Bug 367499 - usability regression: GTK+>3.16.x results in too small GTK3 app UI fonts when logical DPI>96
Summary: usability regression: GTK+>3.16.x results in too small GTK3 app UI fonts when...
Status: RESOLVED UPSTREAM
Alias: None
Product: kde-gtk-config
Classification: Plasma
Component: general (show other bugs)
Version: unspecified
Platform: unspecified Linux
: NOR major
Target Milestone: ---
Assignee: Manuel Tortosa
URL:
Keywords: accessibility, usability
Depends on:
Blocks:
 
Reported: 2016-08-18 13:32 UTC by Felix Miata
Modified: 2017-11-28 23:22 UTC (History)
5 users (show)

See Also:
Latest Commit:
Version Fixed In:
Sentry Crash Report:


Attachments
168 DPI screenshot with RV45 and RV48 Firefoxes loaded over/under in Plasma (145.66 KB, image/jpeg)
2016-08-18 13:32 UTC, Felix Miata
Details

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Description Felix Miata 2016-08-18 13:32:08 UTC
Created attachment 100663 [details]
168 DPI screenshot with RV45 and RV48 Firefoxes loaded over/under in Plasma

After https://bugzilla.mozilla.org/show_bug.cgi?id=1269274 was closed WONTFIX, I asked about this several places:
https://mail.gnome.org/archives/gtk-devel-list/2016-July/msg00028.html
https://lists.fedoraproject.org/archives/list/kde@lists.fedoraproject.org/thread/ZPIFOVGR6572ZR7L4TXMUXRYHQESBOPW/
http://trinity-devel.pearsoncomputing.net/?0::15168
None generated any response.

According to the mozilla bug, https://git.gnome.org/browse/gtk+/commit/?id=bdf0820c501437a2150d8ff0d5340246e713f73f caused the regression.

Upstream bug that could have fixed this was WONTFIX'd last October:
https://bugzilla.gnome.org/show_bug.cgi?id=757142

If there happens to be an XFT.dpi setting equal to the actual Xorg display density, then UI font sizes are OK. What seems to be needed is a way for Xorg density to be automatically converted into an Xft.dpi value for the exclusive benefit of these GTK3-built apps.
Comment 1 Aleix Pol 2016-08-19 00:16:14 UTC
I'm not sure what can we do about it from kde-gtk-config really... :/
Comment 2 Vishnu 2017-06-20 06:31:19 UTC
Same issue with a 117 DPI monitor. Firefox seems very out of place.
Comment 3 Nate Graham 2017-11-28 21:57:31 UTC
I don't think there's anything we can do here. Seems like if the GTK folks refuse to fix the issue in GTK itself, we're kind of stuck. :( All we can do is boycott GTK apps and move to Wayland. :p
Comment 4 Felix Miata 2017-11-28 22:14:08 UTC
As Xft.dpi is how KDE already forces DPI, it seems logical anyone with appropriate skillset who wanted a fix should be able to create a method to read Xorg's actual DPI, extract the value, and inject that value for Xft.dpi into the xrdb environment. Thus resolving this upstream serves only to dissuade anyone from trying to create a fix.
Comment 5 Nate Graham 2017-11-28 22:19:33 UTC
Yes, a fix is definitely possible. But it would be a fix for GTK itself, or a workaround in xrdb or some other piece of software that makes everything play nice. This is the KDE bug tracker; we can only track issues in KDE software here. Working around GTK's frustrating bugs in the manner you suggest is distro work (and why distros exist), not something we can do.
Comment 6 Felix Miata 2017-11-28 22:48:26 UTC
Of course the ideal fix would be for GTK to undo the damage it caused - that goes without saying.

Is KDE forcing DPI using Xft.dpi not a workaround for some other upstream problem?

Saying it's not a KDE problem is no help to those suffering, because it's KDE users who do the suffering here, not Gnome users. Upstream's only incentive to fix is minimal, to have its apps play nice in other environments. So users need a workaround from somewhere, and since KDE users are one of the suffering groups, and KDE is already aware of how to alter Xft.dpi, it seems sensible for a workaround to be provided by KDE alone rather than each individual distro providing KDE.
Comment 7 Nate Graham 2017-11-28 22:51:38 UTC
It sounds like you have substantial technical knowledge of the subsystems in play here. Would you like to have a go at producing a patch?
Comment 8 Felix Miata 2017-11-28 23:22:19 UTC
(In reply to Nate Graham from comment #7)
> It sounds like you have substantial technical knowledge of the subsystems in
> play here. Would you like to have a go at producing a patch?

If I thought I actually had the required knowledge I might, but I'm not a programmer. The way Xorg works is to me a barely navigable maze that seems to have nearly as many variations as there are Linux distros, a miracle that it works as well as it does. The only patches I've ever submitted as bug fixes anywhere have been to CSS in Mozilla.

At this point I'm still hopeful that other distros will follow openSUSE's lead (reverting upstream commit[1]), and the ideal fix will ultimately come from upstream reversion.

[1] https://bugzilla.opensuse.org/show_bug.cgi?id=1022830
GTK3 apps not honoring system-wide DPI settings nor KDE mouse cursor