Bug 423655

Summary: cannot display all of very large SVG images
Product: [Applications] gwenview Reporter: Soren Harward <stharward>
Component: generalAssignee: Gwenview Bugs <gwenview-bugs-null>
Status: RESOLVED DUPLICATE    
Severity: normal CC: postix
Priority: NOR    
Version: 20.04.2   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:
Attachments: very large SVG image
Screenshot: Gwenview displaying a perf flamegraph
Screenshot: Gwenview displaying the very_large_picture.svg

Description Soren Harward 2020-06-29 13:00:51 UTC
SUMMARY
When displaying a SVG that is much larger than screen size, Gwenview does not display all of the image.  Maybe only a quarter of it?

STEPS TO REPRODUCE
Load a SVG that is much larger than screen resolution; I'll attach a 6000×6000 demo file.

OBSERVED RESULT
Gwenview displays only part of the image.  Zooming in and out scales the image properly, but only a part of it is displayed.  Scrolling/panning stops at the wrong place.


EXPECTED RESULT
Full image should be displayed, with proper zooming and panning.

SOFTWARE/OS VERSIONS
Linux: recent Gentoo
KDE Plasma Version: 5.19.0
KDE Frameworks Version: 5.71.0
Qt Version: 5.14.2

ADDITIONAL INFORMATION
I'm using LXQT as my desktop environment, with kwin_x11 as the window manager.  I'm not running a full KDE/plasma environment.
Comment 1 Soren Harward 2020-06-29 13:01:48 UTC
Created attachment 129762 [details]
very large SVG image
Comment 2 Soren Harward 2020-06-29 13:04:03 UTC
possibly also relevant: I have a hidpi display: 24", 3840×2160, 185dpi
Comment 3 Soren Harward 2020-07-16 13:28:20 UTC
More details:

Setting QT_AUTO_SCREEN_SCALE_FACTOR=0 shows the entire SVG, but the scaling of the image is messed up.  What gwenview thinks is 100% is more like 50%.  12pt text in image is 6pt high on screen.

Setting QT_AUTO_SCREEN_SCALE_FACTOR=1 results in the behavior explained above: the scaling of the image is correct (12pt looks like 12pt), but I can only scroll the middle quarter of the image.
Comment 4 postix 2021-07-10 15:02:55 UTC
Created attachment 139983 [details]
Screenshot: Gwenview displaying a perf flamegraph

I can confirm this behavior on

Operating System: openSUSE Tumbleweed 20210707
KDE Plasma Version: 5.22.2
KDE Frameworks Version: 5.83.0
Qt Version: 5.15.2
Kernel Version: 5.13.0-1-default (64-bit)
Graphics Platform: X11
Scaling: 2.0

however,

`QT_AUTO_SCREEN_SCALE_FACTOR=1 gwenview ~/Downloads/very_large_picture.svg`

OR

`QT_AUTO_SCREEN_SCALE_FACTOR=0 gwenview ~/Downloads/very_large_picture.svg`

did not make any differences for me. The result was always the same. Opening the image in Inkscape however worked absolutely fine!
Comment 5 postix 2021-07-10 15:04:02 UTC
Created attachment 139984 [details]
Screenshot: Gwenview displaying the very_large_picture.svg
Comment 6 postix 2021-07-10 15:27:00 UTC

*** This bug has been marked as a duplicate of bug 336436 ***