HiDPI screen completely messed up with 1.20

[omgold]

Expected behaviour

With mate 1.20 on HiDPI screens everything should look and work nicely, as with 1.18 (maybe minus some smaller HiDPI bugs in the panel)

Actual behaviour

• when running mate 1.20 on my HiDPI laptop various sizes are off:

  • font resolution under appearance is set to double the x11 value
  • panel height is double the specified value in pixels
  • many application font sizes are too big

• weird stuff happens with panel widgets

  • some are stretched or too small
  • some flicker around continuously, while producing 100% load on one CPU core

Steps to reproduce the behaviour

• create a fresh user on a hidpi laptop
• startup mate desktop

More details

When I noticed the problem first, I had X11 configured to 200 DPI by setting the DisplaySize option in the Monitor section of xorg.conf:

xdpyinfo|grep resolution resolution: 200x200 dots per inch

To rule out the idea that the migration of the old mate config failed, I created a new test user. What I go was this desktop:

• fonts and panel much too large
• notification area stretched horizontally
• desktop switcher compressed vertically

The font resolution in appearance showed as 400 DPI. When I reduced it to the desired 200 DPI, I got this:

• fonts and panel reasonable sized
• notification area stretched horizontally and flickering around
• desktop switcher compressed vertically

Then I tried to do everything from fresh, with a new user again, but before removing the DPI increase in X11 config, falling back to the default 96 DPI. The result was that desktop:

• fonts and panel reasonable sized (appearence says 192 DPI)
• notification area flickering around
• date/time widget text placement faulty
• desktop switcher compressed vertically

MATE general version

1.20.0

Package version

mate-settings-daemon 1.20.0 mate-panel 1.20.0

Linux Distribution

Arch

[lukefromdc]

The panel widget problem is the same issue as https://github.com/mate-desktop/mate-panel/issues/668 , which is a problem with applets shipped with the panel not scaling correctly when built out of process. If you are building the panel yourself, rebuilding with --with-in-process-applets=all will tix that.

If you want to restore the same behavior you had with 1.18, open dconf-editor, go to org>mate>desktop>interface and set window-scaling-factor to "1" as the default value of "0" is to autodetect a hidpi screen. A value of "2" is used to force double-scaling, for the opposite problem.

[lukefromdc]

Also keep in mind that both font-scaling AND window-scaling change the size of essentially everything, and font-scaling normally changes automatically in response to changing window scaling factor. Wonder if some setups are having issues with that on autodetection, as my tests have to be done by manually forcing window-scaling-factor=2 on a 1920x1080 display

[omgold]

Can confirm that window-scaling-factor=1 helps.

The panel issue doesn't look like being same as mate-panel#668 to me. That one was present since quite some time ago, and only concerning the notification area. Also the flickering widgets is something quite new to me.

[lukefromdc]

That bug report only mentioned the notification area, but others have reported the same problem with things like the workspace-switcher, in all cases when built out-of-process

[vkareh]

Closing this as the applets flickering issue is a duplicate of mate-desktop/mate-applets/issues/308