window: Appear as focused while focusing

Prevent focused window from blinking after switching to another
workspace on X11.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/850

src/core/stack.c

@@ -34,6 +34,7 @@
 #include "core/frame.h"
 #include "core/main-private.h"
 #include "core/meta-workspace-manager-private.h"
+#include "core/workspace-private.h"
 #include "core/window-private.h"
 #include "meta/group.h"
 #include "meta/prefs.h"
@@ -1016,7 +1017,8 @@ window_contains_point (MetaWindow *window,
 }
 
 static gboolean
-window_can_get_default_focus (MetaWindow *window)
+window_can_get_default_focus (MetaWindow    *window,
+                              MetaWorkspace *workspace)
 {
   if (window->unmaps_pending > 0)
     return FALSE;
@@ -1027,7 +1029,10 @@ window_can_get_default_focus (MetaWindow *window)
   if (!meta_window_is_focusable (window))
     return FALSE;
 
-  if (!meta_window_should_be_showing (window))
+  if (!meta_window_showing_on_its_workspace (window))
+    return FALSE;
+
+  if (!meta_window_located_on_workspace (window, workspace))
     return FALSE;
 
   if (window->type == META_WINDOW_DOCK)
@@ -1063,7 +1068,7 @@ get_default_focus_window (MetaStack     *stack,
       if (window == not_this_one)
         continue;
 
-      if (!window_can_get_default_focus (window))
+      if (!window_can_get_default_focus (window, workspace))
         continue;
 
       if (must_be_at_point && !window_contains_point (window, root_x, root_y))
@@ -1134,7 +1139,7 @@ meta_stack_get_default_focus_candidates (MetaStack     *stack,
     {
       GList *next = l->next;
 
-      if (!window_can_get_default_focus (l->data))
+      if (!window_can_get_default_focus (l->data, workspace))
         windows = g_list_delete_link (windows, l);
 
       l = next;

src/core/window-private.h

@@ -550,6 +550,9 @@ struct _MetaWindow
   guint unmanage_idle_id;
 
   pid_t client_pid;
+
+  /* Prevent blinking when focusing */
+  gboolean focusing;
 };
 
 struct _MetaWindowClass
@@ -704,6 +707,8 @@ void        meta_window_get_session_geometry (MetaWindow  *window,
 
 void        meta_window_update_unfocused_button_grabs (MetaWindow *window);
 
+void        meta_window_appears_focused_changed (MetaWindow *window);
+
 void     meta_window_set_focused_internal (MetaWindow *window,
                                            gboolean    focused);
 

src/core/window.c

@@ -251,6 +251,10 @@ prefs_changed_callback (MetaPreference pref,
       meta_window_recalc_features (window);
       meta_window_queue (window, META_QUEUE_MOVE_RESIZE);
     }
+  else if (pref == META_PREF_FOCUS_MODE)
+    {
+      meta_window_appears_focused_changed (window);
+    }
 }
 
 static void
@@ -4778,6 +4782,10 @@ meta_window_focus (MetaWindow  *window,
       window = modal_transient;
     }
 
+  /* If the window was already appearing focused, but didn't have has_focus set,
+   * it will now briefly appear unfocused on X11. Set a flag to prevent that. */
+  window->focusing = TRUE;
+
   meta_window_flush_calc_showing (window);
 
   if ((!window->mapped || window->hidden) && !window->shaded)
@@ -4785,6 +4793,7 @@ meta_window_focus (MetaWindow  *window,
       meta_topic (META_DEBUG_FOCUS,
                   "Window %s is not showing, not focusing after all\n",
                   window->desc);
+      window->focusing = FALSE;
       return;
     }
 
@@ -4872,6 +4881,9 @@ set_workspace_state (MetaWindow    *window,
         }
     }
 
+  if (!window->constructing)
+    meta_window_appears_focused_changed (window);
+
   /* queue a move_resize since changing workspaces may change
    * the relevant struts
    */
@@ -5171,7 +5183,7 @@ meta_window_change_workspace_by_index (MetaWindow *window,
     meta_window_change_workspace (window, workspace);
 }
 
-static void
+void
 meta_window_appears_focused_changed (MetaWindow *window)
 {
   set_net_wm_state (window);
@@ -5267,6 +5279,8 @@ meta_window_set_focused_internal (MetaWindow *window,
 {
   MetaWorkspaceManager *workspace_manager = window->display->workspace_manager;
 
+  window->focusing = FALSE;
+
   if (focused)
     {
       window->has_focus = TRUE;
@@ -7255,7 +7269,17 @@ meta_window_get_frame (MetaWindow *window)
 gboolean
 meta_window_appears_focused (MetaWindow *window)
 {
-  return window->has_focus || (window->attached_focus_window != NULL);
+  MetaWorkspaceManager *workspace_manager;
+  MetaWorkspace *workspace;
+  MetaWindow *default_window = NULL;
+
+  workspace_manager = window->display->workspace_manager;
+  workspace = meta_window_get_workspace (window);
+
+  if (workspace && workspace != workspace_manager->active_workspace)
+    default_window = meta_workspace_get_default_focus_window (workspace);
+
+  return window->has_focus || window->focusing || (window->attached_focus_window != NULL) || (window == default_window);
 }
 
 gboolean

src/core/workspace-private.h

@@ -92,6 +92,7 @@ GList* meta_workspace_get_onscreen_region       (MetaWorkspace *workspace);
 GList * meta_workspace_get_onmonitor_region (MetaWorkspace      *workspace,
                                              MetaLogicalMonitor *logical_monitor);
 
+MetaWindow* meta_workspace_get_default_focus_window (MetaWorkspace *workspace);
 void meta_workspace_focus_default_window (MetaWorkspace *workspace,
                                           MetaWindow    *not_this_one,
                                           guint32        timestamp);

src/core/workspace.c

@@ -365,10 +365,27 @@ meta_workspace_remove (MetaWorkspace *workspace)
    */
 }
 
+static void
+workspace_default_focus_changed (MetaWorkspace *workspace,
+                                 MetaWindow    *not_this_one)
+{
+  GSList *windows, *l;
+
+  windows = meta_display_list_windows (workspace->display, META_LIST_DEFAULT);
+  for (l = windows; l; l = l->next) {
+    MetaWindow *window = META_WINDOW (l->data);
+
+    if (meta_window_located_on_workspace (window, workspace) && window != not_this_one)
+      meta_window_appears_focused_changed (window);
+  }
+}
+
 void
 meta_workspace_add_window (MetaWorkspace *workspace,
                            MetaWindow    *window)
 {
+  MetaWorkspaceManager *manager = workspace->display->workspace_manager;
+
   COGL_TRACE_BEGIN_SCOPED (MetaWorkspaceAddWindow,
                            "Workspace (add window)");
 
@@ -385,6 +402,9 @@ meta_workspace_add_window (MetaWorkspace *workspace,
       meta_workspace_invalidate_work_area (workspace);
     }
 
+  if (workspace != manager->active_workspace)
+    workspace_default_focus_changed (workspace, window);
+
   g_signal_emit (workspace, signals[WINDOW_ADDED], 0, window);
   g_object_notify_by_pspec (G_OBJECT (workspace), obj_props[PROP_N_WINDOWS]);
 }
@@ -393,6 +413,8 @@ void
 meta_workspace_remove_window (MetaWorkspace *workspace,
                               MetaWindow    *window)
 {
+  MetaWorkspaceManager *manager = workspace->display->workspace_manager;
+
   COGL_TRACE_BEGIN_SCOPED (MetaWorkspaceRemoveWindow,
                            "Workspace (remove window)");
 
@@ -409,6 +431,9 @@ meta_workspace_remove_window (MetaWorkspace *workspace,
       meta_workspace_invalidate_work_area (workspace);
     }
 
+  if (workspace != manager->active_workspace)
+    workspace_default_focus_changed (workspace, window);
+
   g_signal_emit (workspace, signals[WINDOW_REMOVED], 0, window);
   g_object_notify (G_OBJECT (workspace), "n-windows");
 }
@@ -657,6 +682,7 @@ meta_workspace_activate_with_focus (MetaWorkspace *workspace,
   if (focus_this)
     {
       meta_window_activate (focus_this, timestamp);
+      workspace_default_focus_changed (workspace, focus_this);
     }
   else if (move_window)
     {
@@ -1281,6 +1307,15 @@ meta_workspace_get_name (MetaWorkspace *workspace)
   return meta_prefs_get_workspace_name (meta_workspace_index (workspace));
 }
 
+MetaWindow *
+meta_workspace_get_default_focus_window (MetaWorkspace *workspace)
+{
+  if (meta_prefs_get_focus_mode () == G_DESKTOP_FOCUS_MODE_CLICK)
+    return meta_stack_get_default_focus_window (workspace->display->stack, workspace, NULL);
+
+  return NULL;
+}
+
 void
 meta_workspace_focus_default_window (MetaWorkspace *workspace,
                                      MetaWindow    *not_this_one,