librelist archives

Re: Help needed implementing keyup/keydown

From:

i5m

Date:

2009-11-11 @ 17:20

My thoughts (not worth a lot!) on keyup and keydown on Window and OSX


On Wed, Nov 11, 2009 at 6:06 AM, MenTaLguY <mental@rydia.net> wrote:

> It should be a relatively simple matter of making sure that
> shoes_app_keydown and shoes_app_keyup are called with the right
> arguments at the right times.
>
> -mental
>

I just had to quote that for "It should be relatively simple" ;-)

Anyway, had a quick look at the cocoa.m file and for starters the whole key
bit is very similar to gtk.c so coupled with this post on stackoverflow:


http://stackoverflow.com/questions/275088/how-do-i-collect-key-input-in-a-video-game-style-cocoa-app


<http://stackoverflow.com/questions/275088/how-do-i-collect-key-input-in-a-video-game-style-cocoa-app>it
should hopefully be "relatively simple" to implement on OSX using Mental's
work on gtk.c as a basis.

On Windows, I'm struggling a bit more: there are already cases setup for
WM_KEYDOWN and WM_KEYUP so I would have thought they would be the
appropriate places to link to shoes_app_keyup, etc, rather than using a
bunch of IF statements under WM_SYSKEYDOWN or under WM_CHAR. But I haven't
had any luck so far - not that that in itself is surprising.

I.e. a stab in the dark:

 case WM_KEYDOWN:
     //comment out below for now
     //app->os.altkey = false;

  switch(w)
  {
case VK_RIGHT:{shoes_app_keydown(app, w); } break;
case VK_LEFT:{shoes_app_keydown(app, w) ;} break;
case VK_UP:{ shoes_app_keydown(app, w) ;} break;
case VK_DOWN:{shoes_app_keydown(app, w) ; } break;
default: break;
  }
  break;

This builds and doesn't crash. And a simple app such as the keypress one in
the manual modified with keydown works kind of:

The Up and Down arrow keys cause it to crash
Pressing the left arrow key returns "18"
Pressing the right arrow key returns "19"

I really don't know what I'm doing. Just trying to learn.



Regards,

i5m


-----------------------
i5m.co.uk
GPG Key: 0xA18A602B

On Wed, 2009-11-11 at 17:20 +0000, i5m wrote:

> Anyway, had a quick look at the cocoa.m file and for starters the
> whole key bit is very similar to gtk.c so coupled with this post on
> stackoverflow:
> 
> 
> 
http://stackoverflow.com/questions/275088/how-do-i-collect-key-input-in-a-video-game-style-cocoa-app
> 
> 
> it should hopefully be "relatively simple" to implement on OSX using
> Mental's work on gtk.c as a basis.

The main tricky thing to keep in mind is that keyup/keydown should
always return the key *without* modifiers.  In particular, even though
keypress might return e.g. :shift_enter, keyup/keydown would still
return "\n".

-mental

Bit more progress on the Windows front. See commits here:

http://github.com/i5m/shoes/commit/1a95aab2be9062c9a3242c7f4f8892735dfd04c3
http://github.com/i5m/shoes/commit/0cf7ec09bbfb4d3524f8de5a882ca7801000d67a

It's not exactly right yet. But hopefully not too far off. I  created this
simple Shoes app to test:

http://gist.github.com/232905

(don't laugh too much)

And:

* Modifier keys such as CTRL and ALT don't get reported for Keyup and
Keydown, which I believe is desired. This seems to come by default, i.e. by
leaving code out rather than having to code this in (so more by luck than
skill).
* All character keys come through as capitals.
* If you hold a key down, the keypress field flashes to indicate keypress.
Keydown stays solid, correctly changes when keypress up occurs.

I guess props must go to Mental for making it "relatively simple" to hook in
the shoes_app_keyup and shoe_app_keydown functions. Maybe ashbb can finish
off what I've started? Or at least verify I've not broken anything in the
process?



Regards,

i5m


-----------------------
i5m.co.uk
GPG Key: 0xA18A602B


On Wed, Nov 11, 2009 at 9:30 PM, MenTaLguY <mental@rydia.net> wrote:

>
> The main tricky thing to keep in mind is that keyup/keydown should
> always return the key *without* modifiers.  In particular, even though
> keypress might return e.g. :shift_enter, keyup/keydown would still
> return "\n".
>
> -mental
>
>