Option to use Flatpaks under Linux

This adds a configuration setting "linuxUseFlatpak" which controls
whether Steam should be launched as a Flatpak or not. By default this
is detected automatically based on the path, but an option in the
settings can override the behaviour.

If this option is enabled, we first check if we are able to read from
our config directory. If not, we display an error and ask the user to
give us permission. If we do, then we launch Steam through flatpak
rather than the binary directly.

src/components/settings-components/SettingsView.vue

@@ -355,6 +355,23 @@ import CdnProvider from '../../providers/generic/connection/CdnProvider';
                 'fa-file-alt',
                 () => this.emitInvoke('ShowDependencyStrings')
             ),
+            new SettingsRow(
+                'Other',
+                'Launch as Flatpak (Linux)',
+                'Launch Steam via flatpak',
+                async () => {
+                    switch (this.settings.getContext().global.linuxUseFlatpak) {
+                        case null:
+                            return 'Automatic';
+                        case true:
+                            return 'Flatpak';
+                        case false:
+                            return 'Native';
+                    }
+                },
+                'fa-exchange-alt',
+                () => this.emitInvoke('ToggleLinuxUseFlatpak')
+            ),
         ];
 
         @Watch('search')

src/pages/Manager.vue

@@ -367,6 +367,10 @@ import ModalCard from '../components/ModalCard.vue';
 			this.settings.setFunkyMode(value);
 		}
 
+		setLinuxUseFlatpak(value: boolean) {
+			this.settings.setLinuxUseFlatpak(value);
+		}
+
 		async exportProfile() {
 			if (!this.localModList.length) {
 				const err = new R2Error(
@@ -569,6 +573,9 @@ import ModalCard from '../components/ModalCard.vue';
                 case "ToggleFunkyMode":
                     this.setFunkyMode(!this.settings.getContext().global.funkyModeEnabled);
                     break;
+                case "ToggleLinuxUseFlatpak":
+                    this.setLinuxUseFlatpak(!this.settings.getContext().global.linuxUseFlatpak);
+                    break;
                 case "SwitchTheme":
                     this.toggleDarkTheme();
                     document.documentElement.classList.toggle('html--dark', this.settings.getContext().global.darkTheme);

src/r2mm/launching/runners/linux/SteamGameRunner_Linux.ts

@@ -50,26 +50,50 @@ export default class SteamGameRunner_Linux extends GameRunnerProvider {
         if (args instanceof R2Error) {
             return args
         }
-        return this.start(game, args);
+        return this.start(game, args, profile.getPathOfProfile());
     }
 
     public async startVanilla(game: Game, profile: Profile): Promise<void | R2Error> {
         const instructions = await GameInstructions.getInstructionsForGame(game, profile);
-        return this.start(game, instructions.vanillaParameters);
+        return this.start(game, instructions.vanillaParameters, null);
     }
 
-    async start(game: Game, args: string): Promise<void | R2Error> {
+    async start(game: Game, args: string, profiledir: string | null): Promise<void | R2Error> {
 
         const settings = await ManagerSettings.getSingleton(game);
         const steamDir = await GameDirectoryResolverProvider.instance.getSteamDirectory();
         if(steamDir instanceof R2Error) {
             return steamDir;
         }
+        let as_flatpak = settings.getContext().global.linuxUseFlatpak;
+        if (as_flatpak === null) {
+            // Assume that if the path contains the flatpak directory we must want to use flatpak
+            as_flatpak = steamDir.includes("/com.valvesoftware.Steam/");
+        }
+
+        if (as_flatpak && profiledir) {
+            // Ensure we have permission to read our config dir
+            const visible = await new Promise((resolve) => {
+                const check_cmd = `flatpak run --command='sh' com.valvesoftware.Steam -c 'ls "${profiledir}"'`;
+                exec(check_cmd).on('close', (error) => {
+                    resolve(error == 0);
+                });
+            });
+            if (!visible) {
+                throw new R2Error('Flatpak Permissions Error',
+                    `The directory "${profiledir}" is not visible from within the Flatpak container`,
+                    '`flatpak override com.valvesoftware.Steam --user --filesystem="${XDG_CONFIG_HOME:-$HOME/.config}/r2modmanPlus-local"` to grant access, then restart Steam.');
+            }
+        }
 
         LoggerProvider.instance.Log(LogSeverity.INFO, `Steam directory is: ${steamDir}`);
 
         try {
-            const cmd = `"${steamDir}/steam.sh" -applaunch ${game.activePlatform.storeIdentifier} ${args} ${settings.getContext().gameSpecific.launchParameters}`;
+            let cmd = `"${steamDir}/steam.sh" -applaunch ${game.activePlatform.storeIdentifier} ${args} ${settings.getContext().gameSpecific.launchParameters}`;
+            if (as_flatpak) {
+                cmd = `flatpak run com.valvesoftware.Steam ${cmd}`;
+            }
+
             LoggerProvider.instance.Log(LogSeverity.INFO, `Running command: ${cmd}`);
             await exec(cmd);
         } catch(err) {

src/r2mm/manager/ManagerSettings.ts

@@ -97,6 +97,11 @@ export default class ManagerSettings {
         await this.save();
     }
 
+    public async setLinuxUseFlatpak(enabled: boolean) {
+        ManagerSettings.CONTEXT.global.linuxUseFlatpak = enabled;
+        await this.save();
+    }
+
     public async expandCards() {
         ManagerSettings.CONTEXT.global.expandedCards = true;
         await this.save();

src/r2mm/manager/SettingsDexieStore.ts

@@ -119,7 +119,8 @@ export default class SettingsDexieStore extends Dexie {
                 favouriteGames: [],
                 defaultGame: undefined,
                 defaultStore: undefined,
-                gameSelectionViewMode: GameSelectionViewMode.CARD
+                gameSelectionViewMode: GameSelectionViewMode.CARD,
+                linuxUseFlatpak: null,
             },
             gameSpecific: {
                 version: 2,
@@ -197,6 +198,7 @@ export interface ManagerSettingsInterfaceGlobal_V2 {
     defaultGame: string | undefined;
     defaultStore: StorePlatform | undefined;
     gameSelectionViewMode: GameSelectionViewMode;
+    linuxUseFlatpak: boolean | null;
 }
 
 /**