feat: handle android back button on android (#1656)

packages/web/src/javascripts/Application/Application.ts

@@ -26,6 +26,7 @@ import { isDesktopApplication } from '@/Utils'
 import { DesktopManager } from './Device/DesktopManager'
 import { ArchiveManager, AutolockService, IOService, WebAlertService, ThemeManager } from '@standardnotes/ui-services'
 import { MobileWebReceiver } from './MobileWebReceiver'
+import { AndroidBackHandler } from '@/NativeMobileWeb/AndroidBackHandler'
 
 type WebServices = {
   viewControllerManager: ViewControllerManager
@@ -45,6 +46,7 @@ export class WebApplication extends SNApplication implements WebApplicationInter
   public iconsController: IconsController
   private onVisibilityChange: () => void
   private mobileWebReceiver?: MobileWebReceiver
+  private androidBackHandler?: AndroidBackHandler
 
   constructor(
     deviceInterface: WebOrDesktopDevice,
@@ -76,6 +78,7 @@ export class WebApplication extends SNApplication implements WebApplicationInter
 
     if (this.isNativeMobileWeb()) {
       this.mobileWebReceiver = new MobileWebReceiver(this)
+      this.androidBackHandler = new AndroidBackHandler()
 
       // eslint-disable-next-line no-console
       console.log = (...args) => {
@@ -264,4 +267,17 @@ export class WebApplication extends SNApplication implements WebApplicationInter
       await this.lock()
     }
   }
+
+  handleAndroidBackButtonPressed(): void {
+    if (typeof this.androidBackHandler !== 'undefined') {
+      this.androidBackHandler.notifyEvent()
+    }
+  }
+
+  addAndroidBackHandlerEventListener(listener: () => boolean) {
+    if (typeof this.androidBackHandler !== 'undefined') {
+      return this.androidBackHandler.addEventListener(listener)
+    }
+    return
+  }
 }