.NET Android MvvmCross SystemBars Insets (SafeArea) XML injector

attrs.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
  <declare-styleable name="View">
    <attr name="paddingLeftFitsWindowInsets" format="boolean"/>
    <attr name="paddingRightFitsWindowInsets" format="boolean"/>
    <attr name="paddingTopFitsWindowInsets" format="boolean"/>
    <attr name="paddingBottomFitsWindowInsets" format="boolean"/>

    <attr name="marginLeftFitsWindowInsets" format="boolean"/>
    <attr name="marginRightFitsWindowInsets" format="boolean"/>
    <attr name="marginTopFitsWindowInsets" format="boolean"/>
    <attr name="marginBottomFitsWindowInsets" format="boolean"/>
  </declare-styleable>
</resources>

HostActivityExample.cs

using Android.OS;

using Google.Android.Material.Internal;

using MvvmCross.Platforms.Android.Views;

namespace APP_NAMESPACE;

public class HostActivityExample : MvxActivity {
	protected override void OnCreate(Bundle savedInstanceState) {
		base.OnCreate(savedInstanceState);
		var view = this.BindingInflate(Resource.Layout.page_example, null);
		SetContentView(view);
		EdgeToEdgeUtils.ApplyEdgeToEdge(this.Window, true);
	}
}

item_example.xml

<?xml version="1.0" encoding="utf-8"?>
<com.google.android.material.materialswitch.MaterialSwitch xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    tools:text="Text"
    android:textColor="?attr/colorOnSurface"
    android:textAppearance="?attr/textAppearanceBodyLarge"
    android:layout_width="match_parent"
    android:layout_height="48dp"
    android:paddingLeft="16dp"
    android:paddingRight="24dp"
    android:foreground="?android:attr/selectableItemBackground"
    app:paddingLeftFitsWindowInsets="true"
    app:paddingRightFitsWindowInsets="true"
    app:MvxBind="Text Title; Checked IsChecked"/>

page_example.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.coordinatorlayout.widget.CoordinatorLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="?android:attr/colorBackground">
    <com.google.android.material.appbar.AppBarLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        app:liftOnScrollTargetViewId="@id/mvxrecyclerview"
        app:paddingLeftFitsWindowInsets="true"
        app:paddingRightFitsWindowInsets="true"
        app:paddingTopFitsWindowInsets="true">
        <include layout="@layout/toolbar"/>
    </com.google.android.material.appbar.AppBarLayout>
    <mvvmcross.droidx.recyclerview.MvxRecyclerView
        android:id="@+id/mvxrecyclerview"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:clipToPadding="false"
        app:layout_behavior="@string/appbar_scrolling_view_behavior"
        app:paddingBottomFitsWindowInsets="true"
        app:MvxItemTemplate="@layout/item_example"
        app:MvxBind="ItemsSource Items; ItemClick ItemClickCommand"/>
</androidx.coordinatorlayout.widget.CoordinatorLayout>

Setup.cs

using System;

using Android.Content;
using Android.Views;

using AndroidX.Core.View;

using Google.Android.Material.Internal;

using MvvmCross.Binding;
using MvvmCross.Platforms.Android.Binding;
using MvvmCross.Platforms.Android.Binding.Binders;
using MvvmCross.Platforms.Android.Core;

namespace APP_NAMESPACE;

public class Setup : MvxAndroidSetup<App> {
	protected override MvxBindingBuilder CreateBindingBuilder() {
		return new InsetsAndroidBindingBuilder();
	}

	private class InsetsAndroidBindingBuilder : MvxAndroidBindingBuilder {
		protected override IMvxLayoutInflaterHolderFactoryFactory CreateLayoutInflaterFactoryFactory() {
			return new InsetsLayoutInflaterFactoryFactory();
		}

		private class InsetsLayoutInflaterFactoryFactory : IMvxLayoutInflaterHolderFactoryFactory {
			public IMvxLayoutInflaterHolderFactory Create(object source) {
				return new InsetsBindingLayoutInflaterFactory(source);
			}

			private class InsetsBindingLayoutInflaterFactory : MvxBindingLayoutInflaterFactory {
				public InsetsBindingLayoutInflaterFactory(object source) : base(source) {
				}

				public override View BindCreatedView(View view, Context context, global::Android.Util.IAttributeSet attrs) {
					using var typedArray = context.ObtainStyledAttributes(attrs, Resource.Styleable.View);
					int numStyles = typedArray.IndexCount;
					var flags = WindowInsetsFlags.None;
					for (var i = 0; i < numStyles; ++i) {
						var attributeId = typedArray.GetIndex(i);

						bool attributeValue = typedArray.GetBoolean(attributeId, false);
						if (attributeValue) {
							flags |= attributeId switch {
								Resource.Styleable.View_paddingLeftFitsWindowInsets => WindowInsetsFlags.PaddingLeft,
								Resource.Styleable.View_paddingRightFitsWindowInsets => WindowInsetsFlags.PaddingRight,
								Resource.Styleable.View_paddingTopFitsWindowInsets => WindowInsetsFlags.PaddingTop,
								Resource.Styleable.View_paddingBottomFitsWindowInsets => WindowInsetsFlags.PaddingBottom,

								Resource.Styleable.View_marginLeftFitsWindowInsets => WindowInsetsFlags.MarginLeft,
								Resource.Styleable.View_marginRightFitsWindowInsets => WindowInsetsFlags.MarginRight,
								Resource.Styleable.View_marginTopFitsWindowInsets => WindowInsetsFlags.MarginTop,
								Resource.Styleable.View_marginBottomFitsWindowInsets => WindowInsetsFlags.MarginBottom,

								_ => WindowInsetsFlags.None
							};
						}
					}
					if (flags != WindowInsetsFlags.None)
						ViewUtils.DoOnApplyWindowInsets(view, new OnApplyWindowInsetsListener(flags));
					typedArray.Recycle();
					return base.BindCreatedView(view, context, attrs);
				}
			}
		}

		private class OnApplyWindowInsetsListener : Java.Lang.Object, ViewUtils.IOnApplyWindowInsetsListener {
			private readonly WindowInsetsFlags flags;

			private ViewGroup.MarginLayoutParams initialLayoutParameters;

			public OnApplyWindowInsetsListener(WindowInsetsFlags flags) {
				this.flags = flags;
			}

			public WindowInsetsCompat OnApplyWindowInsets(View view, WindowInsetsCompat insetsCompat, ViewUtils.RelativePadding initialPadding) {
				bool paddingTop = flags.HasFlag(WindowInsetsFlags.PaddingTop);
				bool paddingBottom = flags.HasFlag(WindowInsetsFlags.PaddingBottom);
				bool paddingLeft = flags.HasFlag(WindowInsetsFlags.PaddingLeft);
				bool paddingRight = flags.HasFlag(WindowInsetsFlags.PaddingRight);

				var insets = insetsCompat.GetInsets(WindowInsetsCompat.Type.SystemBars());
				int insetTop = insets.Top;
				int insetBottom = insets.Bottom;
				int insetLeft = insets.Left;
				int insetRight = insets.Right;

				bool isRtl = ViewCompat.GetLayoutDirection(view) == ViewCompat.LayoutDirectionRtl;
				initialPadding.Top += paddingTop ? insetTop : 0;
				initialPadding.Bottom += paddingBottom ? insetBottom : 0;
				int systemWindowInsetLeft = paddingLeft ? insetLeft : 0;
				int systemWindowInsetRight = paddingRight ? insetRight : 0;
				initialPadding.Start += isRtl ? systemWindowInsetRight : systemWindowInsetLeft;
				initialPadding.End += isRtl ? systemWindowInsetLeft : systemWindowInsetRight;
				initialPadding.ApplyToView(view);

				if (view.LayoutParameters is ViewGroup.MarginLayoutParams marginLayoutParameters && initialLayoutParameters == null) {
					initialLayoutParameters = new ViewGroup.MarginLayoutParams(marginLayoutParameters);
				}

				if (initialLayoutParameters != null) {
					bool marginTop = flags.HasFlag(WindowInsetsFlags.MarginTop);
					bool marginBottom = flags.HasFlag(WindowInsetsFlags.MarginBottom);
					bool marginLeft = flags.HasFlag(WindowInsetsFlags.MarginLeft);
					bool marginRight = flags.HasFlag(WindowInsetsFlags.MarginRight);

					if (marginTop || marginBottom || marginLeft || marginRight) {
						var newLayoutParameters = view.LayoutParameters as ViewGroup.MarginLayoutParams;
						newLayoutParameters.TopMargin = initialLayoutParameters.TopMargin + (marginTop ? insetTop : 0);
						newLayoutParameters.BottomMargin = initialLayoutParameters.BottomMargin + (marginBottom ? insetBottom : 0);
						newLayoutParameters.LeftMargin = initialLayoutParameters.LeftMargin + (marginLeft ? insetLeft : 0);
						newLayoutParameters.RightMargin = initialLayoutParameters.RightMargin + (marginRight ? insetRight : 0);
						view.LayoutParameters = newLayoutParameters;
					}
				}

				return insetsCompat;
			}
		}

		[Flags]
		private enum WindowInsetsFlags {
			None						= 0,

			PaddingLeft					= 1 << 0,
			PaddingRight				= 1 << 1,
			PaddingTop					= 1 << 2,
			PaddingBottom				= 1 << 3,

			MarginLeft					= 1 << 4,
			MarginRight					= 1 << 5,
			MarginTop					= 1 << 6,
			MarginBottom				= 1 << 7
		}
	}
}