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Bug 13687 - Add "exposes a bitmap" concept to image/video/canvas for CSS
Summary: Add "exposes a bitmap" concept to image/video/canvas for CSS
Alias: None
Product: WHATWG
Classification: Unclassified
Component: HTML (show other bugs)
Version: unspecified
Hardware: PC Linux
: P2 normal
Target Milestone: Unsorted
Assignee: Ian 'Hixie' Hickson
QA Contact: contributor
Depends on:
Reported: 2011-08-05 19:06 UTC by Tab Atkins Jr.
Modified: 2012-07-18 18:41 UTC (History)
3 users (show)

See Also:


Description Tab Atkins Jr. 2011-08-05 19:06:26 UTC
See discussion starting at <>.

For the element() function defined at <>, I'm defining "exposes a bitmap" as a hook for host languages to allow elements to be referenced even when they're not actively being rendered.  HTML should define that <img>, <video>, and <canvas> "expose a bitmap" in the obvious way.

(Link to the concept definition will follow.)
Comment 1 Tab Atkins Jr. 2011-08-08 19:27:17 UTC
Reference is at <>.  The hook is now called "represents a paint source", and you just have to specify the width, height, and appearance of the element when in this situation.

(This unifies img/video/canvas with the SVG paint servers.)
Comment 2 Tab Atkins Jr. 2011-08-09 00:28:22 UTC
Ah, additional detail.  <img> elements (and maybe <video>?) should only represent a paint source when they're loaded with a valid image.  That is, an out-of-document <img> should not render its alt text (because that depends on rendering details like font-family and such).
Comment 3 Ian 'Hixie' Hickson 2011-08-22 23:42:14 UTC
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Status: Accepted
Change Description: see diff given below
Rationale: Concurred with reporter's comments.
Comment 4 contributor 2011-08-22 23:42:30 UTC
Checked in as WHATWG revision r6520.
Check-in comment: Integration with CSS Images.