Lazy update the launcher menu.

When selecting files, the menu is lazy update to reduce
the ammount of calls for the possible applications.

Updates are force when the menu is shown or an action is
executed.

thunar/thunar-launcher.c

@@ -949,7 +949,7 @@ thunar_launcher_update_idle (gpointer data)
            * Unfortunately this is not supported by GIO directly */
 
           /* drop the default application from the list */
-          applications = g_list_remove (applications, applications->data);
+          applications = g_list_delete_link (applications, applications);
         }
       else if (G_UNLIKELY (n_selected_files == 1))
         {
@@ -1048,6 +1048,13 @@ thunar_launcher_update_idle (gpointer data)
 
       /* FIXME Add desktop actions here. Unfortunately they are not supported by
        * GIO, so we'll have to roll our own thing here */
+
+      /* schedule an update of the "Send To" menu */
+      if (G_LIKELY (launcher->sendto_idle_id == 0))
+        {
+          launcher->sendto_idle_id = g_idle_add_full (G_PRIORITY_LOW, thunar_launcher_sendto_idle,
+                                                      launcher, thunar_launcher_sendto_idle_destroy);
+        }
     }
 
   return FALSE;
@@ -1063,21 +1070,74 @@ thunar_launcher_update_idle_destroy (gpointer data)
 
 
 
+static void
+thunar_launcher_update_check (ThunarLauncher *launcher)
+{
+  _thunar_return_if_fail (THUNAR_IS_LAUNCHER (launcher));
+
+  /* check if the menu is in a dirty state */
+  if (launcher->launcher_idle_id != 0)
+    {
+      /* stop the timeout */
+      g_source_remove (launcher->launcher_idle_id);
+
+      /* force an update */
+      thunar_launcher_update_idle (launcher);
+
+      /* ui update */
+      gtk_ui_manager_ensure_update (launcher->ui_manager);
+    }
+}
+
+
+
 static void
 thunar_launcher_update (ThunarLauncher *launcher)
 {
-  /* schedule an update of the launcher items */
-  if (G_LIKELY (launcher->launcher_idle_id == 0))
+  GSList    *proxies, *lp;
+  GtkWidget *menu;
+  gboolean   instant_update;
+
+  _thunar_return_if_fail (THUNAR_IS_LAUNCHER (launcher));
+
+  proxies = gtk_action_get_proxies (launcher->action_open);
+  instant_update = (proxies == NULL);
+  for (lp = proxies; lp != NULL; lp = lp->next)
     {
-      launcher->launcher_idle_id = g_idle_add_full (G_PRIORITY_LOW, thunar_launcher_update_idle,
-                                                    launcher, thunar_launcher_update_idle_destroy);
+      menu = gtk_widget_get_toplevel (lp->data);
+      if (G_LIKELY (menu != NULL))
+        {
+          /* instant update if a menu is visible */
+          if (gtk_widget_get_visible (menu))
+            instant_update = TRUE;
+
+          /* watch menu changes */
+          g_signal_handlers_disconnect_by_func (G_OBJECT (menu), G_CALLBACK (thunar_launcher_update_check), launcher);
+          g_signal_connect_swapped (G_OBJECT (menu), "show", G_CALLBACK (thunar_launcher_update_check), launcher);
+        }
     }
 
-  /* schedule an update of the "Send To" menu */
-  if (G_LIKELY (launcher->sendto_idle_id == 0))
+  /* stop pending timeouts */
+  if (launcher->launcher_idle_id != 0)
+    g_source_remove (launcher->launcher_idle_id);
+
+  if (instant_update)
+    {
+      /* directly update without interruption */
+      thunar_launcher_update_idle (launcher);
+    }
+  else
     {
-      launcher->sendto_idle_id = g_idle_add_full (G_PRIORITY_LOW + 50, thunar_launcher_sendto_idle,
-                                                  launcher, thunar_launcher_sendto_idle_destroy);
+      /* assume all actions are working */
+      gtk_action_set_sensitive (launcher->action_open, TRUE);
+      gtk_action_set_visible (launcher->action_open_with_other, TRUE);
+      gtk_action_set_visible (launcher->action_open_in_new_window, TRUE);
+      gtk_action_set_visible (launcher->action_open_in_new_tab, TRUE);
+      gtk_action_set_visible (launcher->action_open_with_other_in_menu, TRUE);
+
+      /* delayed update */
+      launcher->launcher_idle_id = g_timeout_add_seconds_full (G_PRIORITY_LOW, 5, thunar_launcher_update_idle,
+                                                               launcher, thunar_launcher_update_idle_destroy);
     }
 }
 
@@ -1263,6 +1323,11 @@ thunar_launcher_action_open (GtkAction      *action,
   _thunar_return_if_fail (GTK_IS_ACTION (action));
   _thunar_return_if_fail (THUNAR_IS_LAUNCHER (launcher));
 
+  /* force update if still dirty */
+  thunar_launcher_update_check (launcher);
+  if (!gtk_action_get_sensitive (action))
+    return;
+
   /* check if we have a mime handler associated with the action */
   app_info = g_object_get_qdata (G_OBJECT (action), thunar_launcher_handler_quark);
   if (G_LIKELY (app_info != NULL))
@@ -1272,19 +1337,22 @@ thunar_launcher_action_open (GtkAction      *action,
       thunar_launcher_open_paths (app_info, selected_paths, launcher);
       thunar_g_file_list_free (selected_paths);
     }
-  else if (g_list_length (launcher->selected_files) == 1)
-    {
-      thunar_browser_poke_file (THUNAR_BROWSER (launcher),
-                                launcher->selected_files->data, launcher->widget,
-                                thunar_launcher_poke_file_finish, NULL);
-    }
-  else
+  else if (launcher->selected_files != NULL)
     {
-      /* resolve files one after another until none is left. Open/execute
-       * the resolved files/directories when all this is done at a later
-       * stage */
-      poke_data = thunar_launcher_poke_data_new (launcher->selected_files);
-      thunar_launcher_poke_files (launcher, poke_data);
+      if (launcher->selected_files->next == NULL)
+        {
+          thunar_browser_poke_file (THUNAR_BROWSER (launcher),
+                                    launcher->selected_files->data, launcher->widget,
+                                    thunar_launcher_poke_file_finish, NULL);
+        }
+      else
+        {
+          /* resolve files one after another until none is left. Open/execute
+           * the resolved files/directories when all this is done at a later
+           * stage */
+           poke_data = thunar_launcher_poke_data_new (launcher->selected_files);
+           thunar_launcher_poke_files (launcher, poke_data);
+        }
     }
 }
 
@@ -1297,6 +1365,11 @@ thunar_launcher_action_open_with_other (GtkAction      *action,
   _thunar_return_if_fail (GTK_IS_ACTION (action));
   _thunar_return_if_fail (THUNAR_IS_LAUNCHER (launcher));
 
+  /* force update if still dirty */
+  thunar_launcher_update_check (launcher);
+  if (!gtk_action_get_visible (action))
+    return;
+
   /* verify that we have atleast one selected file */
   if (G_LIKELY (launcher->selected_files != NULL))
     {
@@ -1314,6 +1387,11 @@ thunar_launcher_action_open_in_new_window (GtkAction      *action,
   _thunar_return_if_fail (GTK_IS_ACTION (action));
   _thunar_return_if_fail (THUNAR_IS_LAUNCHER (launcher));
 
+  /* force update if still dirty */
+  thunar_launcher_update_check (launcher);
+  if (!gtk_action_get_visible (action))
+    return;
+
   /* open the selected directories in new windows */
   thunar_launcher_open_windows (launcher, launcher->selected_files);
 }
@@ -1330,6 +1408,11 @@ thunar_launcher_action_open_in_new_tab (GtkAction      *action,
   _thunar_return_if_fail (GTK_IS_ACTION (action));
   _thunar_return_if_fail (THUNAR_IS_LAUNCHER (launcher));
 
+  /* force update if still dirty */
+  thunar_launcher_update_check (launcher);
+  if (!gtk_action_get_visible (action))
+    return;
+
   /* open all selected directories in a new tab */
   selected_files = thunar_g_file_list_copy (launcher->selected_files);
   for (lp = selected_files; lp != NULL; lp = lp->next)