Ubuntu
xorg-server package

  1. Bug #1307701
  2. Comment #12

Comment 12 for bug 1307701

Revision history for this message
Daniel d'Andrada (dandrader) wrote : Re: Unity does not get touch events when QML apps running

Any QML application at all will do (such as "Item {width:600;height:600}")

What seems to be happening, from what I've learned so far:

- user touches on a qml application
- xserver sends the resulting touch events to both the qmlscene and to compiz/unity7
- xserver offers ownership to compiz/unity7
- qmlscene does XIGrabDevice on the touch screen
- compiz/unity7 rejects the touch
- user lifts finger and touch ends
- qmlscene does XIUngrabDevice on the touch screen
- user lands a new finger, this time on the desktop
- xserver still has in its bookkeeping that the previous touch is active and thus deny pointer emulation for that new touch

And from that point onwards xserver is left with a bogus state, even after the qml app is closed. Restarting it being the sure way to clean it up and reproduce the issue anew (otherwise further issues seem to crop up)