Summary: Allow setting the decoding attribute on img elements to hint at synchronous/asynchronous decoding of image data. We currently decode images asynchronously which can cause flickering in some circumstances (e.g. if the src is changed), while other browsers default to synchronous decoding (which can block the main thread, but avoid flickering). Implementing this attribute may allow us to align our behaviour more closely to the group in the future, without losing the benefit of asynchronous image decoding given sufficient adoption.
Bug: https://bugzilla.mozilla.org/show_bug.cgi?id=1416328 Spec: https://html.spec.whatwg.org/multipage/images.html#image-decoding-hint Platform coverage: All Target release: 63 Preference: None Support in other engines: Safari has already shipped (see https://bugs.webkit.org/show_bug.cgi?id=179432), Chrome has issued its own intent to ship/implement but not yet complete (see https://bugs.chromium.org/p/chromium/issues/detail?id=772470). I haven't see any commitments from Edge. Tests: WPT has basic tests verifying attribute enumeration values. The implementation largely just leverages existing code which can request synchronous decoding on draw for an image element already. Secure Context: No. This is already shipping elsewhere outside a secure context. _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
