DYN-6440 Custom Selection Overlapped

src/DynamoCoreWpf/UI/Themes/Modern/DynamoModern.xaml

@@ -1981,6 +1981,14 @@
                                  Foreground="#F5F5F5"
                                  IsReadOnly="{TemplateBinding IsReadOnly}"
                                  Visibility="Hidden" />
+                        <TextBlock x:Name="PART_ReadOnlyTextBlock"
+                                 Margin="10,0,20,0"
+                                 HorizontalAlignment="Left"
+                                 VerticalAlignment="Center"
+                                 Focusable="True"
+                                 TextWrapping="Wrap"
+                                 TextTrimming="CharacterEllipsis"
+                                 Visibility="{Binding IsVisibleDropDownTextBlock, Converter={StaticResource BooleanToVisibilityCollapsedConverter}}" /> 
                         <Popup Name="Popup"
                                AllowsTransparency="True"
                                Focusable="False"

src/Libraries/CoreNodeModels/Input/CustomSelection.cs

@@ -29,6 +29,23 @@ namespace CoreNodeModels.Input
     public class CustomSelection : DSDropDownBase
     {
         private List<DynamoDropDownItem> serializedItems;
+        private bool isVisibleDropDownTextBlock = false;
+
+        /// <summary>
+        /// This property will Collapse or make Visible the TextBlock for the ComboBox template "RefreshComboBox" (by default will be Collapsed)
+        /// </summary>
+        public bool IsVisibleDropDownTextBlock
+        {
+            get
+            {
+                return isVisibleDropDownTextBlock;
+            }
+            set
+            {
+                isVisibleDropDownTextBlock = value;
+                RaisePropertyChanged(nameof(IsVisibleDropDownTextBlock));
+            }
+        }
 
         /// <summary>
         /// Copy of <see cref="DSDropDownBase.Items"/> to be serialized./>

src/Libraries/CoreNodeModelsWpf/NodeViewCustomizations/CustomSelection.cs

@@ -4,6 +4,8 @@
 using System.Windows.Controls;
 using System.Windows;
 using Dynamo.Wpf;
+using CoreNodeModels;
+using System.Windows.Data;
 
 namespace CoreNodeModelsWpf.Nodes
 {
@@ -19,6 +21,7 @@ public class CustomSelectionNodeViewCustomization : DropDownNodeViewCustomizatio
         /// <param name="nodeView"></param>
         public void CustomizeView(CustomSelection model, NodeView nodeView)
         {
+            const double leftMargin = 40;
             var formControl = new CustomSelectionControl(new CustomSelectionViewModel(model));
 
             nodeView.inputGrid.Children.Add(formControl);
@@ -27,12 +30,44 @@ public void CustomizeView(CustomSelection model, NodeView nodeView)
             base.CustomizeView(model, nodeView);
 
             var dropdown = (ComboBox)nodeView.inputGrid.Children[1];
+            dropdown.MaxWidth = formControl.Width - leftMargin;
 
             formControl.BaseComboBox = dropdown;
+            formControl.BaseComboBox.SelectionChanged += BaseComboBox_SelectionChanged;
 
             // Add margin to the dropdown to show the expander.
-            dropdown.Margin = new Thickness(40, 0, 0, 0);
+            dropdown.Margin = new Thickness(leftMargin, 0, 0, 0);
             dropdown.VerticalAlignment = VerticalAlignment.Top;
+            dropdown.ApplyTemplate();
+
+            var dropDownTextBlock = dropdown.Template.FindName("PART_ReadOnlyTextBlock", dropdown) as TextBlock;
+            if (dropDownTextBlock != null)
+            {
+                model.IsVisibleDropDownTextBlock = true;
+            }
+
+            var dropDownContent = dropdown.Template.FindName("ContentSite", dropdown) as ContentPresenter;
+            if (dropDownContent != null)
+            {
+                dropDownContent.Visibility = Visibility.Collapsed;
+            }
+
+            // Bind the TextBlock to the selected item hash.
+            var bindingVal = new Binding(nameof(DSDropDownBase.SelectedString))
+            {
+                Mode = BindingMode.TwoWay,
+                Source = model
+            };
+            dropDownTextBlock.SetBinding(TextBlock.TextProperty, bindingVal);
+        }
+
+        private void BaseComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e)
+        {
+            var comboSender = sender as ComboBox;
+            if (comboSender != null)
+            {
+                comboSender.ToolTip = comboSender.SelectedItem?.ToString();
+            }           
         }
     }
-}
+}