GtkContainer: Propagate draws in GdkWindow order

Now that we're not drawing the GdkWindows by themeselves we need to
propagate into children in the same order as the windows were painted
otherwise apps can't rely on stacking order to overlay children.

This is still not 100% the same as the old behaviour, because we're
treating all windows that are part of a window at the same time (to allow
e.g. opacity groups), and we're only looking at order for the main
windows of a widget. However, this fixes at least the ordering
of the gnome-boxes fullscreen overlay toolbar.

https://bugzilla.gnome.org/show_bug.cgi?id=699970

diff --git a/gtk/gtkcontainer.c b/gtk/gtkcontainer.c
index dc81530908d436dae5b58879fe217ed071ba2586..49bd0930992268f454b62cf8b6271e2cd517785e 100644 (file)
--- a/gtk/gtkcontainer.c
+++ b/gtk/gtkcontainer.c
@@ -346,6 +346,9 @@ static void    gtk_container_buildable_custom_tag_end (GtkBuildable *buildable,
                                                        const gchar  *tagname,
                                                        gpointer     *data);
 
+static gboolean gtk_container_should_propagate_draw (GtkContainer   *container,
+                                                     GtkWidget      *child,
+                                                     cairo_t        *cr);
 
 /* --- variables --- */
 static const gchar           vadjustment_key[] = "gtk-vadjustment";
@@ -3261,36 +3264,82 @@ gtk_container_show_all (GtkWidget *widget)
   gtk_widget_show (widget);
 }
 
+typedef struct {
+  GtkWidget *child;
+  int window_depth;
+} ChildOrderInfo;
+
 static void
-gtk_container_draw_child (GtkWidget *child,
-                          gpointer   client_data)
+gtk_container_draw_forall (GtkWidget *widget,
+                           gpointer   client_data)
 {
   struct {
-    GtkWidget *container;
+    GtkContainer *container;
+    GArray *child_infos;
     cairo_t *cr;
   } *data = client_data;
+  ChildOrderInfo info;
+  GList *siblings;
+  GdkWindow *window;
 
-  gtk_container_propagate_draw (GTK_CONTAINER (data->container),
-                                child,
-                                data->cr);
+  if (gtk_container_should_propagate_draw (data->container, widget, data->cr))
+    {
+      info.child = widget;
+      info.window_depth = G_MAXINT;
+      if (gtk_widget_get_has_window (widget))
+        {
+          window = gtk_widget_get_window (widget);
+          siblings = gdk_window_peek_children (gdk_window_get_parent (window));
+          info.window_depth = g_list_index (siblings, window);
+        }
+      g_array_append_val (data->child_infos, info);
+    }
+}
+
+static gint
+compare_children_for_draw (gconstpointer  _a,
+                           gconstpointer  _b)
+{
+  const ChildOrderInfo *a = _a;
+  const ChildOrderInfo *b = _b;
+
+  return b->window_depth - a->window_depth;
 }
 
 static gint
 gtk_container_draw (GtkWidget *widget,
                     cairo_t   *cr)
 {
+  GtkContainer *container = GTK_CONTAINER (widget);
+  GArray *child_infos;
+  int i;
+  ChildOrderInfo *child_info;
   struct {
-    GtkWidget *container;
+    GtkContainer *container;
+    GArray *child_infos;
     cairo_t *cr;
   } data;
 
-  data.container = widget;
-  data.cr = cr;
+  child_infos = g_array_new (FALSE, TRUE, sizeof (ChildOrderInfo));
 
-  gtk_container_forall (GTK_CONTAINER (widget),
-                        gtk_container_draw_child,
+  data.container = container;
+  data.cr = cr;
+  data.child_infos = child_infos;
+  gtk_container_forall (container,
+                        gtk_container_draw_forall,
                         &data);
 
+  g_array_sort (child_infos, compare_children_for_draw);
+
+  for (i = 0; i < child_infos->len; i++)
+    {
+      child_info = &g_array_index (child_infos, ChildOrderInfo, i);
+      gtk_container_propagate_draw (container,
+                                    child_info->child, cr);
+    }
+
+  g_array_free (child_infos, TRUE);
+
   return FALSE;
 }
 
@@ -3335,6 +3384,39 @@ gtk_container_unmap (GtkWidget *widget)
                         NULL);
 }
 
+static gboolean
+gtk_container_should_propagate_draw (GtkContainer   *container,
+                                     GtkWidget      *child,
+                                     cairo_t        *cr)
+{
+  GdkEventExpose *event;
+  GdkWindow *event_window, *child_in_window;
+
+  if (!gtk_widget_is_drawable (child))
+    return FALSE;
+
+  /* Only propagate to native child window if we're not handling
+     an expose (i.e. in a pure gtk_widget_draw() call */
+  event = _gtk_cairo_get_event (cr);
+  if (event &&
+      (gtk_widget_get_has_window (child) &&
+       gdk_window_has_native (gtk_widget_get_window (child))))
+    return FALSE;
+
+  /* Never propagate to a child window when exposing a window
+     that is not the one the child widget is in. */
+  event_window = _gtk_cairo_get_event_window (cr);
+  if (gtk_widget_get_has_window (child))
+    child_in_window = gdk_window_get_parent (gtk_widget_get_window (child));
+  else
+    child_in_window = gtk_widget_get_window (child);
+  if (event_window != NULL && child_in_window != event_window)
+    return FALSE;
+
+  return TRUE;
+}
+
+
 /**
  * gtk_container_propagate_draw:
  * @container: a #GtkContainer
@@ -3364,9 +3446,8 @@ gtk_container_propagate_draw (GtkContainer   *container,
                               GtkWidget      *child,
                               cairo_t        *cr)
 {
-  GdkEventExpose *event;
   GtkAllocation allocation;
-  GdkWindow *window, *w, *event_window, *child_in_window;
+  GdkWindow *window, *w;
   int x, y;
 
   g_return_if_fail (GTK_IS_CONTAINER (container));
@@ -3375,25 +3456,7 @@ gtk_container_propagate_draw (GtkContainer   *container,
 
   g_assert (gtk_widget_get_parent (child) == GTK_WIDGET (container));
 
-  if (!gtk_widget_is_drawable (child))
-    return;
-
-  /* Only propagate to native child window if we're not handling
-     an expose (i.e. in a pure gtk_widget_draw() call */
-  event = _gtk_cairo_get_event (cr);
-  if (event &&
-      (gtk_widget_get_has_window (child) &&
-       gdk_window_has_native (gtk_widget_get_window (child))))
-    return;
-
-  /* Never propagate to a child window when exposing a window
-     that is not the one the child widget is in. */
-  event_window = _gtk_cairo_get_event_window (cr);
-  if (gtk_widget_get_has_window (child))
-    child_in_window = gdk_window_get_parent (gtk_widget_get_window (child));
-  else
-    child_in_window = gtk_widget_get_window (child);
-  if (event_window != NULL && child_in_window != event_window)
+  if (!gtk_container_should_propagate_draw (container, child, cr))
     return;
 
   cairo_save (cr);