shell/app: Add new get_icon() method

Now that we can always associate a GIcon with the app, add a method
to access it. While create_icon_texture() is still likely to be more
convenient in most cases, exposing the icon can still be useful, for
example to add it to a different kind of actor or to compare it with
other GIcons.

https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1342

src/shell-app.c

@@ -78,6 +78,7 @@ struct _ShellApp
                           * want (e.g. it will be of TYPE_NORMAL from
                           * the way shell-window-tracker.c works).
                           */
+  GIcon *fallback_icon;
 
   ShellAppRunningState *running_state;
 
@@ -180,11 +181,26 @@ window_backed_app_get_window (ShellApp     *app)
     return NULL;
 }
 
-static GIcon *
+/**
-window_backed_app_get_icon (ShellApp *app)
+ * shell_app_get_icon:
+ *
+ * Look up the icon for this application
+ *
+ * Return value: (transfer none): A #GIcon
+ */
+GIcon *
+shell_app_get_icon (ShellApp *app)
 {
   MetaWindow *window = NULL;
 
+  g_return_val_if_fail (SHELL_IS_APP (app), NULL);
+
+  if (app->info)
+    return g_app_info_get_icon (G_APP_INFO (app->info));
+
+  if (app->fallback_icon)
+    return app->fallback_icon;
+
   /* During a state transition from running to not-running for
    * window-backend apps, it's possible we get a request for the icon.
    * Avoid asserting here and just return a fallback icon
@@ -194,10 +210,18 @@ window_backed_app_get_icon (ShellApp *app)
 
   if (window &&
       meta_window_get_client_type (window) == META_WINDOW_CLIENT_TYPE_X11)
-    return st_texture_cache_bind_cairo_surface_property (st_texture_cache_get_default (),
+    {
+      app->fallback_icon =
+        st_texture_cache_bind_cairo_surface_property (st_texture_cache_get_default (),
                                                       G_OBJECT (window),
                                                       "icon");
-  return g_themed_icon_new ("application-x-executable");
+    }
+  else
+    {
+      app->fallback_icon = g_themed_icon_new ("application-x-executable");
+    }
+
+  return app->fallback_icon;
 }
 
 /**
@@ -212,26 +236,19 @@ ClutterActor *
 shell_app_create_icon_texture (ShellApp   *app,
                                int         size)
 {
-  g_autoptr (GIcon) icon = NULL;
+  GIcon *icon;
   ClutterActor *ret;
 
   ret = st_icon_new ();
   st_icon_set_icon_size (ST_ICON (ret), size);
   st_icon_set_fallback_icon_name (ST_ICON (ret), "application-x-executable");
 
-  if (app->info == NULL)
+  icon = shell_app_get_icon (app);
-    {
-      icon = window_backed_app_get_icon (app);
-      st_widget_add_style_class_name (ST_WIDGET (ret), "fallback-app-icon");
-    }
-  else
-    {
-      icon = g_app_info_get_icon (G_APP_INFO (app->info));
-      g_object_ref (icon);
-    }
-
   st_icon_set_gicon (ST_ICON (ret), icon);
 
+  if (shell_app_is_window_backed (app))
+    st_widget_add_style_class_name (ST_WIDGET (ret), "fallback-app-icon");
+
   return ret;
 }
 
@@ -1541,6 +1558,7 @@ shell_app_dispose (GObject *object)
   ShellApp *app = SHELL_APP (object);
 
   g_clear_object (&app->info);
+  g_clear_object (&app->fallback_icon);
 
   while (app->running_state)
     _shell_app_remove_window (app, app->running_state->windows->data);

src/shell-app.h

@@ -29,6 +29,7 @@ const char *shell_app_get_id (ShellApp *app);
 GDesktopAppInfo *shell_app_get_app_info (ShellApp *app);
 
 ClutterActor *shell_app_create_icon_texture (ShellApp *app, int size);
+GIcon *shell_app_get_icon (ShellApp *app);
 const char *shell_app_get_name (ShellApp *app);
 const char *shell_app_get_description (ShellApp *app);
 gboolean shell_app_is_window_backed (ShellApp *app);