x11: Refactor xevent filtering some more

We now have a GdkX11Display::xevent signal that gets emitted for every
XEvent and allows you to interrupt processing via TRUE/FALSE return
values.
These return values to correspond to GDK_FILTER_REMOVE and
GDK_FILTER_CONTINUE respectively.

The GDK_FILTER_TRANSLATE case from gdk_window_add_filter() is now meant
to be handled via gdk_display_put_event().

8 files changed, 108 insertions, 117 deletions

diff --git a/gdk/gdkmarshalers.list b/gdk/gdkmarshalers.list
index c5df1db202..1281c143b2 100644
--- a/gdk/gdkmarshalers.list
+++ b/gdk/gdkmarshalers.list
@@ -1,2 +1,2 @@
-BOXED:POINTER
+BOOLEAN:POINTER
 VOID:POINTER,POINTER,BOOLEAN,BOOLEAN
diff --git a/gdk/x11/gdkclipboard-x11.c b/gdk/x11/gdkclipboard-x11.c
index ce905b892e..ccbd3c19b3 100644
--- a/gdk/x11/gdkclipboard-x11.c
+++ b/gdk/x11/gdkclipboard-x11.c
@@ -372,10 +372,10 @@ gdk_x11_clipboard_claim_remote (GdkX11Clipboard *cb,
   gdk_x11_clipboard_request_targets (cb);
 }
 
-static GdkEvent *
-gdk_x11_clipboard_translate_event (GdkDisplay   *display,
-                                   const XEvent *xevent,
-                                   gpointer   data)
+static gboolean
+gdk_x11_clipboard_xevent (GdkDisplay   *display,
+                          const XEvent *xevent,
+                          gpointer   data)
 {
   GdkX11Clipboard *cb = GDK_X11_CLIPBOARD (data);
   Window xwindow;
@@ -383,41 +383,41 @@ gdk_x11_clipboard_translate_event (GdkDisplay   *display,
   xwindow = GDK_X11_DISPLAY (display)->leader_window;
 
   if (xevent->xany.window != xwindow)
-    return NULL;
+    return FALSE;
 
   switch (xevent->type)
   {
     case SelectionClear:
       if (xevent->xselectionclear.selection != cb->xselection)
-        return NULL;
+        return FALSE;
 
       if (xevent->xselectionclear.time < cb->timestamp)
         {
           GDK_NOTE(CLIPBOARD, g_printerr ("%s: ignoring SelectionClear with too old timestamp (%lu vs %lu)\n",
                                           cb->selection, xevent->xselectionclear.time, cb->timestamp));
-          return NULL;
+          return FALSE;
         }
 
       GDK_NOTE(CLIPBOARD, g_printerr ("%s: got SelectionClear\n", cb->selection));
       gdk_x11_clipboard_claim_remote (cb, xevent->xselectionclear.time);
-      return gdk_event_new (GDK_NOTHING);
+      return TRUE;
 
     case SelectionNotify:
       /* This code only checks clipboard manager replies, so... */
       if (!g_str_equal (cb->selection, "CLIPBOARD"))
-        return NULL;
+        return FALSE;
 
       /* selection is not for us */
       if (xevent->xselection.selection != gdk_x11_get_xatom_by_name_for_display (display, "CLIPBOARD_MANAGER") ||
           xevent->xselection.target != gdk_x11_get_xatom_by_name_for_display (display, "SAVE_TARGETS"))
-        return NULL;
+        return FALSE;
 
       /* We already received a selectionNotify before */
       if (cb->store_task == NULL)
         {
           GDK_NOTE(CLIPBOARD, g_printerr ("%s: got SelectionNotify for nonexisting task?!\n",
                                           cb->selection));
-          return NULL;
+          return FALSE;
         }
 
       GDK_NOTE(CLIPBOARD, g_printerr ("%s: got SelectionNotify for store task\n",
@@ -430,14 +430,14 @@ gdk_x11_clipboard_translate_event (GdkDisplay   *display,
                                  _("Clipboard manager could not store selection."));
       g_clear_object (&cb->store_task);
       
-      return NULL;
+      return FALSE;
 
     case SelectionRequest:
       {
         const char *target, *property;
 
         if (xevent->xselectionrequest.selection != cb->xselection)
-          return NULL;
+          return FALSE;
 
         target = gdk_x11_get_xatom_name_for_display (display, xevent->xselectionrequest.target);
         if (xevent->xselectionrequest.property == None)
@@ -449,13 +449,13 @@ gdk_x11_clipboard_translate_event (GdkDisplay   *display,
           {
             GDK_NOTE(CLIPBOARD, g_printerr ("%s: got SelectionRequest for %s @ %s even though we don't own the selection, huh?\n",
                                             cb->selection, target, property));
-            return gdk_event_new (GDK_NOTHING);
+            return TRUE;
           }
         if (xevent->xselectionrequest.requestor == None)
           {
             GDK_NOTE(CLIPBOARD, g_printerr ("%s: got SelectionRequest for %s @ %s with NULL window, ignoring\n",
                                             cb->selection, target, property));
-            return gdk_event_new (GDK_NOTHING);
+            return TRUE;
           }
         
         GDK_NOTE(CLIPBOARD, g_printerr ("%s: got SelectionRequest for %s @ %s\n",
@@ -471,7 +471,7 @@ gdk_x11_clipboard_translate_event (GdkDisplay   *display,
                                                  xevent->xselectionrequest.time,
                                                  gdk_x11_clipboard_default_output_handler,
                                                  cb);
-        return gdk_event_new (GDK_NOTHING);
+        return TRUE;
       }
 
     default:
@@ -481,13 +481,13 @@ gdk_x11_clipboard_translate_event (GdkDisplay   *display,
           XFixesSelectionNotifyEvent *sn = (XFixesSelectionNotifyEvent *) xevent;
 
           if (sn->selection != cb->xselection)
-            return NULL;
+            return FALSE;
 
           if (sn->owner == GDK_X11_DISPLAY (display)->leader_window)
             {
               GDK_NOTE(CLIPBOARD, g_printerr ("%s: Ignoring XFixesSelectionNotify for ourselves\n",
                                               cb->selection));
-              return NULL;
+              return FALSE;
             }
 
           GDK_NOTE(CLIPBOARD, g_printerr ("%s: Received XFixesSelectionNotify, claiming selection\n",
@@ -496,7 +496,7 @@ gdk_x11_clipboard_translate_event (GdkDisplay   *display,
           gdk_x11_clipboard_claim_remote (cb, sn->selection_timestamp);
         }
 #endif
-      return NULL;
+      return FALSE;
   }
 }
 
@@ -506,7 +506,7 @@ gdk_x11_clipboard_finalize (GObject *object)
   GdkX11Clipboard *cb = GDK_X11_CLIPBOARD (object);
 
   g_signal_handlers_disconnect_by_func (gdk_clipboard_get_display (GDK_CLIPBOARD (cb)),
-                                        gdk_x11_clipboard_translate_event,
+                                        gdk_x11_clipboard_xevent,
                                         cb);
   g_free (cb->selection);
 
@@ -814,7 +814,7 @@ gdk_x11_clipboard_new (GdkDisplay  *display,
   cb->xselection = gdk_x11_get_xatom_by_name_for_display (display, selection);
 
   gdk_display_request_selection_notification (display, gdk_atom_intern (selection, FALSE));
-  g_signal_connect (display, "translate-event", G_CALLBACK (gdk_x11_clipboard_translate_event), cb);
+  g_signal_connect (display, "xevent", G_CALLBACK (gdk_x11_clipboard_xevent), cb);
   gdk_x11_clipboard_claim_remote (cb, CurrentTime);
 
   return GDK_CLIPBOARD (cb);
diff --git a/gdk/x11/gdkdisplay-x11.c b/gdk/x11/gdkdisplay-x11.c
index b8eaff19d5..ba8b69bc30 100644
--- a/gdk/x11/gdkdisplay-x11.c
+++ b/gdk/x11/gdkdisplay-x11.c
@@ -77,7 +77,7 @@
 #endif
 
 enum {
-  TRANSLATE_EVENT,
+  XEVENT,
   LAST_SIGNAL
 };
 
@@ -3164,21 +3164,19 @@ gdk_x11_display_get_last_seen_time (GdkDisplay *display)
 }
 
 static gboolean
-gdk_x11_display_translate_event_accumulator (GSignalInvocationHint *ihint,
-                                             GValue                *return_accu,
-                                             const GValue          *handler_return,
-                                             gpointer               dummy)
+gdk_boolean_handled_accumulator (GSignalInvocationHint *ihint,
+                                 GValue                *return_accu,
+                                 const GValue          *handler_return,
+                                 gpointer               dummy)
 {
-  GdkEvent *event;
+  gboolean continue_emission;
+  gboolean signal_handled;
 
-  event = g_value_get_boxed (handler_return);
-  if (event == NULL)
-    return TRUE;
+  signal_handled = g_value_get_boolean (handler_return);
+  g_value_set_boolean (return_accu, signal_handled);
+  continue_emission = !signal_handled;
 
-  if (event->type != GDK_NOTHING)
-    g_value_set_boxed (return_accu, event);
-
-  return FALSE;
+  return continue_emission;
 }
 
 static void
@@ -3241,53 +3239,40 @@ gdk_x11_display_class_init (GdkX11DisplayClass * class)
   display_class->get_last_seen_time = gdk_x11_display_get_last_seen_time;
   display_class->set_cursor_theme = gdk_x11_display_set_cursor_theme;
 
-  class->translate_event = gdk_event_source_translate_event;
+  class->xevent = gdk_event_source_xevent;
 
   /**
-   * GdkX11Display::translate-event:
+   * GdkX11Display::xevent:
    * @display: the object on which the signal is emitted
    * @xevent: a pointer to the XEvent to process
    *
-   * The ::translate-event signal is a low level signal that is emitted
-   * whenever an XEvent needs to be translated to a #GdkEvent.
-   *
-   * Handlers to this signal can return one of 3 possible values:
-   * 
-   * 1. %NULL
-   * 
-   * This will result in the next handler being invoked.
-   *
-   * 2. a #GdkEvent
-   *
-   * This will result in no further handlers being invoked and the returned
-   * event being enqueued for further processing by GDK.
-   *
-   * 3. gdk_event_new(GDK_NOTHING)
+   * The ::xevent signal is a low level signal that is emitted
+   * whenever an XEvent has been received.
    *
-   * If a handler returns an event of type GDK_NOTHING, the event will be
-   * discarded and no further handlers will be invoked. Use this if your
-   * function completely handled the @xevent.
+   * When handlers to this signal return %TRUE, no other handlers will be
+   * invoked. In particular, the default handler for this function is
+   * GDK's own event handling mechanism, so by returning %TRUE for an event
+   * that GDK expects to translate, you may break GDK and/or GTK+ in
+   * interesting ways. You have been warned.
    *
-   * Note that the default handler for this function is GDK's own event
-   * translation mechanism, so by translating an event that GDK expects to
-   * translate, you may break GDK and/or GTK+ in interesting ways, so you
-   * have to know what you're doing.
+   * If you want this signal handler to queue a #GdkEvent, you can use
+   * gdk_display_put_event().
    *
    * If you are interested in X GenericEvents, bear in mind that
    * XGetEventData() has been already called on the event, and
    * XFreeEventData() will be called afterwards.
    *
-   * Returns: The translated #GdkEvent or %NULL to invoke further handlers to
-   *     translate the event.
+   * Returns: %TRUE to stop other handlers from being invoked for the event.
+   *   %FALSE to propagate the event further.
    */
-  signals[TRANSLATE_EVENT] =
-    g_signal_new (g_intern_static_string ("translate-event"),
+  signals[XEVENT] =
+    g_signal_new (g_intern_static_string ("xevent"),
 		  G_OBJECT_CLASS_TYPE (object_class),
                   G_SIGNAL_RUN_LAST,
-		  G_STRUCT_OFFSET (GdkX11DisplayClass, translate_event),
-                  gdk_x11_display_translate_event_accumulator, NULL,
-                  _gdk_marshal_BOXED__POINTER,
-                  GDK_TYPE_EVENT, 1, G_TYPE_POINTER);
+		  G_STRUCT_OFFSET (GdkX11DisplayClass, xevent),
+                  gdk_boolean_handled_accumulator, NULL,
+                  _gdk_marshal_BOOLEAN__POINTER,
+                  G_TYPE_BOOLEAN, 1, G_TYPE_POINTER);
 
   _gdk_x11_windowing_init ();
 }
diff --git a/gdk/x11/gdkdisplay-x11.h b/gdk/x11/gdkdisplay-x11.h
index 555b8551e7..efe28911d2 100644
--- a/gdk/x11/gdkdisplay-x11.h
+++ b/gdk/x11/gdkdisplay-x11.h
@@ -168,7 +168,7 @@ struct _GdkX11DisplayClass
 {
   GdkDisplayClass parent_class;
 
-  GdkEvent *            (* translate_event)             (GdkX11Display          *display,
+  gboolean              (* xevent)                      (GdkX11Display          *display,
                                                          const XEvent           *event);
 };
 
diff --git a/gdk/x11/gdkeventsource.c b/gdk/x11/gdkeventsource.c
index ccf4c59a4c..975ed89432 100644
--- a/gdk/x11/gdkeventsource.c
+++ b/gdk/x11/gdkeventsource.c
@@ -263,7 +263,7 @@ handle_touch_synthetic_crossing (GdkEvent *event)
     }
 }
 
-GdkEvent *
+static GdkEvent *
 gdk_event_source_translate_event (GdkX11Display  *x11_display,
                                   const XEvent   *xevent)
 {
@@ -378,6 +378,24 @@ gdk_event_source_translate_event (GdkX11Display  *x11_display,
   return event;
 }
 
+gboolean
+gdk_event_source_xevent (GdkX11Display  *x11_display,
+                         const XEvent   *xevent)
+{
+  GdkDisplay *display = GDK_DISPLAY (x11_display);
+  GdkEvent *event;
+  GList *node;
+
+  event = gdk_event_source_translate_event (x11_display, xevent);
+  if (event == NULL)
+    return FALSE;
+
+  node = _gdk_event_queue_append (display, event);
+  _gdk_windowing_got_event (display, node, event, xevent->xany.serial);
+
+  return TRUE;
+}
+
 static gboolean
 gdk_check_xpending (GdkDisplay *display)
 {
@@ -430,9 +448,9 @@ gdk_event_source_check (GSource *source)
 void
 _gdk_x11_display_queue_events (GdkDisplay *display)
 {
-  GdkEvent *event;
-  XEvent xevent;
   Display *xdisplay = GDK_DISPLAY_XDISPLAY (display);
+  XEvent xevent;
+  gboolean unused;
 
   while (!_gdk_event_queue_find_first (display) && XPending (xdisplay))
     {
@@ -456,24 +474,12 @@ _gdk_x11_display_queue_events (GdkDisplay *display)
         XGetEventData (xdisplay, &xevent.xcookie);
 #endif
 
-      g_signal_emit_by_name (display, "translate-event", &xevent, &event);
+      g_signal_emit_by_name (display, "xevent", &xevent, &unused);
 
 #ifdef HAVE_XGENERICEVENTS
       if (xevent.type == GenericEvent)
         XFreeEventData (xdisplay, &xevent.xcookie);
 #endif
-
-      if (event && event->type == GDK_NOTHING)
-        {
-          gdk_event_free (event);
-        }
-      else if (event)
-        {
-          GList *node;
-
-          node = _gdk_event_queue_append (display, event);
-          _gdk_windowing_got_event (display, node, event, xevent.xany.serial);
-        }
     }
 }
 
diff --git a/gdk/x11/gdkeventsource.h b/gdk/x11/gdkeventsource.h
index 5398f4f936..1344231525 100644
--- a/gdk/x11/gdkeventsource.h
+++ b/gdk/x11/gdkeventsource.h
@@ -38,7 +38,7 @@ void      gdk_x11_event_source_select_events  (GdkEventSource *source,
                                                GdkEventMask    event_mask,
                                                unsigned int    extra_x_mask);
 
-GdkEvent *gdk_event_source_translate_event    (GdkX11Display  *display,
+gboolean  gdk_event_source_xevent             (GdkX11Display  *x11_display,
                                                const XEvent   *xevent);
 
 
diff --git a/gdk/x11/gdkselectioninputstream-x11.c b/gdk/x11/gdkselectioninputstream-x11.c
index 4ad213e073..4a6f501415 100644
--- a/gdk/x11/gdkselectioninputstream-x11.c
+++ b/gdk/x11/gdkselectioninputstream-x11.c
@@ -54,10 +54,10 @@ struct GdkX11SelectionInputStreamPrivate {
 
 G_DEFINE_TYPE_WITH_PRIVATE (GdkX11SelectionInputStream, gdk_x11_selection_input_stream, G_TYPE_INPUT_STREAM);
 
-static GdkEvent *
-gdk_x11_selection_input_stream_translate_event (GdkDisplay   *display,
-                                                const XEvent *xevent,
-                                                gpointer      data);
+static gboolean
+gdk_x11_selection_input_stream_xevent (GdkDisplay   *display,
+                                       const XEvent *xevent,
+                                       gpointer      data);
 
 static gboolean
 gdk_x11_selection_input_stream_has_data (GdkX11SelectionInputStream *stream)
@@ -162,7 +162,7 @@ gdk_x11_selection_input_stream_complete (GdkX11SelectionInputStream *stream)
 
   GDK_X11_DISPLAY (priv->display)->streams = g_slist_remove (GDK_X11_DISPLAY (priv->display)->streams, stream);
   g_signal_handlers_disconnect_by_func (priv->display,
-                                        gdk_x11_selection_input_stream_translate_event,
+                                        gdk_x11_selection_input_stream_xevent,
                                         stream);
 
   g_object_unref (stream);
@@ -378,10 +378,10 @@ err:
 }
 
 
-static GdkEvent *
-gdk_x11_selection_input_stream_translate_event (GdkDisplay   *display,
-                                                const XEvent *xevent,
-                                                gpointer      data)
+static gboolean
+gdk_x11_selection_input_stream_xevent (GdkDisplay   *display,
+                                       const XEvent *xevent,
+                                       gpointer      data)
 {
   GdkX11SelectionInputStream *stream = GDK_X11_SELECTION_INPUT_STREAM (data);
   GdkX11SelectionInputStreamPrivate *priv = gdk_x11_selection_input_stream_get_instance_private (stream);
@@ -396,7 +396,7 @@ gdk_x11_selection_input_stream_translate_event (GdkDisplay   *display,
 
   if (xevent->xany.display != xdisplay ||
       xevent->xany.window != xwindow)
-    return NULL;
+    return FALSE;
 
   switch (xevent->type)
     {
@@ -404,7 +404,7 @@ gdk_x11_selection_input_stream_translate_event (GdkDisplay   *display,
         if (!priv->incr ||
             xevent->xproperty.atom != priv->xproperty ||
             xevent->xproperty.state != PropertyNewValue)
-          return NULL;
+          return FALSE;
 
       bytes = get_selection_property (xdisplay, xwindow, xevent->xproperty.atom, &type, &format);
       if (bytes == NULL)
@@ -432,7 +432,7 @@ gdk_x11_selection_input_stream_translate_event (GdkDisplay   *display,
 
       XDeleteProperty (xdisplay, xwindow, xevent->xproperty.atom);
 
-      return NULL;
+      return FALSE;
 
     case SelectionNotify:
       {
@@ -441,12 +441,12 @@ gdk_x11_selection_input_stream_translate_event (GdkDisplay   *display,
         /* selection is not for us */
         if (priv->xselection != xevent->xselection.selection ||
             priv->xtarget != xevent->xselection.target)
-          return NULL;
+          return FALSE;
 
         /* We already received a selectionNotify before */
         if (priv->pending_task == NULL || 
             g_task_get_source_tag (priv->pending_task) != gdk_x11_selection_input_stream_new_async)
-          return NULL;
+          return FALSE;
 
         GDK_NOTE(SELECTION, g_printerr ("%s:%s: got SelectionNotify\n", priv->selection, priv->target));
 
@@ -498,10 +498,10 @@ gdk_x11_selection_input_stream_translate_event (GdkDisplay   *display,
 
         g_object_unref (task);
       }
-      return gdk_event_new (GDK_NOTHING);
+      return TRUE;
 
     default:
-      return NULL;
+      return FALSE;
     }
 }
 
@@ -530,7 +530,7 @@ gdk_x11_selection_input_stream_new_async (GdkDisplay          *display,
   priv->property = g_strdup_printf ("GDK_SELECTION_%p", stream); 
   priv->xproperty = gdk_x11_get_xatom_by_name_for_display (display, priv->property);
 
-  g_signal_connect (display, "translate-event", G_CALLBACK (gdk_x11_selection_input_stream_translate_event), stream);
+  g_signal_connect (display, "xevent", G_CALLBACK (gdk_x11_selection_input_stream_xevent), stream);
 
   XConvertSelection (GDK_DISPLAY_XDISPLAY (display),
                      priv->xselection,
diff --git a/gdk/x11/gdkselectionoutputstream-x11.c b/gdk/x11/gdkselectionoutputstream-x11.c
index 8428231420..fbca038869 100644
--- a/gdk/x11/gdkselectionoutputstream-x11.c
+++ b/gdk/x11/gdkselectionoutputstream-x11.c
@@ -147,10 +147,10 @@ gdk_x11_pending_selection_notify_send (GdkX11PendingSelectionNotify *notify,
     }
 }
 
-static GdkEvent *
-gdk_x11_selection_output_stream_translate_event (GdkDisplay   *display,
-                                                 const XEvent *xevent,
-                                                 gpointer      data);
+static gboolean
+gdk_x11_selection_output_stream_xevent (GdkDisplay   *display,
+                                        const XEvent *xevent,
+                                        gpointer      data);
 
 static gboolean
 gdk_x11_selection_output_stream_can_flush (GdkX11SelectionOutputStream *stream)
@@ -493,7 +493,7 @@ gdk_x11_selection_output_stream_invoke_close (gpointer stream)
 
   GDK_X11_DISPLAY (priv->display)->streams = g_slist_remove (GDK_X11_DISPLAY (priv->display)->streams, stream);
   g_signal_handlers_disconnect_by_func (priv->display,
-                                        gdk_x11_selection_output_stream_translate_event,
+                                        gdk_x11_selection_output_stream_xevent,
                                         stream);
 
   return G_SOURCE_REMOVE;
@@ -589,10 +589,10 @@ gdk_x11_selection_output_stream_init (GdkX11SelectionOutputStream *stream)
   priv->data = g_byte_array_new ();
 }
 
-static GdkEvent *
-gdk_x11_selection_output_stream_translate_event (GdkDisplay   *display,
-                                                 const XEvent *xevent,
-                                                 gpointer      data)
+static gboolean
+gdk_x11_selection_output_stream_xevent (GdkDisplay   *display,
+                                        const XEvent *xevent,
+                                        gpointer      data)
 {
   GdkX11SelectionOutputStream *stream = GDK_X11_SELECTION_OUTPUT_STREAM (data);
   GdkX11SelectionOutputStreamPrivate *priv = gdk_x11_selection_output_stream_get_instance_private (stream);
@@ -602,7 +602,7 @@ gdk_x11_selection_output_stream_translate_event (GdkDisplay   *display,
 
   if (xevent->xany.display != xdisplay ||
       xevent->xany.window != priv->xwindow)
-    return NULL;
+    return FALSE;
 
   switch (xevent->type)
   {
@@ -610,7 +610,7 @@ gdk_x11_selection_output_stream_translate_event (GdkDisplay   *display,
       if (!priv->incr ||
           xevent->xproperty.atom != priv->xproperty ||
           xevent->xproperty.state != PropertyDelete)
-        return NULL;
+        return FALSE;
 
       GDK_NOTE(SELECTION, g_printerr ("%s:%s: got PropertyNotify Delete during INCR\n",
                                       priv->selection, priv->target));
@@ -618,10 +618,10 @@ gdk_x11_selection_output_stream_translate_event (GdkDisplay   *display,
       if (gdk_x11_selection_output_stream_needs_flush (stream) &
           gdk_x11_selection_output_stream_can_flush (stream))
         gdk_x11_selection_output_stream_perform_flush (stream);
-      return NULL;
+      return FALSE;
 
     default:
-      return NULL;
+      return FALSE;
     }
 }
 
@@ -658,8 +658,8 @@ gdk_x11_selection_output_stream_new (GdkDisplay                   *display,
   priv->timestamp = timestamp;
 
   g_signal_connect (display,
-                    "translate-event",
-                    G_CALLBACK (gdk_x11_selection_output_stream_translate_event),
+                    "xevent",
+                    G_CALLBACK (gdk_x11_selection_output_stream_xevent),
                     stream);
   
   return G_OUTPUT_STREAM (stream);