Subject: Re: Jornada X keyboard problems.
To: <>
From: David Laight <>
List: port-hpcarm
Date: 08/20/2002 17:17:25
> Is it possible to make the touchscreen hold a "mouse" button down and not
> just produce a quick click??  It is very hard to use the menus in twm,
> xterm and probably emacs with just a button click??

I did that for a SA1100 based system with a touch screen, worked
reasonably well - you need to get a 'low priority' process to
keep looking at the touchscreen with a maximum interval.
That way you can drag the pen around (eg for drawing on the screen)
without generating so many events that anything expensive has
horrid time lags.

I had touch screen driver (or at least the first bit of code
that sees the events) know where the virtual keyboard was.
That way the focus stayed with the application when the
keyboard was active.

(Actually I used the mmu to make the virtual keyboard full
width and outside the scope of the normal graphics code,
a virtual tty console was done the same way.)

It also seemed better to generate 'key down'-'key-up' pairs
when the touch screen was released on a keytop (having
highlighted the selected key).  Made mis-typing harder.

One difficulty was generating 'double click', as the pointer
tends to move further than expected between teh clicks.


David Laight: