Flatpak apps installed through Pop!_Shop do not pick up Pop!_OS dark theme

[aral]

Distribution (run cat /etc/os-release):

NAME="Pop!_OS"
VERSION="20.04 LTS"
ID=pop
ID_LIKE="ubuntu debian"
PRETTY_NAME="Pop!_OS 20.04 LTS"
VERSION_ID="20.04"
HOME_URL="https://system76.com/pop"
SUPPORT_URL="http://support.system76.com"
BUG_REPORT_URL="https://github.com/pop-os/pop/issues"
PRIVACY_POLICY_URL="https://system76.com/privacy"
VERSION_CODENAME=focal
UBUNTU_CODENAME=focal
LOGO=distributor-logo-pop-os

Related Application and/or Package Version (run apt policy $PACKAGE NAME):

Pop!_Shop, flatpak, Pop!_OS themes

Issue/Bug Description:

Flatpak apps do not automatically pick up the system theme. However, they do if the theme is installed via flatpak. Since Pop!_OS has FlatHub support in Pop!_Shop now, it should also have the Pop!_OS themes pre-installed from flatpak so installed flatpak apps just work and match the system appearance.

Steps to reproduce (if you know):

1. Install gnomit from Pop!_Shop
2. Make sure the dark theme is set for the system
3. Make a git commit

Expected behavior:

It should match the theme. It doesn’t.

The workaround (which should not be necessary), is to install the Pop!_OS dark theme manually from Flathub:

flatpak install flathub org.gtk.Gtk3theme.Pop-dark

Appearance after workaround:

[mmstick]

@isantop How do we get this to work?

[isantop]

When you install a GTK app from Flathub, Flatpak will automatically try and install your current theme. So if you're currently using the dark theme and you install a GTK app, it will install the Dark theme for you. However, if you were using the light theme when you installed an app, then switched to the dark theme, then you won't have the correct theme.

As a potential solution, we could consider installing the Pop and Pop-dark themes when we add Flathub to the user's configuration.

[mmstick]

Having them pre-installed is a great idea.

[aral]

When you install a GTK app from Flathub, Flatpak will automatically try and install your current theme.

Interesting. AFAIK, I was not on the light theme when I installed it but I wonder if I was perhaps on Adwaita Dark on 19.10 when I first tested the Flathub install.

Regardless, as @mmstick said, having both preinstalled sounds like the safest/easiest route :)