Java class to Xamarin.Android port. Community feedback for Egis answer

NavigationbarSize.cs

    using Android.Content;
    using Android.Graphics;
    using Android.OS;
    using Android.Runtime;
    using Android.Views;
    using Java.Lang;
    using Java.Lang.Reflect;

    public static class NavigationbarSize {
        public static Point getNavigationBarSize(Context context) {
            var appUsableSize = getAppUsableScreenSize(context);
            var realScreenSize = getRealScreenSize(context);

            // navigation bar on the right
            if (appUsableSize.X < realScreenSize.X) {
                return new Point(realScreenSize.X - appUsableSize.X, appUsableSize.Y);
            }

            // navigation bar at the bottom
            return (appUsableSize.Y < realScreenSize.Y)
                ? new Point(appUsableSize.X, realScreenSize.Y - appUsableSize.Y)
                : new Point();

            // navigation bar is not present
        }
        public static Point getAppUsableScreenSize(Context context) {
            var windowManager = context.GetSystemService(Context.WindowService);
            //var display = windowManager.DefaultDisplay;
            var display = JNIEnv.CallObjectMethod(windowManager.Handle, JNIEnv.GetMethodID(JNIEnv.FindClass("android/view/WindowManagerImpl"), "getDefaultDisplay", "()Landroid/view/Display;"));
            var size = new Point();
            //display.GetSize(size);
            JNIEnv.CallVoidMethod(display, JNIEnv.GetMethodID(JNIEnv.FindClass("android/view/Display"), "getSize", "(Landroid/graphics/Point;)V"), new JValue(size.Handle));
            return size;
        }
        public static Point getRealScreenSize(Context context) {
            var windowManager = context.GetSystemService(Context.WindowService);
            //var display = windowManager.DefaultDisplay;
            var display = JNIEnv.CallObjectMethod(windowManager.Handle, JNIEnv.GetMethodID(JNIEnv.FindClass("android/view/WindowManagerImpl"), "getDefaultDisplay", "()Landroid/view/Display;"));
            var size = new Point();

            if (Build.VERSION.SdkInt >= BuildVersionCodes.JellyBeanMr1) {
                //display.GetRealSize(size);
                JNIEnv.CallVoidMethod(display, JNIEnv.GetMethodID(JNIEnv.FindClass("android/view/Display"), "getRealSize", "(Landroid/graphics/Point;)V"), new JValue(size.Handle));
            } else if (Build.VERSION.SdkInt >= BuildVersionCodes.IceCreamSandwich) {
                try {
                    size.X = JNIEnv.CallIntMethod(context.Handle, JNIEnv.GetMethodID(JNIEnv.FindClass("android/view/Display"), "getRawWidth", "()I"));
                    size.Y = JNIEnv.CallIntMethod(context.Handle, JNIEnv.GetMethodID(JNIEnv.FindClass("android/view/Display"), "getRawHeight", "()I"));
                    //size.X = Display::class.java.getMethod("getRawWidth").invoke(display) as Int;
                    //size.Y = Display::class.java.getMethod("getRawHeight").invoke(display) as Int
                } catch (IllegalAccessException e) { } catch (InvocationTargetException e) { } catch (NoSuchMethodException e) { }
            }
            return size;
        }
    }