[android] improve performance of ActivityExtensions.GetWindowFrame (#…

…17256)

* [android] improve performance of ActivityExtensions.GetWindowFrame

I've been working to get back some of our lost startup performance on
Android in .NET MAUI. We are really close, a few changes will get .NET 8
on par or faster than .NET 7.

Profiling startup of a `dotnet new maui` app on a Pixel 5,
`dotnet-trace` reported time spent in:

    20.05ms (0.73%)	0.22ns (<0.01%)	microsoft.maui!Microsoft.Maui.Platform.ActivityExtensions.GetWindowFrame(Android.App.Activity)

What is particularly interesting here, is this method is called multiple
times on startup:

* X
* Y
* Width
* Height
* `WindowHandler.ConnectHandler()`

In the future, we should come up with a way the `PropertyMapper` can
somehow "collapse" these calls so we can do it once.

For now, however, I took the following C# code that looks to do 3 Java
interop calls:

    internal static Rect GetWindowFrame(this Android.App.Activity activity)
    {
        var wmc = WindowMetricsCalculator.Companion.OrCreate;
        var wm = wmc.ComputeCurrentWindowMetrics(activity);
        var bounds = wm.Bounds;
        return activity.FromPixels(bounds);
    }

And moved to Java, so we now have 1:

    @nonnull
    public static Rect getCurrentWindowMetrics(Activity activity) {
        return WindowMetricsCalculator.Companion
            .getOrCreate()
            .computeCurrentWindowMetrics(activity)
            .getBounds();
    }

The result being:

    Before:
    20.05ms (0.73%)	0.22ns (<0.01%)	microsoft.maui!Microsoft.Maui.Platform.ActivityExtensions.GetWindowFrame(Android.App.Activity)
    After:
    11.94ms (0.22%)	0.06ns (<0.01%)	microsoft.maui!Microsoft.Maui.Platform.ActivityExtensions.GetWindowFrame(Android.App.Activity)

I'd estimate this might improve startup by ~8ms.

In future .NET releases, we should revisit the `PropertyMapper` pattern.
This could be *even better* if it was only called once.

* Update maui.aar

src/Core/AndroidNative/maui/build.gradle

@@ -31,5 +31,6 @@ dependencies {
     annotationProcessor 'com.github.bumptech.glide:compiler:4.15.1'
 
     implementation 'androidx.appcompat:appcompat:1.3.1'
+    implementation 'androidx.window:window:1.1.0'
     implementation 'com.google.android.material:material:1.4.0'
 }

src/Core/AndroidNative/maui/src/main/java/com/microsoft/maui/PlatformInterop.java

@@ -1,5 +1,6 @@
 package com.microsoft.maui;
 
+import android.app.Activity;
 import android.content.Context;
 import android.content.res.ColorStateList;
 import android.graphics.BlendMode;
@@ -10,6 +11,7 @@
 import android.graphics.Path;
 import android.graphics.PathEffect;
 import android.graphics.PorterDuff;
+import android.graphics.Rect;
 import android.graphics.Typeface;
 import android.graphics.drawable.Drawable;
 import android.graphics.drawable.PaintDrawable;
@@ -35,6 +37,7 @@
 import androidx.coordinatorlayout.widget.CoordinatorLayout;
 import androidx.viewpager2.adapter.FragmentStateAdapter;
 import androidx.viewpager2.widget.ViewPager2;
+import androidx.window.layout.WindowMetricsCalculator;
 
 import com.bumptech.glide.Glide;
 import com.bumptech.glide.RequestBuilder;
@@ -550,6 +553,19 @@ public static void setLengthFilter(@NonNull EditText editText, int maxLength)
         }
     }
 
+    /**
+     * Computes the current WindowMetrics' bounds
+     * @param activity
+     * @return Rect value of the bounds
+     */
+    @NonNull
+    public static Rect getCurrentWindowMetrics(Activity activity) {
+        return WindowMetricsCalculator.Companion
+            .getOrCreate()
+            .computeCurrentWindowMetrics(activity)
+            .getBounds();
+    }
+
     private static class ColorStates
     {
         static final int[] EMPTY = new int[] { };

src/Core/src/Platform/Android/ActivityExtensions.cs

@@ -1,4 +1,3 @@
-using AndroidX.Window.Layout;
 using Microsoft.Maui.Graphics;
 
 namespace Microsoft.Maui.Platform
@@ -7,9 +6,7 @@ internal static partial class ActivityExtensions
 	{
 		internal static Rect GetWindowFrame(this Android.App.Activity activity)
 		{
-			var wmc = WindowMetricsCalculator.Companion.OrCreate;
-			var wm = wmc.ComputeCurrentWindowMetrics(activity);
-			var bounds = wm.Bounds;
+			var bounds = PlatformInterop.GetCurrentWindowMetrics(activity);
 			return activity.FromPixels(bounds);
 		}