From 9adc3c29752f9653367bcda8c6c0a8b0798ff976 Mon Sep 17 00:00:00 2001
From: TheXamlGuy <dan_clark@outlook.com>
Date: Tue, 16 Jul 2024 20:22:37 +0100
Subject: [PATCH] Add a ContentBadge control

---
 .../ContentBadge/ContentBadge.axaml           | 15 +++
 .../ContentBadge/ContentBadge.cs              | 97 +++++++++++++++++++
 .../Overflow/Overflow.cs                      | 10 +-
 .../Themes/ControlResources.axaml             |  1 +
 4 files changed, 115 insertions(+), 8 deletions(-)
 create mode 100644 Toolkit.UI.Controls.Avalonia/ContentBadge/ContentBadge.axaml
 create mode 100644 Toolkit.UI.Controls.Avalonia/ContentBadge/ContentBadge.cs

diff --git a/Toolkit.UI.Controls.Avalonia/ContentBadge/ContentBadge.axaml b/Toolkit.UI.Controls.Avalonia/ContentBadge/ContentBadge.axaml
new file mode 100644
index 0000000..26b79d6
--- /dev/null
+++ b/Toolkit.UI.Controls.Avalonia/ContentBadge/ContentBadge.axaml
@@ -0,0 +1,15 @@
+<ResourceDictionary
+    xmlns="https://github.com/avaloniaui"
+    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+    xmlns:controls="using:Toolkit.UI.Controls.Avalonia">
+    <ControlTheme x:Key="{x:Type controls:ContentBadge}" TargetType="controls:ContentBadge">
+        <Setter Property="Template">
+            <ControlTemplate>
+                <Grid>
+                    <ContentPresenter Content="{TemplateBinding Content}" ContentTemplate="{TemplateBinding ContentTemplate}" />
+                    <ContentControl x:Name="BadgeContent" />
+                </Grid>
+            </ControlTemplate>
+        </Setter>
+    </ControlTheme>
+</ResourceDictionary>
diff --git a/Toolkit.UI.Controls.Avalonia/ContentBadge/ContentBadge.cs b/Toolkit.UI.Controls.Avalonia/ContentBadge/ContentBadge.cs
new file mode 100644
index 0000000..2b0d87a
--- /dev/null
+++ b/Toolkit.UI.Controls.Avalonia/ContentBadge/ContentBadge.cs
@@ -0,0 +1,97 @@
+using Avalonia;
+using Avalonia.Controls;
+using Avalonia.Controls.Primitives;
+using Avalonia.Media;
+using Path = Avalonia.Controls.Shapes.Path;
+
+namespace Toolkit.UI.Controls.Avalonia;
+
+public class ContentBadge : 
+    ContentControl
+{
+    public static readonly StyledProperty<string?> BadgePathProperty =
+        AvaloniaProperty.Register<ContentBadge, string?>(nameof(BadgePath));
+
+    public static readonly StyledProperty<double> BadgeSizeProperty =
+        AvaloniaProperty.Register<ContentBadge, double>(nameof(BadgeSize), 14);
+
+    private ContentControl? badgeContent;
+
+    public string? BadgePath
+    {
+        get => GetValue(BadgePathProperty);
+        set => SetValue(BadgePathProperty, value);
+    }
+
+    public double BadgeSize
+    {
+        get => GetValue(BadgeSizeProperty);
+        set => SetValue(BadgeSizeProperty, value);
+    }
+
+    public void UpdateClip()
+    {
+        if (Content is Control content &&
+            badgeContent is not null &&
+            BadgePath is { Length: > 0 } && 
+            Geometry.Parse(BadgePath) is Geometry geometry)
+        {
+            double backgroundWidth = DesiredSize.Width;
+            double backgroundHeight = DesiredSize.Height;
+
+            double scaleX = BadgeSize / geometry.Bounds.Width;
+            double scaleY = BadgeSize / geometry.Bounds.Height;
+
+            double adjustedStrokeWidth = Math.Min(scaleX, scaleY) * 8;
+
+            Geometry knockoutGeometry = geometry.GetWidenedGeometry(new Pen(new SolidColorBrush(Colors.Transparent), adjustedStrokeWidth);
+
+            TransformGroup transformGroup = new();
+            transformGroup.Children.Add(new ScaleTransform(scaleX, scaleY));
+
+            double scaledWidth = knockoutGeometry.Bounds.Width * scaleX;
+            double scaledHeight = knockoutGeometry.Bounds.Height * scaleY;
+            double offsetX = backgroundWidth - scaledWidth;
+            double offsetY = backgroundHeight - scaledHeight;
+
+            transformGroup.Children.Add(new TranslateTransform(offsetX, offsetY));
+            knockoutGeometry.Transform = transformGroup;
+
+            CombinedGeometry combinedGeometry = new()
+            {
+                GeometryCombineMode = GeometryCombineMode.Exclude,
+                Geometry1 = new RectangleGeometry { Rect = new Rect(0, 0, backgroundWidth, backgroundHeight) },
+                Geometry2 = knockoutGeometry
+            };
+
+            content.Clip = combinedGeometry;
+
+            Geometry overlayGeometry = geometry.Clone();
+
+            TransformGroup overlayTransformGroup = new();
+            overlayTransformGroup.Children.Add(new ScaleTransform(scaleX, scaleY));
+
+            overlayTransformGroup.Children.Add(new TranslateTransform(offsetX, offsetY));
+            overlayGeometry.Transform = overlayTransformGroup;
+
+            badgeContent.Content = new Path
+            {
+                Data = overlayGeometry,
+                Fill = Foreground
+            };
+        }
+    }
+
+    protected override void OnApplyTemplate(TemplateAppliedEventArgs args)
+    {
+        base.OnApplyTemplate(args);
+        badgeContent = args.NameScope.Get<ContentControl>("BadgeContent");
+    }
+
+    protected override void OnSizeChanged(SizeChangedEventArgs args)
+    {
+        base.OnSizeChanged(args);
+        UpdateClip();
+    }
+}
+
diff --git a/Toolkit.UI.Controls.Avalonia/Overflow/Overflow.cs b/Toolkit.UI.Controls.Avalonia/Overflow/Overflow.cs
index e6a0754..a8f2b9d 100644
--- a/Toolkit.UI.Controls.Avalonia/Overflow/Overflow.cs
+++ b/Toolkit.UI.Controls.Avalonia/Overflow/Overflow.cs
@@ -84,16 +84,10 @@ public class Overflow :
         base.OnApplyTemplate(args);
 
         primaryListBox = args.NameScope.Get<ListBox>("PrimaryListBox");
-        if (primaryListBox is not null)
-        {
-            primaryListBox.SetValue(ItemsControl.ItemsSourceProperty, primaryCollection);
-        }
+        primaryListBox?.SetValue(ItemsControl.ItemsSourceProperty, primaryCollection);
 
         secondaryListBox = args.NameScope.Get<ListBox>("SecondaryListBox");
-        if (secondaryListBox is not null)
-        {
-            secondaryListBox.SetValue(ItemsControl.ItemsSourceProperty, secondaryCollection);
-        }
+        secondaryListBox?.SetValue(ItemsControl.ItemsSourceProperty, secondaryCollection);
 
         InitializeCollections();
         UpdateOverflow();
diff --git a/Toolkit.UI.Controls.Avalonia/Themes/ControlResources.axaml b/Toolkit.UI.Controls.Avalonia/Themes/ControlResources.axaml
index 196bb1a..b943686 100644
--- a/Toolkit.UI.Controls.Avalonia/Themes/ControlResources.axaml
+++ b/Toolkit.UI.Controls.Avalonia/Themes/ControlResources.axaml
@@ -7,6 +7,7 @@
                 <MergeResourceInclude Source="../PersonPicture/PersonPicture.axaml" />
                 <MergeResourceInclude Source="../SettingsExpander/SettingsExpander.axaml" />
                 <MergeResourceInclude Source="../Overflow/Overflow.axaml" />
+                <MergeResourceInclude Source="../ContentBadge/ContentBadge.axaml" />
             </ResourceDictionary.MergedDictionaries>
         </ResourceDictionary>
     </Styles.Resources>