Tablets with GIMP

[Patrick Horgan]

On 11/21/2010 06:20 PM, Neil Whelchel wrote:
> On Sunday, November 21, 2010 05:44:32 pm Peter Hutterer wrote:
>> ... elision by patrick ...
>> gimp grabs the device when a button press is registered on the canvas, but
>> does not do so for events outside the canvas (well, because it wouldn't get
>> them since they don't arrive on the canvas)
> Maybe I was not clear. The GIMP scales the entire tablet area to the size of
> the canvas when it is in Window mode.  Even though the actual tool is on the
> canvas because of scaling, clicks are not passed to the GIMP if you are
> outside of the area that the pointer would be on the canvas if GIMP was not
> scaling it.
>
> I can see this by the way that it acts. There is a problem there, however.
> Since SendCoreEvents is false, the core pointer moves in response to the
> mouse, not the tablet. In this case, you would think that having the window
> active would be enough to allow it to receive tablet events (since GIMP is
> configured to look for the tablet events in its exended input configuration),
> but that is not how it works.
That's not true though, because until gimp grabs the 
pointer the mapping of the tablet to the window hasn't 
started yet.  Your touching at the edge of the tablet, 
not yet mapped in gimp doesn't get delivered to gimp 
because it's outside the window as far as X is concerned.
> The point is that when GIMP is set in Window mode, the entire tablet surface
> is scaled to the size of the drawing window. As I move the pen to the edge of
> the tablet, the tool is positioned at the edge of the window. Where things go
> bad is that even though the tool is in the window, when I click the pen, GIMP
> does not see the event. It is like xorg is not seeing the fact that GIMP is
> scaling the input and that the tool *IS* in the window. If you don't account
> for scaling and click in a place where the tool WOULD be in the window if
> scaling were not applied, it works as expected, and continues to work when you
> drag the pen outside of the unscaled area. There is no documentation to
> explain this or work around this issue.
That's just the way it works.  That's exactly why I use 
Screen mode in GIMP.  Windows mode turns out to be a 
pain unless your drawing window is fullscreened.

Patrick