Re: Event handling in clipping conditions

Hi Doug,

www-svg-request@w3.org wrote on 12/04/2008 10:43:58 AM:

> The SVG WG has resolved on an erratum [1] which we believe will clarify
> this issue:
> 
> [[
> 14.3.6 Clipping paths and geometry
> [...]
> With regards to pointer-events, while the visible parts of a clipped
> element receive pointer events normally, parts of a clipped element
> which are outside the extent of the clipping path must be treated as if
> they have a 'visibility' property value of 'hidden'. Therefore, an
> element which has 'pointer-events' property values which depend upon the
> visibility of the element (i.e. 'visiblePainted', 'visibleFill',
> 'visibleStroke', 'visible') will not receive pointer events for the
> occluded parts of the element.

   So does this apply to Mask as well, which has _exactly_ the same
appearance implications in many cases?  If so at what level of 
opacity does the Mask stop transmitting events?

> We believe that this is the most consistent and predictable behavior,
> and that it should be relatively simple to implement.

   It's not very consistent with the mask element.  And implementing
it with mask may not be relatively simple to implement...

   There are of course other cases that have similar issues like
filters where the actual geometry can be offset from the apparent
geometry.

   My personal opinion is that content authors should handle these cases
with 'hidden' event targets that gives them much more control over the
behavior they desire.