[GTK] Correct scaling for DPI. #26938

gwhitney · 2024-04-06T20:17:03Z

`69ad530`

[GTK] Correct scaling for DPI.
https://bugs.webkit.org/show_bug.cgi?id=247980

Reviewed by NOBODY (OOPS!).

Move the scaling factor formerly in WebKitWebView.cpp (responsive to
the xft-dpi setting) into WebKitWebViewBase.cpp, and split it into two
scaling factors. The first, a page scaling factor, uses screenDPI to
ensure that a length specified by a CSS unit of 1in will appear on the
screen as one physical inch. The second, a text scaling factor, ensures
that text specified as 96px in size will have a height on-screen as
specified by fontDPI (which is primarily driven by the xft-dpi setting),
in terms of the number of screen pixels taken up.

The two scaling factors are refreshed when any one of the inputs for
computing them changes: the GDK_SCALE factor, the xft-dpi setting, or
the screenDPI of the device it is displayed on (say by being dragged
to a different monitor). Throughout, at the default zoom level, a CSS
1in dimension is kept at one physical inch.

The scale factors are kept internal to WebKitWebViewBase (which helps
keep GTK dependencies grouped and reduces the total code in WebKitWebView
enclosed in `#ifdef PLATFORM(GTK)`) but made available to WebKitWebView
so that its external interfaces can maintain zoom level 1 as the default
zoom level, and zoom in and out from there.

So indeed, if a user of WebKitWebView asks for a zoom level of 1.5, a
length specified in CSS as 1in will then occupy one and a half physical
inches on screen.

* Source/WebCore/platform/gtk/PlatformScreenGtk.cpp:
(WebCore::fontDPI):
* Source/WebKit/UIProcess/API/glib/WebKitWebView.cpp:
(webkitWebViewConstructed):
(webkitWebViewDispose):
(webkit_web_view_set_zoom_level):
(webkit_web_view_get_zoom_level):
* Source/WebKit/UIProcess/API/gtk/WebKitWebViewBase.cpp:
(_WebKitWebViewBasePrivate::_WebKitWebViewBasePrivate):
(refreshInternalScaling):
(webkitWebViewBaseUpdateDisplayID):
(webkitWebViewBaseDispose):
(webkitWebViewBaseGetScaleFactors):
(deviceScaleFactorChanged):
(webkitWebViewBaseCreateWebPage):
* Source/WebKit/UIProcess/API/gtk/WebKitWebViewBasePrivate.h:

69ad530

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	~~🧪 wpe-wk2~~
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	~~🧪 api-mac~~	~~🧪 api-wpe~~
	~~🧪 ios-wk2-wpt~~	✅ 🧪 mac-wk1	✅ 🛠 wpe-skia
	~~🧪 api-ios~~	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 tv	~~🧪 mac-AS-debug-wk2~~	~~🧪 gtk-wk2~~
	~~🛠 tv-sim~~	~~🧪 mac-wk2-stress~~	~~🧪 api-gtk~~
✅ 🛠 🧪 merge	✅ 🛠 watch
	❌ 🛠 watch-sim

webkit-early-warning-system · 2024-04-06T20:17:09Z

EWS run on previous version of this PR (hash 77f5097)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-skia
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 tv	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
	✅ 🛠 watch
	✅ 🛠 watch-sim

mcatanzaro · 2024-04-06T23:41:29Z

Hi, we'll look closer at this next week, but for now please start by splitting this into two pull requests because unfortunately each pull request has to have exactly one commit in order to land. Probably best to squash that second commit into the first one.

I'm going to mark this one as Draft for now. You can create a separate pull request with just one commit (corresponding to the first two commits from this pull request). Then after that pull request lands, you can rebase this one such that it contains only the third commit, and remove the Draft status.

gwhitney · 2024-04-07T00:32:50Z

OK,will do ASAP.

gwhitney · 2024-04-07T17:39:43Z

Filed #26954.

mcatanzaro · 2024-04-15T14:02:07Z

Reminder: after #26954 lands, rebase this pull request and then ping @WebKit/glib-reviewers to re-request review.

gwhitney · 2024-04-16T09:53:37Z

OK, I see that #26954 has landed. I will rebase/update this pull request as soon as I am able and mention the handle you gave when it is done. Thanks.

webkit-early-warning-system · 2024-04-17T23:45:00Z

EWS run on previous version of this PR (hash 9025e8d)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	✅ 🧪 wpe-wk2
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	✅ 🧪 api-mac	✅ 🧪 api-wpe
	✅ 🧪 ios-wk2-wpt	✅ 🧪 mac-wk1	✅ 🛠 wpe-skia
	✅ 🧪 api-ios	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 tv	✅ 🧪 mac-AS-debug-wk2	✅ 🧪 gtk-wk2
	✅ 🛠 tv-sim	✅ 🧪 mac-wk2-stress	✅ 🧪 api-gtk
	✅ 🛠 watch
	✅ 🛠 watch-sim

gwhitney · 2024-04-17T23:47:14Z

This bugfix has been updated with respect to the further discussion in https://bugs.webkit.org/show_bug.cgi?id=247980 and rebased on top of #26954. I believe it resolves the associated issue, and would welcome @bubbleguuum to test it if possible. Thanks in advance for reviewing, @WebKit/glib-reviewers.

mcatanzaro

Looks fine to me. Just a few nits regarding style.

Source/WebCore/platform/gtk/PlatformScreenGtk.cpp

Source/WebKit/UIProcess/API/gtk/WebKitWebViewBase.cpp

Source/WebCore/platform/gtk/PlatformScreenGtk.cpp

mcatanzaro

Thanks for your comment in https://bugs.webkit.org/show_bug.cgi?id=250138. I'm going to click the Approve button. Time to update with my suggested changes and mark as ready rather than Draft.

gwhitney · 2024-04-24T19:21:22Z

OK, I will amend the commit as requested and unmark as draft within the next 24 hours. Thanks!

webkit-early-warning-system · 2024-04-29T19:34:14Z

EWS run on current version of this PR (hash 69ad530)

Misc	iOS, tvOS & watchOS	macOS	Linux	Windows
✅ 🧪 style	✅ 🛠 ios	✅ 🛠 mac	✅ 🛠 wpe	✅ 🛠 wincairo
✅ 🧪 bindings	✅ 🛠 ios-sim	✅ 🛠 mac-AS-debug	~~🧪 wpe-wk2~~
✅ 🧪 webkitperl	✅ 🧪 ios-wk2	~~🧪 api-mac~~	~~🧪 api-wpe~~
	~~🧪 ios-wk2-wpt~~	✅ 🧪 mac-wk1	✅ 🛠 wpe-skia
	~~🧪 api-ios~~	✅ 🧪 mac-wk2	✅ 🛠 gtk
	✅ 🛠 tv	~~🧪 mac-AS-debug-wk2~~	~~🧪 gtk-wk2~~
	~~🛠 tv-sim~~	~~🧪 mac-wk2-stress~~	~~🧪 api-gtk~~
✅ 🛠 🧪 merge	✅ 🛠 watch
	❌ 🛠 watch-sim

gwhitney · 2024-04-29T19:37:30Z

Sorry about the delay resulting from the conversation on webkit bugzilla 250138. Hope this is ready to go now, even if that conversation was unsatisfactory.

mcatanzaro

Unfortunately this breaks the Large Text accessibility setting, see https://bugs.webkit.org/show_bug.cgi?id=250138. We'll need to figure this out before landing.

mcatanzaro

Whoops, sorry... I failed to test whether it worked without changes, and it doesn't. Seems the large text setting is ~~only respected when running in flatpak~~ not respected if I fail to change it properly. Let's not block on this.

https://bugs.webkit.org/show_bug.cgi?id=247980 Reviewed by Michael Catanzaro. Move the scaling factor formerly in WebKitWebView.cpp (responsive to the xft-dpi setting) into WebKitWebViewBase.cpp, and split it into two scaling factors. The first, a page scaling factor, uses screenDPI to ensure that a length specified by a CSS unit of 1in will appear on the screen as one physical inch. The second, a text scaling factor, ensures that text specified as 96px in size will have a height on-screen as specified by fontDPI (which is primarily driven by the xft-dpi setting), in terms of the number of screen pixels taken up. The two scaling factors are refreshed when any one of the inputs for computing them changes: the GDK_SCALE factor, the xft-dpi setting, or the screenDPI of the device it is displayed on (say by being dragged to a different monitor). Throughout, at the default zoom level, a CSS 1in dimension is kept at one physical inch. The scale factors are kept internal to WebKitWebViewBase (which helps keep GTK dependencies grouped and reduces the total code in WebKitWebView enclosed in `#ifdef PLATFORM(GTK)`) but made available to WebKitWebView so that its external interfaces can maintain zoom level 1 as the default zoom level, and zoom in and out from there. So indeed, if a user of WebKitWebView asks for a zoom level of 1.5, a length specified in CSS as 1in will then occupy one and a half physical inches on screen. * Source/WebCore/platform/gtk/PlatformScreenGtk.cpp: (WebCore::fontDPI): * Source/WebKit/UIProcess/API/glib/WebKitWebView.cpp: (webkitWebViewConstructed): (webkitWebViewDispose): (webkit_web_view_set_zoom_level): (webkit_web_view_get_zoom_level): * Source/WebKit/UIProcess/API/gtk/WebKitWebViewBase.cpp: (_WebKitWebViewBasePrivate::_WebKitWebViewBasePrivate): (refreshInternalScaling): (webkitWebViewBaseUpdateDisplayID): (webkitWebViewBaseDispose): (webkitWebViewBaseGetScaleFactors): (deviceScaleFactorChanged): (webkitWebViewBaseCreateWebPage): * Source/WebKit/UIProcess/API/gtk/WebKitWebViewBasePrivate.h: Canonical link: https://commits.webkit.org/278128@main

webkit-commit-queue · 2024-04-29T22:18:14Z

Committed 278128@main (eb01eca): https://commits.webkit.org/278128@main

Reviewed commits have been landed. Closing PR #26938 and removing active labels.

aperezdc · 2024-05-02T13:41:15Z

Backported into the 2.44 branch as commit 9864937

gwhitney requested review from zdobersek, a team and cdumez as code owners April 6, 2024 20:17

gwhitney changed the title ~~Correct scaling for DPI in under GTK.~~ Correct scaling for DPI under GTK. Apr 6, 2024

gwhitney changed the title ~~Correct scaling for DPI under GTK.~~ [GTK] Correct scaling for monitor and Xft DPI. Apr 6, 2024

gwhitney changed the title ~~[GTK] Correct scaling for monitor and Xft DPI.~~ [GTK] Correct scaling for DPI. Apr 17, 2024

gwhitney force-pushed the gtk_dpi branch from 77f5097 to 9025e8d Compare April 17, 2024 23:42

mcatanzaro added the GLib Suggested Backport Suggest this merge request be backported to current WPE/GTK stable branch label Apr 18, 2024

mcatanzaro reviewed Apr 18, 2024

View reviewed changes

gwhitney marked this pull request as draft April 18, 2024 21:49

mcatanzaro approved these changes Apr 24, 2024

View reviewed changes

gwhitney force-pushed the gtk_dpi branch from 9025e8d to 69ad530 Compare April 29, 2024 19:34

gwhitney marked this pull request as ready for review April 29, 2024 19:36

mcatanzaro requested changes Apr 29, 2024

View reviewed changes

mcatanzaro approved these changes Apr 29, 2024

View reviewed changes

mcatanzaro added the merge-queue Applied to send a pull request to merge-queue label Apr 29, 2024

webkit-commit-queue force-pushed the gtk_dpi branch from 69ad530 to eb01eca Compare April 29, 2024 22:18

webkit-commit-queue merged commit eb01eca into WebKit:main Apr 29, 2024

webkit-commit-queue removed the merge-queue Applied to send a pull request to merge-queue label Apr 29, 2024

aperezdc removed the GLib Suggested Backport Suggest this merge request be backported to current WPE/GTK stable branch label May 2, 2024

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[GTK] Correct scaling for DPI. #26938

[GTK] Correct scaling for DPI. #26938

gwhitney commented Apr 6, 2024 •

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[GTK] Correct scaling for DPI. #26938

[GTK] Correct scaling for DPI. #26938

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69ad530

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