[whatwg] Non-blocking SVG Canvas?

Boris Zbarsky bzbarsky at MIT.EDU
Thu Aug 5 14:49:54 PDT 2010


On 8/5/10 4:40 PM, Kevin Ar18 wrote:
> I guess that would solve future issues... but it involves a new spec right?

Well, any sort of clarification here does, yes.

> My concern is that we get this specific HTML5-SVG interaction right now

It needs a new spec no matter what, no matter where it lives...

>  Since the problem area is Firefox

In the sense that in Gecko <svg> is not transparent to events by default?

Note that transparency to events is not even interoperable inside HTML; 
e.g. an empty div will block events in some browsers but not others.

That said, support for pointer-events:none on arbitrary elements makes 
this point moot; you just assume the worst and add styles that describe 
the exact behavior you want.

> However, I am not clear on the specs

The specs do not define event targeting behavior at all.

> According to here (http://www.w3.org/TR/SVG11/struct.html#SVGElement) pointer-events is a property of the svg tag.

Correct.

> According to here (http://www.w3.org/TR/SVG11/interact.html#PointerEventsProperty) pointer-events is not a property of the svg tag since svg is not part of the graphical elements group.

Not quite.  It doesn't _apply_ to the <svg> tag.  But it's a property of 
all elements.  And since it inherits by default, this distinction is a 
meaningful one (e.g. you can set pointer-events to some value on an 
<svg> to set it to that value on all graphical elements contained in the 
<svg>).

> So, does this actually mean a browser should not support pointer-events for the svg tag within a html document?

Technically, per SVG spec, yes.  I believe there is common agreement 
(well, at least in Webkit and Gecko) that this needs a spec change to 
give better behavior.

>  I was considering filing a report for Firefox about not supporting pointer-events:painted for the svg tag inside an html document.

The thing is... as "painted" is defined in the SVG spec, it doesn't make 
sense for <svg> (which never has any fill or stroke that actually do 
anything).  This is why a separate spec is needed to define the behavior 
here.

That said, you may be interested in 
https://bugzilla.mozilla.org/show_bug.cgi?id=380573

-Boris


More information about the whatwg mailing list