Position node autocomplete UI against respective input port

src/DynamoCore/Core/DynamoSelection.cs

@@ -160,7 +160,7 @@ public void AddRange(IEnumerable<T> range)
         {
             foreach (var item in range)
             {
-                Items.Add(item);
+                Add(item);
             }
 
             this.OnPropertyChanged(new PropertyChangedEventArgs("Count"));

src/DynamoCore/Graph/Nodes/NodeModel.cs

@@ -64,12 +64,14 @@ public abstract class NodeModel : ModelBase, IRenderPackageSource<NodeModel>, ID
         private ObservableCollection<PortModel> inPorts = new ObservableCollection<PortModel>();
         private ObservableCollection<PortModel> outPorts = new ObservableCollection<PortModel>();
 
+        private readonly Dictionary<int, Tuple<int, NodeModel>> inputNodes;
+        private readonly Dictionary<int, HashSet<Tuple<int, NodeModel>>> outputNodes;
+
         #endregion
 
-        #region public members
+        internal const double HeaderHeight = 25;
 
-        private readonly Dictionary<int, Tuple<int, NodeModel>> inputNodes;
-        private readonly Dictionary<int, HashSet<Tuple<int, NodeModel>>> outputNodes;
+        #region public members
 
         /// <summary>
         /// The unique name that was created the node by

src/DynamoCore/Graph/Nodes/PortModel.cs

@@ -163,10 +163,9 @@ public Point2D Center
             get
             {
                 double halfHeight = Height * 0.5;
-                const double headerHeight = 25;
 
                 double offset = Owner.GetPortVerticalOffset(this);
-                double y = Owner.Y + headerHeight + 5 + halfHeight + offset;
+                double y = Owner.Y + NodeModel.HeaderHeight + 5 + halfHeight + offset;
 
                 switch (PortType)
                 {

src/DynamoCoreWpf/Controls/NodeAutoCompleteSearchControl.xaml.cs

@@ -36,8 +36,16 @@ public NodeAutoCompleteSearchControl()
             {
                 Application.Current.Deactivated += currentApplicationDeactivated;
             }
+            Loaded += NodeAutoCompleteSearchControl_Loaded;
             Unloaded += NodeAutoCompleteSearchControl_Unloaded;
+        }
 
+        private void NodeAutoCompleteSearchControl_Loaded(object sender, RoutedEventArgs e)
+        {
+            if (ViewModel != null && ViewModel.PortViewModel != null)
+            {
+                ViewModel.PortViewModel.PlaceNodeAutocompleteWindow(this, e);
+            }
         }
 
         private void NodeAutoCompleteSearchControl_Unloaded(object sender, RoutedEventArgs e)

src/DynamoCoreWpf/ViewModels/Core/PortViewModel.cs

@@ -1,8 +1,10 @@
 using System;
 using System.Windows;
+using System.Windows.Controls.Primitives;
 using Dynamo.Graph.Nodes;
 using Dynamo.Models;
 using Dynamo.UI.Commands;
+using Dynamo.UI.Controls;
 using Dynamo.Utilities;
 
 namespace Dynamo.ViewModels
@@ -16,6 +18,7 @@ public partial class PortViewModel : ViewModelBase
         private readonly NodeViewModel _node;
         private DelegateCommand _useLevelsCommand;
         private DelegateCommand _keepListStructureCommand;
+        private const double autocompleteUISpacing = 2.5;
 
         /// <summary>
         /// Port model.
@@ -226,6 +229,36 @@ public override void Dispose()
             _node.WorkspaceViewModel.PropertyChanged -= Workspace_PropertyChanged;
         }
 
+        /// <summary>
+        /// Places the node autocomplete window relative to the respective port 
+        /// once the control is loaded and when its actual width is known.
+        /// The UI is first placed w.r.t to the X, Y position of the node (to which the port belongs),
+        /// then offset from that based on the port, the width of the UI itself and in some cases, the node width.
+        /// </summary>
+        /// <param name="sender"></param>
+        /// <param name="e"></param>
+        internal void PlaceNodeAutocompleteWindow(object sender, EventArgs e)
+        {
+            var control = sender as NodeAutoCompleteSearchControl;
+            var popup = control.Parent as Popup;
+
+            double x;
+            if (PortModel.PortType == PortType.Input)
+            {
+                // Position node autocomplete UI offset left by its width from X position of node.
+                x = _node.X - (control.ActualWidth + autocompleteUISpacing);
+            }
+            else
+            {
+                // Position node autocomplete UI offset right by node width from X position of node.
+                x = _node.X + _node.NodeModel.Width + autocompleteUISpacing;
+            }
+            // Position UI down from the top of the node but offset down by the node header and against the respective port.
+            var y = _node.Y + NodeModel.HeaderHeight + PortModel.Index * PortModel.Height;
+
+            popup.PlacementRectangle = new Rect(x, y, 0, 0);
+        }
+
         private void Workspace_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
         {
             switch (e.PropertyName)
@@ -367,10 +400,11 @@ private bool CanConnect(object parameter)
         // Handler to invoke node Auto Complete
         private void AutoComplete(object parameter)
         {
-            DynamoViewModel dynamoViewModel = _node.DynamoViewModel;
-            var svm = dynamoViewModel.CurrentSpaceViewModel.NodeAutoCompleteSearchViewModel as NodeAutoCompleteSearchViewModel;
-            svm.PortViewModel = parameter as PortViewModel;
-            dynamoViewModel.CurrentSpaceViewModel.OnRequestNodeAutoCompleteSearch(ShowHideFlags.Show);
+            var wsViewModel = _node.WorkspaceViewModel;
+            var svm = wsViewModel.NodeAutoCompleteSearchViewModel as NodeAutoCompleteSearchViewModel;
+            svm.PortViewModel = this;
+
+            wsViewModel.OnRequestNodeAutoCompleteSearch(ShowHideFlags.Show);
         }
 
         private bool CanAutoComplete(object parameter)

src/DynamoCoreWpf/ViewModels/Core/WorkspaceViewModel.cs

@@ -163,9 +163,8 @@ private void OnRequestShowInCanvasSearch(object param)
 
         internal event Action<ShowHideFlags> RequestNodeAutoCompleteSearch;
 
-        internal void OnRequestNodeAutoCompleteSearch(object param)
+        internal void OnRequestNodeAutoCompleteSearch(ShowHideFlags flag)
         {
-            var flag = (ShowHideFlags)param;
             RequestNodeAutoCompleteSearch?.Invoke(flag);
         }
 
@@ -1401,6 +1400,7 @@ private void RefreshViewOnSelectionChange(object sender, NotifyCollectionChanged
             RaisePropertyChanged("AnyNodeVisible");
             RaisePropertyChanged("SelectionArgumentLacing");            
         }
+
     }
 
     public class ViewModelEventArgs : EventArgs

src/DynamoCoreWpf/ViewModels/Search/NodeAutoCompleteSearchViewModel.cs

@@ -1,6 +1,5 @@
 using System.Collections.Generic;
 using System.Linq;
-using Dynamo.Controls;
 using Dynamo.Search.SearchElements;
 using Dynamo.Wpf.ViewModels;
 

src/DynamoCoreWpf/ViewModels/Search/NodeSearchElementViewModel.cs

@@ -290,10 +290,7 @@ protected virtual void CreateAndConnectToPort(object parameter)
             DynamoSelection.Instance.ClearSelection();
             var inputNodes = initialNode.InputNodes.Values.Where(x => x != null).Select(y => y.Item2);
 
-            foreach (var inputNode in inputNodes)
-            {
-                DynamoSelection.Instance.Selection.AddUnique(inputNode);
-            }
+            DynamoSelection.Instance.Selection.AddRange(inputNodes);
         }
 
         protected virtual bool CanCreateAndConnectToPort(object parameter)

src/DynamoCoreWpf/Views/Core/WorkspaceView.xaml

@@ -349,8 +349,6 @@
                StaysOpen="True"
                AllowsTransparency="True"
                IsOpen="False"
-               Placement="MousePoint"
-               HorizontalOffset="-290"
                DataContext="{Binding NodeAutoCompleteSearchViewModel}">
             <ui:NodeAutoCompleteSearchControl RequestShowNodeAutoCompleteSearch="ShowHideNodeAutoCompleteControl" />
         </Popup>

src/DynamoCoreWpf/Views/Core/WorkspaceView.xaml.cs

@@ -146,6 +146,7 @@ private void removeViewModelsubscriptions(WorkspaceViewModel ViewModel)
             ViewModel.Model.RequestNodeCentered -= vm_RequestNodeCentered;
             ViewModel.Model.RequestNodeCentered -= vm_RequestNodeCentered;
             ViewModel.Model.CurrentOffsetChanged -= vm_CurrentOffsetChanged;
+            ViewModel.RequestNodeAutoCompleteSearch -= ShowHideNodeAutoCompleteControl;
         }
 
         void OnWorkspaceViewUnloaded(object sender, RoutedEventArgs e)
@@ -364,7 +365,7 @@ void OnWorkspaceViewDataContextChanged(object sender, DependencyPropertyChangedE
                 oldViewModel.RequestAddViewToOuterCanvas -= vm_RequestAddViewToOuterCanvas;
                 oldViewModel.WorkspacePropertyEditRequested -= VmOnWorkspacePropertyEditRequested;
                 oldViewModel.RequestSelectionBoxUpdate -= VmOnRequestSelectionBoxUpdate;
-                this.removeViewModelsubscriptions(oldViewModel);
+                removeViewModelsubscriptions(oldViewModel);
             }
 
             if (ViewModel != null)