BetterLyrics/BetterLyrics.WinUI3/BetterLyrics.WinUI3/Controls/ShadowImage.xaml.cs

using Microsoft.UI.Xaml;
using Microsoft.UI.Xaml.Controls;
using Microsoft.UI.Xaml.Media;
using System;

// To learn more about WinUI, the WinUI project structure,
// and more about our project templates, see: http://aka.ms/winui-project-info.

namespace BetterLyrics.WinUI3.Controls
{
    public sealed partial class ShadowImage : UserControl
    {
        public int CornerRadiusAmount
        {
            get { return (int)GetValue(CornerRadiusAmountProperty); }
            set { SetValue(CornerRadiusAmountProperty, value); }
        }

        public static readonly DependencyProperty CornerRadiusAmountProperty =
            DependencyProperty.Register(nameof(CornerRadiusAmount), typeof(int), typeof(ShadowImage), new PropertyMetadata(0, OnDependencyPropertyChanged));

        public int ShadowAmount
        {
            get { return (int)GetValue(ShadowAmountProperty); }
            set { SetValue(ShadowAmountProperty, value); }
        }

        public static readonly DependencyProperty ShadowAmountProperty =
            DependencyProperty.Register(nameof(ShadowAmount), typeof(int), typeof(ShadowImage), new PropertyMetadata(0, OnDependencyPropertyChanged));

        public ImageSource? Source
        {
            get { return (ImageSource?)GetValue(SourceProperty); }
            set { SetValue(SourceProperty, value); }
        }

        public static readonly DependencyProperty SourceProperty =
            DependencyProperty.Register(nameof(Source), typeof(ImageSource), typeof(ShadowImage), new PropertyMetadata(null));

        public ShadowImage()
        {
            InitializeComponent();
        }

        private static void OnDependencyPropertyChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
        {
            if (d is ShadowImage shadowImage)
            {
                if (e.Property == CornerRadiusAmountProperty)
                {
                    shadowImage.UpdateShadowCastGridCornerRadius();
                    shadowImage.UpdateShadowRectCornerRadius();
                }
                else if (e.Property == ShadowAmountProperty)
                {
                    shadowImage.UpdateShadowRectShadow();
                }
            }
        }

        private void UpdateShadowRectShadow()
        {
            ShadowRect.Translation = new(0, 0, ShadowAmount);
        }

        private void UpdateShadowCastGridCornerRadius()
        {
            var minSize = Math.Min(ShadowCastGrid.ActualHeight, ShadowCastGrid.ActualWidth);
            ShadowCastGrid.CornerRadius = new(CornerRadiusAmount / 100.0 * (minSize / 2));
        }

        private void UpdateShadowRectCornerRadius()
        {
            var minSize = Math.Min(ShadowRect.ActualHeight, ShadowRect.ActualWidth);
            ShadowRect.CornerRadius = new(CornerRadiusAmount / 100.0 * (minSize / 2));
        }

        private void ShadowCastGrid_SizeChanged(object sender, SizeChangedEventArgs e)
        {
            UpdateShadowCastGridCornerRadius();
        }

        private void ShadowRect_SizeChanged(object sender, SizeChangedEventArgs e)
        {
            UpdateShadowRectCornerRadius();
        }

        private void ShadowRect_Loaded(object sender, RoutedEventArgs e)
        {
            Shadow.Receivers.Add(ShadowCastGrid);
        }
    }
}