Bug 395215

Summary:	Font settings affect scaling in an unexpected way
Product:	[Plasma] plasmashell	Reporter:	Ilya Bizyaev <bizyaev>
Component:	general	Assignee:	David Edmundson <kde>
Status:	RESOLVED INTENTIONAL
Severity:	normal	CC:	nate, plasma-bugs
Priority:	NOR
Version:	5.12.5
Target Milestone:	1.0
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed In:
Attachments:	Case #1, Roboto 10 Case #1, Roboto 11 Case #2, Kickoff, Noto Sans Case #2, Kickoff, Zilla Slab (same size) Case #2, Kickoff, Catamaran (same size) Case #2, notification, Noto Sans Case #2, notification, Zilla Slab (same size) Case #2, notification, Catamaran (same size)

Description Ilya Bizyaev 2018-06-10 15:14:33 UTC

Using a different font family than Noto Sans or different sizes results in unexpected scaling changes that affect Kickoff, notifications and other parts of the UI.

Apart from that, the issue prevents from using any other DPI setting than X11's default 96.

I attach a number of screenshots which show how the scaling may change depending on user's settings.

Comment 1 Ilya Bizyaev 2018-06-10 15:15:50 UTC

Created attachment 113195 [details]
Case #1, Roboto 10

Comment 2 Ilya Bizyaev 2018-06-10 15:16:14 UTC

Created attachment 113196 [details]
Case #1, Roboto 11

Comment 3 Ilya Bizyaev 2018-06-10 15:17:57 UTC

Created attachment 113197 [details]
Case #2, Kickoff, Noto Sans

Comment 4 Ilya Bizyaev 2018-06-10 15:18:33 UTC

Created attachment 113198 [details]
Case #2, Kickoff, Zilla Slab (same size)

Comment 5 Ilya Bizyaev 2018-06-10 15:19:13 UTC

Created attachment 113199 [details]
Case #2, Kickoff, Catamaran (same size)

Comment 6 Ilya Bizyaev 2018-06-10 15:20:21 UTC

Created attachment 113200 [details]
Case #2, notification, Noto Sans

Comment 7 Ilya Bizyaev 2018-06-10 15:20:51 UTC

Created attachment 113201 [details]
Case #2, notification, Zilla Slab (same size)

Comment 8 Ilya Bizyaev 2018-06-10 15:21:29 UTC

Created attachment 113202 [details]
Case #2, notification, Catamaran (same size)

Comment 9 Ilya Bizyaev 2018-06-10 15:22:37 UTC

The first screenshot in each series shows the expected UI scaling.

Comment 10 Nate Graham 2021-03-10 03:30:22 UTC

This is pretty much intentional, to ensure that the relative proportions of the UI remain the same as the font is changed. It breaks down if you crank the font too high, after which point it would make more sense to use a scale factor to make things bigger or smaller. The Fonts KCM now advises you to do this if you try. :)

Sadly it's true that there can be minor bugs introduced based on the metrics of the fonts; for example 11pt Noto Sans is 22% bigger than 10pt Noto Sans, not 10% bigger as yo would expect. As a result going to 11pt Noto Sans makes everything enormous. This is a bug in Noto Sans itself, sadly. See Bug 431947 for details.

Those issues should be tracked separately though.