W3C home > Mailing lists > Public > www-dom@w3.org > April to June 2011

Re: [DOM3Events] keydown/keyup asymmetry for held keys (key repeating)

From: L. David Baron <dbaron@dbaron.org>
Date: Wed, 22 Jun 2011 12:03:43 -0700
To: Ojan Vafai <ojan@chromium.org>
Cc: www-dom@w3.org
Message-ID: <20110622190343.GA29539@pickering.dbaron.org>
On Wednesday 2011-06-22 11:33 -0700, Ojan Vafai wrote:
> While I agree that having keydown/keyup be symmetric would be a better API,
> every browser currently implements it repeating keydown events. I don't
> think we could change this without taking a significant compatibility hit.

It was as I propose in Gecko as recently as Firefox 3.6, which is
still quite widely used (and supported with security updates), so I
don't think it should be a big compatibility hit.  (It changed in
Firefox 4 to match the spec.)

(My testcase is holding down the "a" key on
http://dbaron.org/tmp/key-event-dumper.html .)

-David

> On Wed, Jun 22, 2011 at 11:25 AM, L. David Baron <dbaron@dbaron.org> wrote:
> 
> > http://www.w3.org/TR/DOM-Level-3-Events/#events-keyboardevents says:
> >  # Holding down a key must result in the repeating the events
> >  # keydown, keypress (when supported by the user agent), and
> >  # textinput (when the keypress results in text input) in this
> >  # order, at a rate determined by the system configuration.
> >
> > I think this is a bad idea because it introduces asymmetry between
> > the keydown and keyup events (which I think authors would reasonably
> > expect to be symmetric) and because it defines keydown in a way that
> > also violates a reasonable expectation -- that it be fired when the
> > key is pressed (just like the existing "mousedown" event).
> >
> > Instead, I propose that key repetition be handled by repetitions of
> > the keypress and textinput events, but that the keydown event not
> > repeat.
> >
> > Changing this would also require that the keypress event fire for
> > keys that do not produce a character value (e.g., arrow keys,
> > backspace), which
> > http://www.w3.org/TR/DOM-Level-3-Events/#events-keyboard-event-order
> > says is not the case, since authors do need to detect repetitions of
> > those keys.

-- 
L. David Baron                                 http://dbaron.org/
Mozilla Corporation                       http://www.mozilla.com/
Received on Wednesday, 22 June 2011 19:04:09 GMT

This archive was generated by hypermail 2.2.0+W3C-0.50 : Friday, 22 June 2012 06:14:07 GMT