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Ripple/RippleEffect/RippleEffect.cs

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+using Avalonia;
+using Avalonia.Animation;
+using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
+using Avalonia.Controls.Shapes;
+using Avalonia.Media;
+using Avalonia.Styling;
+using System;
+
+namespace Ripple
+{
+    public class RippleEffect : ContentControl
+    {
+        #region Styled properties
+
+        public static readonly StyledProperty<Brush> RippleFillProperty =
+        AvaloniaProperty.Register<RippleEffect, Brush>(nameof(RippleFill));
+
+        public Brush RippleFill
+        {
+            get { return GetValue(RippleFillProperty); }
+            set { SetValue(RippleFillProperty, value); }
+        }
+
+        public static readonly StyledProperty<double> RippleOpacityProperty =
+       AvaloniaProperty.Register<RippleEffect, double>(nameof(RippleOpacity));
+
+        public double RippleOpacity
+        {
+            get { return GetValue(RippleOpacityProperty); }
+            set { SetValue(RippleOpacityProperty, value); }
+        }
+
+        public static readonly StyledProperty<Action> PressedActionProperty =
+            AvaloniaProperty.Register<RippleEffect, Action>(nameof(PressedAction));
+        public Action PressedAction
+		{
+            get => GetValue(PressedActionProperty);
+            set => SetValue(PressedActionProperty, value);
+		}
+
+        #endregion Styled properties
+
+        private Ellipse _circle;
+        private Animation _ripple;
+        private Point _pointer;
+        private IAnimationSetter _toWidth;
+        private IAnimationSetter _fromMargin;
+        private IAnimationSetter _toMargin;
+        private bool _isRunning;
+
+        public RippleEffect()
+        {
+            this.AddHandler(PointerPressedEvent, async (s, e) =>
+            {
+                if (_isRunning)
+                {
+                    return;
+                }
+                _pointer = e.GetPosition(this);
+                _isRunning = true;
+                var maxWidth = Math.Max(Bounds.Width, Bounds.Height) * 2.2D;
+                _toWidth.Value = maxWidth;
+                _fromMargin.Value = _circle.Margin = new Thickness(_pointer.X, _pointer.Y, 0, 0);
+                _toMargin.Value = new Thickness(_pointer.X - maxWidth / 2, _pointer.Y - maxWidth / 2, 0, 0);
+
+                await _ripple.RunAsync(_circle);
+
+                _isRunning = false;
+
+                PressedAction.Invoke();
+            });
+        }
+
+        protected override void OnApplyTemplate(TemplateAppliedEventArgs e)
+        {
+            base.OnApplyTemplate(e);
+
+            _circle = e.NameScope.Find<Ellipse>("Circle");
+
+            var style = _circle.Styles[0] as Style;
+            _ripple = style.Animations[0] as Animation;
+            _toWidth = _ripple.Children[1].Setters[1];
+            _fromMargin = _ripple.Children[0].Setters[0];
+            _toMargin = _ripple.Children[1].Setters[0];
+
+            style.Animations.Remove(_ripple);
+        }
+    }
+}