window/x11: Add a is_ssd helper

Would be useful for moving frame field to WindowX11 in the upcoming commits

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3254>

src/core/constraints.c

@@ -91,7 +91,7 @@ constrain_whatever (MetaWindow         *window,
   // we know we can return TRUE here because we exited early
   // if the constraint could not be satisfied; not that the
   // return value is heeded in this case...
-  return TRUE; 
+  return TRUE;
 }
 ```
 */
@@ -709,9 +709,14 @@ update_onscreen_requirements (MetaWindow     *window,
   /* Update whether we want future constraint runs to require the
    * titlebar to be visible.
    */
-  if (window->frame && window->decorated)
+#ifdef HAVE_X11_CLIENT
+  if (window->client_type == META_WINDOW_CLIENT_TYPE_X11 && window->decorated)
     {
       MtkRectangle titlebar_rect, frame_rect;
+      MetaFrame *frame = meta_window_x11_get_frame (window);
+
+      if (!frame)
+        return;
 
       meta_window_get_titlebar_rect (window, &titlebar_rect);
       meta_window_get_frame_rect (window, &frame_rect);
@@ -730,6 +735,7 @@ update_onscreen_requirements (MetaWindow     *window,
                     window->desc,
                     window->require_titlebar_visible ? "TRUE" : "FALSE");
     }
+#endif
 }
 
 static inline void
@@ -1703,12 +1709,21 @@ constrain_to_single_monitor (MetaWindow         *window,
                              ConstraintPriority  priority,
                              gboolean            check_only)
 {
+  /* a quirk for x11 clients that tries to move their windows
+   * by themselves when doing interactive moves.
+   */
+  gboolean client_driven_interactive_move = TRUE;
   MetaMonitorManager *monitor_manager =
     meta_backend_get_monitor_manager (info->backend);
 
   if (priority > PRIORITY_ENTIRELY_VISIBLE_ON_SINGLE_MONITOR)
     return TRUE;
 
+#ifdef HAVE_X11_CLIENT
+  if (window->client_type == META_WINDOW_CLIENT_TYPE_X11)
+    client_driven_interactive_move = meta_window_x11_get_frame (window) == NULL;
+#endif
+
   /* Exit early if we know the constraint won't apply--note that this constraint
    * is only meant for normal windows (e.g. we don't want docks to be shoved
    * "onscreen" by their own strut) and we can't apply it to frameless windows
@@ -1718,7 +1733,7 @@ constrain_to_single_monitor (MetaWindow         *window,
       window->type == META_WINDOW_DOCK ||
       meta_monitor_manager_get_num_logical_monitors (monitor_manager) == 1 ||
       !window->require_on_single_monitor ||
-      !window->frame ||
+      client_driven_interactive_move ||
       info->is_user_action ||
       meta_window_get_placement_rule (window))
     return TRUE;

src/core/window.c

@@ -808,9 +808,11 @@ client_window_should_be_mapped (MetaWindow *window)
     }
 #endif
 
+#ifdef HAVE_X11_CLIENT
   if (window->client_type == META_WINDOW_CLIENT_TYPE_X11 &&
-      window->decorated && !window->frame)
+      window->decorated && !meta_window_x11_is_ssd (window))
     return FALSE;
+#endif
 
   return TRUE;
 }
@@ -1701,9 +1703,11 @@ meta_window_is_showable (MetaWindow *window)
     return FALSE;
 #endif
 
+#ifdef HAVE_X11_CLIENT
   if (window->client_type == META_WINDOW_CLIENT_TYPE_X11 &&
-      window->decorated && !window->frame)
+      window->decorated && !meta_window_x11_is_ssd (window))
     return FALSE;
+#endif
 
   return TRUE;
 }

src/x11/events.c

@@ -1483,7 +1483,7 @@ handle_other_xevent (MetaX11Display *x11_display,
               window = meta_x11_display_lookup_x_window (x11_display,
                                                          client_window);
 
-              if (window != NULL && window->decorated && !window->frame)
+              if (window != NULL && window->decorated && !meta_window_x11_is_ssd (window))
                 {
                   meta_window_x11_set_frame_xwindow (window,
                                                      event->xmaprequest.window);

src/x11/window-x11-private.h

@@ -133,4 +133,7 @@ void meta_window_x11_group_leader_changed (MetaWindow *window);
 
 void meta_window_x11_set_frame_xwindow (MetaWindow *window,
                                         Window      xframe);
+
+gboolean meta_window_x11_is_ssd (MetaWindow *window);
+
 G_END_DECLS

src/x11/window-x11.c

@@ -2035,6 +2035,13 @@ meta_window_x11_set_transient_for (MetaWindow *window,
   return TRUE;
 }
 
+gboolean
+meta_window_x11_is_ssd (MetaWindow *window)
+{
+  /* Will be updated in the next commits once frame field is moved to WindowX11 */
+  return window->frame != NULL;
+}
+
 static void
 meta_window_x11_constructed (GObject *object)
 {
@@ -2404,7 +2411,7 @@ meta_window_x11_update_input_region (MetaWindow *window)
 
   if (window->decorated)
     {
-      if (!window->frame)
+      if (!meta_window_x11_is_ssd (window))
         {
           if (priv->input_region)
             meta_window_set_input_region (window, NULL);
@@ -2689,7 +2696,7 @@ meta_window_move_resize_request (MetaWindow  *window,
 		  window->type);
     }
 
-  if (window->decorated && !window->frame)
+  if (window->decorated && !meta_window_x11_is_ssd (window))
     {
       width = new_width;
       height = new_height;
@@ -3921,7 +3928,7 @@ meta_window_x11_new (MetaDisplay       *display,
                                "effect", effect,
                                "attributes", &attrs,
                                "xwindow", xwindow,
-                               NULL);    
+                               NULL);
     }
   else
 #endif