[Laszlo-dev] What was the reason for cancelling the events with keycode == 0 ?

[Max Carlson]

The canceling code was left for compatibility reasons - André mentions 
in his changeset: 'this is actually wrong, see LPP-8200, but reduces 
testing effort right now.'

Control keys are already being processed by 
LzKeyboardKernel.__updateControlKeys() so removing this bit _shouldn't_ 
matter.  Please test with test/lfc/legals/keyboardandmouse.lzx?lzr=dhtml 
to verify.  Also note it won't help with Firefox - again from André's 
changeset: '"keyCode" is set to 0 for mouse-events in IE, Opera, Safari, 
so you only need to test for keyCode==0 (Firefox is irrelevant in this 
case, because it sets keyCode to `undefined` for mouse-events).'

I sent mail to André to confirm which one of us is supposed to finish 
the change that will clean all this up...

Henry Minsky wrote:
> The last thing that is preventing text selection from working in IE7 is 
> this code in the MouseKernel.__mouseEvent which
> which explicitly cancels a mouse event when it's keyCode == 0.
> 
> Now, I'm trying to understand why we need this code.
> 
> As I understand it, the LzKeyboardKernel.__cancelKeys flag is being set 
> by the LzInputTextSprite
> when it wants to make sure that a text field does not respond to any 
> mouse or keyboard events (?).
> 
> In addition, the reason we're passing the mouse event at all to 
> KeyboardKernel is to inspect it's keyCode field for control keys that 
> might be down, but that we didn't get explicit keyboard events for.
> 
> So ... if I were to remove this block of code from 
> LzMouseKernel.__mouseEvent, what would
> I be breaking?
> 
> It seems like if I removed this code, then in some cases input text 
> fields may respond to
> mouse events when we don't want them to?
> 
> 
> 
>          // send option/shift/ctrl key events
>          if (window['LzKeyboardKernel'] && 
> LzKeyboardKernel['__updateControlKeys']) {
>              LzKeyboardKernel.__updateControlKeys(e);
> -
> -            // FIXME: [20090602 anba] this prevents text selection, see 
> LPP-8200
> -            if (LzKeyboardKernel.__cancelKeys && e.keyCode == 0) {
> -                e.cancelBubble = true;
> -                e.returnValue = false;
> -            }
> 
> 
> 
> 
> -- 
> Henry Minsky
> Software Architect
> hminsky at laszlosystems.com <mailto:hminsky at laszlosystems.com>
> 
> 

-- 
Regards,
Max Carlson
OpenLaszlo.org