Tuesday, March 03, 2009

TabletPCs: fix eraser detection in xournal

Some weeks ago I got a bugreport for SUSE about problems with automatic eraser detection of Wacom tablets/TabletPCs in xournal. After taking a deeper look into the problem, I discovered that it's again a problem with the naming of the wacom input devices in the xorg.conf.

To find out if the eraser is used, xournal checks for GDK_SOURCE_ERASER. And as it looks GDK can only identify an input device as GDK_SOURCE_ERASER if the devicename starts with eraser. But this is not the case at SUSE products since we use SaX2 which use Mouse[*] as device name.

I wrote a patch for xournal to use xsetwacom to find out if the currently used input device is a eraser, so that the automatic detection is working again and you can use the eraser without selecting the eraser tool again and again. You can find updated xournal packages for openSUSE/SLED in my OSBS repo.

In my opinion the real problem is, that there is (AFAIK) currently no way do mark and identify input devices in X.org as e.g. stylus/eraser/touch. It would make it much easier for applications if there would be a device name independent solution in X in the future.
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