[DYN-7839] Wires & Pins: improve snapping tolerance

src/DynamoCore/Configuration/Configurations.cs

@@ -58,6 +58,16 @@ public class Configurations
         /// </summary>
         public static readonly double ZoomToFitPaddingFactor = 3.5;
 
+        /// <summary>
+        /// Const used to define the interaction or hit area thickness for connectors in the workspace.
+        /// </summary>
+        public static readonly double ConnectorBaseThickness = 3;
+
+        /// <summary>
+        /// Const defining the scaling factor for adjusting connector stroke thickness based on zoom level.
+        /// </summary>
+        public const double ConnectorZoomScalingFactor = 2.0;
+
         #endregion
 
         #region Usage Reporting Error Message

src/DynamoCore/PublicAPI.Unshipped.txt

@@ -36,6 +36,7 @@ abstract Dynamo.Search.SearchElements.SearchElementBase.Type.get -> string
 abstract Dynamo.Search.SearchElements.SearchElementBase.Weight.get -> double
 abstract Dynamo.Search.SearchElements.SearchElementBase.Weight.set -> void
 const Dynamo.Configuration.Configurations.NotificationsDefaultTimeOut = 10000 -> int
+const Dynamo.Configuration.Configurations.ConnectorZoomScalingFactor = 2 -> double
 const Dynamo.Configuration.Context.NONE = "None" -> string
 const Dynamo.Configuration.Context.REVIT_2014 = "Revit 2014" -> string
 const Dynamo.Configuration.Context.REVIT_2015 = "Revit 2015" -> string
@@ -3001,6 +3002,7 @@ static readonly Dynamo.Configuration.Configurations.AutodeskAsString -> string
 static readonly Dynamo.Configuration.Configurations.BackupFolderName -> string
 static readonly Dynamo.Configuration.Configurations.CBNMaxPortNameLength -> int
 static readonly Dynamo.Configuration.Configurations.CodeBlockOutputPortHeightInPixels -> double
+static readonly Dynamo.Configuration.Configurations.ConnectorBaseThickness -> double
 static readonly Dynamo.Configuration.Configurations.DoubleSliderTextBoxWidth -> double
 static readonly Dynamo.Configuration.Configurations.DynamoAsString -> string
 static readonly Dynamo.Configuration.Configurations.DynamoNodeHelpDocs -> string

src/DynamoCoreWpf/PublicAPI.Unshipped.txt

@@ -1824,6 +1824,8 @@ Dynamo.ViewModels.ConnectorViewModel.DotLeft.get -> double
 Dynamo.ViewModels.ConnectorViewModel.DotLeft.set -> void
 Dynamo.ViewModels.ConnectorViewModel.DotTop.get -> double
 Dynamo.ViewModels.ConnectorViewModel.DotTop.set -> void
+Dynamo.ViewModels.ConnectorViewModel.DynamicStrokeThickness.get -> double
+Dynamo.ViewModels.ConnectorViewModel.DynamicStrokeThickness.set -> void
 Dynamo.ViewModels.ConnectorViewModel.EndDotSize.get -> double
 Dynamo.ViewModels.ConnectorViewModel.EndDotSize.set -> void
 Dynamo.ViewModels.ConnectorViewModel.GoToEndNodeCommand.get -> Dynamo.UI.Commands.DelegateCommand

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

@@ -5,7 +5,8 @@
                       xmlns:i="clr-namespace:Dynamo.Microsoft.Xaml.Behaviors;assembly=Dynamo.Microsoft.Xaml.Behaviors"
                       xmlns:views="clr-namespace:Dynamo.Controls;assembly=DynamoCoreWpf"
                       xmlns:nodes="clr-namespace:Dynamo.Nodes;assembly=DynamoCoreWpf"
-                      xmlns:mouse="clr-namespace:Dynamo.Wpf.UI;assembly=DynamoCoreWpf">
+                      xmlns:mouse="clr-namespace:Dynamo.Wpf.UI;assembly=DynamoCoreWpf"
+                      xmlns:configuration="clr-namespace:Dynamo.Configuration;assembly=DynamoCore">
 
     <ResourceDictionary.MergedDictionaries>
         <ui:SharedResourceDictionary Source="{x:Static ui:SharedDictionaryManager.DynamoConvertersDictionaryUri}" />
@@ -126,10 +127,15 @@
             </Canvas>
 
             <!--Bezier Path-->
-            <Path Stroke="{DynamicResource BConnectorSelection}" StrokeThickness="3"
+            <Path Stroke="{DynamicResource BConnectorSelection}" StrokeThickness="{Binding Source={x:Static configuration:Configurations.ConnectorBaseThickness}}"
               Name="connector"
               Visibility="{Binding IsCollapsed, Converter={StaticResource InverseBoolToVisibilityCollapsedConverter}, UpdateSourceTrigger=PropertyChanged}" 
-              Style="{StaticResource SConnector}" Canvas.ZIndex="-1" 
+              Style="{StaticResource SConnector}" Canvas.ZIndex="-2" 
+                  Data="{Binding ComputedBezierPathGeometry, UpdateSourceTrigger=PropertyChanged}">
+            </Path>
+            <Path Stroke="Transparent" StrokeThickness="{Binding DynamicStrokeThickness}"
+                  Visibility="{Binding IsCollapsed, Converter={StaticResource InverseBoolToVisibilityCollapsedConverter}, UpdateSourceTrigger=PropertyChanged}"
+                  Style="{StaticResource SConnector}" Canvas.ZIndex="-1"
                   Data="{Binding ComputedBezierPathGeometry, UpdateSourceTrigger=PropertyChanged}">
                 <i:Interaction.Behaviors>
                     <mouse:MouseBehaviour MouseX="{Binding PanelX, Mode=OneWayToSource, UpdateSourceTrigger=PropertyChanged}" MouseY="{Binding PanelY, Mode=OneWayToSource,  UpdateSourceTrigger=PropertyChanged}" />

src/DynamoCoreWpf/ViewModels/Core/ConnectorViewModel.cs

@@ -8,6 +8,7 @@
 using System.Windows.Media;
 using System.Windows.Shapes;
 using System.Windows.Threading;
+using Dynamo.Configuration;
 using Dynamo.Graph;
 using Dynamo.Graph.Connectors;
 using Dynamo.Graph.Nodes;
@@ -48,6 +49,7 @@ public partial class ConnectorViewModel : ViewModelBase
         private double dotLeft;
         private double endDotSize = 6;
         private double zIndex = 3;
+        private double dynamicStrokeThickness;
 
         private Point curvePoint1;
         private Point curvePoint2;
@@ -568,6 +570,16 @@ public PathGeometry ComputedBezierPathGeometry
             }
         }
 
+        public double DynamicStrokeThickness
+        {
+            get => dynamicStrokeThickness;
+            set
+            {
+                dynamicStrokeThickness = value;
+                RaisePropertyChanged(nameof(DynamicStrokeThickness));
+            }
+        }
+
         #endregion
 
         /// <summary>
@@ -959,13 +971,15 @@ public ConnectorViewModel(WorkspaceViewModel workspace, PortModel port)
             this.workspaceViewModel = workspace;
             ConnectorPinViewCollection = new ObservableCollection<ConnectorPinViewModel>();
             ConnectorPinViewCollection.CollectionChanged += HandleCollectionChanged;
+            workspaceViewModel.PropertyChanged += WorkspaceViewModel_PropertyChanged;
 
             IsHidden = !workspaceViewModel.DynamoViewModel.IsShowingConnectors;
             IsConnecting = true;
             MouseHoverOn = false;
             activeStartPort = port;
             ZIndex = SetZIndex();
 
+            UpdateDynamicStrokeThickness();
             Redraw(port.Center);
 
             InitializeCommands();
@@ -1001,6 +1015,7 @@ public ConnectorViewModel(WorkspaceViewModel workspace, ConnectorModel connector
 
             ConnectorPinViewCollection = new ObservableCollection<ConnectorPinViewModel>();
             ConnectorPinViewCollection.CollectionChanged += HandleCollectionChanged;
+            workspaceViewModel.PropertyChanged += WorkspaceViewModel_PropertyChanged;
 
 
             if (connectorModel.ConnectorPinModels != null)
@@ -1028,6 +1043,7 @@ public ConnectorViewModel(WorkspaceViewModel workspace, ConnectorModel connector
                 NodeEnd.PropertyChanged += nodeEndViewModel_PropertyChanged;
             }
 
+            UpdateDynamicStrokeThickness();
             Redraw();
             InitializeCommands();
 
@@ -1164,6 +1180,24 @@ private void HandleCollectionChanged(object sender, NotifyCollectionChangedEvent
             Redraw();
         }
 
+        private void WorkspaceViewModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
+        {
+            if (e.PropertyName == nameof(workspaceViewModel.Zoom))
+            {
+                UpdateDynamicStrokeThickness();
+            }
+        }
+
+        private void UpdateDynamicStrokeThickness()
+        {
+            DynamicStrokeThickness = Math.Max(
+                Configurations.ConnectorBaseThickness,
+                Configurations.ConnectorBaseThickness *
+                (1 / workspaceViewModel.Zoom) *
+                Configurations.ConnectorZoomScalingFactor
+            );
+        }
+
         /// <summary>
         /// Dispose function
         /// </summary>
@@ -1190,6 +1224,8 @@ public override void Dispose()
             }
             ConnectorPinViewCollection.CollectionChanged -= HandleCollectionChanged;
 
+            workspaceViewModel.PropertyChanged -= WorkspaceViewModel_PropertyChanged;
+
             foreach (var pin in ConnectorPinViewCollection.ToList())
             {
                 pin.RequestRedraw -= HandlerRedrawRequest;