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Starred by 5 users

Issue metadata

Status: Fixed
Closed: Mar 2017
EstimatedDays: ----
NextAction: ----
OS: All
Pri: 3
Type: Bug

Blocked on:
issue 689527

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Issue 654861: Consider dropping support for hover:on-demand

Reported by, Oct 11 2016 Project Member

Issue description

hover and any-hover media queries apparently no longer support "on-demand":

I'm kinda surprised this was removed from the spec without (as far as I can tell) any bug being filed on blink (or me hearing about it via some other channel).

That said I always thought on-demand was a little silly, I agree it's better to just call such devices hover:none.  I just don't know if it's still going to be web compatible to make that change.

From twitter discussion:

Comment 1 by, Oct 11 2016

Though IIRC mobile Safari never used the "on-demand" value.  If that's the case, we can probably safely change to copy them.

Comment 3 by, Oct 11 2016

Confirming that Safari (currently, and in at least the last version as well) reports "none" rather than "on-demand" - using to test

Comment 4 by, Oct 11 2016

A quick blind /text search/ for "on-demand" in httparchive:har.2016_05_15 shows 8236 matches in 18738746 pages (<0.044%). The real counts should be much lower I believe since "on-demand" is a well-known English term.

Comment 5 by, Oct 11 2016

Labels: Hotlist-Interop
Status: Available (was: Untriaged)

Comment 6 by, Oct 11 2016

Components: -Blink>CSS
I've restricted the component to Blink>Input for now - I think that team needs to make the call about whether to drop support or not.

Feel free to redirect to Blink>CSS for (un?)implementation once the decision's been made.

Comment 7 by, Oct 12 2016

Filed bug against Edge

Firefox doesn't currently/yet support CSS4 MQ Interaction Media Features at all, it seems.

Comment 8 by, Oct 12 2016

For completeness, added a note to bugzilla for Firefox

Comment 9 by, Oct 12 2016

Perhaps we could do this in two stages:

1) Make hover:none true for touchscreens matching Safari.  I think this is low risk, probably something we can just do easily now (no intent etc.).  At the same time add usage metrics for hover:on-demand.

2) Deprecate/remove support for hover:on-demand based on usage data.  If metrics show non-trivial usage, we could perhaps consider making it an alias for "none".

Comment 10 by, Feb 3 2017

Status: Started (was: Available)

Comment 12 by, Feb 7 2017

Labels: ReleaseBlock-Beta M-57
We will merge the counter to M57 and then consider full removal from M58/59.

Comment 13 by, Feb 7 2017

This bug is reported as Release Block beta for this Wednesday (02/08/17) Beta release. Please have the fix ready and request a merge to M57 ASAP. Fix has to be merged to M57 branch 2987 latest by 5:00 PM PT tomorrow, Tuesday (02/07/17) in order to make it to this week Beta cut. Thank you.

Also if this is a Beta blocker, shouldn't be P3, right?

Comment 14 by, Feb 7 2017

Blockedon: 689527

Comment 15 by, Feb 7 2017

Labels: -ReleaseBlock-Beta -M-57 M-58
I will merge only the change in #c11 above. I have created  Issue 689527  to isolate the merge request.

Comment 16 by, Feb 8 2017

Project Member

Comment 17 Deleted

Comment 18 by, Mar 6 2017

Correction to my last (deleted) post:

Here are our observations for the usage of hover:on-demand in the wild:

- As of today, we have UseCounter data from Beta and Dev until Mar 4 which suggests that ~0.02% of page visits parses CSSValueOnDemand.

- In, “hover *: *on-demand” regexp search finds a single case (, rank: #333357).

- In HttpArchive 2015-01-15 data, there are ~35 sites matching r"hover:\s*on-demand". Here are the sites along with their approx ranking:

Comment 19 by, Mar 23 2017

Project Member
The following revision refers to this bug:

commit 344035e6942d313099c3ceb741f2eb8231de1a2c
Author: mustaq <>
Date: Thu Mar 23 21:20:16 2017

Drop hover:on-demand support & let touch-screens report "none" instead.

The "hover" and "any-hover" media query features was originally speced to
have three possible values {"none", "on-demand", "hover"}. The "on-demand"
value has been removed from the spec recently:
so we are considering removing support for this value.

Through this CL, chromium drops the support for the "on-demand" value.
Touch-screens will now report "none" instead to match mobile Safari.

Blink intent thread:!topic/blink-dev/-sTmxMpl6iI

BUG= 654861 

Cr-Commit-Position: refs/heads/master@{#459223}


Comment 20 by, Mar 24 2017

Status: Fixed (was: Started)

Comment 21 by, Mar 24 2017

 Issue 699114  has been merged into this issue.

Comment 22 by, Mar 28 2017

Labels: -M-58 M-59
This will be exposed in M59.

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