gehgassi_app/gehGassiApp/gehGassi.Toolkit/Extensions/Window/WindowExtensions.Android.cs

#if ANDROID

using AndroidX.Core.View;
using AndroidX.AppCompat.App;
using Android.Views;
using Android.OS;
using AView = Android.Views.View;
using Microsoft.Maui.Handlers;
using Microsoft.Maui.Platform;

namespace gehGassi.Toolkit.Extensions.Window
{
    // https://developer.android.com/develop/ui/views/layout/edge-to-edge

    public static partial class WindowExtensions
    {
        private static Color defaultStatusBarColor = Colors.Transparent;
        private static Color defaultNavigationBarColor = Colors.Black;
        private static bool defaultStatusBarLightElements = false;
        private static bool defaultNavigationBarLightElements = true;

        /// <summary>
        /// Forces application content to be displayed behind system bars (status and navigation bars) on Android and iOS.
        /// </summary>
        /// <param name="builder">The builder for your .NET MAUI application and services.</param>
        /// <returns>The builder.</returns>
        public static MauiAppBuilder DisplayContentBehindBars(this MauiAppBuilder builder)
        {
            WindowHandler.Mapper.AppendToMapping("DisplayContentBehindBars", (handler, window) =>
            {
                var activity = handler.PlatformView as AppCompatActivity;

                WindowCompat.SetDecorFitsSystemWindows(activity.Window, false);

                window.SetStatusBarAppearance();
            });

            WindowHandler.Mapper.AppendToMapping("Insets", (handler, window) =>
            {
                var activity = handler.PlatformView as AppCompatActivity;

                if (window is not Element elmentWindow)
                    return;

                // If I use just activity.Window.DecorView, set colors of the bars are overridden.
                ViewCompat.SetOnApplyWindowInsetsListener(
                    (activity.Window.DecorView as ViewGroup).GetChildAt(0),
                    new SimpleOnApplyWindowInsetsListener(elmentWindow.Id, InvokeListenersIfChanged));
            });

            return builder;
        }

        /// <summary>
        /// Changes the status bar appearance of all windows.
        /// </summary>
        /// <param name="builder">The builder for your .NET MAUI application and services.</param>
        /// <param name="color">New background color of the status bar.</param>
        /// <param name="lightElements">Whether text and icons should be light or dark.</param>
        /// <returns>The builder.</returns>
        public static MauiAppBuilder SetDefaultStatusBarAppearance(this MauiAppBuilder builder, Color color = null, bool lightElements = true)
        {
            defaultStatusBarColor = color;
            defaultStatusBarLightElements = lightElements;

            WindowHandler.Mapper.AppendToMapping("DefaultStatusBarAppearance", (handler, window) =>
            {
                window.SetStatusBarAppearance(color, lightElements);
            });

            return builder;
        }

        /// <summary>
        /// Changes the navigation bar appearance of all windows.
        /// </summary>
        /// <param name="builder">The builder for your .NET MAUI application and services.</param>
        /// <param name="color">New background color of the navigation bar.</param>
        /// <param name="lightElements">Whether text and icons should be light or dark.</param>
        /// <returns>The builder.</returns>
        public static MauiAppBuilder SetDefaultNavigationBarAppearance(this MauiAppBuilder builder, Color color = null, bool lightElements = true)
        {
            defaultNavigationBarColor = color;
            defaultNavigationBarLightElements = lightElements;

            WindowHandler.Mapper.AppendToMapping("DefaultNavigationBarAppearance", (handler, window) =>
            {
                window.SetNavigationBarAppearance(color, lightElements);
            });

            return builder;
        }

        /// <summary>
        /// Changes the status bar appearance of a window.
        /// </summary>
        /// <param name="window">The window.</param>
        /// <param name="color">New background color of the status bar.</param>
        /// <param name="lightElements">Whether text and icons should be light or dark.</param>
        public static void SetStatusBarAppearance(this IWindow window, Color color = null, bool? lightElements = null)
        {
            var activity = window.Handler.PlatformView as AppCompatActivity;

            var windowInsetController = WindowCompat.GetInsetsController(activity.Window, activity.Window.DecorView);
            if (windowInsetController is not null)
            {
                windowInsetController.AppearanceLightStatusBars = !(lightElements ?? defaultStatusBarLightElements);
            }
            else if (Build.VERSION.SdkInt < BuildVersionCodes.R)
            {
                int uiOptions = (int)activity.Window.DecorView.SystemUiVisibility;

                if (!(lightElements ?? defaultStatusBarLightElements))
                    uiOptions |= (int)SystemUiFlags.LightStatusBar;
                else
                    uiOptions &= ~(int)SystemUiFlags.LightStatusBar;

                activity.Window.DecorView.SystemUiVisibility = (StatusBarVisibility)uiOptions;
            }

            activity.Window.SetStatusBarColor((color ?? defaultStatusBarColor).ToPlatform());
        }

        /// <summary>
        /// Changes the navigation bar appearance of a window.
        /// </summary>
        /// <param name="window">The window.</param>
        /// <param name="color">New background color of the navigation bar.</param>
        /// <param name="lightElements">Whether text and icons should be light or dark.</param>
        public static void SetNavigationBarAppearance(this IWindow window, Color color = null, bool? lightElements = null)
        {
            var activity = window.Handler.PlatformView as AppCompatActivity;

            var windowInsetController = ViewCompat.GetWindowInsetsController(activity.Window.DecorView);
            if (windowInsetController is not null)
            {
                windowInsetController.AppearanceLightNavigationBars = !(lightElements ?? defaultNavigationBarLightElements);
            }
            else if (Build.VERSION.SdkInt < BuildVersionCodes.R)
            {
                int uiOptions = (int)activity.Window.DecorView.SystemUiVisibility;

                if (!(lightElements ?? defaultNavigationBarLightElements))
                    uiOptions |= (int)SystemUiFlags.LightNavigationBar;
                else
                    uiOptions &= ~(int)SystemUiFlags.LightNavigationBar;

                activity.Window.DecorView.SystemUiVisibility = (StatusBarVisibility)uiOptions;
            }

            activity.Window.SetNavigationBarColor((color ?? defaultNavigationBarColor).ToPlatform());
        }
    }

    internal class SimpleOnApplyWindowInsetsListener : Java.Lang.Object, IOnApplyWindowInsetsListener
    {
        private readonly Guid windowId;
        private readonly Action<Guid, Thickness> action;

        public SimpleOnApplyWindowInsetsListener(Guid windowId, Action<Guid, Thickness> action)
        {
            this.windowId = windowId;
            this.action = action;
        }

        public WindowInsetsCompat OnApplyWindowInsets(AView v, WindowInsetsCompat insets)
        {
            var barsInsets = insets.GetInsets(WindowInsetsCompat.Type.SystemBars());
            var density = DeviceDisplay.MainDisplayInfo.Density;

            action?.Invoke(windowId, new Thickness(barsInsets.Left / density, barsInsets.Top / density, barsInsets.Right / density, barsInsets.Bottom / density));

            return ViewCompat.OnApplyWindowInsets(v, insets.Inset(barsInsets));
            //return ViewCompat.OnApplyWindowInsets(v, insets.Inset(0,0,0,0));
        }
    }
}

#endif