Plugin: disallow overriding window overview

lib/Plugin.vala

@@ -18,8 +18,7 @@
 namespace Gala {
     public enum PluginFunction {
         ADDITION,
-        WINDOW_SWITCHER,
-        WINDOW_OVERVIEW
+        WINDOW_SWITCHER
     }
 
     public enum LoadPriority {

src/DesktopIntegration.vala

@@ -242,10 +242,6 @@ public class Gala.DesktopIntegration : GLib.Object {
     }
 
     public void show_windows_for (string app_id) throws IOError, DBusError {
-        if (wm.window_overview == null) {
-            throw new IOError.FAILED ("Window overview not provided by window manager");
-        }
-
         App app;
         if ((app = AppSystem.get_default ().lookup_app (app_id)) == null) {
             throw new IOError.NOT_FOUND ("App not found");

src/PluginManager.vala

@@ -22,7 +22,6 @@ public class Gala.PluginManager : Object {
     }
 
     public string? window_switcher_provider { get; private set; default = null; }
-    public string? window_overview_provider { get; private set; default = null; }
 
     private HashTable<string,Plugin> plugins;
     private File plugin_dir;
@@ -125,18 +124,12 @@ public class Gala.PluginManager : Object {
     private bool check_provides (string name, PluginFunction provides) {
         var message = "Plugins %s and %s both provide %s functionality, using first one only";
         switch (provides) {
-            case PluginFunction.WINDOW_OVERVIEW:
-                if (window_overview_provider != null) {
-                    warning (message, window_overview_provider, name, "window overview");
-                    return false;
-                }
-                window_overview_provider = name;
-                return true;
             case PluginFunction.WINDOW_SWITCHER:
                 if (window_switcher_provider != null) {
                     warning (message, window_switcher_provider, name, "window switcher");
                     return false;
                 }
+
                 window_switcher_provider = name;
                 return true;
             default:

src/WindowManager.vala

@@ -77,7 +77,7 @@ namespace Gala {
 
         private WindowSwitcher? window_switcher = null;
 
-        public ActivatableComponent? window_overview { get; private set; }
+        public WindowOverview window_overview { get; private set; }
 
         public ScreenSaverManager? screensaver { get; private set; }
 
@@ -290,12 +290,8 @@ namespace Gala {
                 Meta.KeyBinding.set_custom_handler ("switch-group-backward", window_switcher.handle_switch_windows);
             }
 
-            if (plugin_manager.window_overview_provider == null
-                || (window_overview = (plugin_manager.get_plugin (plugin_manager.window_overview_provider) as ActivatableComponent)) == null
-            ) {
-                window_overview = new WindowOverview (this);
-                ui_group.add_child ((Clutter.Actor) window_overview);
-            }
+            window_overview = new WindowOverview (this);
+            ui_group.add_child (window_overview);
 
             // Add the remaining components that should be on top
             shell_group = new Clutter.Actor ();
@@ -884,7 +880,7 @@ namespace Gala {
                     launch_action (ActionKeys.PANEL_MAIN_MENU_ACTION);
                     break;
                 case ActionType.WINDOW_OVERVIEW:
-                    if (window_overview == null || filter_action (WINDOW_OVERVIEW)) {
+                    if (filter_action (WINDOW_OVERVIEW)) {
                         break;
                     }
 
@@ -896,7 +892,7 @@ namespace Gala {
                     critical ("Window overview is deprecated");
                     break;
                 case ActionType.WINDOW_OVERVIEW_ALL:
-                    if (window_overview == null || filter_action (WINDOW_OVERVIEW)) {
+                    if (filter_action (WINDOW_OVERVIEW)) {
                         break;
                     }