Add project files.

2022-11-01 15:26:08 +00:00
parent daa7b59f22
commit 7e4f880821
408 changed files with 16863 additions and 0 deletions
@@ -0,0 +1,85 @@
+using System.Collections.ObjectModel;
+using System.Collections.Specialized;
+using System.Windows;
+
+namespace TheXamlGuy.UI.WPF;
+
+internal class VisualStateManagerContext : IDisposable
+{
+    private static readonly DependencyProperty VisualStateManagerContextProperty =
+        DependencyProperty.RegisterAttached("VisualStateManagerContext",
+            typeof(VisualStateManagerContext), typeof(VisualStateManagerContext));
+
+    private VisualStateManagerContext(FrameworkElement element)
+    {
+        Element = element;
+
+        VisualStateGroups = (ObservableCollection<VisualStateGroup>) element.GetValue(VisualStateManager.VisualStateGroupsProperty);
+
+        VisualStateGroups.CollectionChanged += CollectionChanged;
+        ApplyElement(VisualStateGroups);
+    }
+
+    private FrameworkElement? Element { get; set; }
+
+    private ObservableCollection<VisualStateGroup>? VisualStateGroups { get; set; }
+
+    public void Dispose()
+    {
+        RemoveElement(VisualStateGroups);
+        if (VisualStateGroups is not null)
+        {
+            VisualStateGroups.CollectionChanged -= CollectionChanged;
+        }
+
+        Element = null;
+        VisualStateGroups = null;
+    }
+
+    internal static void Set(FrameworkElement element)
+    {
+        VisualStateManagerContext hook = new(element);
+        element.SetValue(VisualStateManagerContextProperty, hook);
+    }
+
+    internal static void UnSet(FrameworkElement element)
+    {
+        if (element.GetValue(VisualStateManagerContextProperty) is VisualStateManagerContext hook)
+        {
+            element.SetValue(VisualStateManagerContextProperty, null);
+            hook.Dispose();
+        }
+    }
+
+    private void CollectionChanged(object? sender, NotifyCollectionChangedEventArgs args)
+    {
+        if (args.NewItems != null)
+        {
+            ApplyElement(args.NewItems.OfType<VisualStateGroup>());
+        }
+
+        if (args.OldItems != null)
+        {
+            RemoveElement(args.OldItems.OfType<VisualStateGroup>());
+        }
+    }
+
+    private void ApplyElement(IEnumerable<VisualStateGroup> visualStateGroups)
+    {
+        foreach (VisualStateExtension? state in visualStateGroups.SelectMany(group => group.States.OfType<VisualStateExtension>()))
+        {
+            state.Element = Element;
+        }
+    }
+
+    private void RemoveElement(IEnumerable<VisualStateGroup>? visualStateGroups)
+    {
+        if (visualStateGroups is not null)
+        {
+            foreach (VisualStateExtension? state in visualStateGroups.SelectMany(group => group.States.OfType<VisualStateExtension>()))
+            {
+                state.Element = null;
+            }
+        }
+    }
+}