Add branding extensions (#51)

* Add branding extensions

* prettier

* Update docs and types.

Author: Half-Shot

src/lifecycles/BrandingExtensions.ts

@@ -0,0 +1,47 @@
+interface AppTitleBase {
+    /**
+     * The configured brand name.
+     * @example Element
+     */
+    brand: string;
+    /**
+     * Is the client sync loop in an error state.
+     */
+    syncError: boolean;
+    /**
+     * The current unread notification count.
+     */
+    unreadNotificationCount?: number;
+    /**
+     * Has the client muted notifications.
+     */
+    notificationsMuted?: boolean;
+}
+
+export interface AppTitleInRoom extends AppTitleBase {
+    /**
+     * The room name, may be undefined if the room has no name.
+     */
+    roomName?: string;
+    /**
+     * The room ID of the room in view.
+     */
+    roomId: string;
+}
+
+export type AppTitleContext = AppTitleBase | AppTitleInRoom;
+
+export interface ProvideBrandingExtensions {
+    /**
+     * Called whenever the client would update the document title.
+     * @param context Current application context used to generate the title.
+     * @returns A string to be used for the full title, or null to use the default title.
+     */
+    getAppTitle(context: AppTitleContext): string | null;
+}
+
+export abstract class BrandingExtensionsBase implements ProvideBrandingExtensions {
+    public getAppTitle(context: AppTitleContext): string | null {
+        return null;
+    }
+}

src/types/extensions.ts

@@ -13,10 +13,12 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
+import { ProvideBrandingExtensions } from "../lifecycles/BrandingExtensions";
 import { ProvideCryptoSetupExtensions } from "../lifecycles/CryptoSetupExtensions";
 import { ProvideExperimentalExtensions } from "../lifecycles/ExperimentalExtensions";
 
 export type AllExtensions = {
+    branding?: ProvideBrandingExtensions;
     cryptoSetup?: ProvideCryptoSetupExtensions;
     experimental?: ProvideExperimentalExtensions;
 };