refactor Poptip & Magnifier

src/Shared/HandyControl_Shared/Controls/Base/AdornerElement.cs

@@ -0,0 +1,87 @@
+using System;
+using System.ComponentModel;
+using System.Windows;
+using System.Windows.Controls;
+using HandyControl.Data;
+
+namespace HandyControl.Controls
+{
+    public abstract class AdornerElement : Control, IDisposable
+    {
+        protected FrameworkElement ElementTarget { get; set; }
+
+        public static readonly DependencyProperty TargetProperty = DependencyProperty.Register(
+            "Target", typeof(FrameworkElement), typeof(AdornerElement), new PropertyMetadata(default(FrameworkElement), OnTargetChanged));
+
+        private static void OnTargetChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+        {
+            var ctl = (AdornerElement)d;
+            ctl.OnTargetChanged(ctl.ElementTarget, false);
+            ctl.OnTargetChanged((FrameworkElement)e.NewValue, true);
+        }
+
+        [Bindable(true), Category("Layout")]
+        [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]
+        public FrameworkElement Target
+        {
+            get => (FrameworkElement) GetValue(TargetProperty);
+            set => SetValue(TargetProperty, value);
+        }
+
+        public static readonly DependencyProperty InstanceProperty = DependencyProperty.RegisterAttached(
+            "Instance", typeof(AdornerElement), typeof(AdornerElement), new PropertyMetadata(default(AdornerElement), OnInstanceChanged));
+
+        private static void OnInstanceChanged(DependencyObject d, DependencyPropertyChangedEventArgs e)
+        {
+            if (!(d is FrameworkElement target)) return;
+            var element = (AdornerElement)e.NewValue;
+            element.OnInstanceChanged(target);
+        }
+
+        protected virtual void OnInstanceChanged(FrameworkElement target) => Target = target;
+
+        public static void SetInstance(DependencyObject element, AdornerElement value)
+            => element.SetValue(InstanceProperty, value);
+
+        public static AdornerElement GetInstance(DependencyObject element)
+            => (AdornerElement) element.GetValue(InstanceProperty);
+
+        public static readonly DependencyProperty IsInstanceProperty = DependencyProperty.RegisterAttached(
+            "IsInstance", typeof(bool), typeof(AdornerElement), new PropertyMetadata(ValueBoxes.TrueBox));
+
+        public static void SetIsInstance(DependencyObject element, bool value)
+            => element.SetValue(IsInstanceProperty, value);
+
+        public static bool GetIsInstance(DependencyObject element)
+            => (bool) element.GetValue(IsInstanceProperty);
+
+        protected virtual void OnTargetChanged(FrameworkElement element, bool isNew)
+        {
+            if (element == null) return;
+
+            if (!isNew)
+            {
+                element.Unloaded -= TargetElement_Unloaded;
+                ElementTarget = null;
+            }
+            else
+            {
+                element.Unloaded += TargetElement_Unloaded;
+                ElementTarget = element;
+            }
+        }
+
+        private void TargetElement_Unloaded(object sender, RoutedEventArgs e)
+        {
+            if (sender is FrameworkElement element)
+            {
+                element.Unloaded -= TargetElement_Unloaded;
+                Dispose();
+            }
+        }
+
+        protected abstract void Dispose();
+
+        void IDisposable.Dispose() => Dispose();
+    }
+}