Only select for button and pointer event on toplevels

These event types propagate up the hierarchy anyway, so this means
we avoid setting it unnecessarily. This is especially important
for button press event, since only one client can select for this
on each window, causing X errors if two clients do it.

diff --git a/gdk/gdkwindow.c b/gdk/gdkwindow.c
index 4130b52c2a4c928374bef020798cefdcad938c6d..d4ce49264fb32382cfe6811bb59e0f5ffce9c791 100644 (file)
--- a/gdk/gdkwindow.c
+++ b/gdk/gdkwindow.c
@@ -1163,25 +1163,44 @@ get_native_event_mask (GdkWindowObject *private)
     return private->event_mask;
   else
     {
-      return
-       /* We need thse for all native window so we can emulate
-          events on children: */
+      GdkEventMask mask;
+
+      /* Do whatever the app asks to, since the app
+       * may be asking for weird things for native windows,
+       * but filter out things that override the special
+       * requests below. */
+      mask = private->event_mask &
+       ~(GDK_POINTER_MOTION_HINT_MASK |
+         GDK_BUTTON_MOTION_MASK |
+         GDK_BUTTON1_MOTION_MASK |
+         GDK_BUTTON2_MOTION_MASK |
+         GDK_BUTTON3_MOTION_MASK);
+
+      /* We need thse for all native windows so we can
+        emulate events on children: */
+      mask |=
        GDK_EXPOSURE_MASK |
        GDK_VISIBILITY_NOTIFY_MASK |
-       GDK_POINTER_MOTION_MASK |
-       GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
-       GDK_ENTER_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK |
-       GDK_SCROLL_MASK |
-       /* Then do whatever the app asks to, since the app
-        * may be asking for weird things for native windows,
-        * but filter out things that override the above
-        * requests somehow. */
-       (private->event_mask &
-        ~(GDK_POINTER_MOTION_HINT_MASK |
-          GDK_BUTTON_MOTION_MASK |
-          GDK_BUTTON1_MOTION_MASK |
-          GDK_BUTTON2_MOTION_MASK |
-          GDK_BUTTON3_MOTION_MASK));
+       GDK_ENTER_NOTIFY_MASK | GDK_LEAVE_NOTIFY_MASK;
+
+      /* Additionally we select for pointer and button events
+       * for toplevels as we need to get these to emulate
+       * them for non-native subwindows. Even though we don't
+       * select on them for all native windows we will get them
+       * as the events are propagated out to the first window
+       * that select for them.
+       * Not selecting for button press on all windows is an
+       * important thing, because in X only one client can do
+       * so, and we don't want to unexpectedly prevent another
+       * client from doing it.
+       */
+      if (gdk_window_is_toplevel (private))
+       mask |=
+         GDK_POINTER_MOTION_MASK |
+         GDK_BUTTON_PRESS_MASK | GDK_BUTTON_RELEASE_MASK |
+         GDK_SCROLL_MASK;
+
+      return mask;
     }
 }