Update usage instructions for Flatpak

And also add Flatpak-specific build instructions.

README.md

@@ -3,7 +3,6 @@ Spotify adblocker for Linux (macOS untested) that works by wrapping `getaddrinfo
 
 ### Notes
 * This **does not** work with the snap Spotify package.
-* This **might not** work with the Flatpak Spotify package, depending on your system's shared libraries' versions.
 * On Debian-based distributions (e.g. Ubuntu), the Debian Spotify package can be installed by following the instructions at the bottom of [this page](https://www.spotify.com/us/download/linux/). *(recommended)*
 
 ## Build
@@ -14,32 +13,44 @@ Prerequisites:
 * [Cargo](https://doc.rust-lang.org/cargo/)
 
 ```bash
-$ git clone https://github.com/abba23/spotify-adblock.git
-$ cd spotify-adblock
-$ make
+git clone https://github.com/abba23/spotify-adblock.git
+cd spotify-adblock
+make
 ```
 
-## Install
+#### Build (Flatpak)
+
+You only need `git` and `podman` (or `docker`) installed:
+
 ```bash
-$ sudo make install
+git clone https://github.com/abba23/spotify-adblock.git
+cd spotify-adblock
+# This is a Docker-compatible command
+podman run -it --rm -v $(pwd):/src:Z ubuntu:24.10 sh -c 'apt update && apt install -y --no-install-recommends ca-certificates cargo make && make -C /src'
 ```
 
-#### Flatpak
+## Install
 ```bash
-$ mkdir -p ~/.spotify-adblock && cp target/release/libspotifyadblock.so ~/.spotify-adblock/spotify-adblock.so
-$ mkdir -p ~/.config/spotify-adblock && cp config.toml ~/.config/spotify-adblock
-$ flatpak override --user --filesystem="~/.spotify-adblock/spotify-adblock.so" --filesystem="~/.config/spotify-adblock/config.toml" com.spotify.Client
+sudo make install
 ```
 
-## Usage
-### Command-line
+#### Install (Flatpak)
 ```bash
-$ LD_PRELOAD=/usr/local/lib/spotify-adblock.so spotify
+mkdir -p ~/.var/app/com.spotify.Client/config/spotify-adblock
+cp target/release/libspotifyadblock.so ~/.var/app/com.spotify.Client
+cp config.toml ~/.var/app/com.spotify.Client/config/spotify-adblock
+flatpak --user override "--env=LD_PRELOAD=$HOME/.var/app/com.spotify.Client/libspotifyadblock.so" com.spotify.Client
 ```
 
-#### Flatpak
+## Usage
+
+### Flatpak
+
+No extra configuration needed, just launch the app.
+
+### Command-line
 ```bash
-$ flatpak run --command=sh com.spotify.Client -c 'eval "$(sed s#LD_PRELOAD=#LD_PRELOAD=$HOME/.spotify-adblock/spotify-adblock.so:#g /app/bin/spotify)"'
+LD_PRELOAD=/usr/local/lib/spotify-adblock.so spotify
 ```
 
 ### Desktop file
@@ -51,7 +62,7 @@ Examples:
   <summary>Debian Package</summary>
   <p>
 
-```
+```ini
 [Desktop Entry]
 Type=Application
 Name=Spotify (adblock)
@@ -67,39 +78,21 @@ StartupWMClass=spotify
   </p>
 </details>
 
-<details>
-  <summary>Flatpak</summary>
-  <p>
-
-```
-[Desktop Entry]
-Type=Application
-Name=Spotify (adblock)
-GenericName=Music Player
-Icon=com.spotify.Client
-Exec=flatpak run --file-forwarding --command=sh com.spotify.Client -c 'eval "$(sed s#LD_PRELOAD=#LD_PRELOAD=$HOME/.spotify-adblock/spotify-adblock.so:#g /app/bin/spotify)"' @@u %U @@
-Terminal=false
-MimeType=x-scheme-handler/spotify;
-Categories=Audio;Music;Player;AudioVideo;
-StartupWMClass=spotify
-```
-  </p>
-</details>
-
 ## Uninstall
 ```bash
-$ sudo make uninstall
+sudo make uninstall
 ```
 
-#### Flatpak
+#### Uninstall (Flatpak)
 ```bash
-$ rm -r ~/.spotify-adblock ~/.config/spotify-adblock
-$ flatpak override --user --reset com.spotify.Client
+flatpak --user override --unset-env=LD_PRELOAD com.spotify.Client
+rm -rv ~/.var/app/com.spotify.Client/{config/spotify-adblock,libspotifyadblock.so}
 ```
 
 ## Configuration
 The allowlist and denylist can be configured in a config file located at (in descending order of precedence):
 * `config.toml` in the working directory
 * `$XDG_CONFIG_HOME/spotify-adblock/config.toml`
 * `~/.config/spotify-adblock/config.toml`
+* `~/.var/app/com.spotify.Client/config/spotify-adblock/config.toml` *(Flatpak)*
 * `/etc/spotify-adblock/config.toml` *(default)*