[gtk/wip/chergert/macos-fix-backdrop] macos: fix backdrop when displaying popover

[Christian Hergert <chergert src gnome org>]

commit c0ede8d46e1fa97926f7531c3c7cd3771793ff16
Author: Christian Hergert <christian hergert me>
Date:   Tue Feb 22 00:08:00 2022 -0800

    macos: fix backdrop when displaying popover
    
    Previously, the popover would cause the window to go into the :backdrop
    state which is not what we want for consistency with other platforms. This
    fixes that by walking up the surface chain when we get notified of
    loosing or acquiring "key" input from the display server.

 gdk/macos/gdkmacosdisplay.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)
---
diff --git a/gdk/macos/gdkmacosdisplay.c b/gdk/macos/gdkmacosdisplay.c
index f14a1b16f8..36f94f2b63 100644
--- a/gdk/macos/gdkmacosdisplay.c
+++ b/gdk/macos/gdkmacosdisplay.c
@@ -480,6 +480,21 @@ _gdk_macos_display_surface_became_key (GdkMacosDisplay *self,
   event = gdk_focus_event_new (GDK_SURFACE (surface), keyboard, TRUE);
   _gdk_event_queue_append (GDK_DISPLAY (self), event);
 
+  /* For each parent surface, we want them to look like they
+   * are also still focused, so ensure they have that same
+   * state associated with them.
+   */
+  if (GDK_IS_POPUP (surface))
+    {
+      for (GdkSurface *parent = GDK_SURFACE (surface)->parent;
+           parent != NULL;
+           parent = parent->parent)
+        {
+          if (GDK_IS_TOPLEVEL (parent))
+            gdk_synthesize_surface_state (parent, 0, GDK_TOPLEVEL_STATE_FOCUSED);
+        }
+    }
+
   /* We just became the active window.  Unlike X11, Mac OS X does
    * not send us motion events while the window does not have focus
    * ("is not key").  We send a dummy motion notify event now, so that
@@ -516,6 +531,21 @@ _gdk_macos_display_surface_resigned_key (GdkMacosDisplay *self,
                                 _gdk_display_get_next_serial (GDK_DISPLAY (self)));
     }
 
+  /* For each parent surface, we want them to look like they
+   * are also still focused, so ensure they have that same
+   * state associated with them.
+   */
+  if (GDK_IS_POPUP (surface))
+    {
+      for (GdkSurface *parent = GDK_SURFACE (surface)->parent;
+           parent != NULL;
+           parent = parent->parent)
+        {
+          if (GDK_IS_TOPLEVEL (parent))
+            gdk_synthesize_surface_state (parent, GDK_TOPLEVEL_STATE_FOCUSED, 0);
+        }
+    }
+
   _gdk_macos_display_clear_sorting (self);
 }