Proof of concept for having multiple window in Android for autofill support and navigating with the help of an Extended splash page.

src/Core/App.xaml.cs

@@ -10,6 +10,7 @@ using Bit.Core.Abstractions;
 using Bit.Core.Enums;
 using Bit.Core.Models.Data;
 using Bit.Core.Models.Response;
+using Bit.Core.Pages;
 using Bit.Core.Services;
 using Bit.Core.Utilities;
 
@@ -74,6 +75,8 @@ namespace Bit.App
         }   
 
         public static Window CurrentWindow { get; private set; }
+        public static Window AutofillWindow { get; private set; }
+        public static Window MainWindow { get; private set; }
 
         public void SetOptions(AppOptions appOptions)
         {
@@ -84,28 +87,28 @@ namespace Bit.App
         {
             if (activationState != null 
                 && activationState.State.TryGetValue("autofillFramework", out string autofillFramework)
-                && autofillFramework == "true") //TODO: There are likely better ways to filter this. Maybe using Options.
+                && autofillFramework == "true"
+                && activationState.State.ContainsKey("autofillFrameworkCipherId")) //AutofillExternalActivity
             {
-                if (activationState.State.ContainsKey("autofillFrameworkCipherId")) //TODO: There are likely better ways to filter this. Maybe using Options.
+                return new Window(new NavigationPage()); //No actual page needed. Only used for auto-filling the fields directly (externally)
-                {
+            }
-                    return new Window(new NavigationPage()); //No actual page needed. Only used for auto-filling the fields directly (externally)
+            else if (Options.FromAutofillFramework || Options.Uri != null || Options.OtpData != null || Options.CreateSend != null) //"Internal" Autofill and Uri/Otp/CreateSend
-                }
+            {
-                else
+                AutofillWindow = new Window(new NavigationPage(new AndroidExtSplashPage(Options)));
-                {
+                CurrentWindow = AutofillWindow;
-                    //TODO: IMPORTANT Question: this works if we want to show the CipherSelection, but we are skipping all our ASYNC Navigation workflows where we (for example) check if the user is logged in and/or needs to enter auth again.
+                return CurrentWindow;
-                    var autofillWindow = new Window(new NavigationPage(new CipherSelectionPage(Options)));
-                    return autofillWindow;
-                }
             }
             else if(CurrentWindow != null)
             {
                 //TODO: This likely crashes if we try to have two apps side-by-side on Android
                 //TODO: Question: In these scenarios should a new Window be created or can the same one be reused?
+                CurrentWindow = MainWindow;
                 return CurrentWindow;
             }
             else
             {
-                CurrentWindow = new Window(new NavigationPage(new HomePage(Options)));
+                MainWindow = new Window(new NavigationPage(new HomePage(Options)));
+                CurrentWindow = MainWindow;
                 return CurrentWindow;
             }
         }

src/Core/Core.csproj

@@ -64,7 +64,6 @@
     <Folder Include="Resources\Fonts\" />
     <Folder Include="Effects\" />
     <Folder Include="Resources\Raw\" />
-    <Folder Include="Pages\" />
     <Folder Include="Behaviors\" />
     <Folder Include="Controls\" />
     <Folder Include="Lists\" />
@@ -92,4 +91,9 @@
       <AutoGen>True</AutoGen>
     </Compile>
 	</ItemGroup>
+	<ItemGroup>
+	  <MauiXaml Update="Pages\AndroidExtSplashPage.xaml">
+	    <Generator>MSBuild:Compile</Generator>
+	  </MauiXaml>
+	</ItemGroup>
 </Project>

src/Core/Pages/AndroidExtSplashPage.xaml

@@ -0,0 +1,10 @@
+<?xml version="1.0" encoding="utf-8" ?>
+<ContentPage xmlns="http://schemas.microsoft.com/dotnet/2021/maui"
+             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
+             x:Class="Bit.Core.Pages.AndroidExtSplashPage"
+             Title="AndroidExtSplashPage"
+             Loaded="AndroidExtSplashPage_OnLoaded">
+    <Grid>
+        <ActivityIndicator VerticalOptions="Center" HorizontalOptions="Center" IsRunning="True" />
+    </Grid>
+</ContentPage>

src/Core/Pages/AndroidExtSplashPage.xaml.cs

@@ -0,0 +1,105 @@
+using Bit.App.Models;
+using Bit.App.Pages;
+using Bit.App.Utilities.AccountManagement;
+using Bit.Core.Abstractions;
+using Bit.Core.Utilities;
+
+namespace Bit.Core.Pages;
+
+public partial class AndroidExtSplashPage : ContentPage
+{
+    private IConditionedAwaiterManager _conditionedAwaiterManager;
+    private IVaultTimeoutService _vaultTimeoutService;
+    private IStateService _stateService;
+    private AppOptions _appOptions;
+
+	public AndroidExtSplashPage(AppOptions appOptions)
+	{
+		InitializeComponent();
+        _appOptions = appOptions;
+        _conditionedAwaiterManager = ServiceContainer.Resolve<IConditionedAwaiterManager>();
+        _vaultTimeoutService = ServiceContainer.Resolve<IVaultTimeoutService>("vaultTimeoutService");
+        _stateService = ServiceContainer.Resolve<IStateService>();
+	}
+
+    private async Task GetNavigationToExecuteAsync(AppOptions options, Window window)
+    {
+        await _conditionedAwaiterManager.GetAwaiterForPrecondition(AwaiterPrecondition.EnvironmentUrlsInited);
+
+        var authed = await _stateService.IsAuthenticatedAsync();
+        if (authed)
+        {
+            if (await _vaultTimeoutService.IsLoggedOutByTimeoutAsync() ||
+                await _vaultTimeoutService.ShouldLogOutByTimeoutAsync())
+            {
+                // TODO implement orgIdentifier flow to SSO Login page, same as email flow below
+                // var orgIdentifier = await _stateService.GetOrgIdentifierAsync();
+
+                var email = await _stateService.GetEmailAsync();
+                options.HideAccountSwitcher = await _stateService.GetActiveUserIdAsync() == null;
+                var navParams = new LoginNavigationParams(email);
+                if (navParams is LoginNavigationParams loginParams)
+                {
+                    window.Page = new NavigationPage(new LoginPage(loginParams.Email, options));
+                }
+            }
+            else if (await _vaultTimeoutService.IsLockedAsync() ||
+                     await _vaultTimeoutService.ShouldLockAsync())
+            {
+                /* //TODO: is lockParams needed here?
+                if (navParams is LockNavigationParams lockParams)
+                {
+                    return () => new Window(new NavigationPage(new LockPage(Options, lockParams.AutoPromptBiometric)));
+                }
+                else
+                {*/
+                    window.Page = new NavigationPage(new LockPage(options));
+                /*}*/
+            }
+            else if (options.FromAutofillFramework && options.SaveType.HasValue)
+            {
+                window.Page = new NavigationPage(new CipherAddEditPage(appOptions: options));
+            }
+            else if (options.Uri != null)
+            {
+                window.Page = new NavigationPage(new CipherSelectionPage(options));
+            }
+            else if (options.OtpData != null)
+            {
+                window.Page = new NavigationPage(new CipherSelectionPage(options));
+            }
+            else if (options.CreateSend != null)
+            {
+                window.Page = new NavigationPage(new SendAddEditPage(options));
+            }
+            else
+            {
+                window.Page = new TabsPage(options);
+            }
+        }
+        else
+        {
+            options.HideAccountSwitcher = await _stateService.GetActiveUserIdAsync() == null;
+            if (await _vaultTimeoutService.IsLoggedOutByTimeoutAsync() ||
+                await _vaultTimeoutService.ShouldLogOutByTimeoutAsync())
+            {
+                // TODO implement orgIdentifier flow to SSO Login page, same as email flow below
+                // var orgIdentifier = await _stateService.GetOrgIdentifierAsync();
+
+                var email = await _stateService.GetEmailAsync();
+                await _stateService.SetRememberedEmailAsync(email);
+
+                window.Page = new NavigationPage(new HomePage(options));
+            }
+            else
+            {
+                window.Page = new NavigationPage(new HomePage(options));
+            }
+        }
+    }
+
+    private async void AndroidExtSplashPage_OnLoaded(object sender, EventArgs e)
+    {
+        await GetNavigationToExecuteAsync(_appOptions, this.Window);
+    }
+}

src/Core/Pages/TabsPage.cs

@@ -144,7 +144,17 @@ namespace Bit.App.Pages
 
         private void OnUnloaded(object sender, EventArgs e)
         {
-            Handler?.DisconnectHandler();
+            try
+            {
+                Handler?.DisconnectHandler();
+            }
+            catch (Exception ex)
+            {
+                //Workaround: Currently the Disconnect Handler needs to be manually called from the App: https://github.com/dotnet/maui/issues/3604
+                // In some specific edges cases the MauiContext can be gone when we call this. (for example filling a field using Accessibility)
+                // In those scenarios the app should just be "closing" anyway, so we just want to avoid the exception.
+                System.Diagnostics.Debug.WriteLine(ex.Message);
+            }
         }
 
         public void ResetToVaultPage()