ISSUE-2040 (image fallback): Consider adding placeholders or fallback for unresolved resources [SVG Core 2.0]

ISSUE-2040 (image fallback): Consider adding placeholders or fallback for unresolved resources [SVG Core 2.0]

http://www.w3.org/Graphics/SVG/WG/track/issues/2040

Raised by: Doug Schepers
On product: SVG Core 2.0

When a resource (like an image href) can't be resolved, SVG should put some sort of checkerboard or broken-link indicator (perhaps in the status bar) to indicate to the user that the SVG is not rendering as intended by the author.

Consider wording or functionality like the following to linking.html:

	  <p id="fallback">If an element in the <a href="intro.html#TermRenderingTree"><span class="svg-term">rendering tree</span></a> (e.g., <a href="struct.html#UseElement"><span class="element-name">'use'</span></a>, <a href="struct.html#ImageElement"><span class="element-name">'image'</span></a>, <a href="multimedia.html#AnimationElement"><span class="element-name">'animation'</span></a>, <a href="multimedia.html#AudioElement"><span class="element-name">'audio'</span></a>, <a href="multimedia.html#VideoElement"><span class="element-name">'video'</span></a>) has an unresolved reference for the <a href="animate.html#HrefAttribute"><span class="attr-name">'xlink:href'</span></a> attribute, the user agent must display instead any fallback content supplied as a child of the element, in the following order of preference: any element in the <a href="intro.html#TermRenderingTree"><span class="svg-term">rendering tree</span></a> which does not contain invalid references, or its child content that matches the same criteria; or the contents of any <a href="struct.html#TitleElement"><span class="element-name">'title'</span></a> or <a href="struct.html#DescElement"><span class="element-name">'desc'</span></a> element.  If no adequate fallback content is supplied, the user agent should provide a placeholder rectangle with a gray checkerboard pattern or an image with the position and dimensions specified by the element's attributes, if specified, or custom dimension otherwise, and the name of the invalid resource as visible text or as a tooltip.  If fallback content is rendered, the user agent may display an outline of the content, to indicate that the primary element contained an invalid resource.  For more details, see the <a href="intro.html#TermBoundingBox"><span class="svg-term">bounding box</span></a> definition.</p>

Received on Sunday, 24 August 2008 08:32:50 UTC