some UI and text input thoughts

Marcos Mezo mmezo at
Thu Jan 15 01:19:52 CET 2009

On Thursday 15 January 2009 00:42:49 Carsten Haitzler wrote:
> On Wed, 14 Jan 2009 10:01:20 +0000 Andy Green <andy at> babbled:
> nothing to do with hardware here - all to do with software stack. the fact
> is there is no generic "zoom" control for apps - and apps have no concept
> of one. you also need to think about where in the stack you sit - if you go
> to /dev/input... you will be doing your own driver work specific to 1
> hardware type - if that changes - you are going to have to adapt. the best
> bet is to do this higher up at the x level - but here you hit a problem.
> mouse events ONLY go to the window they are on (or to who grabbed the
> mouse). so in this case every app/toolkit needs to handle these themselves
> - OR you uxe an extension like xevie and we put in an indirector for all
> events - this indirector can/will be responsible for:
> 1. filtering (removing events, delaying and getting rid of garbage - it it
> wants)
> 2. selectively passing along some events and not others possibly with
> modifications (eg translate/scale the input/output - needed for a
> compositor if you do things like scale the window output in the compositor)
> 3. can interpret series of events into gestures and then produce some form
> of message (the protocol and standard are yet to be defined) that can be
> sent to the root window o the focused window - or possibly just execute
> some command etc. etc.
Not really knowing anything about it, but it seems to me that that's what 
tslib is doing for right mouse button emulation.

Maybe somebody with the knowledge could extend tslib with some more gestures, 
like for example the said (counter)clockwise circling that could emulate a 
mouse wheel, which is not standard, but common for zooming in a lot of photo 
viewers for example. It would also be useful to scroll texts,.... Or maybe 
something like ^ for emulating the "up" key or "page-up" or....

The problem is always that for example people drawing on the touchscreen 
(pypennotes?) or for that matter playing with numptyphysics would not be very 
happy :-), so if implemented it should be at least easily disabled/enabled 
both with a gui and also with something accesible for scripts to be added on 
application launchers.


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