->button.device = source_event->button.device;
       event->button.axes = g_memdup (source_event->button.axes,
                                      sizeof (gdouble) * gdk_device_get_n_axes (source_event->button.device));
+      event->button.touch_id = source_event->button.touch_id;
 
       gdk_event_set_source_device (event, source_device);
 
       if (type == GDK_BUTTON_PRESS)
 	_gdk_event_button_generate (display, event);
-      return TRUE;
+      break;
 
     case GDK_SCROLL:
       event->scroll.direction = source_event->scroll.direction;
@@ -9410,12 +9693,39 @@ proxy_button_event (GdkEvent *source_event,
       event->scroll.state = state;
       event->scroll.device = source_event->scroll.device;
       gdk_event_set_source_device (event, source_device);
-      return TRUE;
+      break;
 
     default:
       return FALSE;
     }
 
+  if (type == GDK_TOUCH_RELEASE)
+    {
+      GdkTouchCluster *cluster;
+      GHashTable *by_touch;
+      guint touch_id;
+
+      touch_id = source_event->button.touch_id;
+
+      /* Remove the touch ID from any touch cluster it could pertain to */
+      cluster = _gdk_window_lookup_touch_cluster (event_win, source_event);
+
+      if (cluster)
+        gdk_touch_cluster_remove_touch (cluster, touch_id);
+
+      /* Remove in any case the touch ID from the event tracker */
+      by_touch = g_hash_table_lookup (event_win->touch_event_tracker, source_device);
+
+      if (by_touch)
+        g_hash_table_remove (by_touch, GUINT_TO_POINTER (touch_id));
+
+      /* Only remove the grab if it was the last pending touch on the window */
+      *handle_ungrab = (g_hash_table_size (by_touch) == 0);
+    }
+  else if (type == GDK_TOUCH_PRESS)
+    store_touch_event (event_win, gdk_event_copy (event),
+                       event->button.touch_id);
+
   return TRUE; /* Always unlink original, we want to obey the emulated event mask */
 }
 
@@ -9504,7 +9814,7 @@ _gdk_windowing_got_event (GdkDisplay *display,
   GdkDeviceGrabInfo *button_release_grab;
   GdkPointerWindowInfo *pointer_info;
   GdkDevice *device, *source_device;
-  gboolean is_toplevel;
+  gboolean is_toplevel, handle_ungrab = TRUE;
 
   if (gdk_event_get_time (event) != GDK_CURRENT_TIME)
     display->last_event_time = gdk_event_get_time (event);
@@ -9630,7 +9940,9 @@ _gdk_windowing_got_event (GdkDisplay *display,
   pointer_info->toplevel_y = y;
   gdk_event_get_state (event, &pointer_info->state);
   if (event->type == GDK_BUTTON_PRESS ||
-      event->type == GDK_BUTTON_RELEASE)
+      event->type == GDK_BUTTON_RELEASE ||
+      event->type == GDK_TOUCH_PRESS ||
+      event->type == GDK_TOUCH_RELEASE)
     pointer_info->button = event->button.button;
 
   if (device &&
@@ -9645,9 +9957,12 @@ _gdk_windowing_got_event (GdkDisplay *display,
 					serial);
   else if (is_button_type (event->type))
     unlink_event = proxy_button_event (event,
-				       serial);
+                                       serial,
+                                       &handle_ungrab);
 
-  if (event->type == GDK_BUTTON_RELEASE &&
+  if (handle_ungrab &&
+      (event->type == GDK_BUTTON_RELEASE ||
+       event->type == GDK_TOUCH_RELEASE) &&
       !event->any.send_event)
     {
       button_release_grab =
@@ -10886,3 +11201,124 @@ gdk_property_delete (GdkWindow *window,
 {
   GDK_WINDOW_IMPL_GET_CLASS (window->impl)->delete_property (window, property);
 }
+
+static void
+touch_cluster_touch_added (GdkTouchCluster *cluster,
+                           guint            touch_id,
+                           gpointer         user_data)
+{
+  GdkWindow *window;
+  TouchEventInfo *info;
+  GHashTable *by_touch;
+  GdkDevice *device;
+
+  device = gdk_touch_cluster_get_device (cluster);
+
+  if (!device)
+    return;
+
+  window = user_data;
+  by_touch = g_hash_table_lookup (window->touch_event_tracker, device);
+  g_assert (by_touch != NULL);
+
+  info = g_hash_table_lookup (by_touch, GUINT_TO_POINTER (touch_id));
+
+  if (info->cluster == cluster)
+    return;
+
+  if (info->cluster)
+    {
+      /* Remove touch from old cluster, but keep the stored data around */
+      g_hash_table_steal (by_touch, GUINT_TO_POINTER (touch_id));
+
+      gdk_touch_cluster_remove_touch (info->cluster, touch_id);
+
+      g_hash_table_insert (by_touch,
+                           GUINT_TO_POINTER (touch_id),
+                           info);
+    }
+
+  info->cluster = cluster;
+  gdk_make_multitouch_event (window, GDK_MULTITOUCH_ADDED,
+                             cluster, device, touch_id,
+                             NULL);
+}
+
+static void
+touch_cluster_touch_removed (GdkTouchCluster *cluster,
+                             guint            touch_id,
+                             gpointer         user_data)
+{
+  GdkWindow *window;
+  GdkDevice *device;
+  GHashTable *by_touch;
+
+  window = user_data;
+  device = gdk_touch_cluster_get_device (cluster);
+  by_touch = g_hash_table_lookup (window->touch_event_tracker, device);
+
+  g_assert (by_touch != NULL);
+
+  gdk_make_multitouch_event (window, GDK_MULTITOUCH_REMOVED,
+                             cluster, device, touch_id,
+                             NULL);
+
+  g_hash_table_remove (by_touch, GUINT_TO_POINTER (touch_id));
+}
+
+/**
+ * gdk_window_create_touch_cluster:
+ * @window: a #GdkWindow
+ *
+ * Creates a #GdkTouchCluster associated to @window.
+ *
+ * Returns: (transfer none): a newly created @GdkTouchCluster. This
+ *          object is owned by @window and must be freed through
+ *          gdk_window_remove_touch_cluster().
+ **/
+GdkTouchCluster *
+gdk_window_create_touch_cluster (GdkWindow *window)
+{
+  GdkTouchCluster *cluster;
+
+  g_return_val_if_fail (GDK_IS_WINDOW (window), NULL);
+
+  cluster = g_object_new (GDK_TYPE_TOUCH_CLUSTER, NULL);
+  g_signal_connect (cluster, "touch-added",
+                    G_CALLBACK (touch_cluster_touch_added), window);
+  g_signal_connect (cluster, "touch-removed",
+                    G_CALLBACK (touch_cluster_touch_removed), window);
+
+  window->touch_clusters = g_list_prepend (window->touch_clusters, cluster);
+
+  return cluster;
+}
+
+/**
+ * gdk_window_remove_touch_cluster:
+ * @window: a #GdkWindow
+ * @cluster: a #GdkTouchCluster from @window
+ *
+ * Removes @cluster from @window. All contained touches will be
+ * removed one by one, causing %GDK_MULTITOUCH_REMOVED events
+ * for these before destroying @cluster.
+ **/
+void
+gdk_window_remove_touch_cluster (GdkWindow       *window,
+                                 GdkTouchCluster *cluster)
+{
+  g_return_if_fail (GDK_IS_WINDOW (window));
+  g_return_if_fail (GDK_IS_TOUCH_CLUSTER (cluster));
+
+  if (!window->touch_clusters ||
+      !g_list_find (window->touch_clusters, cluster))
+    return;
+
+  gdk_touch_cluster_remove_all (cluster);
+
+  g_signal_handlers_disconnect_by_func (cluster, "touch-added", window);
+  g_signal_handlers_disconnect_by_func (cluster, "touch-removed", window);
+
+  window->touch_clusters = g_list_remove (window->touch_clusters, cluster);
+  g_object_unref (cluster);
+}

gdk/gdkwindow.h

@@ -33,6 +33,7 @@
 
 #include <gdk/gdktypes.h>
 #include <gdk/gdkevents.h>
+#include <gdk/gdktouchcluster.h>
 
 G_BEGIN_DECLS
 
@@ -862,6 +863,11 @@ void       gdk_window_set_support_multidevice (GdkWindow *window,
                                                gboolean   support_multidevice);
 gboolean   gdk_window_get_support_multidevice (GdkWindow *window);
 
+/* Multitouch support */
+GdkTouchCluster * gdk_window_create_touch_cluster (GdkWindow       *window);
+void              gdk_window_remove_touch_cluster (GdkWindow       *window,
+                                                   GdkTouchCluster *cluster);
+
 G_END_DECLS
 
 #endif /* __GDK_WINDOW_H__ */

gdk/x11/gdkdevice-xi2.c

@@ -687,6 +687,17 @@ _gdk_x11_device_xi2_translate_event_mask (GdkEventMask  event_mask,
       XISetMask (mask, XI_FocusOut);
     }
 
+#ifdef XINPUT_2_1
+  if (event_mask & GDK_TOUCH_MASK)
+    {
+      XISetMask (mask, XI_TouchBegin);
+      XISetMask (mask, XI_TouchMotion);
+      XISetMask (mask, XI_TouchMotionUnowned);
+      XISetMask (mask, XI_TouchEnd);
+      XISetMask (mask, XI_TouchOwnership);
+    }
+#endif /* XINPUT_2_1 */
+
   return mask;
 }
 

gdk/x11/gdkdevicemanager-x11.c

@@ -47,7 +47,11 @@ _gdk_x11_device_manager_new (GdkDisplay *display)
           int major, minor;
 
           major = 2;
+#ifdef XINPUT_2_1
+	  minor = 1;
+#else
           minor = 0;
+#endif /* XINPUT_2_1 */
 
           if (!_gdk_disable_multidevice &&
               XIQueryVersion (xdisplay, &major, &minor) != BadRequest)

gdk/x11/gdkdevicemanager-xi2.c

@@ -147,8 +147,10 @@ _gdk_x11_device_manager_xi2_select_events (GdkDeviceManager *device_manager,
 static void
 translate_valuator_class (GdkDisplay          *display,
                           GdkDevice           *device,
-                          XIValuatorClassInfo *info,
-                          gint                 n_valuator)
+                          Atom                 valuator_label,
+                          gdouble              min,
+                          gdouble              max,
+                          gdouble              resolution)
 {
   static gboolean initialized = FALSE;
   static Atom label_atoms [GDK_AXIS_LAST] = { 0 };
@@ -169,24 +171,19 @@ translate_valuator_class (GdkDisplay          *display,
 
   for (i = GDK_AXIS_IGNORE; i <= GDK_AXIS_LAST; i++)
     {
-      if (label_atoms[i] == info->label)
+      if (label_atoms[i] == valuator_label)
         {
           use = i;
           break;
         }
     }
 
-  if (info->label != None)
-    label = gdk_x11_xatom_to_atom_for_display (display, info->label);
+  if (valuator_label != None)
+    label = gdk_x11_xatom_to_atom_for_display (display, valuator_label);
   else
     label = GDK_NONE;
 
-  _gdk_device_add_axis (device,
-                        label,
-                        use,
-                        info->min,
-                        info->max,
-                        info->resolution);
+  _gdk_device_add_axis (device, label, use, min, max, resolution);
 }
 
 static void
@@ -195,7 +192,7 @@ translate_device_classes (GdkDisplay      *display,
                           XIAnyClassInfo **classes,
                           guint            n_classes)
 {
-  gint i, n_valuator = 0;
+  gint i;
 
   g_object_freeze_notify (G_OBJECT (device));
 
@@ -217,11 +214,28 @@ translate_device_classes (GdkDisplay      *display,
           }
           break;
         case XIValuatorClass:
-          translate_valuator_class (display, device,
-                                    (XIValuatorClassInfo *) class_info,
-                                    n_valuator);
-          n_valuator++;
+          {
+            XIValuatorClassInfo *valuator_info = (XIValuatorClassInfo *) class_info;
+            translate_valuator_class (display, device,
+                                      valuator_info->label,
+                                      valuator_info->min,
+                                      valuator_info->max,
+                                      valuator_info->resolution);
+          }
           break;
+#ifdef XINPUT_2_1
+        case XITouchValuatorClass:
+          {
+            XITouchValuatorClassInfo *valuator_info = (XITouchValuatorClassInfo *) class_info;
+
+            translate_valuator_class (display, device,
+                                      valuator_info->label,
+                                      valuator_info->min,
+                                      valuator_info->max,
+                                      valuator_info->resolution);
+          }
+          break;
+#endif /* XINPUT_2_1 */
         default:
           /* Ignore */
           break;
@@ -256,6 +270,8 @@ create_device (GdkDeviceManager *device_manager,
       else if (strstr (tmp_name, "wacom") ||
                strstr (tmp_name, "pen"))
         input_source = GDK_SOURCE_PEN;
+      else if (strstr (tmp_name, "multitouch"))
+        input_source = GDK_SOURCE_TOUCH;
       else
         input_source = GDK_SOURCE_MOUSE;
 
@@ -883,6 +899,12 @@ get_event_window (GdkEventTranslator *translator,
     case XI_ButtonPress:
     case XI_ButtonRelease:
     case XI_Motion:
+#ifdef XINPUT_2_1
+    case XI_TouchMotion:
+    case XI_TouchMotionUnowned:
+    case XI_TouchBegin:
+    case XI_TouchEnd:
+#endif /* XINPUT_2_1 */
       {
         XIDeviceEvent *xev = (XIDeviceEvent *) ev;
 
@@ -1063,56 +1085,54 @@ gdk_x11_device_manager_xi2_translate_event (GdkEventTranslator *translator,
       break;
     case XI_ButtonPress:
     case XI_ButtonRelease:
+#ifdef XINPUT_2_1
+    case XI_TouchBegin:
+    case XI_TouchEnd:
+#endif /* XINPUT_2_1 */
       {
         XIDeviceEvent *xev = (XIDeviceEvent *) ev;
         GdkDevice *source_device;
 
-        switch (xev->detail)
+        if (ev->evtype == XI_ButtonPress &&
+            (xev->detail >= 4 && xev->detail <= 7))
           {
-          case 4:
-          case 5:
-          case 6:
-          case 7:
-             /* Button presses of button 4-7 are scroll events */
-            if (ev->evtype == XI_ButtonPress)
-              {
-                event->scroll.type = GDK_SCROLL;
+            /* Button presses of button 4-7 are scroll events */
+            event->scroll.type = GDK_SCROLL;
 
-                if (xev->detail == 4)
-                  event->scroll.direction = GDK_SCROLL_UP;
-                else if (xev->detail == 5)
-                  event->scroll.direction = GDK_SCROLL_DOWN;
-                else if (xev->detail == 6)
-                  event->scroll.direction = GDK_SCROLL_LEFT;
-                else
-                  event->scroll.direction = GDK_SCROLL_RIGHT;
+            if (xev->detail == 4)
+              event->scroll.direction = GDK_SCROLL_UP;
+            else if (xev->detail == 5)
+              event->scroll.direction = GDK_SCROLL_DOWN;
+            else if (xev->detail == 6)
+              event->scroll.direction = GDK_SCROLL_LEFT;
+            else
+              event->scroll.direction = GDK_SCROLL_RIGHT;
 
-                event->scroll.window = window;
-                event->scroll.time = xev->time;
-                event->scroll.x = (gdouble) xev->event_x;
-                event->scroll.y = (gdouble) xev->event_y;
-                event->scroll.x_root = (gdouble) xev->root_x;
-                event->scroll.y_root = (gdouble) xev->root_y;
+            event->scroll.window = window;
+            event->scroll.time = xev->time;
+            event->scroll.x = (gdouble) xev->event_x;
+            event->scroll.y = (gdouble) xev->event_y;
+            event->scroll.x_root = (gdouble) xev->root_x;
+            event->scroll.y_root = (gdouble) xev->root_y;
 
-                event->scroll.device = g_hash_table_lookup (device_manager->id_table,
-                                                            GUINT_TO_POINTER (xev->deviceid));
+            event->scroll.device = g_hash_table_lookup (device_manager->id_table,
+                                                        GUINT_TO_POINTER (xev->deviceid));
 
-                source_device = g_hash_table_lookup (device_manager->id_table,
-                                                     GUINT_TO_POINTER (xev->sourceid));
-                gdk_event_set_source_device (event, source_device);
+            source_device = g_hash_table_lookup (device_manager->id_table,
+                                                 GUINT_TO_POINTER (xev->sourceid));
+            gdk_event_set_source_device (event, source_device);
 
-                event->scroll.state = _gdk_x11_device_xi2_translate_state (&xev->mods, &xev->buttons, &xev->group);
-                break;
-              }
-            /* Button presses of button 4-7 are scroll events, so ignore the release */
-            else if (ev->evtype == XI_ButtonRelease)
-              {
-                return_val = FALSE;
-                break;
-              }
-            /* else (XI_ButtonRelease) fall thru */
-          default:
-            event->button.type = (ev->evtype == XI_ButtonPress) ? GDK_BUTTON_PRESS : GDK_BUTTON_RELEASE;
+            event->scroll.state = _gdk_x11_device_xi2_translate_state (&xev->mods, &xev->buttons, &xev->group);
+          }
+        else
+          {
+#ifdef XINPUT_2_1
+            if (ev->evtype == XI_TouchBegin ||
+                ev->evtype == XI_TouchEnd)
+              event->button.type = (ev->evtype == XI_TouchBegin) ? GDK_TOUCH_PRESS : GDK_TOUCH_RELEASE;
+            else
+#endif /* XINPUT_2_1 */
+              event->button.type = (ev->evtype == XI_ButtonPress) ? GDK_BUTTON_PRESS : GDK_BUTTON_RELEASE;
 
             event->button.window = window;
             event->button.time = xev->time;
@@ -1144,7 +1164,17 @@ gdk_x11_device_manager_xi2_translate_event (GdkEventTranslator *translator,
               }
 
             event->button.state = _gdk_x11_device_xi2_translate_state (&xev->mods, &xev->buttons, &xev->group);
-            event->button.button = xev->detail;
+
+#ifdef XINPUT_2_1
+            if (ev->evtype == XI_TouchBegin ||
+                ev->evtype == XI_TouchEnd)
+              {
+                event->button.button = 1;
+                event->button.touch_id = xev->detail;
+              }
+            else
+#endif /* XINPUT_2_1 */
+              event->button.button = xev->detail;
           }
 
         if (return_val == FALSE)
@@ -1161,11 +1191,32 @@ gdk_x11_device_manager_xi2_translate_event (GdkEventTranslator *translator,
         break;
       }
     case XI_Motion:
+#ifdef XINPUT_2_1
+    case XI_TouchMotion:
+    case XI_TouchMotionUnowned:
+      /* FIXME: Unowned events should be rollback-able,
+       * the easiest way to go could be just storing the
+       * events so they can be replayed in arrival order
+       * when an ownership event arrives, needs further
+       * investigation though.
+       */
+#endif /* XINPUT_2_1 */
       {
         XIDeviceEvent *xev = (XIDeviceEvent *) ev;
         GdkDevice *source_device;
 
-        event->motion.type = GDK_MOTION_NOTIFY;
+        if (ev->evtype == XI_Motion)
+          {
+            event->motion.touch_id = 0;
+            event->motion.type = GDK_MOTION_NOTIFY;
+          }
+#ifdef XINPUT_2_1
+        else
+          {
+            event->motion.touch_id = xev->detail;
+            event->motion.type = GDK_TOUCH_MOTION;
+          }
+#endif
 
         event->motion.window = window;
 
@@ -1252,6 +1303,7 @@ gdk_x11_device_manager_xi2_translate_event (GdkEventTranslator *translator,
 
         return_val = FALSE;
       }
+      break;
     default:
       return_val = FALSE;
       break;
@@ -1297,7 +1349,8 @@ gdk_x11_device_manager_xi2_get_handled_events (GdkEventTranslator *translator)
           GDK_BUTTON2_MOTION_MASK |
           GDK_BUTTON3_MOTION_MASK |
           GDK_BUTTON_MOTION_MASK |
-          GDK_FOCUS_CHANGE_MASK);
+          GDK_FOCUS_CHANGE_MASK |
+          GDK_TOUCH_MASK);
 }
 
 static void

gtk/gtkmain.c

@@ -1869,6 +1869,12 @@ gtk_main_do_event (GdkEvent *event)
     case GDK_BUTTON_RELEASE:
     case GDK_PROXIMITY_IN:
     case GDK_PROXIMITY_OUT:
+    case GDK_TOUCH_MOTION:
+    case GDK_TOUCH_PRESS:
+    case GDK_TOUCH_RELEASE:
+    case GDK_MULTITOUCH_ADDED:
+    case GDK_MULTITOUCH_REMOVED:
+    case GDK_MULTITOUCH_UPDATED:
       gtk_propagate_event (grab_widget, event);
       break;
 
@@ -1912,6 +1918,7 @@ gtk_main_do_event (GdkEvent *event)
       || event->type == GDK_DRAG_ENTER
       || event->type == GDK_GRAB_BROKEN
       || event->type == GDK_MOTION_NOTIFY
+      || event->type == GDK_TOUCH_MOTION
       || event->type == GDK_SCROLL)
     {
       _gtk_tooltip_handle_event (event);

gtk/gtkwidget.c

@@ -471,6 +471,7 @@ enum {
   QUERY_TOOLTIP,
   DRAG_FAILED,
   STYLE_UPDATED,
+  MULTITOUCH_EVENT,
   LAST_SIGNAL
 };
 
@@ -2844,6 +2845,15 @@ gtk_widget_class_init (GtkWidgetClass *klass)
 		  G_TYPE_BOOLEAN, 1,
 		  GDK_TYPE_EVENT | G_SIGNAL_TYPE_STATIC_SCOPE);
 
+  widget_signals[MULTITOUCH_EVENT] =
+    g_signal_new (I_("multitouch-event"),
+		  G_TYPE_FROM_CLASS (klass),
+		  G_SIGNAL_RUN_LAST,
+		  G_STRUCT_OFFSET (GtkWidgetClass, multitouch_event),
+		  _gtk_boolean_handled_accumulator, NULL,
+		  _gtk_marshal_BOOLEAN__BOXED,
+		  G_TYPE_BOOLEAN, 1,
+		  GDK_TYPE_EVENT | G_SIGNAL_TYPE_STATIC_SCOPE);
   /**
    * GtkWidget::query-tooltip:
    * @widget: the object which received the signal
@@ -5993,15 +6003,18 @@ gtk_widget_event_internal (GtkWidget *widget,
 	case GDK_BUTTON_PRESS:
 	case GDK_2BUTTON_PRESS:
 	case GDK_3BUTTON_PRESS:
+        case GDK_TOUCH_PRESS:
 	  signal_num = BUTTON_PRESS_EVENT;
 	  break;
 	case GDK_SCROLL:
 	  signal_num = SCROLL_EVENT;
 	  break;
 	case GDK_BUTTON_RELEASE:
+        case GDK_TOUCH_RELEASE:
 	  signal_num = BUTTON_RELEASE_EVENT;
 	  break;
 	case GDK_MOTION_NOTIFY:
+        case GDK_TOUCH_MOTION:
 	  signal_num = MOTION_NOTIFY_EVENT;
 	  break;
 	case GDK_DELETE:
@@ -6069,6 +6082,11 @@ gtk_widget_event_internal (GtkWidget *widget,
 	case GDK_DAMAGE:
 	  signal_num = DAMAGE_EVENT;
 	  break;
+        case GDK_MULTITOUCH_ADDED:
+        case GDK_MULTITOUCH_REMOVED:
+        case GDK_MULTITOUCH_UPDATED:
+          signal_num = MULTITOUCH_EVENT;
+          break;
 	default:
 	  g_warning ("gtk_widget_event(): unhandled event type: %d", event->type);
 	  signal_num = -1;

gtk/gtkwidget.h

@@ -423,6 +423,10 @@ struct _GtkWidgetClass
 
   void         (* style_updated)          (GtkWidget *widget);
 
+  /* Multitouch */
+  gboolean (* multitouch_event) (GtkWidget          *widget,
+                                 GdkEventMultiTouch *event);
+
   /*< private >*/
 
   /* Padding for future expansion */
@@ -433,7 +437,6 @@ struct _GtkWidgetClass
   void (*_gtk_reserved5) (void);
   void (*_gtk_reserved6) (void);
   void (*_gtk_reserved7) (void);
-  void (*_gtk_reserved8) (void);
 };
 
 struct _GtkWidgetAuxInfo