Option to use Flatpaks under Linux

src/components/settings-components/SettingsView.vue

@@ -347,6 +347,23 @@ 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

@@ -370,6 +370,10 @@ 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(
@@ -583,6 +587,9 @@ 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

@@ -53,26 +53,50 @@ export default class SteamGameRunner_Linux extends GameRunnerProvider {
         if (args instanceof R2Error) {
             return args
         }
-        return this.start(game, args);
+        return this.start(game, args, profile.getProfilePath());
     }
 
     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 folder 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;
 }
 
 /**