Re: Change to common definition of "hidden" in ARIA specs

+1

—Michiel

> On 3 Mar 2016, at 01:15, Amelia Bellamy-Royds <amelia.bellamy.royds@gmail.com> wrote:
> 
> In SVG, it is possible for an element to be invisible (visibility: hidden) but still interactive to click events (through the pointer-events style property).  It is used, for example, to create an image-map behavior with a raster image file, or to create large click regions for small data points in a chart.  
> 
> For the SVG accessibility mappings, we therefore want to make sure that these interactive-but-invisible elements can be included in the accessibility tree, so that assisstive technologies can forward events correctly.  The current definition of "hidden" that is shared by all ARIA specs (and which refers to elements that should be excluded from the accessibility tree) doesn't factor this in.
> 
> Current definition:
> Hidden
> Indicates that the element <http://127.0.0.1:55557/svg-aam/svg-aam.html#dfn-element> is not visible or perceivable <http://127.0.0.1:55557/svg-aam/svg-aam.html#dfn-perceivable> to any user. An element is considered hidden if it or any one of its ancestor elements is not rendered or explicitly hidden.
> 
> Proposed definition:
> Hidden
> Indicates that the element is not visible, perceivable, or interactive for any user. An element is considered hidden if it or any one of its ancestor elements is not rendered or is explicitly hidden.
> 
> The rest of the definition I think is flexible enough to work for both SVG and HTML.  I've already proposed explicit definitions of "not rendered" in SVG which is distinct from visibility.
> 
> ~Amelia