[gtk+] wayland: Update parent of dialogs without transient

[Olivier Fourdan <ofourdan src gnome org>]

commit 120088b15f082c2da62a8cea25ba7da53ddb69d6
Author: Olivier Fourdan <ofourdan redhat com>
Date:   Tue Dec 8 16:33:45 2015 +0100

    wayland: Update parent of dialogs without transient
    
    X11 has the notions of "transient for group", and while it's an ICCCM
    violation, it's commonly used and documented that a window manager
    would treat a window with transient_for set to None to transient for all
    windows of its group.
    
    gtk uses this when an application sets a dialog type window but does not
    specify an explicit transient.
    
    While this works on X11, there is no such thing as groups in Wayland and
    the closest equivalent which is set_parent() in xdg-shell takes only one
    parent. This is what is used for modal dialogs.
    
    To get something similar in behavior to what is available on X11, a
    solution is to update the parent() of the dialogs without transient when
    the active surface changes.
    
    Bugzilla: https://bugzilla.gnome.org/show_bug.cgi?id=759161

 gdk/wayland/gdkwindow-wayland.c |   69 +++++++++++++++++++++++++++++++++++---
 1 files changed, 63 insertions(+), 6 deletions(-)
---
diff --git a/gdk/wayland/gdkwindow-wayland.c b/gdk/wayland/gdkwindow-wayland.c
index 1e88633..8e74ef4 100644
--- a/gdk/wayland/gdkwindow-wayland.c
+++ b/gdk/wayland/gdkwindow-wayland.c
@@ -182,6 +182,16 @@ _gdk_window_impl_wayland_init (GdkWindowImplWayland *impl)
   impl->initial_fullscreen_monitor = -1;
 }
 
+/* Keep a list of orphaned dialogs (i.e. without parent) */
+static GList *orphan_dialogs;
+
+static void
+_gdk_wayland_screen_add_orphan_dialog (GdkWindow *window)
+{
+  if (!g_list_find (orphan_dialogs, window))
+    orphan_dialogs = g_list_prepend (orphan_dialogs, window);
+}
+
 /*
  * gdk_wayland_window_update_size:
  * @drawable: a #GdkDrawableImplWayland.
@@ -714,18 +724,23 @@ gdk_wayland_window_configure (GdkWindow *window,
 }
 
 static void
-gdk_wayland_window_sync_parent (GdkWindow *window)
+gdk_wayland_window_sync_parent (GdkWindow *window,
+                                GdkWindow *parent)
 {
   GdkWindowImplWayland *impl = GDK_WINDOW_IMPL_WAYLAND (window->impl);
+  GdkWindowImplWayland *impl_parent = NULL;
   struct xdg_surface *parent_surface;
 
   if (!impl->xdg_surface)
     return;
 
   if (impl->transient_for)
-    {
-      GdkWindowImplWayland *impl_parent = GDK_WINDOW_IMPL_WAYLAND (impl->transient_for->impl);
+    impl_parent = GDK_WINDOW_IMPL_WAYLAND (impl->transient_for->impl);
+  else if (parent)
+    impl_parent = GDK_WINDOW_IMPL_WAYLAND (parent->impl);
 
+  if (impl_parent)
+    {
       /* XXX: Is this correct? */
       if (!impl_parent->surface)
         return;
@@ -739,6 +754,31 @@ gdk_wayland_window_sync_parent (GdkWindow *window)
 }
 
 static void
+gdk_wayland_window_update_dialogs (GdkWindow *window)
+{
+  GList *l;
+
+  if (!orphan_dialogs)
+    return;
+
+  for (l = orphan_dialogs; l; l = l->next)
+    {
+      GdkWindow *w = l->data;
+      GdkWindowImplWayland *impl = GDK_WINDOW_IMPL_WAYLAND (w->impl);
+
+      if (w == window)
+       continue;
+      if (impl->hint != GDK_WINDOW_TYPE_HINT_DIALOG)
+        continue;
+      if (impl->transient_for)
+        continue;
+
+      /* Update the parent relationship only for dialogs without transients */
+      gdk_wayland_window_sync_parent (w, window);
+    }
+}
+
+static void
 gdk_wayland_window_sync_title (GdkWindow *window)
 {
   GdkWindowImplWayland *impl = GDK_WINDOW_IMPL_WAYLAND (window->impl);
@@ -991,6 +1031,9 @@ xdg_surface_configure (void               *data,
   _gdk_set_window_state (window, new_state);
   gdk_wayland_window_sync_margin (window);
   xdg_surface_ack_configure (xdg_surface, serial);
+  if (impl->hint != GDK_WINDOW_TYPE_HINT_DIALOG &&
+      new_state & GDK_WINDOW_STATE_FOCUSED)
+    gdk_wayland_window_update_dialogs (window);
 }
 
 static void
@@ -1032,7 +1075,7 @@ gdk_wayland_window_create_xdg_surface (GdkWindow *window)
   impl->xdg_surface = xdg_shell_get_xdg_surface (display_wayland->xdg_shell, impl->surface);
   xdg_surface_add_listener (impl->xdg_surface, &xdg_surface_listener, window);
 
-  gdk_wayland_window_sync_parent (window);
+  gdk_wayland_window_sync_parent (window, NULL);
   gdk_wayland_window_sync_title (window);
   gdk_wayland_window_sync_margin (window);
 
@@ -1049,6 +1092,9 @@ gdk_wayland_window_create_xdg_surface (GdkWindow *window)
 
   maybe_set_gtk_surface_dbus_properties (window);
   maybe_set_gtk_surface_modal (window);
+
+  if (impl->hint == GDK_WINDOW_TYPE_HINT_DIALOG)
+    _gdk_wayland_screen_add_orphan_dialog (window);
 }
 
 static void
@@ -1537,6 +1583,9 @@ gdk_wayland_window_hide_surface (GdkWindow *window)
 
       g_slist_free (impl->outputs);
       impl->outputs = NULL;
+
+      if (impl->hint == GDK_WINDOW_TYPE_HINT_DIALOG && !impl->transient_for)
+        orphan_dialogs = g_list_remove (orphan_dialogs, window);
     }
 
   impl->pending_commit = FALSE;
@@ -1986,6 +2035,7 @@ gdk_wayland_window_set_transient_for (GdkWindow *window,
                                       GdkWindow *parent)
 {
   GdkWindowImplWayland *impl = GDK_WINDOW_IMPL_WAYLAND (window->impl);
+  GdkWindow *previous_parent;
 
   if (check_transient_for_loop (window, parent))
     {
@@ -1996,10 +2046,17 @@ gdk_wayland_window_set_transient_for (GdkWindow *window,
   if (impl->subsurface)
     unmap_subsurface (window);
 
+  previous_parent = impl->transient_for;
   impl->transient_for = parent;
 
-  gdk_wayland_window_sync_parent (window);
-
+  if (impl->hint == GDK_WINDOW_TYPE_HINT_DIALOG)
+    {
+      if (!parent)
+        _gdk_wayland_screen_add_orphan_dialog (window);
+      else if (!previous_parent)
+        orphan_dialogs = g_list_remove (orphan_dialogs, window);
+    }
+  gdk_wayland_window_sync_parent (window, NULL);
   if (should_map_as_subsurface (window) &&
       parent && gdk_window_is_visible (window))
     gdk_wayland_window_create_subsurface (window);