DYN-9724: Allow Pins to Stay Until Connector is Actually Disconnected

src/DynamoCore/Graph/Connectors/ConnectorModel.cs

@@ -8,6 +8,7 @@
 using Dynamo.Graph.Workspaces;
 using Dynamo.Utilities;
 using Newtonsoft.Json;
+using System.Linq;
 
 namespace Dynamo.Graph.Connectors
 {
@@ -122,6 +123,21 @@ public override Guid GUID
             }
         }
 
+        /// <summary>
+        /// Returns a snapshot of pin top-left canvas coordinates for this connector.
+        /// </summary>
+        internal IEnumerable<(double X, double Y)> GetPinLocations()
+        {
+            if (ConnectorPinModels == null || ConnectorPinModels.Count == 0)
+            {
+                return Enumerable.Empty<(double X, double Y)>();
+            }
+
+            return ConnectorPinModels
+                .Select(pin => (pin.X, pin.Y))
+                .ToList();
+        }
+
         #endregion 
 
         #region constructors

src/DynamoCore/Models/DynamoModelCommands.cs

@@ -43,6 +43,7 @@ public void ExecuteCommand(RecordableCommand command)
 
         private PortModel[] activeStartPorts;
         private PortModel firstStartPort;
+        private Dictionary<Guid, List<(double X, double Y)>> reconnectionPinLocationsByStartPortId;
 
         protected virtual void OpenFileImpl(OpenFileCommand command)
         {
@@ -373,6 +374,7 @@ private void BeginConnection(Guid nodeId, int portIndex, PortType portType)
         {
             bool isInPort = portType == PortType.Input;
             activeStartPorts = null;
+            reconnectionPinLocationsByStartPortId = null;
 
             if (CurrentWorkspace.GetModelInternal(nodeId) is not NodeModel node)
                 return;
@@ -384,12 +386,13 @@ private void BeginConnection(Guid nodeId, int portIndex, PortType portType)
                 // to somewhere else (we don't allow the grabbing of the start connector).
                 if (portModel.Connectors.Count > 0 && portModel.Connectors[0].Start != portModel)
                 {
-                    activeStartPorts = new PortModel[] { portModel.Connectors[0].Start };
-                    firstStartPort = portModel.Connectors[0].Start;
+                    ConnectorModel connector = portModel.Connectors[0];
+                    activeStartPorts = new PortModel[] { connector.Start };
+                    firstStartPort = connector.Start;
+                    RecordReconnectionPinLocations(connector.Start, connector);
                     // Disconnect the connector model from its start and end ports
                     // and remove it from the connectors collection. This will also
                     // remove the view model.
-                    ConnectorModel connector = portModel.Connectors[0];
                     if (CurrentWorkspace.Connectors.Contains(connector))
                     {
                         var models = new List<ModelBase> { connector };
@@ -411,6 +414,8 @@ private void BeginConnection(Guid nodeId, int portIndex, PortType portType)
 
         private void BeginDuplicateConnection(Guid nodeId, int portIndex, PortType portType)
         {
+            reconnectionPinLocationsByStartPortId = null;
+
             // If the port clicked is an output port, begin connection as per normal
             if (portType == PortType.Output)
             {
@@ -441,6 +446,7 @@ private void BeginShiftReconnections(Guid nodeId, int portIndex, PortType portTy
         {
             if (portType == PortType.Input) return; //only handle multiple connections when the port selected is an output port
             if (!(CurrentWorkspace.GetModelInternal(nodeId) is NodeModel node)) return;
+            reconnectionPinLocationsByStartPortId = null;
 
             PortModel selectedPort = node.OutPorts[portIndex];
 
@@ -462,6 +468,7 @@ private void BeginShiftReconnections(Guid nodeId, int portIndex, PortType portTy
             {
                 ConnectorModel connector = selectedConnectors[i];
                 activeStartPorts[i] = connector.End;
+                RecordReconnectionPinLocations(connector.End, connector);
             }
             CurrentWorkspace.SaveAndDeleteModels(selectedConnectors.ToList<ModelBase>());
             return;
@@ -481,11 +488,15 @@ private void EndConnection(Guid nodeId, int portIndex, PortType portType)
 
             PortModel portModel = isInPort ? node.InPorts[portIndex] : node.OutPorts[portIndex];
 
-            var models = GetConnectorsToAddAndDelete(portModel, activeStartPorts[0]);
+            var models = GetConnectorsToAddAndDelete(
+                portModel,
+                activeStartPorts[0],
+                ConsumeReconnectionPinLocations(activeStartPorts[0]));
 
             WorkspaceModel.RecordModelsForUndo(models, CurrentWorkspace.UndoRecorder);
             activeStartPorts = null;
             firstStartPort = null;
+            reconnectionPinLocationsByStartPortId = null;
         }
 
         private void EndShiftReconnections(Guid nodeId, int portIndex, PortType portType)
@@ -496,17 +507,24 @@ private void EndShiftReconnections(Guid nodeId, int portIndex, PortType portType
             if (!(CurrentWorkspace.GetModelInternal(nodeId) is NodeModel node)) return;
             PortModel selectedPort = node.OutPorts[portIndex];
 
-            var firstModel = GetConnectorsToAddAndDelete(selectedPort, activeStartPorts[0]);
+            var firstModel = GetConnectorsToAddAndDelete(
+                selectedPort,
+                activeStartPorts[0],
+                ConsumeReconnectionPinLocations(activeStartPorts[0]));
             for (int i = 1; i < activeStartPorts.Count(); i++)
             {
-                var models = GetConnectorsToAddAndDelete(selectedPort, activeStartPorts[i]);
+                var models = GetConnectorsToAddAndDelete(
+                    selectedPort,
+                    activeStartPorts[i],
+                    ConsumeReconnectionPinLocations(activeStartPorts[i]));
                 foreach (var m in models)
                 {
                     firstModel.Add(m.Key, m.Value);
                 }
             }
             WorkspaceModel.RecordModelsForUndo(firstModel, CurrentWorkspace.UndoRecorder);
             activeStartPorts = null;
+            reconnectionPinLocationsByStartPortId = null;
             return;
         }
 
@@ -528,11 +546,14 @@ private void CancelConnections()
             CurrentWorkspace.DeleteSavedModels();
             activeStartPorts = null;
             firstStartPort = null;
+            reconnectionPinLocationsByStartPortId = null;
             return;
         }
 
         private static Dictionary<ModelBase, UndoRedoRecorder.UserAction> GetConnectorsToAddAndDelete(
-            PortModel endPort, PortModel startPort)
+            PortModel endPort,
+            PortModel startPort,
+            IEnumerable<(double X, double Y)> pinLocations = null)
         {
             ConnectorModel connectorToRemove = null;
 
@@ -573,10 +594,52 @@ private void CancelConnections()
             if (newConnectorModel != null)
             {
                 models.Add(newConnectorModel, UndoRedoRecorder.UserAction.Creation);
+
+                if (pinLocations != null)
+                {
+                    foreach (var pinLocation in pinLocations)
+                    {
+                        var connectorPinModel = new ConnectorPinModel(
+                            pinLocation.X,
+                            pinLocation.Y,
+                            Guid.NewGuid(),
+                            newConnectorModel.GUID);
+
+                        newConnectorModel.AddPin(connectorPinModel);
+                        models.Add(connectorPinModel, UndoRedoRecorder.UserAction.Creation);
+                    }
+                }
             }
             return models;
         }
 
+        private void RecordReconnectionPinLocations(PortModel activeStartPort, ConnectorModel connector)
+        {
+            if (activeStartPort == null || connector == null)
+            {
+                return;
+            }
+
+            reconnectionPinLocationsByStartPortId ??= new Dictionary<Guid, List<(double X, double Y)>>();
+            reconnectionPinLocationsByStartPortId[activeStartPort.GUID] = connector.GetPinLocations().ToList();
+        }
+
+        private IEnumerable<(double X, double Y)> ConsumeReconnectionPinLocations(PortModel activeStartPort)
+        {
+            if (activeStartPort == null || reconnectionPinLocationsByStartPortId == null)
+            {
+                return Array.Empty<(double X, double Y)>();
+            }
+
+            if (!reconnectionPinLocationsByStartPortId.TryGetValue(activeStartPort.GUID, out var pinLocations))
+            {
+                return Array.Empty<(double X, double Y)>();
+            }
+
+            reconnectionPinLocationsByStartPortId.Remove(activeStartPort.GUID);
+            return pinLocations;
+        }
+
         private void DeleteModelImpl(DeleteModelCommand command)
         {
             RequestHideNodeAutoCompleteBar?.Invoke();

src/DynamoCoreWpf/PublicAPI.Unshipped.txt

@@ -1890,6 +1890,8 @@ Dynamo.ViewModels.ConnectorPinViewModel.IsHidden.get -> bool
 Dynamo.ViewModels.ConnectorPinViewModel.IsHidden.set -> void
 Dynamo.ViewModels.ConnectorPinViewModel.IsHoveredOver.get -> bool
 Dynamo.ViewModels.ConnectorPinViewModel.IsHoveredOver.set -> void
+Dynamo.ViewModels.ConnectorPinViewModel.IsInteractive.get -> bool
+Dynamo.ViewModels.ConnectorPinViewModel.IsInteractive.set -> void
 Dynamo.ViewModels.ConnectorPinViewModel.IsSelected.get -> bool
 Dynamo.ViewModels.ConnectorPinViewModel.IsTemporarilyVisible.get -> bool
 Dynamo.ViewModels.ConnectorPinViewModel.IsTemporarilyVisible.set -> void

src/DynamoCoreWpf/ViewModels/Core/ConnectorPinViewModel.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Linq;
 using Dynamo.Configuration;
 using Dynamo.Graph;
@@ -225,6 +225,22 @@ public bool IsTemporarilyVisible
             }
         }
 
+        private bool isInteractive;
+        /// <summary>
+        /// Gets or sets whether the pin is interactive (can be hovered over, clicked on, etc.) and updates the command state when this changes.
+        /// </summary>
+        [JsonIgnore]
+        public bool IsInteractive
+        {
+            get => isInteractive;
+            set
+            {
+                if (isInteractive == value) return;
+                isInteractive = value;
+                RaisePropertyChanged(nameof(IsInteractive));
+            }
+        }
+
         private bool isInGroup;
         /// <summary>
         /// Gets or sets whether the pin is in a group and updates the command state when this changes.