Draft of handling urls

src/BasePlatform.ts

@@ -524,4 +524,10 @@ export default abstract class BasePlatform {
      * @returns {Promise<boolean>} True if the lock was acquired, false otherwise.
      */
     public abstract getSessionLock(_onNewInstance: () => Promise<void>): Promise<boolean>;
+
+    /**
+     * 
+     * @param urlPattern 
+     */
+    public registerProtocolHandler?(urlPattern: `${string}%s`): Promise<void>
 }

src/Views.ts

@@ -43,6 +43,10 @@ enum Views {
 
     // Another instance of the application has started up. We just show an error page.
     LOCK_STOLEN,
+
+    // Another instance of the application has opened and this session had a matrixuri, so we
+    // just show a warning and close.
+    SENT_URI,
 }
 
 export default Views;

src/components/structures/MatrixChat.tsx

@@ -140,6 +140,7 @@ import { ShareFormat, type SharePayload } from "../../dispatcher/payloads/ShareP
 import Markdown from "../../Markdown";
 import { sanitizeHtmlParams } from "../../Linkify";
 import { isOnlyAdmin } from "../../utils/membership";
+import mxModuleApi from "../../modules/Api";
 
 // legacy export
 export { default as Views } from "../../Views";
@@ -234,6 +235,7 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
     private fontWatcher?: FontWatcher;
     private readonly stores: SdkContextClass;
     private loadSessionAbortController = new AbortController();
+    private newUriBroadcastChannel = new BroadcastChannel("io.element.broadcast.new_uri");
 
     private sessionLoadStarted = false;
 
@@ -283,6 +285,12 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
         // object field used for tracking the status info appended to the title tag.
         // we don't do it as react state as i'm scared about triggering needless react refreshes.
         this.subTitleStatus = "";
+
+        this.newUriBroadcastChannel.addEventListener("message", (ev) => {
+            const { screen, params } = ev.data;
+            console.log(ev,  ev.data);
+            this.showScreen(screen, params);
+        });
     }
 
     /**
@@ -470,6 +478,7 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
 
         initSentry(SdkConfig.get("sentry"));
         window.addEventListener("resize", this.onWindowResized);
+        console.log("MatrixCHAT IS LOADING")
 
         // Once we start loading the MatrixClient, we can't stop, even if MatrixChat gets unmounted (as it does
         // in React's Strict Mode). So, start loading the session now, but only if this MatrixChat was not previously
@@ -478,8 +487,18 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
             this.sessionLoadStarted = true;
             const platform = PlatformPeg.get();
             if (platform && !platform.checkSessionLockFree()) {
-                // another instance holds the lock; confirm its theft before proceeding
-                setTimeout(() => this.setState({ view: Views.CONFIRM_LOCK_THEFT }), 0);
+                console.log("screenAfterLogin", this.screenAfterLogin);
+                if (this.screenAfterLogin?.screen.startsWith("matrix")) {
+                    console.log("Got URI req");
+                    // The user has clicked on a matrixuri link, so we need to forward it to them.
+                    this.newUriBroadcastChannel.postMessage({screen: this.screenAfterLogin.screen, params: this.screenAfterLogin.params});
+                    // This will put the application in a final state so the other instance can handle the URI.
+                    setTimeout(() => this.setState({ view: Views.SENT_URI }), 0);
+                } else {
+                    // another instance holds the lock; confirm its theft before proceeding
+                    setTimeout(() => this.setState({ view: Views.CONFIRM_LOCK_THEFT }), 0);
+
+                }
             } else {
                 this.startInitSession();
             }
@@ -1752,6 +1771,10 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
     }
 
     public showScreen(screen: string, params?: { [key: string]: any }): void {
+        if (this.state.view === Views.SENT_URI) {
+            // Ignore any screens once we've reached this state.
+            return;
+        }
         const cli = MatrixClientPeg.get();
         const isLoggedOutOrGuest = !cli || cli.isGuest();
         if (!isLoggedOutOrGuest && AUTH_SCREENS.includes(screen)) {
@@ -1817,6 +1840,11 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
             }
         } else if (screen === "settings") {
             dis.fire(Action.ViewUserSettings);
+        } else if (screen.startsWith("matrix")) {
+            console.log("matrix:", screen, params);
+            mxModuleApi.navigation.toMatrixToLink(screen, false).catch((ex) => {
+                console.log('Failed to handle matrix uri', ex);
+            })
         } else if (screen === "welcome") {
             dis.dispatch({
                 action: "view_welcome_page",
@@ -2098,6 +2126,10 @@ export default class MatrixChat extends React.PureComponent<IProps, IState> {
                     }}
                 />
             );
+        } else if (this.state.view === Views.SENT_URI) {
+            view = (
+                <b>PLACEHOLDER: The URI has been broadcast to the other app.</b>
+            );
         } else if (this.state.view === Views.COMPLETE_SECURITY) {
             view = <CompleteSecurity onFinished={this.onCompleteSecurityE2eSetupFinished} />;
         } else if (this.state.view === Views.E2E_SETUP) {

src/components/views/settings/tabs/user/PreferencesUserSettingsTab.tsx

@@ -363,6 +363,8 @@ export default class PreferencesUserSettingsTab extends React.Component<IProps,
                     <SettingsSubsection heading={_t("common|general")} stretchContent>
                         {this.renderGroup(PreferencesUserSettingsTab.GENERAL_SETTINGS)}
 
+                        <SettingsFlag name="protocolHandlerRegistered" level={SettingLevel.DEVICE} />
+
                         <SettingsFlag name="Electron.showTrayIcon" level={SettingLevel.PLATFORM} hideIfCannotSet />
                         <SettingsFlag
                             name="Electron.enableHardwareAcceleration"

src/settings/Settings.tsx

@@ -50,6 +50,7 @@ import { SortingAlgorithm } from "../stores/room-list-v3/skip-list/sorters/index
 import MediaPreviewConfigController from "./controllers/MediaPreviewConfigController.ts";
 import InviteRulesConfigController from "./controllers/InviteRulesConfigController.ts";
 import { type ComputedInviteConfig } from "../@types/invite-rules.ts";
+import ProtocolHandlerController from "./controllers/ProtocolHandlerController.ts";
 
 export const defaultWatchManager = new WatchManager();
 
@@ -370,6 +371,7 @@ export interface Settings {
     "mediaPreviewConfig": IBaseSetting<MediaPreviewConfig>;
     "inviteRules": IBaseSetting<ComputedInviteConfig>;
     "Developer.elementCallUrl": IBaseSetting<string>;
+    protocolHandlerRegistered: IBaseSetting<boolean>;
 }
 
 export type SettingKey = keyof Settings;
@@ -1345,6 +1347,11 @@ export const SETTINGS: Settings = {
         // Contains room IDs
         shouldExportToRageshake: false,
     },
+    "protocolHandlerRegistered": {
+        default: false,
+        controller: new ProtocolHandlerController(),
+        supportedLevels: LEVELS_DEVICE_ONLY_SETTINGS_WITH_CONFIG,
+    },
     /**
      * Enable or disable the release announcement feature
      */

src/settings/controllers/ProtocolHandlerController.ts

@@ -0,0 +1,26 @@
+/*
+Copyright 2024 New Vector Ltd.
+Copyright 2020 The Matrix.org Foundation C.I.C.
+
+SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE files in the repository root for full details.
+*/
+
+import SettingController from "./SettingController";
+import PlatformPeg from "../../PlatformPeg";
+
+export default class ProtocolHandlerController extends SettingController {
+    public constructor() {
+        super();
+    }
+
+    public get settingDisabled() {
+        return PlatformPeg.get()?.registerProtocolHandler === undefined;
+    }
+
+    public onChange(): void {
+        const platform = PlatformPeg.get()!;
+        const uri = platform.baseUrl;
+        platform.registerProtocolHandler!(`${uri}#/%s`);
+    }
+}

src/vector/platform/WebPlatform.ts

@@ -277,4 +277,8 @@ export default class WebPlatform extends BasePlatform {
     public async getSessionLock(onNewInstance: () => Promise<void>): Promise<boolean> {
         return SessionLock.getSessionLock(onNewInstance);
     }
+    
+    public async registerProtocolHandler(urlPattern: `${string}%s`) {
+        navigator.registerProtocolHandler("matrix", urlPattern);
+    }
 }