Adds CSS support for shadows and a simpler way of defining shadows in XAML

src/Controls/src/Core/Properties/AssemblyInfo.cs

@@ -160,6 +160,8 @@
 [assembly: StyleProperty("-maui-vertical-text-alignment", typeof(Label), nameof(TextAlignmentElement.VerticalTextAlignmentProperty))]
 [assembly: StyleProperty("-maui-thumb-color", typeof(Switch), nameof(Switch.ThumbColorProperty))]
 
+[assembly: StyleProperty("-maui-shadow", typeof(VisualElement), nameof(VisualElement.ShadowProperty))]
+
 //shell
 [assembly: StyleProperty("-maui-flyout-background", typeof(Shell), nameof(Shell.FlyoutBackgroundColorProperty))]
 [assembly: StyleProperty("-maui-shell-background", typeof(Element), nameof(Shell.BackgroundColorProperty), PropertyOwnerType = typeof(Shell))]

src/Controls/src/Core/PublicAPI/net-android/PublicAPI.Unshipped.txt

@@ -147,4 +147,4 @@ static readonly Microsoft.Maui.Controls.TitleBar.SubtitleProperty -> Microsoft.M
 static readonly Microsoft.Maui.Controls.TitleBar.TitleProperty -> Microsoft.Maui.Controls.BindableProperty!
 static readonly Microsoft.Maui.Controls.TitleBar.TrailingContentProperty -> Microsoft.Maui.Controls.BindableProperty!
 static readonly Microsoft.Maui.Controls.Window.TitleBarProperty -> Microsoft.Maui.Controls.BindableProperty!
-virtual Microsoft.Maui.Controls.Application.ActivateWindow(Microsoft.Maui.Controls.Window! window) -> void
+virtual Microsoft.Maui.Controls.Application.ActivateWindow(Microsoft.Maui.Controls.Window! window) -> void

src/Controls/src/Core/PublicAPI/net-ios/PublicAPI.Unshipped.txt

@@ -341,4 +341,4 @@ virtual Microsoft.Maui.Controls.Handlers.Items2.ItemsViewController2<TItemsView>
 virtual Microsoft.Maui.Controls.Handlers.Items2.ItemsViewDelegator2<TItemsView, TViewController>.GetVisibleItemsIndex() -> (bool VisibleItems, int First, int Center, int Last)
 virtual Microsoft.Maui.Controls.Handlers.Items2.ItemsViewHandler2<TItemsView>.UpdateLayout() -> void
 override Microsoft.Maui.Controls.Handlers.Compatibility.FrameRenderer.MovedToWindow() -> void
-~Microsoft.Maui.Controls.Internals.TypedBindingBase.UpdateSourceEventName.set -> void
+~Microsoft.Maui.Controls.Internals.TypedBindingBase.UpdateSourceEventName.set -> void

src/Controls/src/Core/PublicAPI/net-maccatalyst/PublicAPI.Unshipped.txt

@@ -341,4 +341,4 @@ virtual Microsoft.Maui.Controls.Handlers.Items2.ItemsViewController2<TItemsView>
 virtual Microsoft.Maui.Controls.Handlers.Items2.ItemsViewController2<TItemsView>.UpdateVisibility() -> void
 virtual Microsoft.Maui.Controls.Handlers.Items2.ItemsViewDelegator2<TItemsView, TViewController>.GetVisibleItemsIndex() -> (bool VisibleItems, int First, int Center, int Last)
 virtual Microsoft.Maui.Controls.Handlers.Items2.ItemsViewHandler2<TItemsView>.UpdateLayout() -> void
-override Microsoft.Maui.Controls.Handlers.Compatibility.FrameRenderer.MovedToWindow() -> void
+override Microsoft.Maui.Controls.Handlers.Compatibility.FrameRenderer.MovedToWindow() -> void

src/Controls/src/Core/PublicAPI/net-tizen/PublicAPI.Unshipped.txt

@@ -142,4 +142,4 @@ static readonly Microsoft.Maui.Controls.TitleBar.SubtitleProperty -> Microsoft.M
 static readonly Microsoft.Maui.Controls.TitleBar.TitleProperty -> Microsoft.Maui.Controls.BindableProperty!
 static readonly Microsoft.Maui.Controls.TitleBar.TrailingContentProperty -> Microsoft.Maui.Controls.BindableProperty!
 static readonly Microsoft.Maui.Controls.Window.TitleBarProperty -> Microsoft.Maui.Controls.BindableProperty!
-virtual Microsoft.Maui.Controls.Application.ActivateWindow(Microsoft.Maui.Controls.Window! window) -> void
+virtual Microsoft.Maui.Controls.Application.ActivateWindow(Microsoft.Maui.Controls.Window! window) -> void

src/Controls/src/Core/PublicAPI/net-windows/PublicAPI.Unshipped.txt

@@ -148,4 +148,4 @@ static readonly Microsoft.Maui.Controls.TitleBar.SubtitleProperty -> Microsoft.M
 static readonly Microsoft.Maui.Controls.TitleBar.TitleProperty -> Microsoft.Maui.Controls.BindableProperty!
 static readonly Microsoft.Maui.Controls.TitleBar.TrailingContentProperty -> Microsoft.Maui.Controls.BindableProperty!
 static readonly Microsoft.Maui.Controls.Window.TitleBarProperty -> Microsoft.Maui.Controls.BindableProperty!
-virtual Microsoft.Maui.Controls.Application.ActivateWindow(Microsoft.Maui.Controls.Window! window) -> void
+virtual Microsoft.Maui.Controls.Application.ActivateWindow(Microsoft.Maui.Controls.Window! window) -> void

src/Controls/src/Core/PublicAPI/net/PublicAPI.Unshipped.txt

@@ -142,4 +142,4 @@ static readonly Microsoft.Maui.Controls.TitleBar.SubtitleProperty -> Microsoft.M
 static readonly Microsoft.Maui.Controls.TitleBar.TitleProperty -> Microsoft.Maui.Controls.BindableProperty!
 static readonly Microsoft.Maui.Controls.TitleBar.TrailingContentProperty -> Microsoft.Maui.Controls.BindableProperty!
 static readonly Microsoft.Maui.Controls.Window.TitleBarProperty -> Microsoft.Maui.Controls.BindableProperty!
-virtual Microsoft.Maui.Controls.Application.ActivateWindow(Microsoft.Maui.Controls.Window! window) -> void
+virtual Microsoft.Maui.Controls.Application.ActivateWindow(Microsoft.Maui.Controls.Window! window) -> void

src/Controls/src/Core/PublicAPI/netstandard/PublicAPI.Unshipped.txt

@@ -142,4 +142,4 @@ static readonly Microsoft.Maui.Controls.TitleBar.SubtitleProperty -> Microsoft.M
 static readonly Microsoft.Maui.Controls.TitleBar.TitleProperty -> Microsoft.Maui.Controls.BindableProperty!
 static readonly Microsoft.Maui.Controls.TitleBar.TrailingContentProperty -> Microsoft.Maui.Controls.BindableProperty!
 static readonly Microsoft.Maui.Controls.Window.TitleBarProperty -> Microsoft.Maui.Controls.BindableProperty!
-virtual Microsoft.Maui.Controls.Application.ActivateWindow(Microsoft.Maui.Controls.Window! window) -> void
+virtual Microsoft.Maui.Controls.Application.ActivateWindow(Microsoft.Maui.Controls.Window! window) -> void

src/Controls/src/Core/ShadowTypeConverter.cs

@@ -0,0 +1,186 @@
+#nullable disable
+
+using System;
+using System.ComponentModel;
+using System.Globalization;
+using System.Linq;
+using System.Text.RegularExpressions;
+using Microsoft.Maui.Graphics;
+using Microsoft.Maui.Graphics.Converters;
+
+namespace Microsoft.Maui.Controls
+{
+	/// <summary>
+	/// Type converter for converting a properly formatted string to a Shadow.
+	/// </summary>
+	internal class ShadowTypeConverter : TypeConverter
+    {
+        readonly ColorTypeConverter _colorTypeConverter = new ColorTypeConverter();
+
+        /// <summary>
+        /// Checks whether the given <paramref name="sourceType" /> is a string.
+        /// </summary>
+        /// <param name="context">The context to use for conversion.</param>
+        /// <param name="sourceType">The type to convert from.</param>
+        /// <returns></returns>
+        public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
+            => sourceType == typeof(string);
+
+        /// <summary>
+        /// Checks whether the given <paramref name="destinationType" /> is a Shadow.
+        /// </summary>
+        /// <param name="context">The context to use for conversion.</param>
+        /// <param name="destinationType">The type to convert to.</param>
+        /// <returns></returns>
+        public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
+            => destinationType == typeof(Shadow);
+
+        /// <summary>
+        /// Converts <paramref name="value" /> to a Shadow.
+        /// </summary>
+        /// <param name="context">The context to use for conversion.</param>
+        /// <param name="culture">The culture to use for conversion.</param>
+        /// <param name="value">The value to convert.</param>
+        /// <returns></returns>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="value" /> is null.</exception>
+        /// <exception cref="InvalidOperationException">Thrown when <paramref name="value" /> is not a valid Shadow.</exception>
+        public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
+        {
+            var strValue = value?.ToString();
+
+            if (strValue == null)
+            {
+                throw new ArgumentNullException(nameof(strValue));
+            }
+
+            try
+            {
+                var regex = new Regex(@"
+                    # Match colors
+                    (
+                        \#([0-9a-fA-F]{3,8}) # Hex colors (#RGB, #RRGGBB, #RRGGBBAA)
+                        |rgb\(\s*\d+%\s*,\s*\d+%\s*,\s*\d+%\s*\) # rgb(percent, percent, percent)
+                        |rgba\(\s*\d+%\s*,\s*\d+%\s*,\s*\d+%\s*,\s*\d+(?:\.\d+)?\s*\) # rgba(percent, percent, percent, alpha)
+                        |rgb\(\s*\d+\s*,\s*\d+\s*,\s*\d+\s*\) # rgb(int, int, int)
+                        |rgba\(\s*\d+\s*,\s*\d+\s*,\s*\d+\s*,\s*\d+(?:\.\d+)?\s*\) # rgba(int, int, int, alpha)
+                        |hsl\(\s*\d+\s*,\s*\d+%\s*,\s*\d+%\s*\) # hsl(hue, saturation, lightness)
+                        |hsla\(\s*\d+\s*,\s*\d+%\s*,\s*\d+%\s*,\s*\d+(?:\.\d+)?\s*\) # hsla(hue, saturation, lightness, alpha)
+                        |hsv\(\s*\d+\s*,\s*\d+%\s*,\s*\d+%\s*\) # hsl(hue, saturation, value)
+                        |hsva\(\s*\d+\s*,\s*\d+%\s*,\s*\d+%\s*,\s*\d+(?:\.\d+)?\s*\) # hsla(hue, saturation, value, alpha)
+                        |[a-zA-Z]+ # X11 named colors (e.g., AliceBlue, limegreen)
+
+                    )
+                    | # Match numbers
+                    (
+                        -?\d+(?:\.\d+)?(?:[eE][+-]?\d+)?  # Floats or scientific notation
+                    )
+                ", RegexOptions.IgnorePatternWhitespace);
+
+                var matches = regex.Matches(strValue);
+                //var parts = matches.Select(m => m.Value).ToArray();
+
+                if (matches.Count == 3) // <color> | <float> | <float> e.g. #000000 4 4
+                {
+                    var brush = ParseBrush(matches[0].Value);
+                    var offsetX = float.Parse(matches[1].Value, CultureInfo.InvariantCulture);
+                    var offsetY = float.Parse(matches[2].Value, CultureInfo.InvariantCulture);
+
+                    return new Shadow
+                    {
+                        Brush = brush,
+                        Offset = new Point(offsetX, offsetY)
+                    };
+                }
+                else if (matches.Count == 4) // <float> | <float> | <float> | <color> e.g. 4 4 16 #000000
+                {
+                    var offsetX = float.Parse(matches[0].Value, CultureInfo.InvariantCulture);
+                    var offsetY = float.Parse(matches[1].Value, CultureInfo.InvariantCulture);
+                    var radius = float.Parse(matches[2].Value, CultureInfo.InvariantCulture);
+                    var brush = ParseBrush(matches[3].Value);
+
+                    return new Shadow
+                    {
+                        Offset = new Point(offsetX, offsetY),
+                        Radius = radius,
+                        Brush = brush
+                    };
+                }
+                else if (matches.Count == 5) // <float> | <float> | <float> | <color> | <float> e.g. 4 4 16 #000000 0.5
+                {
+                    var offsetX = float.Parse(matches[0].Value, CultureInfo.InvariantCulture);
+                    var offsetY = float.Parse(matches[1].Value, CultureInfo.InvariantCulture);
+                    var radius = float.Parse(matches[2].Value, CultureInfo.InvariantCulture);
+                    var brush = ParseBrush(matches[3].Value);
+                    var opacity = float.Parse(matches[4].Value, CultureInfo.InvariantCulture);
+
+                    return new Shadow
+                    {
+                        Offset = new Point(offsetX, offsetY),
+                        Radius = radius,
+                        Brush = brush,
+                        Opacity = opacity
+                    };
+                }
+            }
+            catch (Exception ex)
+            {
+                throw new InvalidOperationException($"Cannot convert \"{strValue}\" into {typeof(Shadow)}.", ex);
+            }
+
+            throw new InvalidOperationException($"Cannot convert \"{strValue}\" into {typeof(IShadow)}.");
+        }
+
+        /// <summary>
+        /// Converts a Shadow to a string.
+        /// </summary>
+        /// <param name="context">The context to use for conversion.</param>
+        /// <param name="culture">The culture to use for conversion.</param>
+        /// <param name="value">The Shadow to convert.</param>
+        /// <param name="destinationType">The type to convert to.</param>
+        /// <returns>A string representation of the Shadow.</returns>
+        /// <exception cref="ArgumentNullException">Thrown when <paramref name="value" /> is null.</exception>
+        /// <exception cref="InvalidOperationException">Thrown when <paramref name="value" /> is not a Shadow or the Brush is not a SolidColorBrush.</exception>
+        public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
+        {
+            if (value is null)
+            {
+                throw new ArgumentNullException(nameof(value));
+            }
+
+            if (value is Shadow shadow)
+            {
+                var offsetX = shadow.Offset.X.ToString(CultureInfo.InvariantCulture);
+                var offsetY = shadow.Offset.Y.ToString(CultureInfo.InvariantCulture);
+                var radius = shadow.Radius.ToString(CultureInfo.InvariantCulture);
+                var color = (shadow.Brush as SolidColorBrush)?.Color.ToHex();
+                var opacity = shadow.Opacity.ToString(CultureInfo.InvariantCulture);
+
+                if (color == null)
+                {
+                    throw new InvalidOperationException("Cannot convert Shadow to string: Brush is not a valid SolidColorBrush or has no Color.");
+                }
+
+                return $"{offsetX} {offsetY} {radius} {color} {opacity}";
+            }
+
+            throw new InvalidOperationException($"Cannot convert \"{value}\" into string.");
+        }
+
+        /// <summary>
+        /// Parses a string value into a SolidColorBrush.
+        /// </summary>
+        /// <param name="value">The value to parse.</param>
+        /// <returns>A SolidColorBrush.</returns>
+        /// <exception cref="InvalidOperationException">Thrown when the value is not a SolidColorBrush or has no Color.</exception>
+        SolidColorBrush ParseBrush(string value)
+		{
+            // If the value is a color, return a SolidColorBrush
+            if (_colorTypeConverter.ConvertFrom(value) is Color color)
+            {
+                return new SolidColorBrush(color);
+            }
+
+            throw new InvalidOperationException("Cannot convert Shadow to string: Brush is not a valid SolidColorBrush or has no Color.");
+        }
+    }
+}

src/Controls/src/Core/VisualElement/VisualElement.cs

@@ -1851,6 +1851,7 @@ private protected override void OnHandlerChangedCore()
 		/// <summary>
 		/// Gets or sets the shadow effect cast by the element. This is a bindable property.
 		/// </summary>
+		[TypeConverter(typeof(ShadowTypeConverter))]
 		public Shadow Shadow
 		{
 			get { return (Shadow)GetValue(ShadowProperty); }

src/Controls/tests/Core.UnitTests/ShadowTests.cs

@@ -1,3 +1,4 @@
+using System;
 using Microsoft.Maui.Graphics;
 using Xunit;
 
@@ -27,5 +28,65 @@ public void ShadowInitializesCorrectly()
 			Assert.Equal(expectedOpacity, shadow.Opacity);
 			Assert.Equal(expectedRadius, shadow.Radius);
 		}
+
+		[Theory]
+		[InlineData("#000000 4 4")]
+		[InlineData("rgb(6, 201, 198) 4 4")]
+		[InlineData("rgba(6, 201, 188, 0.2) 4 8")]
+		[InlineData("hsl(6, 20%, 45%) 1 5")]
+		[InlineData("hsla(6, 20%, 45%,0.75) 6 3")]
+		[InlineData("fuchsia 4 4")]
+		[InlineData("rgb(100%, 32%, 64%) 8 5")]
+		[InlineData("rgba(100%, 32%, 64%,0.27) 16 5")]
+		[InlineData("hsv(6, 20%, 45%) 1 5")]
+		[InlineData("hsva(6, 20%, 45%,0.75) 6 3")]
+		[InlineData("4 4 16 #FF00FF")]
+		[InlineData("4 4 16 AliceBlue")]
+		[InlineData("5 8 8 rgb(6, 201, 198)")]
+		[InlineData("7 5 4 rgba(6, 201, 188, 0.2)")]
+		[InlineData("9 4 6 hsl(6, 20%, 45%)")]
+		[InlineData("8 1 5 hsla(6, 20%, 45%,0.75)")]
+		[InlineData("5 2 8 rgb(100%, 32%, 64%)")]
+		[InlineData("1 5 3 rgba(100%, 32%, 64%,0.27)")]
+		[InlineData("4 4 16 #00FF00 0.5")]
+		[InlineData("4 4 16 limegreen 0.5")]
+		[InlineData("5 8 8 rgb(6, 201, 198) 0.5")]
+		[InlineData("7 5 4 rgba(6, 201, 188, 0.2) 0.5")]
+		[InlineData("9 4 6 hsl(6, 20%, 45%) 0.5")]
+		[InlineData("8 1 5 hsla(6, 20%, 45%,0.75) 0.5")]
+		[InlineData("9 4 6 hsv(6, 20%, 45%) 0.5")]
+		[InlineData("8 1 5 hsva(6, 20%, 45%,0.75) 0.5")]
+		[InlineData("5 2 8 rgb(100%, 32%, 64%) 0.5")]
+		[InlineData("1 5 3 rgba(100%, 32%, 64%,0.27) 0.5")]
+		public void ShadowTypeConverter_Valid(string value)
+		{
+			var converter = new ShadowTypeConverter();
+			Assert.True(converter.CanConvertFrom(typeof(string)));
+
+			bool actual = converter.IsValid(value);
+			Assert.True(actual);
+		}
+
+		[Theory]
+		[InlineData(null)]
+		[InlineData("")]
+		[InlineData("invalid")]
+		[InlineData("#ZZZZZZ 4 4")]
+		[InlineData("4 4 #000000")]
+		[InlineData("4 4 dotnetpurple")]
+		[InlineData("rgb(6, 14.5, 198) 4 4")]
+		[InlineData("argb(0.2, 6, 201, 188) 4 8")]
+		[InlineData("hsl(6, 20%, 45.8%) 1 5")]
+		[InlineData("hsla(6.8, 20%, 45%,0.75) 6 3")]
+		[InlineData("hsv(6, 20%, 45.8%) 1 5")]
+		[InlineData("hsva(6.8, 20%, 45%,0.75) 6 3")]
+		[InlineData("rgb(100%, 32.9%, 64%) 8 5")]
+		[InlineData("argb(0.27, 100%, 32%, 64%) 16 5")]
+		public void ShadowTypeConverter_Invalid(string value)
+		{
+			ShadowTypeConverter converter = new ShadowTypeConverter();
+			bool actual = converter.IsValid(value);
+			Assert.False(actual);
+		}
 	}
 }