Android - fix api 36 compat (#20112)

src/Android/Avalonia.Android/AvaloniaActivity.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Diagnostics;
 using System.Diagnostics.CodeAnalysis;
 using System.Runtime.Versioning;
 using Android.App;
@@ -7,6 +8,7 @@ using Android.Content.PM;
 using Android.OS;
 using Android.Runtime;
 using Android.Views;
+using Android.Window;
 using AndroidX.AppCompat.App;
 using Avalonia.Android.Platform;
 using Avalonia.Android.Platform.Storage;
@@ -19,7 +21,7 @@ namespace Avalonia.Android;
 /// Common implementation of android activity that is integrated with Avalonia views.
 /// If you need a base class for main activity of Avalonia app, see <see cref="AvaloniaMainActivity"/> or <see cref="AvaloniaMainActivity{TApp}"/>.  
 /// </summary>
-public class AvaloniaActivity : AppCompatActivity, IAvaloniaActivity
+public class AvaloniaActivity : AppCompatActivity, IAvaloniaActivity, IOnBackInvokedCallback
 {
     private EventHandler<ActivatedEventArgs>? _onActivated, _onDeactivated;
     private GlobalLayoutListener? _listener;
@@ -77,6 +79,13 @@ public class AvaloniaActivity : AppCompatActivity, IAvaloniaActivity
     [ObsoletedOSPlatform("android33.0")]
     public override void OnBackPressed()
     {
+        // For now, if target sdk version is api 36, skip raising BackRequested on OnBackPressed.
+        // This behavior would be different for Net 10
+        if (OperatingSystem.IsAndroidVersionAtLeast(33) 
+            && Build.VERSION.SdkInt >= (BuildVersionCodes)36 
+            && ApplicationContext?.ApplicationInfo?.TargetSdkVersion >= (BuildVersionCodes)36)
+            return;
+
         var eventArgs = new AndroidBackRequestedEventArgs();
 
         BackRequested?.Invoke(this, eventArgs);
@@ -120,12 +129,23 @@ public class AvaloniaActivity : AppCompatActivity, IAvaloniaActivity
     protected override void OnStop()
     {
         _onDeactivated?.Invoke(this, new ActivatedEventArgs(ActivationKind.Background));
+
+        if (OperatingSystem.IsAndroidVersionAtLeast(33))
+        {
+            OnBackInvokedDispatcher.UnregisterOnBackInvokedCallback(this);
+        }
+
         base.OnStop();
     }
 
     protected override void OnStart()
     {
         _onActivated?.Invoke(this, new ActivatedEventArgs(ActivationKind.Background));
+
+        if (OperatingSystem.IsAndroidVersionAtLeast(33))
+        {
+            OnBackInvokedDispatcher.RegisterOnBackInvokedCallback(IOnBackInvokedDispatcher.PriorityDefault, this);
+        }
         base.OnStart();
     }
 
@@ -186,6 +206,13 @@ public class AvaloniaActivity : AppCompatActivity, IAvaloniaActivity
         _view = new AvaloniaView(this) { Content = initialContent };
     }
 
+    public void OnBackInvoked()
+    {
+        var eventArgs = new AndroidBackRequestedEventArgs();
+
+        BackRequested?.Invoke(this, eventArgs);
+    }
+
     private class GlobalLayoutListener : Java.Lang.Object, ViewTreeObserver.IOnGlobalLayoutListener
     {
         private readonly AvaloniaView _view;

src/Android/Avalonia.Android/Platform/AndroidInsetsManager.cs

@@ -285,7 +285,9 @@ namespace Avalonia.Android.Platform
                 if (_isDisplayEdgeToEdgeForced)
                 {
                     // Allow having fully transparent navbars when on api level 35
-                    if (OperatingSystem.IsAndroidVersionAtLeast(35))
+                    if (OperatingSystem.IsAndroidVersionAtLeast(36))
+                        Window.NavigationBarContrastEnforced = false;
+                    else if (OperatingSystem.IsAndroidVersionAtLeast(35))
                         Window.NavigationBarContrastEnforced = _systemBarColor != Colors.Transparent;
                     return;
                 }