[Bug]: system theme not detected and applied

[hellsworth]

What happened?

I just installed signal-desktop and on the first run I went to set the dark theme, to make it match my system theme. I see that the system theme was selected already, indicating that the app is not picking up that I have a dark system theme applied (the default yaru dark). So I had to manually set the dark theme in signal-desktop, which worked.

What should have happened?

The theme should have been dark because it is set system-wide.

Output of snap info $snap_name

heather@fenrir:~/Downloads$ snap info signal-desktop
name:      signal-desktop
summary:   Speak Freely - Private Messenger
publisher: Snapcrafters
store-url: https://snapcraft.io/signal-desktop
contact:   https://github.com/snapcrafters/signal-desktop/issues
license:   AGPL-3.0-only
description: |
  **Note: To use the Signal desktop app, you must first install Signal on your phone.**
  
  Millions of people use Signal every day for free and instantaneous communication anywhere in the
  world. Send and receive high-fidelity messages, participate in HD voice/video calls, and explore a
  growing set of new features that help you stay connected. Signal's advanced privacy-preserving
  technology is always enabled, so you can focus on sharing the moments that matter with the people
  who matter to you.
  
  - Say anything - State-of-the-art end-to-end encryption (powered by the open source Signal
  Protocol™) keeps your conversations secure. Privacy isn't an optional mode; it's just the way that
  Signal works. Every message, every call, every time.
  - Go fast - Messages are delivered quickly and reliably, even on slow networks. Signal is
  optimized to operate in the most constrained environment possible.
  - Feel free - Signal is a completely independent 501c3 nonprofit. Development is supported by
  users like you. No advertisements. No trackers. No kidding.
  - Be yourself - You can use your existing phone number and address book to securely communicate
  with your friends.
  - Speak up - Whether they live across town or across the ocean, Signal's enhanced audio and video
  quality will make your friends and family feel closer.
  - Whisper in the shadows - Switch to the dark theme if you refuse to see the light.
  
  **Are you having issues?**
  
  Let us know by creating a new issue here: https://github.com/snapcrafters/signal-desktop/issues
  
  **Authors**
  
  This snap is maintained by the Snapcrafters community, and is not necessarily endorsed or
  officially maintained by the upstream developers.
commands:
  - signal-desktop
snap-id:      r4LxMVp7zWramXsJQAKdamxy6TAWlaDD
tracking:     latest/stable
refresh-date: today at 15:30 MST
channels:
  latest/stable:    6.8.0 2023-03-02 (456) 193MB -
  latest/candidate: 6.7.0 2023-03-02 (459) 193MB -
  latest/beta:      ↑                            
  latest/edge:      ↑                            
installed:          6.8.0            (456) 193MB -

Output of snap connections $snap_name

heather@fenrir:~/Downloads$ snap connections signal-desktop
Interface               Plug                                   Slot                            Notes
audio-playback          signal-desktop:audio-playback          :audio-playback                 -
audio-record            signal-desktop:audio-record            :audio-record                   -
browser-support         signal-desktop:browser-support         :browser-support                -
camera                  signal-desktop:camera                  :camera                         -
content[gnome-42-2204]  signal-desktop:gnome-42-2204           gnome-42-2204:gnome-42-2204     -
content[gtk-3-themes]   signal-desktop:gtk-3-themes            gtk-common-themes:gtk-3-themes  -
content[icon-themes]    signal-desktop:icon-themes             gtk-common-themes:icon-themes   -
content[sound-themes]   signal-desktop:sound-themes            gtk-common-themes:sound-themes  -
desktop                 signal-desktop:desktop                 :desktop                        -
desktop-legacy          signal-desktop:desktop-legacy          :desktop-legacy                 -
gsettings               signal-desktop:gsettings               :gsettings                      -
home                    signal-desktop:home                    :home                           -
network                 signal-desktop:network                 :network                        -
opengl                  signal-desktop:opengl                  :opengl                         -
removable-media         signal-desktop:removable-media         -                               -
screen-inhibit-control  signal-desktop:screen-inhibit-control  :screen-inhibit-control         -
unity7                  signal-desktop:unity7                  :unity7                         -
wayland                 signal-desktop:wayland                 :wayland                        -
x11                     signal-desktop:x11                     :x11                            -

Output of snap version

heather@fenrir:~/Downloads$ snap version
snap    2.58.3+23.04
snapd   2.58.3+23.04
series  16
ubuntu  23.04
kernel  5.19.0-21-generic

Relevant log output

No response

Teminal output of app

No response

[lucyllewy]

I'm thinking this is either an issue with how Signal discovers the theme, or there is a deficiency in the desktop plugs/snaps?

[jnsgruk]

This appears to be working now - a fair bit has changed since this was filed, and I've been able to confirm that switching the system theme while signal is open results in an immediate change on both 22.04 and 24.04. I'll close for now, please feel free to comment if it's still an issue!