[maemo-developers] Problem with three keys pressed

[From: klaus.k.pedersen at nokia.com]

On  Saturday, May 06, 2012, Paolo wrote:

> > The only workaround is to suppress the 3'rd key (which will appear as
> > two new keys) if the pressed keys form a rectangle in the keyboard
> > matrix.
> I tried but it's really not easy (maybe impossible).

There is only one way to "fix" the ghost key problem - that is to suppress all *new* key events that are part of a  ghost key "rectangle".

> Also in the case of a+x+up arrow I get a sequence of:
> Key: 111 Pressed time 1175712370

Key event 111 send

> Key: 33 Pressed time 1175712398
> Key: 38 Pressed time 1175712398
> Key: 53 Pressed time 1175712398

Suppress all.

> But if I press a+x+p (which is the ghost key I get using the previous
> sequence) I get:
> Key: 38 Pressed time 1175773269
> Key: 53 Pressed time 1175773269'

Key event 38 and 53 send

> Key: 33 Pressed time 1175773284
> Key: 111 Pressed time 1175773284

Both suppressed


> The key with code 33 (the p) is always fired before the 111 (up arrow) so
> there's no way I can say if the user really pressed the p or the up arrow.

No that is the point - from the HW point of view there is no way to see which
one is really pressed.

The only thing you can do is to hide the problem.