Hi Simon, 1. The main problem is that GTK2 has no support for hotplugging input devices while the application is running. The list returned by gdk_devices_list() is constructed once at startup and never updated subsequently. It still contains devices that have been unplugged, and does not contain devices plugged after application startup.
(Xournal has to work around this to avoid some crashes, see the call to gdk_error_trap_push/pop() in emergency_enable_xinput() in src/xo-misc.c, since otherwise re-enabling the dead devices causes the program to crash... the latter function needed to work around more GTK2 issues, with a range of GTK versions from 2.17 to somewhere before 2.24 if we leave the drawing area we need to emergency disable all XInput devices so the interface won't become unresponsive. In 2.24 this is only needed for text box edition and not for other cases anymore. In short, it's a mess.) Hacking into the internal GTK2 data structures would be theoretically possible but a huge mess to maintain in terms of compatibility. Without GTK2 being aware of the devices, the events they generate can't be processed the normal way either. So: in short, no hotplugging support as long as we rely on GTK2. The GTK3 port of xournal that Daniel German has been working on would hopefully fix this. However... 2. I'm pretty sure that the approach of emulating USB unplugs and reassigning devices just so you can figure what their original geometry was is not the best one -- especially if it causes device ids to change! For example, in increasing order of efficiency: (a) your script could store in a temporary file, if not already found, the geometry of the device when it is first called; this way, the next time you run it, it could retrieve the original geometry from the existing file on disk (instead of querying Area which is no longer the default value). (b) if your version of xsetwacom support it, xsetwacom set "device name" ResetArea will reset the Area parameter (assuming this is what you were modifying and lost) without having to hotplug/unplug. (c) xsetwacom set "device name" MapToOutput 500x600+400+300 maps the device area to a 500x600 window located at coordinates 400,300 -- and can be run repeatedly safely as far as I can tell. This is a much better way to rescale the device than to change the Area parameter. (Besides a window geometry you can also specify a display name, or "desktop" for the whole desktop area, which has the effect of undoing a previous MapToOutput command; but you can do successive MapToOutput commands without undoing them in between.) Also: 3. In principle there's a GDK_MODE_WINDOW mode and a GDK_MODE_SCREEN mode for GTK2 input devices. Xournal sets things to SCREEN (use the whole screen) because of its tablet origins, but you could try seeing what happens if you recompile the source code after changing GDK_MODE_SCREEN to GDK_MODE_WINDOW in both places where it occurs. On my Tablet PC it doesn't do the right thing at all (not to mention that just doing this would remap all devices, not just the wacom tablet, to the window), so I assume GDK_MODE_WINDOW is broken and the correct approaches are those in item 2 above. Hope this helps. Denis ------------------------------------------------------------------------------ _______________________________________________ Xournal-devel mailing list Xournal-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/xournal-devel
