Use GDK's current window tracking when synthesizing events in GTK+

Add gdk_device_get_last_event_window(), and use to implement the window
tracking we need for synthesizing crossing events for sensitivity changes
and gtk grabs, rather than keeping the information in qdata and updating
it based when GTK+ gets events.

https://bugzilla.gnome.org/show_bug.cgi?id=726187

5 files changed, 71 insertions, 78 deletions

diff --git a/docs/reference/gdk/gdk3-sections.txt b/docs/reference/gdk/gdk3-sections.txt
index d23183a3dd..51963aa48c 100644
--- a/docs/reference/gdk/gdk3-sections.txt
+++ b/docs/reference/gdk/gdk3-sections.txt
@@ -736,6 +736,7 @@ GdkTimeCoord
 gdk_device_get_axis
 gdk_device_list_axes
 gdk_device_get_axis_value
+gdk_device_get_last_event_window
 
 <SUBSECTION Standard>
 GDK_TYPE_AXIS_USE
diff --git a/gdk/gdkdevice.c b/gdk/gdkdevice.c
index 9508a7be13..24499d7965 100644
--- a/gdk/gdkdevice.c
+++ b/gdk/gdkdevice.c
@@ -1717,3 +1717,30 @@ _gdk_device_window_at_position (GdkDevice        *device,
                                                             mask,
                                                             get_toplevel);
 }
+
+/**
+ * gdk_device_get_last_event_window:
+ * @device: a #GdkDevice, with a source other than %GDK_SOURCE_KEYBOARD
+ *
+ * Gets information about which window the given pointer device is in, based on
+ * that have been received so far from the display server. If another application
+ * has a pointer grab, or this application has a grab with owner_events = %FALSE,
+ * %NULL may be returned even if the pointer is physically over one of this
+ * application's windows.
+ *
+ * Returns: (transfer none) (allow-none): the last window the device
+ */
+GdkWindow *
+gdk_device_get_last_event_window (GdkDevice *device)
+{
+  GdkDisplay *display;
+  GdkPointerWindowInfo *info;
+
+  g_return_val_if_fail (GDK_IS_DEVICE (device), NULL);
+  g_return_val_if_fail (gdk_device_get_source (device) != GDK_SOURCE_KEYBOARD, NULL);
+
+  display = gdk_device_get_display (device);
+  info = _gdk_display_get_pointer_info (display, device);
+
+  return info->window_under_pointer;
+}
diff --git a/gdk/gdkdevice.h b/gdk/gdkdevice.h
index a67f4b5890..23b3551d09 100644
--- a/gdk/gdkdevice.h
+++ b/gdk/gdkdevice.h
@@ -271,6 +271,8 @@ gboolean gdk_device_grab_info_libgtk_only (GdkDisplay  *display,
                                            GdkWindow  **grab_window,
                                            gboolean    *owner_events);
 
+GDK_AVAILABLE_IN_3_12
+GdkWindow *gdk_device_get_last_event_window (GdkDevice *device);
 
 G_END_DECLS
 
diff --git a/gtk/gtkmain.c b/gtk/gtkmain.c
index c3367e1af4..9e8fea5817 100644
--- a/gtk/gtkmain.c
+++ b/gtk/gtkmain.c
@@ -1736,22 +1736,12 @@ gtk_main_do_event (GdkEvent *event)
       break;
 
     case GDK_ENTER_NOTIFY:
-      if (event->crossing.detail != GDK_NOTIFY_VIRTUAL &&
-          event->crossing.detail != GDK_NOTIFY_NONLINEAR_VIRTUAL)
-        _gtk_widget_set_device_window (event_widget,
-                                       gdk_event_get_device (event),
-                                       event->any.window);
       if (gtk_widget_is_sensitive (grab_widget) &&
           !_gtk_propagate_captured_event (grab_widget, event, topmost_widget))
         gtk_widget_event (grab_widget, event);
       break;
 
     case GDK_LEAVE_NOTIFY:
-      if (event->crossing.detail != GDK_NOTIFY_VIRTUAL &&
-          event->crossing.detail != GDK_NOTIFY_NONLINEAR_VIRTUAL)
-        _gtk_widget_set_device_window (event_widget,
-                                       gdk_event_get_device (event),
-                                       NULL);
       if (gtk_widget_is_sensitive (grab_widget) &&
           !_gtk_propagate_captured_event (grab_widget, event, topmost_widget))
         gtk_widget_event (grab_widget, event);
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index 5c691a1cbf..5488c66abd 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -855,7 +855,6 @@ static GQuark		quark_accel_closures = 0;
 static GQuark		quark_event_mask = 0;
 static GQuark           quark_device_event_mask = 0;
 static GQuark		quark_parent_window = 0;
-static GQuark		quark_pointer_window = 0;
 static GQuark		quark_shape_info = 0;
 static GQuark		quark_input_shape_info = 0;
 static GQuark		quark_pango_context = 0;
@@ -1022,7 +1021,6 @@ gtk_widget_class_init (GtkWidgetClass *klass)
   quark_event_mask = g_quark_from_static_string ("gtk-event-mask");
   quark_device_event_mask = g_quark_from_static_string ("gtk-device-event-mask");
   quark_parent_window = g_quark_from_static_string ("gtk-parent-window");
-  quark_pointer_window = g_quark_from_static_string ("gtk-pointer-window");
   quark_shape_info = g_quark_from_static_string ("gtk-shape-info");
   quark_input_shape_info = g_quark_from_static_string ("gtk-input-shape-info");
   quark_pango_context = g_quark_from_static_string ("gtk-pango-context");
@@ -4627,9 +4625,6 @@ gtk_widget_unmap (GtkWidget *widget)
       g_signal_emit (widget, widget_signals[UNMAP], 0);
 
       gtk_widget_pop_verify_invariants (widget);
-
-      /* Unset pointer/window info */
-      g_object_set_qdata (G_OBJECT (widget), quark_pointer_window, NULL);
     }
 }
 
@@ -11780,49 +11775,14 @@ _gtk_widget_peek_request_cache (GtkWidget *widget)
   return &widget->priv->requests;
 }
 
-/*
- * _gtk_widget_set_device_window:
- * @widget: a #GtkWidget
- * @device: a #GdkDevice
- * @window: the new device window
- *
- * Sets pointer window for @widget and @device.
- * Does not ref @window.
- */
-void
-_gtk_widget_set_device_window (GtkWidget *widget,
-                               GdkDevice *device,
-                               GdkWindow *window)
+static gboolean
+is_my_window (GtkWidget *widget,
+              GdkWindow *window)
 {
-  GHashTable *device_window;
-
-  g_return_if_fail (GTK_IS_WIDGET (widget));
-  g_return_if_fail (GDK_IS_DEVICE (device));
-  g_return_if_fail (window == NULL || GDK_IS_WINDOW (window));
-
-  if (!gtk_widget_get_mapped (widget))
-    return;
-
-  device_window = g_object_get_qdata (G_OBJECT (widget), quark_pointer_window);
-
-  if (!device_window && window)
-    {
-      device_window = g_hash_table_new (NULL, NULL);
-      g_object_set_qdata_full (G_OBJECT (widget),
-                               quark_pointer_window,
-                               device_window,
-                               (GDestroyNotify) g_hash_table_destroy);
-    }
-
-  if (window)
-    g_hash_table_insert (device_window, device, window);
-  else if (device_window)
-    {
-      g_hash_table_remove (device_window, device);
+  gpointer user_data;
 
-      if (g_hash_table_size (device_window) == 0)
-        g_object_set_qdata (G_OBJECT (widget), quark_pointer_window, NULL);
-    }
+  gdk_window_get_user_data (window, &user_data);
+  return (user_data == widget);
 }
 
 /*
@@ -11830,26 +11790,44 @@ _gtk_widget_set_device_window (GtkWidget *widget,
  * @widget: a #GtkWidget
  * @device: a #GdkDevice
  *
- * Returns: the device window set on @widget, or %NULL
+ * Returns: the window of @widget that @device is in, or %NULL
  */
 GdkWindow *
 _gtk_widget_get_device_window (GtkWidget *widget,
                                GdkDevice *device)
 {
-  GHashTable *device_window;
+  GdkWindow *window;
 
   g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);
   g_return_val_if_fail (GDK_IS_DEVICE (device), NULL);
 
-  if (!gtk_widget_get_mapped (widget))
+  window = gdk_device_get_last_event_window (device);
+  if (window && is_my_window (widget, window))
+    return window;
+  else
     return NULL;
+}
 
-  device_window = g_object_get_qdata (G_OBJECT (widget), quark_pointer_window);
-
-  if (!device_window)
-    return NULL;
+static void
+list_devices (GtkWidget        *widget,
+              GdkDeviceManager *device_manager,
+              GdkDeviceType     device_type,
+              GList           **result)
+{
+  GList *devices = gdk_device_manager_list_devices (device_manager, device_type);
+  GList *l;
 
-  return g_hash_table_lookup (device_window, device);
+  for (l = devices; l; l = l->next)
+    {
+      GdkDevice *device = l->data;
+      if (gdk_device_get_source (device) != GDK_SOURCE_KEYBOARD)
+        {
+          GdkWindow *window = gdk_device_get_last_event_window (device);
+          if (window && is_my_window (widget, window))
+            *result = g_list_prepend (*result, device);
+        }
+    }
+  g_list_free (devices);
 }
 
 /*
@@ -11864,27 +11842,22 @@ _gtk_widget_get_device_window (GtkWidget *widget,
 GList *
 _gtk_widget_list_devices (GtkWidget *widget)
 {
-  GHashTableIter iter;
-  GHashTable *device_window;
-  GList *devices = NULL;
-  gpointer key, value;
+  GdkDisplay *display;
+  GdkDeviceManager *device_manager;
+  GList *result = NULL;
 
   g_return_val_if_fail (GTK_IS_WIDGET (widget), NULL);
 
+  display = gtk_widget_get_display (widget);
+  device_manager = gdk_display_get_device_manager (display);
   if (!gtk_widget_get_mapped (widget))
     return NULL;
 
-  device_window = g_object_get_qdata (G_OBJECT (widget), quark_pointer_window);
+  list_devices (widget, device_manager, GDK_DEVICE_TYPE_MASTER, &result);
+  /* Rare, but we can get events for grabbed slave devices */
+  list_devices (widget, device_manager, GDK_DEVICE_TYPE_SLAVE, &result);
 
-  if (G_UNLIKELY (!device_window))
-    return NULL;
-
-  g_hash_table_iter_init (&iter, device_window);
-
-  while (g_hash_table_iter_next (&iter, &key, &value))
-    devices = g_list_prepend (devices, key);
-
-  return devices;
+  return result;
 }
 
 static void