[snap] cursor theme isn't respected

[Olivier Tilloy]

(initially reported at https://discourse.ubuntu.com/t/call-for-testing-chromium-browser-deb-to-snap-transition/11179/85)

When changing the cursor theme with gnome-tweaks, I can observe that some themes aren't respected in the chromium snap. This appears to be specific to chromium, other snaps like evince or gimp use the correct cursors.

Yaru and Adwaita are fine, but Redglass or Whiteglass aren't.

[Olivier Tilloy (osomon)]

Possibly relevant code in chromium: ui/base/cursor/cursor_loader_x11.cc

[Olivier Tilloy (osomon)]

See also bug #1833611.

[Joel Linn (jl-o)]

Broken on KDE by default.

[Merlijn Sebrechts (merlijn-sebrechts)]

The KDE theme isn't supported because gtk-common-themes doesn't include the default KDE cursor theme. This MR fixes that: https://gitlab.gnome.org/Community/Ubuntu/gtk-common-themes/merge_requests/17

[Brian Ibs (brian-ibs-uo)]

Fixed for me (Kubuntu 19.10 default mouse theme) as is https://bugs.launchpad.net/bugs/1833611 ("[snap] mouse pointer on Ubuntu flavours is retro-looking when hovering over links").

[Andrei Shevchuk (shevchuk)]

Confirm, this and #1833611 are both fixed for me (Kubuntu 19.10, Breeze)

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Sean Davis (bluesabre)]

Fix committed in xubuntu-default-settings:
- https://github.com/Xubuntu/xubuntu-default-settings/commit/7ea4e59df2394140b28cf92b2651d327a800f00f
- https://github.com/Xubuntu/xubuntu-default-settings/commit/f2ee8c4526862248edba19dc8a1aca9dfa10059b

Basically, we were referencing a theme that no longer exists, "Human", so the theme was falling back on Default. There is no default theme in gtk-common-themes, so the fallback X11 theme was used instead.

[Olivier Tilloy (osomon)]

Probably related: bug #1892085.

[Launchpad Janitor (janitor)]

This bug was fixed in the package xubuntu-default-settings - 21.04.0

---------------
xubuntu-default-settings (21.04.0) hirsute; urgency=medium

  * etc/xdg/xdg-xubuntu/xfce4/xfconf/xfce-perchannel-xml/xsettings.xml:
    - Set Gtk/CursorThemeName to DMZ-White (LP: #1838008)
  * etc/xdg/xdg-xubuntu/menus/xfce-applications.menu:
    - Hide confusing xfce4-terminal-settings.desktop
  * usr/share/xubuntu/applications/xfce4-terminal.desktop:
    - Dropped, enable showing in the menu (LP: #1851387)
  * etc/xdg/xdg-xubuntu/xfce4/panel/default.xml:
    - Migrate statusnotifier to systray and remove from panel (LP: #1907871)
    - Remove separator between clock and tray, add padding
    - Enable pulseaudio plugin window focus support
  * etc/xdg/xdg-xubuntu/xfce4/helpers.rc:
    - Change FileManager key to lowercase thunar to fix defaults
  * debian/live/whiskermenu-1.rc,
    etc/xdg/xdg-xubuntu/menus/xfce-applications.menu,
    etc/xdg/xdg-xubuntu/xfce4/whiskermenu/defaults.rc,
    usr/share/xubuntu/applications/defaults.list:
    - Replace exo-* with xfce4-* commands
  * etc/xdg/xdg-xubuntu/xfce4/xfconf/xfce-perchannel-xml/xfce4-desktop.xml:
    - Hide default icons: File System and Removable Devices
    - Exclude applications menu on desktop right click
  * etc/xdg/xdg-xubuntu/xfce4/xfconf/xfce-perchannel-xml/thunar.xml:
    - Switch default location selector to path bar
    - Enabled opening folders in new tab on middle click
    - Disabled changing window icon for special folders
  * etc/xdg/xdg-xubuntu/xfce4/xfconf/xfce-perchannel-xml/xfce4-keyboard-shortcuts.xml:
    - Apply upstream keyboard bindings:
      - Ctrl+Alt+Delete: xfce4-session-logout
      - Ctrl+Shift+Escape: xfce4-taskmanager
      - Super+R: xfrun4
      - Super+E, Ctrl+Alt+F: exo-open --launch FileManager

 -- Sean Davis <email address hidden> Sat, 12 Dec 2020 14:26:01 -0500

[Sebastien Bacher (seb128)]

The themes listed in the description are now included in gtk-common-themes which should resolve the issue

[xexz (xexz)]

you:~$ cp /var/lib/snapd/snaps/gtk-common-themes_1535.snap ~/
you:~$unsquashfs gtk-common-themes_1535.snap
you:~$ cp -rf xxx squashfs-root/share/icons/default/
you:~$ mksquashfs squashfs-root/ gtk-common-themes_1535.snap.n -all-root -comp lzo
you:~$ sudo mv gtk-common-themes_1535.snap.n /var/lib/snapd/snaps/gtk-common-themes_1535.snap

[Olivier Tilloy (osomon)]

So you're unpacking gtk-common-themes, adding something (xxx ?) to the icon theme, and repacking it. Can you explain why you're doing that?

The correct way would be to submit a PR against https://github.com/ubuntu/gtk-common-themes, which would address the problem you're encountering for everyone, and would ensure your modifications aren't discarded the next time the snap is updated.