Bug 1214239

Summary:	GTK application use wrong DPI scale under Plasma
Product:	[openSUSE] openSUSE Distribution	Reporter:	Linus Kardell <linus.kardell>
Component:	KDE Workspace (Plasma)	Assignee:	E-Mail List <opensuse-kde-bugs>
Status:	NEW ---	QA Contact:	E-mail List <qa-bugs>
Severity:	Normal
Priority:	P5 - None	CC:	vkrevs
Version:	Leap 15.5
Target Milestone:	---
Hardware:	Other
OS:	Other
Whiteboard:
Found By:	---	Services Priority:
Business Priority:		Blocker:	---
Marketing QA Status:	---	IT Deployment:	---

Description Linus Kardell 2023-08-14 08:46:44 UTC

After updating today, GTK applications use completely the wrong DPI scale. It's not consistent either, I might change it and change it back in the Plasma settings, and end up with GTK applications using a different scale they started with. For example, I might have the Global Scale slider set to 125%, with GTK applications getting a 1.5x scale (according to Firefox about:support "Window Device Pixel Ratios"). Then I change the slider to 300%, and "Window Device Pixel Ratios" changes to 1.2x (but the text in Firefox becomes much tinier than that). Then I change the slider back down to 125%, and Firefox gets a 3.5294117647058822x scale, making everything huge.

Operating System: openSUSE Leap 15.5
KDE Plasma Version: 5.27.4
KDE Frameworks Version: 5.103.0
Qt Version: 5.15.8
Kernel Version: 5.14.21-150500.55.12-default (64-bit)
Graphics Platform: X11
Processors: 16 × AMD Ryzen 7 1700X Eight-Core Processor
Memory: 62.7 Gibyte of RAM
Graphics Processor: NVIDIA GeForce GT 1030/PCIe/SSE2

Comment 1 Linus Kardell 2023-08-14 09:14:38 UTC

Part of it seems to be that layout.css.devPixelsPerPx was set to 1.2, probably some remnant I set when the scale wasn't properly communicated to Firefox. Resetting that makes the scale more correct, but that still leaves the issue that setting large scale and then a small scale makes everything huge.