[gtk/fix-unfocus-on-unmap] Fix unsetting focus

[Matthias Clasen <matthiasc src gnome org>]

commit 3dbf5038fab8eb0d8c112ad179c5647e0306656e
Author: Matthias Clasen <mclasen redhat com>
Date:   Fri Jan 29 21:41:16 2021 -0500

    Fix unsetting focus
    
    Make _gtk_window_unset_focus_and_default queue the changes
    for after the next draw. This achieves two things: first,
    it avoids invalidating css at the wrong time (e.g. when
    setting child-visible during size-allocation), and second,
    it defers the focus change until after the widget is
    hidden, so that moving the focus has the desired effect
    of picking a different, visible widget.
    
    Fixes: #3623

 gtk/gtkwindow.c | 59 ++++++++++++++++++++++++++++-----------------------------
 1 file changed, 29 insertions(+), 30 deletions(-)
---
diff --git a/gtk/gtkwindow.c b/gtk/gtkwindow.c
index 30f310197a..ac7f050738 100644
--- a/gtk/gtkwindow.c
+++ b/gtk/gtkwindow.c
@@ -225,6 +225,9 @@ typedef struct
 
   guint    hide_on_close             : 1;
   guint    in_emit_close_request     : 1;
+  guint    move_focus                : 1;
+  guint    unset_default             : 1;
+
 
   GtkGesture *click_gesture;
   GtkEventController *application_shortcut_controller;
@@ -4547,12 +4550,33 @@ surface_size_changed (GtkWidget *widget,
   gtk_widget_queue_allocate (widget);
 }
 
+static void
+maybe_unset_focus_and_default (GtkWindow *window)
+{
+  GtkWindowPrivate *priv = gtk_window_get_instance_private (window);
+
+  if (priv->move_focus)
+    {
+      gtk_widget_child_focus (GTK_WIDGET (window), GTK_DIR_TAB_FORWARD);
+      priv->move_focus = FALSE;
+    }
+
+  if (priv->unset_default)
+    {
+      gtk_window_set_default_widget (window, NULL);
+      priv->unset_default = FALSE;
+    }
+}
+
 static gboolean
 surface_render (GdkSurface     *surface,
                 cairo_region_t *region,
                 GtkWidget      *widget)
 {
+  GtkWindow *window = GTK_WINDOW (widget);
+
   gtk_widget_render (widget, surface, region);
+  maybe_unset_focus_and_default (window);
 
   return TRUE;
 }
@@ -4991,39 +5015,14 @@ _gtk_window_unset_focus_and_default (GtkWindow *window,
 {
   GtkWindowPrivate *priv = gtk_window_get_instance_private (window);
   GtkWidget *child;
-  GtkWidget *parent;
-  GtkWidget *focus;
 
-  g_object_ref (window);
-  g_object_ref (widget);
-
-  focus = priv->focus_widget;
-  if (focus && (focus == widget || gtk_widget_is_ancestor (focus, widget)))
-    {
-      parent = _gtk_widget_get_parent (widget);
-
-      while (parent)
-        {
-          if (_gtk_widget_get_visible (parent))
-            {
-              if (gtk_widget_grab_focus (parent))
-                break;
-            }
-
-          parent = gtk_widget_get_parent (parent);
-        }
-    }
+  child = priv->focus_widget;
+  if (child && (child == widget || gtk_widget_is_ancestor (child, widget)))
+    priv->move_focus = TRUE;
 
   child = priv->default_widget;
-
-  while (child && child != widget)
-    child = _gtk_widget_get_parent (child);
-
-  if (child == widget)
-    gtk_window_set_default_widget (window, NULL);
-
-  g_object_unref (widget);
-  g_object_unref (window);
+  if (child && (child == widget || gtk_widget_is_ancestor (child, widget)))
+    priv->unset_default = TRUE;
 }
 
 #undef INCLUDE_CSD_SIZE