[whatwg] hit regions: moving an element out of the shadow tree

[Rik Cabanier]

Another question: it is currently valid to pass in a control that is not
part of the canvas shadow tree.
Doing this will ignore the control. Shouldn't this be invalid and throw an
error?


On Tue, Feb 4, 2014 at 11:05 AM, Ian Hickson <ian at hixie.ch> wrote:

> On Tue, 4 Feb 2014, Rik Cabanier wrote:
> > On Tue, Feb 4, 2014 at 9:13 AM, Ian Hickson <ian at hixie.ch> wrote:
> > > On Mon, 3 Feb 2014, Rik Cabanier wrote:
> > > >
> > > > The spec is currently silent what should happen when an element that
> > > > is associated with a hit region, is moved to another location in the
> > > > document, another document or deleted.
> > > >
> > > > This should result in removal of the hit region. Maybe this is
> > > > defined in the HTML spec?
> > >
> > > It results in the region no longer having a backing control (see the
> > > definition of "the control represented by a region"), but why would it
> > > remove the region? The region might be there for other reasons, e.g.
> > > it might have a cursor or ID specified, or the author might be using
> > > it to play a sound when the user tries to click on the space where the
> > > control used to be drawn, to indicate to the user that the control is
> > > gone.
> >
> > Ok, link:
> >
> http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#the-control-represented-by-a-region
> >
> > It's a bit weird that you can do "ctx.addHitRegion({});" :-)
>
> Or even just c.addHitRegion(). An author might want to do that to
> introduce a "dead" zone in a canvas, where the cursor reverts to the
> canvas default cursor, there's no AT implications, and the hit testing in
> mouse events doesn't give a region ID any more. This is similar to <area>
> elements with no href="".
>
> --
> Ian Hickson               U+1047E                )\._.,--....,'``.    fL
> http://ln.hixie.ch/       U+263A                /,   _.. \   _\  ;`._ ,.
> Things that are impossible just take longer.   `._.-(,_..'--(,_..'`-.;.'
>