new method TryGetNextAncestorDropTargetElement

used in DropInfo
punker76 · Mar 17, 2015 · a850796 · a850796
1 parent 3cce250
commit a850796
Show file tree

Hide file tree

Showing 2 changed files with 31 additions and 9 deletions.
diff --git a/GongSolutions.Wpf.DragDrop/DropInfo.cs b/GongSolutions.Wpf.DragDrop/DropInfo.cs
@@ -45,15 +45,14 @@ public DropInfo(object sender, DragEventArgs e, DragInfo dragInfo)
       this.KeyStates = e.KeyStates;
 
       this.VisualTarget = sender as UIElement;
-      // if drop target isn't a ItemsControl
-      if (!(this.VisualTarget is ItemsControl)) {
-        // try to find next ItemsControl
-        var itemsControl = VisualTreeExtensions.GetVisualAncestor<ItemsControl>(this.VisualTarget);
-        if (itemsControl != null) {
-          // now check if this ItemsControl is a drop target
-          if (DragDrop.GetIsDropTarget(itemsControl)) {
-            this.VisualTarget = itemsControl;
-          }
+      // if there is no drop target, find another
+      if (!this.VisualTarget.IsDropTarget())
+      {
+        // try to find next element
+        var element = this.VisualTarget.TryGetNextAncestorDropTargetElement();
+        if (element != null)
+        {
+          this.VisualTarget = element;
         }
       }
       // visual target can be null, so give us a point...

diff --git a/GongSolutions.Wpf.DragDrop/Utilities/VisualTreeExtensions.cs b/GongSolutions.Wpf.DragDrop/Utilities/VisualTreeExtensions.cs
@@ -10,6 +10,29 @@ namespace GongSolutions.Wpf.DragDrop.Utilities
 {
   public static class VisualTreeExtensions
   {
+    /// <summary>
+    /// Gets the next ancestor element which is a drop target.
+    /// </summary>
+    /// <param name="element">The start element.</param>
+    /// <returns>The first element which is a drop target.</returns>
+    public static UIElement TryGetNextAncestorDropTargetElement(this UIElement element)
+    {
+      if (element == null)
+      {
+        return null;
+      }
+      var ancestor = element.GetVisualAncestor<UIElement>();
+      while (ancestor != null)
+      {
+        if (ancestor.IsDropTarget())
+        {
+          return ancestor;
+        }
+        ancestor = ancestor.GetVisualAncestor<UIElement>();
+      }
+      return null;
+    }
+
     internal static DependencyObject FindVisualTreeRoot(this DependencyObject d)
     {
       var current = d;