Intent to Deprecate: HTMLVideoElement-specific prefixed fullscreen API

[Philip Jägenstedt]

Primary eng (and PM) emails

phi...@opera.com

Summary

Deprecate these APIs on HTMLVideoElement:

readonly attribute boolean webkitSupportsFullscreen;

readonly attribute boolean webkitDisplayingFullscreen;

void webkitEnterFullscreen();

void webkitExitFullscreen();

// Note the different capitalization of the "S" in FullScreen.

void webkitEnterFullScreen();

void webkitExitFullScreen();

Motivation

This is an early incarnation of fullscreen in WebKit, which has not been standardized and is now replaced by a generic fullscreen API: http://fullscreen.spec.whatwg.org/

Usage information from UseCounter

These numbers were provided to me by Adam Barth:

PrefixedVideoSupportsFullscreen   0.0078%

PrefixedVideoDisplayingFullscreen 0.0010%

PrefixedVideoEnterFullscreen      0.00024%

PrefixedVideoExitFullscreen       0.00018%

PrefixedVideoEnterFullScreen    < 0.00001%

PrefixedVideoExitFullScreen     < 0.00001%

These counters have, IIUC, just reached the stable channel, so another check will be needed before removal.

Compatibility Risk

When removed, sites that use *only* this API with no fallback will simply stop supporting fullscreen. Given the usage counts this does not seem catastrophic, and it's likely that at least some of the current pages using this would fall back to another code path if the APIs were removed.

Row on feature dashboard?

No.

Requesting approval to remove too?

No, I'd like to deprecate first and wait until after the next branch point, so that the deprecation message will be visible in one stable release before removal.

[TAMURA, Kent]

lgtm

--
TAMURA Kent
Software Engineer, Google

[Eric Seidel]

lgtm2.

[Adam Barth]

LGTM

[PhistucK]

The compatibility risk section should also note that an exception would be thrown for calling an undefined method. Not only would the video no go full screen, but the code would crash as well.

☆PhistucK

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[Philip Jägenstedt]

On Thu, Jan 16, 2014 at 2:00 PM, PhistucK <phis...@gmail.com> wrote:
>
> The compatibility risk section should also note that an exception would be thrown for calling an undefined method. Not only would the video no go full screen, but the code would crash as well.

Yes, indeed. However, since HTMLVideoElement::webkitEnterFullscreen
checks that it's being called from a "user gesture", typically a click
event handler, so the impact is limited to code that follows in that
same handler, which is very unlikely to be page-breaking.

Philip

[PhistucK]

Not totally page breaking, but there can be any sort of logic within a click handler.

(That is not the say I am against removing it. I just want to show the whole picture)

☆PhistucK

[Darin Fisher]

LGTM