don't close the popupbox when mouse capture is lost to a descendant of the popupbox

Author: jonfunkhouser

MainDemo.Wpf/MainWindow.xaml

@@ -169,6 +169,7 @@
                                 <ListBoxItem>Hello World</ListBoxItem>
                                 <ListBoxItem>Nice Popup</ListBoxItem>
                                 <ListBoxItem>Goodbye.</ListBoxItem>
+                                <ListBoxItem><Button x:Name="PopupButton" Content="Button" Click="PopupButton_OnClick"/></ListBoxItem>
                             </ListBox>
                         </materialDesign:PopupBox>
                         <TextBlock HorizontalAlignment="Center" VerticalAlignment="Center" FontSize="22">Material Design In XAML Toolkit</TextBlock>

MainDemo.Wpf/MainWindow.xaml.cs

@@ -17,5 +17,10 @@ private void UIElement_OnPreviewMouseLeftButtonUp(object sender, MouseButtonEven
         {
             MenuToggleButton.IsChecked = false;
         }
+
+        private void PopupButton_OnClick(object sender, RoutedEventArgs e)
+        {
+            MessageBox.Show("PopupButton Clicked");
+        }
     } 
 }

MaterialDesignThemes.Wpf/Extensions.cs

@@ -41,6 +41,28 @@ public static IEnumerable<DependencyObject> GetVisualAncestory(this DependencyOb
                 yield return leaf;
                 leaf = VisualTreeHelper.GetParent(leaf);
             }
-        } 
+        }
+
+        public static IEnumerable<DependencyObject> GetLogicalAncestory(this DependencyObject leaf)
+        {
+            while (leaf != null)
+            {
+                yield return leaf;
+                leaf = LogicalTreeHelper.GetParent(leaf);
+            }
+        }
+
+        public static bool HasAncestor(this DependencyObject leaf, DependencyObject ancestor)
+        {
+            var visualAncestry = leaf.GetVisualAncestory().ToArray();
+            if (visualAncestry.Contains(ancestor))
+            {
+                return true;
+            }
+
+            var lastVisualAncestor = visualAncestry.LastOrDefault();
+            var logicalAncestry = GetLogicalAncestory(lastVisualAncestor);
+            return logicalAncestry.Contains(ancestor);
+        }
     }
 }

MaterialDesignThemes.Wpf/PopupBox.cs

@@ -578,7 +578,7 @@ private static void OnLostMouseCapture(object sender, MouseEventArgs e)
             {
                 if (e.OriginalSource == popupBox)
                 {
-                    if (Mouse.Captured == null || popupBox._popup == null || !(Mouse.Captured as DependencyObject).GetVisualAncestory().Contains(popupBox._popup))
+                    if (Mouse.Captured == null || popupBox._popup == null || !(Mouse.Captured as DependencyObject).HasAncestor(popupBox._popup))
                     {
                         popupBox.Close();
                     }