ApplicationManager and better memory management

app/assets/javascripts/applicationManager.js

@@ -0,0 +1,125 @@
+import { WebApplication } from './application';
+import { removeFromArray } from 'snjs';
+import {
+  ArchiveManager,
+  DesktopManager,
+  KeyboardManager,
+  LockManager,
+  NativeExtManager,
+  PreferencesManager,
+  StatusManager,
+  ThemeManager,
+  AppState
+} from './services';
+
+export class ApplicationManager {
+  /* @ngInject */
+  constructor($compile, $rootScope, $timeout) {
+    this.$compile = $compile;
+    this.$timeout = $timeout;
+    this.$rootScope = $rootScope;
+    this.applications = [];
+    this.changeObservers = [];
+    this.onApplicationDeinit = this.onApplicationDeinit.bind(this);
+    this.createDefaultApplication();
+  }
+  
+  /** @access private */
+  createDefaultApplication() {
+    this.activeApplication = this.createNewApplication();
+    this.applications.push(this.activeApplication);
+    this.notifyObserversOfAppChange();
+  }
+
+  /** @callback */
+  onApplicationDeinit(application) {
+    removeFromArray(this.applications, application);
+    if(this.activeApplication === application) {
+      this.activeApplication = null;
+    }
+    if (this.applications.length === 0) {
+      this.createDefaultApplication();
+    }
+    this.notifyObserversOfAppChange();
+  }
+
+  /** @access private */
+  createNewApplication() {
+    const scope = this.$rootScope.$new(true);
+    const application = new WebApplication(
+      this.$compile,
+      this.$timeout,
+      scope,
+      this.onApplicationDeinit
+    );
+    const appState = new AppState(
+      this.$rootScope,
+      this.$timeout,
+      application
+    );
+    const archiveService = new ArchiveManager(
+      application
+    );
+    const desktopService = new DesktopManager(
+      this.$rootScope,
+      this.$timeout,
+      application
+    );
+    const keyboardService = new KeyboardManager();
+    const lockService = new LockManager(
+      application
+    );
+    const nativeExtService = new NativeExtManager(
+      application
+    );
+    const prefsService = new PreferencesManager(
+      application
+    );
+    const statusService = new StatusManager();
+    const themeService = new ThemeManager(
+      application,
+    );
+    application.setWebServices({
+      appState,
+      archiveService,
+      desktopService,
+      keyboardService,
+      lockService,
+      nativeExtService,
+      prefsService,
+      statusService,
+      themeService
+    });
+    return application;
+  }
+
+  get application() {
+    return this.activeApplication;
+  }
+
+  /** @access public */
+  getApplications() {
+    return this.applications.slice();
+  }
+
+  /**
+   * Notifies observer when the active application has changed.
+   * Any application which is no longer active is destroyed, and
+   * must be removed from the interface.
+   * @access public
+   * @param {function} callback 
+   */
+  addApplicationChangeObserver(callback) {
+    this.changeObservers.push(callback);
+    if (this.application) {
+      callback();
+    }
+  }
+
+  notifyObserversOfAppChange() {
+    for (const observer of this.changeObservers) {
+      observer();
+    }
+  }
+
+}