[whatwg] focus change inside keypress event handler
Michael A. Puls II
shadow2531 at gmail.com
Tue Nov 3 00:26:05 PST 2009
On Thu, 29 Oct 2009 21:58:29 -0400, Michael A. Puls II
<shadow2531 at gmail.com> wrote:
> I'll put together a new description with the changes to see if sounds
> good.
O.K., this description might be better and sounds more like what Firefox
does for compat with the net:
-------
Fire 'keydown' first.
The default action for 'keydown' is to set the acceptKeypress flag to
true. Using preventDefault() (either explicitly or implicitly through
return false) prevents the default action and results in the
acceptKeypress flag remaining false.
Changing the focus from one object to another inside the 'keydown' handler
changes the current Context Object (what the action will be performed on)
for the following 'keypress' handler.
After the 'keydown' handler runs, fire 'keypress'.
The default action for 'keypress' is to allow the keypress if the
acceptKeypress flag is true.
If acceptKeypress is not true or if preventDefault() is called in the
'keypress' handler (either explicitly or implicitly through return false),
then the keypress is not allowed.
If the keypress is allowed then perform the action on the current Context
Object. The action could be text insertion, text deletion, scrolling etc.
If the keypress is not allowed, then do not perform the action unless the
UA does not allow preventing the action, which in that case, perform the
action.
Note that a focus change inside a 'keypress' handler does not change the
current Context Object for the keypress.
If the a key is being held down and Repeat Processing is supported,
process the above over and over. (e.g. keydown -> keyup -> keydown ->
keyup)
When the key is finally released, fire 'keyup'.
However, note that if alert(), confirm() or prompt() is used inside a
'keydown' handler and or inside a 'keypress' handler, whether 'keyup'
fires varies between implementations.
Also note that alert(), confirm(), prompt(), setTimeout and setInterval()
inside the 'keydown' , 'keypress' and 'keyup' handlers may result in some
code inside the handlers running in a different order than 'keydown' ->
'keypress' -> 'keyup'.
-------
That's how Firefox appears to work, in my words, from the outside looking
in.
Again though, even if that's not right, I still want the spec to go into
details like that.
--
Michael
More information about the whatwg
mailing list