Add support for WM_PROTOCOLS to the ClutterStage window

Supporting WM_PROTOCOLS allows handling the WM_DELETE_WINDOW ClientMessage,
which is then relayed to the ClutterStage actor in form of the "delete-event"
signal. Returning TRUE will block the propagation and won't close the
stage window.

clutter/clutter-event.h

@@ -58,7 +58,8 @@ typedef enum
   CLUTTER_SCROLL,
   CLUTTER_STAGE_STATE,
   CLUTTER_DESTROY_NOTIFY,
-  CLUTTER_CLIENT_MESSAGE
+  CLUTTER_CLIENT_MESSAGE,
+  CLUTTER_DELETE
 } ClutterEventType;
 
 typedef enum
@@ -80,6 +81,7 @@ typedef enum
 typedef enum
 {
   CLUTTER_FILTER_CONTINUE,
+  CLUTTER_FILTER_TRANSLATE,
   CLUTTER_FILTER_REMOVE
 } ClutterFilterResponse;
 

clutter/clutter-main.c

@@ -153,11 +153,23 @@ clutter_main_do_event (ClutterEvent *event,
     case CLUTTER_MOTION:
       g_signal_emit_by_name (stage, "motion-event", event);
       break;
-    case CLUTTER_DESTROY_NOTIFY:
-      g_signal_emit_by_name (stage, "delete-event");
+    case CLUTTER_DELETE:
+      {
+        gboolean res = FALSE;
+
+        g_object_ref (stage);
+        g_signal_emit_by_name (stage, "delete-event", event, &res);
+        if (!res)
+          clutter_main_quit ();
+        g_object_unref (stage);
+      }
       break;
     case CLUTTER_STAGE_STATE:
       break;
+    case CLUTTER_DESTROY_NOTIFY:
+      break;
+    case CLUTTER_CLIENT_MESSAGE:
+      break;
     }
 }
 

clutter/clutter-stage.c

@@ -92,19 +92,6 @@ enum
 
 static guint stage_signals[LAST_SIGNAL] = { 0 };
 
-static gboolean
-clutter_stage_delete_event (ClutterStage    *stage,
-                            ClutterAnyEvent *event)
-{
-  /* FIXME - destroy the main stage, probably attaching a weak ref
-   * to it from the backend, so that it gets destroyed too.
-   */
-  CLUTTER_NOTE (EVENT, "Received a destroy notification");
-
-  /* we don't want to block */
-  return FALSE;
-}
-
 static void
 clutter_stage_paint (ClutterActor *actor)
 {
@@ -208,8 +195,6 @@ clutter_stage_class_init (ClutterStageClass *klass)
 
   actor_class->paint = clutter_stage_paint;
 
-  stage_class->delete_event = clutter_stage_delete_event;
-
   /**
    * ClutterStage:fullscreen
    *

clutter/glx/clutter-event-glx.c

@@ -60,7 +60,9 @@
 #define XEMBED_UNREGISTER_ACCELERATOR   13
 #define XEMBED_ACTIVATE_ACCELERATOR     14
 
-static Atom Atom_XEMBED = 0;
+static Atom Atom_XEMBED       = 0;
+static Atom Atom_WM_PROTOCOLS = 0;
+
 static Window ParentEmbedderWin = None;
 
 typedef struct _ClutterEventSource      ClutterEventSource;
@@ -172,6 +174,7 @@ _clutter_events_init (ClutterBackend *backend)
   CLUTTER_NOTE (EVENT, "Connection number: %d", connection_number);
 
   Atom_XEMBED = XInternAtom (backend_glx->xdpy, "_XEMBED", False);
+  Atom_WM_PROTOCOLS = XInternAtom (backend_glx->xdpy, "WM_PROTOCOLS", False);
 
   source = backend_glx->event_source = clutter_event_source_new (backend);
   event_source = (ClutterEventSource *) source;
@@ -211,14 +214,13 @@ _clutter_events_uninit (ClutterBackend *backend)
 
 
 static void
-set_user_time (Display      *display,
-               Window       *xwindow,
-               ClutterEvent *event)
+set_user_time (Display *display,
+               Window  *xwindow,
+               long     timestamp)
 {
-  if (clutter_event_get_time (event) != CLUTTER_CURRENT_TIME)
+  if (timestamp != CLUTTER_CURRENT_TIME)
     {
       Atom atom_WM_USER_TIME;
-      long timestamp = clutter_event_get_time (event);
 
       atom_WM_USER_TIME = XInternAtom (display, "_NET_WM_USER_TIME", False);
 
@@ -282,7 +284,43 @@ translate_key_event (ClutterBackend *backend,
                                         0); /* FIXME: index with modifiers */
 }
 
-static void
+static gboolean
+handle_wm_protocols_event (ClutterBackendGlx *backend_glx,
+                           XEvent            *xevent)
+{
+  Atom atom = (Atom) xevent->xclient.data.l[0];
+  Atom Atom_WM_DELETE_WINDOW;
+
+  ClutterStage *stage = CLUTTER_STAGE (backend_glx->stage);
+  Window stage_xwindow = clutter_glx_get_stage_window (stage);
+
+  Atom_WM_DELETE_WINDOW = XInternAtom (backend_glx->xdpy,
+                                       "WM_DELETE_WINDOW",
+                                        False);
+
+  if (atom == Atom_WM_DELETE_WINDOW &&
+      xevent->xany.window == stage_xwindow)
+    {
+      /* the WM_DELETE_WINDOW is a request: we do not destroy
+       * the window right away, as it might contain vital data;
+       * we relay the event to the application and we let it
+       * handle the request
+       */
+      CLUTTER_NOTE (EVENT, "delete window:\twindow: %ld",
+                    xevent->xclient.window);
+
+      set_user_time (backend_glx->xdpy,
+                     &stage_xwindow,
+                     xevent->xclient.data.l[1]);
+
+      return TRUE;
+    }
+
+  /* do not send the WM_PROTOCOLS events to the queue */
+  return FALSE;
+}
+
+static gboolean
 handle_xembed_event (ClutterBackendGlx *backend_glx,
                      XEvent            *xevent)
 {
@@ -322,6 +360,9 @@ handle_xembed_event (ClutterBackendGlx *backend_glx,
       CLUTTER_NOTE (EVENT, "got unknown XEMBED message");
       break;
     }
+
+  /* do not propagate the XEMBED events to the stage */
+  return FALSE;
 }
 
 static gboolean
@@ -366,7 +407,7 @@ clutter_event_translate (ClutterBackend *backend,
     case KeyPress:
       event->type = CLUTTER_KEY_PRESS;
       translate_key_event (backend, event, xevent);
-      set_user_time (backend_glx->xdpy, &xwindow, event);
+      set_user_time (backend_glx->xdpy, &xwindow, xevent->xkey.time);
       break;
     case KeyRelease:
       event->type = CLUTTER_KEY_RELEASE;
@@ -408,7 +449,7 @@ clutter_event_translate (ClutterBackend *backend,
           break;
         }
 
-      set_user_time (backend_glx->xdpy, &xwindow, event);
+      set_user_time (backend_glx->xdpy, &xwindow, event->button.time);
       break;
     case ButtonRelease:
       /* scroll events don't have a corresponding release */
@@ -442,9 +483,16 @@ clutter_event_translate (ClutterBackend *backend,
       break;
     case ClientMessage:
       CLUTTER_NOTE (EVENT, "client message");
-      if (xevent->xclient.message_type == Atom_XEMBED)
-        handle_xembed_event (backend_glx, xevent);
+      
       event->type = event->any.type = CLUTTER_CLIENT_MESSAGE;
+      
+      if (xevent->xclient.message_type == Atom_XEMBED)
+        res = handle_xembed_event (backend_glx, xevent);
+      else if (xevent->xclient.message_type == Atom_WM_PROTOCOLS)
+        {
+          res = handle_wm_protocols_event (backend_glx, xevent);
+          event->type = event->any.type = CLUTTER_DELETE;
+        }
       break;
     default:
       /* ignore every other event */

clutter/glx/clutter-stage-glx.c

@@ -108,6 +108,20 @@ clutter_stage_glx_unrealize (ClutterActor *actor)
     }
 }
 
+static void
+set_wm_protocols (Display *xdisplay,
+                  Window   xwindow)
+{
+  Atom protocols[3];
+  int n = 0;
+  
+  protocols[n++] = XInternAtom (xdisplay, "WM_DELETE_WINDOW", False);
+  protocols[n++] = XInternAtom (xdisplay, "WM_TAKE_FOCUS", False);
+  protocols[n++] = XInternAtom (xdisplay, "_NET_WM_PING", False);
+
+  XSetWMProtocols (xdisplay, xwindow, protocols, n);
+}
+
 static void
 clutter_stage_glx_realize (ClutterActor *actor)
 {
@@ -168,6 +182,8 @@ clutter_stage_glx_realize (ClutterActor *actor)
 		    ButtonPressMask | ButtonReleaseMask |
 		    PropertyChangeMask);
 
+      set_wm_protocols (stage_glx->xdpy, stage_glx->xwin);
+
       if (stage_glx->gl_context)
 	glXDestroyContext (stage_glx->xdpy, stage_glx->gl_context);
 

doc/reference/tmpl/clutter-event.sgml

@@ -47,6 +47,7 @@ Windowing events handled by Clutter.
 </para>
 
 @CLUTTER_FILTER_CONTINUE: 
+@CLUTTER_FILTER_TRANSLATE: 
 @CLUTTER_FILTER_REMOVE: 
 
 <!-- ##### ENUM ClutterScrollDirection ##### -->
@@ -86,6 +87,7 @@ Windowing events handled by Clutter.
 @CLUTTER_STAGE_STATE: 
 @CLUTTER_DESTROY_NOTIFY: 
 @CLUTTER_CLIENT_MESSAGE: 
+@CLUTTER_DELETE: 
 
 <!-- ##### UNION ClutterEvent ##### -->
 <para>