Bug 353910

Summary:	if plasma screen scaling is used because of HiDPI, the image viewport gets also scaled
Product:	[Applications] gwenview	Reporter:	moert09
Component:	general	Assignee:	Gwenview Bugs <gwenview-bugs-null>
Status:	RESOLVED DUPLICATE
Severity:	normal	CC:	artem.rizhov, bugzilla, mklapetek, moert09, myriam
Priority:	NOR
Version:	Other (add details in bug description)
Target Milestone:	---
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Attachments:	screenshot which illustrates the issue

Description moert09 2015-10-14 21:18:28 UTC

If you set a value greater 1 for screen scaling in system settings -> screen -> scale screen (because using a HiDPI screen) to make the UI look good, the actual image displaying in the viewport area of gwenview gets scaled to. This looks pretty bad, because it pixelates every image. 
If you open a screenshot of your desktop for example, and you view the image in original size one would expect, that everything on the screenshot has the same size than the original component. But if you set a scaling factor of 2, the plasma panel is twice as large as the original one. On top of that everything is pixelated.

Reproducible: Always

Steps to Reproduce:
1. Set display scaling factor greater than one in system settings
2. open any picture in gwenview (best seen when opening a screenshot)

Actual Results:  
The scaling factor is applied to the image, making everything look pixelated and to large when viewing in original size

Expected Results:  
Scaling is only applied to the UI, not the viewport, so that one pixel of the image matches one pixel of the screen

I'm using Lenovo Yoga 2 pro with a native screen resolution of 3200x1800px

Comment 1 moert09 2015-10-14 21:21:59 UTC

Created attachment 94997 [details]
screenshot which illustrates the issue

Comment 2 moert09 2015-10-14 21:26:04 UTC

Arch package version is 15.08.2

Comment 3 Gery 2016-09-10 22:19:22 UTC

Unfortunately, this is still an issue in Applications 16.08.

Comment 4 artem 2016-12-22 20:11:44 UTC

Same problem in Gwenview 16.04.3 on Ubuntu 16.04 with Plasma 5.8.4.

I also noticed that the button icons on the toolbar and on the sidebar are also pixilated. Seems like this app does not yet support scaling.

Why this bug is still unconfirmed? What info is needed to confirm the problem exists?

Comment 5 Christoph Feck 2016-12-22 20:59:58 UTC

The bug status does not matter. We need someone working on a patch.

Comment 6 Martin Klapetek 2016-12-22 23:20:03 UTC

Closing as duplicate of 373178 because that one also has a patch.

*** This bug has been marked as a duplicate of bug 373178 ***