Chris Peterson [:cpeterson] Reporter
	Description • 7 years ago

The Gecko implementation was bug 1328868.

/**
 * This setting corresponds to a global text zoom setting affecting
 * all content that is not already subject to font size inflation.
 * It is interpreted as a percentage value that is applied on top
 * of the document's current text zoom setting.
 *
 * The resulting total zoom factor (text zoom * system font scale)
 * will be limited by zoom.minPercent and maxPercent.
 */
pref("font.size.systemFontScale", 100);

	Manish Goregaokar [:manishearth]
	Comment 1 • 7 years ago

It looks like we already support this; Stylo already uses mEffectiveTextZoom, and always has.

Is there evidence stating that we don't support this?

	Manish Goregaokar [:manishearth]
	Comment 2 • 7 years ago

Makoto, do you have more info on what's not working here?

	Makoto Kato [:m_kato]
	Comment 3 • 7 years ago

failed log is here.

https://treeherder.mozilla.org/logviewer.html#?job_id=134365073&repo=try&lineNumber=2774

10:39:33 INFO - 188 INFO TEST-UNEXPECTED-FAIL | mobile/android/tests/browser/chrome/test_settings_fontinflation.html | reftest comparison: != fontScaleOn fontScaleOff
10:39:43 INFO - 191 INFO TEST-UNEXPECTED-FAIL | mobile/android/tests/browser/chrome/test_settings_fontinflation.html | reftest comparison: == fontScaleOn cssZoom
10:39:43 INFO - 195 INFO TEST-UNEXPECTED-FAIL | mobile/android/tests/browser/chrome/test_settings_fontinflation.html | reftest comparison: == fontScaleOn textZoom
10:40:15 INFO - 215 INFO TEST-UNEXPECTED-FAIL | mobile/android/tests/browser/chrome/test_settings_fontinflation.html | reftest comparison: != noZoom fontScaleNoFontInflation 


To build Fennec/sytlo, it requires bug 1397764.

	Manish Goregaokar [:manishearth]
	Comment 4 • 7 years ago

I'm in Montreal for the week and the hashmap stuff will take priority so I probably won't be able to get to this for a while (and i don't yet have an android build). Unassigning for now. I can answer questions about the zoom stuff though.

As far as I can tell this should work; because both we and Gecko use mEffectiveTextZoom. Perhaps we don't send the correct change hint?

	Hiroyuki Ikezoe (:hiro) Assignee
	Comment 5 • 7 years ago

I did setup android build. I can take a look into this.

	Hiroyuki Ikezoe (:hiro) Assignee
	Comment 6 • 7 years ago

It seems to me that the android's system font size stuff (or just the failure test case) relies on MediaFeatureValuesChanged call in nsPresContext::UpdateEffectiveTextZoom().  In stylo the call is skipped basically, if I tweaked that MediaFeatureValuesChanged is called for stylo, the failure test passed normally.

I am not yet sure whether we should fix stylo or android side, but probably we should fix android implementation (or the test case).

	Hiroyuki Ikezoe (:hiro) Assignee
	Comment 7 • 7 years ago

In the test case, test_settings_fontinflation.html, when nsPresContext::UpdateEffectiveTextZoom() is called, stylist.device.default_values has been already created with not-yet-zoomed value even if PresShell::DidInitialized() is false.  So in servo case we should regenerate the default values.  And to do that, I think calling MediaFeatureValuesChanged() is fine.

	Hiroyuki Ikezoe (:hiro) Assignee
	Comment 8 • 7 years ago

Let's see what happens.
https://treeherder.mozilla.org/#/jobs?repo=try&revision=c69dbc388be3839f6734075193efdcd4d4d893d5

	Cameron McCormack (:heycam)
	Comment 10 • 7 years ago
mozreview-review

Comment on attachment 8919136 [details]
Bug 1404545 - Force to call MediaFeatureValuesChanged for stylo in UpdateEffectiveTextZoom.

https://reviewboard.mozilla.org/r/190050/#review195274

	Hiroyuki Ikezoe (:hiro) Assignee
	Comment 11 • 7 years ago

Thank you for the review!

	Pulsebot
	Comment 12 • 7 years ago

Pushed by hikezoe@mozilla.com:
https://hg.mozilla.org/integration/autoland/rev/1ccba28267ff
Force to call MediaFeatureValuesChanged for stylo in UpdateEffectiveTextZoom. r=heycam

	Sebastian Hengst [:aryx] (needinfo me if it's about an intermittent or backout)
	Comment 13 • 7 years ago
bugherder

https://hg.mozilla.org/mozilla-central/rev/1ccba28267ff