From Fedora Project Wiki

Grab override


Grab override is a new feature in X that allows partial overriding of existing device grabs.


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Current status

  • Targeted release: Fedora 19
  • Last updated: 00:41, 17 August 2012 (UTC)
  • Percentage of completion: 0%

Detailed Description

Grab override is a new feature in the X Input Extension that allows clients to intercept key or button events even if there is an existing device grab. This allows for global shortcuts such as Alt+Tab to work at all times.

Benefit to Fedora

Device grabs result in a number of UI deficiencies. For example:

  • if a device grab is active, Alt+Tab will not work
  • if a device grab is active, the volume keys do not work
  • if a device grab is active, the screen saver cannot kick in

Examples for device grabs are direct grabs (qemu) or passive grabs when popup menus are active, including right-click popup-menus, the location bar in Firefox, standard application menus, etc.

Allowing for grab overrides resolves these issues.


Defined and release new upstream X Input Extension protocol version, integrate support into the X server and libX11.

How To Test


User Experience

This is a plumbing layer feature only and will not directly be visible until applications or toolkits make use of the feature. Once available in the X.Org stack, applications can be modified to request grab overrides for specific keys or key combinations. Such combinations will then be ignored by the active grab.


This feature requires upstream releases for xorg-x11-server and xorg-x11-proto-devel. Since we ship the packages anyway, we'll just take whichever one is out at the time.

Contingency Plan

None necessary.

If the feature isn't ready upstream in time, it will not be part of our xorg rpms.



Release Notes

Comments and Discussion