Precise X staging

Chase Douglas chase.douglas at
Sat Dec 24 22:26:08 UTC 2011

Hi all,

At UDS we decided to use the 1.11 server with the input subsystem
backported from 1.12 for multitouch. The upstream 1.12 server
development branch just landed the multitouch support, so I packaged it
up for Precise.

Ubuntu has had multitouch support in our X server since 11.04, but it
was a prototype implementation. The protocol specification and
implementation merged upstream is very similar, but includes a few key

Over the past week, Chris Halse-Rogers and I have created a staging PPA
(ppa:ubuntu-x-swat/x-testing) for all the X packages and any packages
that need fixes due to the input protocol changes. This PPA is as much
for our own development benefit as it as a chance for others to test it
out. We would gladly appreciate feedback on ubuntu-x at
However, note that the code is still rather unstable.

We need to determine what to do about the qt4-x11 package in particular.
The Ubuntu package includes a patch that enables multitouch using the
prototype implementation. I have reworked the patch for the upstream
implementation (it was far easier than I thought it would be :), and it
is available in the ppa as well. For the transition, we could do one of
the following:

1. Drop the patch from qt4-x11 now, and add it back in after the X
packages land in precise.

2. Synchronize the X package and Qt package uploads and use "Breaks"
debian control clauses to hold back packages during the transition period.

I proposed option #1 to Scott on irc this past week. I think it's the
least hassle because it does not require significant synchronization
between the kubuntu packagers and the ubuntu-x teams. There are no
API/ABI changes from the patch, it merely hooks up the plumbing in the
qt x11 implementation. I am also unaware of any applications in the
archive using the qt multitouch capability yet. However, I have no
issues with either approach. Any thoughts?


-- Chase

More information about the ubuntu-devel mailing list