OS15 0.90 alt tab doesnt work

[tonyforster]

OS15 0.90 alt tab doesnt swap activities, a regression on 0.88 OS373pyg

[erikos]

Ok, would be great if someone on F14 (non-olpc) could test that.

[erikos]

Reproduced on latest Soas build as well.

The logs do indicate that another activity might already have access to key '<alt>tab'...

[tomeu]

Replying to erikos:

Ok, would be great if someone on F14 (non-olpc) could test that.

Reproduced on regular F14 installation.

[sascha_silbe]

This looks like the Fedora equivalent of #2300.

[erikos]

Looks like metacity grabbed that key. When I disable the gconf key "/apps/metacity/global_keybindings/switch_windows" and restart Sugar our keygrabber is able to grab that key to tab through windows.

[erikos]

Tracked at OLPC as  http://dev.laptop.org/ticket/10693

[sascha_silbe]

Replying to erikos:

Looks like metacity grabbed that key. When I disable the gconf key "/apps/metacity/global_keybindings/switch_windows" and restart Sugar our keygrabber is able to grab that key to tab through windows.

I bet you're hitting the  known  issue that metacity doesn't properly ungrab the keys, but doesn't handle them either.

Upstream ticket is  Gnome#629210; unfortunately the bug description does a rather bad job of explaining what the actual issue is.

FWIW, personally I'm re-enabling the metacity keybindings in my ~/.xsession (using a hack with a sleeping background subshell) so I can switch windows faster, using different shortcuts (Grab Key + cursor keys) that are easier for me to type.

[erikos]

As I understand from Bernie's comment the root issue is actually in the X server. The commit that should have  fixed it is the following (which is part of 1.9.4 the version included in F14):

commit 9a1bfa5664a80f03cedeb89b9f8a86115a08e7af
Author: Peter Hutterer <peter.hutterer@who-t.net>
Date:   Mon Jul 20 16:39:16 2009 +1000

    input: remove XI2 keysym grabs, use keycode grabs instead.
    
    Keysym grabs are tricky in the details, keycode grabs are known to work. So
    for now, provide keycode grabs only.
    
    Requires inputproto 1.9.99.15.
    
    Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

diff --git a/dix/grabs.c b/dix/grabs.c
index 06d6d03..4a351d6 100644
--- a/dix/grabs.c
+++ b/dix/grabs.c
@@ -451,7 +451,7 @@ DeletePassiveGrabFromList(GrabPtr pMinuendGrab)
     any_modifier = (pMinuendGrab->grabtype == GRABTYPE_XI2) ?
                    (unsigned int)XIAnyModifier : (unsigned int)AnyModifier;
     any_key = (pMinuendGrab->grabtype == GRABTYPE_XI2) ?
-                   (unsigned int)XIAnyKeysym : (unsigned int)AnyKey;
+                   (unsigned int)XIAnyKeycode : (unsigned int)AnyKey;
     ndels = nadds = nups = 0;
     ok = TRUE;
     for (grab = wPassiveGrabs(pMinuendGrab->window);

[erikos]

Bernie's patch to metacity that does remove the call to ungrab_all_keys which calls XUngrabKey (AnyKey, AnyModifier) and replaces it with individual XGrabKey calls:

 http://people.sugarlabs.org/bernie/patches/gnome/metacity/pending/ungrab-x-keybindings-when-they-are-disabled.patch

This is the previous ungrab_all_keys call in metacity:  http://people.gnome.org/~tthurman/docs/metacity/keybindings_8c-source.html#l01144

[erikos]

With the help of Bernie I filed a bug at the xorg-server:  https://bugs.freedesktop.org/show_bug.cgi?id=34358