Re: Touch Screen

[Tristan Van Berkom <tristan van berkom gmail com>]

On Tue, 9 Nov 2004 20:26:45 +0000 (UTC), Alf C Stockton
<alf stockton co za> wrote:
> On Tue, 9 Nov 2004, Tristan Van Berkom wrote:
>
> > On Tue, 9 Nov 2004 19:58:57 +0000 (UTC), Alf C Stockton
> > <alf stockton co za> wrote:
> > > I need to create a touch screen application and have little or no idea about
> > > where to start. Suggestions please.
> >
> > Hah, at the beginning :-)
> I assumed that but my problem is finding the beginning.....:-)
> >   I (along with my team ofcouse) write applications for an embedded jukebox
> > system which uses touchscreen Gtk+ driven UIs, If you have any questions,
> > I might have some answers.
> Do I need a particular library to create the screens?
> The only thing I have seen so far is a VB application that uses a dll to access
> the touch screen.

I guess it depends on your platform, We're using linux and X, X drives
a touchscreen as a core pointer, in Gtk+ it comes over just like a mouse.

The input module in X always does
    - PostMotionEvent
    - PostButtonEvent

(or just postmotion if there is a "drag"), so the pointer position is
always updated
before the mouse button down event comes through.

This makes for sequences like:
  "enter-notify-event" --> "motion-notify-event" --> "button-press-event"
All at once, in most cases this works fine.

Cheers,
                                                 -Tristan