Support Heroic Games Launcher

[MattSturgeon]

Many users prefer to use the Heroic Games Launcher, instead of the various official games launchers it replaces. This is especially true on Linux, where it is a native & well integrated application, unlike most official launchers.

Heroic makes use of store-specific tools (currently Legendary, gogdl & Nile). These tools can be used separately from Heroic to install & launch games owned on the respective store. However I don't think those tools keep track of and "manage" installed games, per-se. (Might be wrong about that, I've not used those tools directly).

Heroic can be installed via Flatpak, AppImage, via distro packages or manually from a tarball. This probably won't be too relevant since regardless of Heroic's installation method, users can install games to any location they wish on their system. Although, Heroic's cache & config will be at a different path when it's installed as a flatpak.

Since users can install games anywhere, would probably need to scan the relevant config/list/database that catalogs installed games.

See also https://github.com/Nexus-Mods/NexusMods.App/issues/1695

[erri120]

Some research notes:

Heroic writes data to app.getPath(userData). A list of installed GOG games can be found in gog_store/installed.json:

{
	"installed": [
		{
			"platform": "windows",
			"executable": "",
			"install_path": "/home/user/Games/Heroic/Treasure Adventure Game",
			"install_size": "105.91 MiB",
			"is_dlc": false,
			"version": "1.0",
			"appName": "1207659013",
			"installedDLCs": [],
			"language": "en-US",
			"versionEtag": "\"1232499704\"",
			"buildId": "51402546720039850",
			"pinnedVersion": false
		}
	]
}

[MattSturgeon]

Heroic writes data to app.getPath(userData).

Note: when heroic is installed using flatpak, this won't be the same XDG_DATA_HOME that "normal" programs see (~/.local/share by default).

Flatpak gives its sandboxed apps a) an overlayed $HOME directory and b) custom XDG dirs, usually in ~/.var/app/com.heroicgameslauncher.hgl.

---

When NM.A is installed "normally" it should be trivial to also scan flatpak's sandbox locations from the host environment, however if NM.A ever supports being installed as a flatpak, then accessing the host system (or other flatpaks) becomes more difficult.

Though that's a much wider issue mostly unrelated to this one.