EnableSnapping完成

AIStudio.Wpf.DiagramDesigner.Demo/ViewModels/Links/PathGeneratorsViewModel.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Windows;
+
+namespace AIStudio.Wpf.DiagramDesigner.Demo.ViewModels
+{
+    class PathGeneratorsViewModel : BaseViewModel
+    {
+        public PathGeneratorsViewModel()
+        {
+            Title = "Link Path Generators";
+            Info = "Path generators are functions that take as input the calculated route and output SVG paths, " +
+                "alongside the markers positions and their angles. There are currently two generators: Straight and Smooth.";
+
+            _service.ColorViewModel.FillColor.Color = System.Windows.Media.Colors.Orange;
+
+            DiagramViewModel = new DiagramViewModel();
+            DiagramViewModel.PageSizeType = PageSizeType.Custom;
+            DiagramViewModel.PageSize = new Size(double.NaN, double.NaN);
+
+            DefaultDesignerItemViewModel node1 = new DefaultDesignerItemViewModel() { Left = 50, Top = 80, Text = "1" };
+            DiagramViewModel.DirectAddItemCommand.Execute(node1);
+
+            DefaultDesignerItemViewModel node2 = new DefaultDesignerItemViewModel() { Left = 300, Top = 350, Text = "2" };
+            DiagramViewModel.DirectAddItemCommand.Execute(node2);
+
+            DefaultDesignerItemViewModel node3 = new DefaultDesignerItemViewModel() { Left = 400, Top = 100, Text = "3" };
+            DiagramViewModel.DirectAddItemCommand.Execute(node3);
+
+            ConnectionViewModel connector1 = new ConnectionViewModel(node1.RightConnector, node2.LeftConnector, DrawMode.ConnectingLineStraight, RouterMode.RouterNormal);
+            connector1.AddLabel("Straight");
+            DiagramViewModel.DirectAddItemCommand.Execute(connector1);
+
+            ConnectionViewModel connector2 = new ConnectionViewModel(node2.RightConnector, node3.LeftConnector, DrawMode.ConnectingLineSmooth, RouterMode.RouterNormal);
+            connector2.AddLabel("Smooth");
+            DiagramViewModel.DirectAddItemCommand.Execute(connector2);
+        }
+    }
+}

AIStudio.Wpf.DiagramDesigner.Demo/ViewModels/Links/RoutersViewModel.cs

@@ -0,0 +1,40 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Windows;
+
+namespace AIStudio.Wpf.DiagramDesigner.Demo.ViewModels
+{
+    class RoutersViewModel : BaseViewModel
+    {
+        public RoutersViewModel()
+        {
+            Title = "Link Routers";
+            Info = "Routers are functions that take as input the link's vertices and can add points in between. " +
+                "There are currently two routers: Normal and Orthogonal.";
+
+            _service.ColorViewModel.FillColor.Color = System.Windows.Media.Colors.Orange;
+
+            DiagramViewModel = new DiagramViewModel();
+            DiagramViewModel.PageSizeType = PageSizeType.Custom;
+            DiagramViewModel.PageSize = new Size(double.NaN, double.NaN);
+
+            DefaultDesignerItemViewModel node1 = new DefaultDesignerItemViewModel() { Left = 50, Top = 80, Text = "1" };
+            DiagramViewModel.DirectAddItemCommand.Execute(node1);
+
+            DefaultDesignerItemViewModel node2 = new DefaultDesignerItemViewModel() { Left = 300, Top = 350, Text = "2" };
+            DiagramViewModel.DirectAddItemCommand.Execute(node2);
+
+            DefaultDesignerItemViewModel node3 = new DefaultDesignerItemViewModel() { Left = 350, Top = 100, Text = "3" };
+            DiagramViewModel.DirectAddItemCommand.Execute(node3);
+
+            ConnectionViewModel connector1 = new ConnectionViewModel(node1.RightConnector, node2.LeftConnector, DrawMode.ConnectingLineSmooth, RouterMode.RouterNormal);
+            connector1.AddLabel("Normal");
+            DiagramViewModel.DirectAddItemCommand.Execute(connector1);
+
+            ConnectionViewModel connector2 = new ConnectionViewModel(node2.RightConnector, node3.LeftConnector, DrawMode.ConnectingLineStraight, RouterMode.RouterOrthogonal);
+            connector2.AddLabel("Orthogonal");
+            DiagramViewModel.DirectAddItemCommand.Execute(connector2);
+        }
+    }
+}

AIStudio.Wpf.DiagramDesigner.Demo/ViewModels/Links/SnappingViewModel.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Windows;
+
+namespace AIStudio.Wpf.DiagramDesigner.Demo.ViewModels
+{
+    class SnappingViewModel : BaseViewModel
+    {
+        public SnappingViewModel()
+        {
+            Title = "Link Snapping";
+            Info = "While dragging a new link, it will try to find (and link) to the closest target within a radius.";
+
+            _service.ColorViewModel.FillColor.Color = System.Windows.Media.Colors.Orange;
+
+            DiagramViewModel = new DiagramViewModel();
+            DiagramViewModel.PageSizeType = PageSizeType.Custom;
+            DiagramViewModel.PageSize = new Size(double.NaN, double.NaN);
+            DiagramViewModel.EnableSnapping = true;
+
+            DefaultDesignerItemViewModel node1 = new DefaultDesignerItemViewModel() { Left = 50, Top = 50, Text = "1" };
+            DiagramViewModel.DirectAddItemCommand.Execute(node1);
+
+            DefaultDesignerItemViewModel node2 = new DefaultDesignerItemViewModel() { Left = 300, Top = 300, Text = "2" };
+            DiagramViewModel.DirectAddItemCommand.Execute(node2);
+
+            DefaultDesignerItemViewModel node3 = new DefaultDesignerItemViewModel() { Left = 300, Top = 50, Text = "3" };
+            DiagramViewModel.DirectAddItemCommand.Execute(node3);
+        }
+    }
+}

AIStudio.Wpf.DiagramDesigner.Demo/Views/Links/PathGeneratorsView.xaml

@@ -0,0 +1,16 @@
+<UserControl x:Class="AIStudio.Wpf.DiagramDesigner.Demo.Views.PathGeneratorsView"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
+             xmlns:dd="https://gitee.com/akwkevin/aistudio.-wpf.-diagram"
+             xmlns:controls="clr-namespace:AIStudio.Wpf.DiagramDesigner.Demo.Controls"
+             mc:Ignorable="d" 
+             d:DesignHeight="450" d:DesignWidth="800">
+    <Grid>
+        <!-- Diagram Control -->
+        <dd:DiagramControl x:Name="diagram" DataContext="{Binding DiagramViewModel}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
+
+        <controls:TitleControl/>
+    </Grid>
+</UserControl>

AIStudio.Wpf.DiagramDesigner.Demo/Views/Links/PathGeneratorsView.xaml.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+namespace AIStudio.Wpf.DiagramDesigner.Demo.Views
+{
+    /// <summary>
+    /// PathGeneratorsView.xaml 的交互逻辑
+    /// </summary>
+    public partial class PathGeneratorsView : UserControl
+    {
+        public PathGeneratorsView()
+        {
+            InitializeComponent();
+        }
+    }
+}

AIStudio.Wpf.DiagramDesigner.Demo/Views/Links/RoutersView.xaml

@@ -0,0 +1,16 @@
+<UserControl x:Class="AIStudio.Wpf.DiagramDesigner.Demo.Views.RoutersView"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
+             xmlns:dd="https://gitee.com/akwkevin/aistudio.-wpf.-diagram"
+             xmlns:controls="clr-namespace:AIStudio.Wpf.DiagramDesigner.Demo.Controls"
+             mc:Ignorable="d" 
+             d:DesignHeight="450" d:DesignWidth="800">
+    <Grid>
+        <!-- Diagram Control -->
+        <dd:DiagramControl x:Name="diagram" DataContext="{Binding DiagramViewModel}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
+
+        <controls:TitleControl/>
+    </Grid>
+</UserControl>

AIStudio.Wpf.DiagramDesigner.Demo/Views/Links/RoutersView.xaml.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+namespace AIStudio.Wpf.DiagramDesigner.Demo.Views
+{
+    /// <summary>
+    /// RoutersView.xaml 的交互逻辑
+    /// </summary>
+    public partial class RoutersView : UserControl
+    {
+        public RoutersView()
+        {
+            InitializeComponent();
+        }
+    }
+}

AIStudio.Wpf.DiagramDesigner.Demo/Views/Links/SnappingView.xaml

@@ -0,0 +1,16 @@
+<UserControl x:Class="AIStudio.Wpf.DiagramDesigner.Demo.Views.SnappingView"
+             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
+             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
+             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
+             xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
+             xmlns:dd="https://gitee.com/akwkevin/aistudio.-wpf.-diagram"
+             xmlns:controls="clr-namespace:AIStudio.Wpf.DiagramDesigner.Demo.Controls"
+             mc:Ignorable="d" 
+             d:DesignHeight="450" d:DesignWidth="800">
+    <Grid>
+        <!-- Diagram Control -->
+        <dd:DiagramControl x:Name="diagram" DataContext="{Binding DiagramViewModel}" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" />
+
+        <controls:TitleControl/>
+    </Grid>
+</UserControl>

AIStudio.Wpf.DiagramDesigner.Demo/Views/Links/SnappingView.xaml.cs

@@ -0,0 +1,26 @@
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Windows;
+using System.Windows.Controls;
+using System.Windows.Data;
+using System.Windows.Documents;
+using System.Windows.Input;
+using System.Windows.Media;
+using System.Windows.Media.Imaging;
+using System.Windows.Navigation;
+using System.Windows.Shapes;
+
+namespace AIStudio.Wpf.DiagramDesigner.Demo.Views
+{
+    /// <summary>
+    /// SnappingView.xaml 的交互逻辑
+    /// </summary>
+    public partial class SnappingView : UserControl
+    {
+        public SnappingView()
+        {
+            InitializeComponent();
+        }
+    }
+}

AIStudio.Wpf.DiagramDesigner/Controls/DesignerCanvas.cs

@@ -17,8 +17,20 @@ namespace AIStudio.Wpf.DiagramDesigner
 {
     public class DesignerCanvas : Canvas
     {
-        private IDiagramViewModel _viewModel { get { return DataContext as IDiagramViewModel; } }
+        private IDiagramViewModel _viewModel
-        private IDiagramServiceProvider _service { get { return DiagramServicesProvider.Instance.Provider; } }
+        {
+            get
+            {
+                return DataContext as IDiagramViewModel;
+            }
+        }
+        private IDiagramServiceProvider _service
+        {
+            get
+            {
+                return DiagramServicesProvider.Instance.Provider;
+            }
+        }
 
         private ConnectionViewModel partialConnection;
         private List<Connector> connectorsHit = new List<Connector>();
@@ -54,6 +66,22 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
+        private bool EnableSnapping
+        {
+            get
+            {
+                return _viewModel.EnableSnapping;
+            }
+        }
+
+        private double SnappingRadius
+        {
+            get
+            {
+                return _viewModel.SnappingRadius;
+            }
+        }
+
         #region GridCellSize
 
         public static readonly DependencyProperty GridCellSizeProperty =
@@ -64,8 +92,14 @@ namespace AIStudio.Wpf.DiagramDesigner
 
         public Size GridCellSize
         {
-            get { return (Size)GetValue(GridCellSizeProperty); }
+            get
-            set { SetValue(GridCellSizeProperty, value); }
+            {
+                return (Size)GetValue(GridCellSizeProperty);
+            }
+            set
+            {
+                SetValue(GridCellSizeProperty, value);
+            }
         }
 
         #endregion
@@ -80,8 +114,14 @@ namespace AIStudio.Wpf.DiagramDesigner
 
         public bool ShowGrid
         {
-            get { return (bool)GetValue(ShowGridProperty); }
+            get
-            set { SetValue(ShowGridProperty, value); }
+            {
+                return (bool)GetValue(ShowGridProperty);
+            }
+            set
+            {
+                SetValue(ShowGridProperty, value);
+            }
         }
 
         #endregion
@@ -96,8 +136,14 @@ namespace AIStudio.Wpf.DiagramDesigner
 
         public Color GridColor
         {
-            get { return (Color)GetValue(GridColorProperty); }
+            get
-            set { SetValue(GridColorProperty, value); }
+            {
+                return (Color)GetValue(GridColorProperty);
+            }
+            set
+            {
+                SetValue(GridColorProperty, value);
+            }
         }
 
         #endregion
@@ -112,8 +158,14 @@ namespace AIStudio.Wpf.DiagramDesigner
 
         public Size GridMarginSize
         {
-            get { return (Size)GetValue(GridMarginSizeProperty); }
+            get
-            set { SetValue(GridMarginSizeProperty, value); }
+            {
+                return (Size)GetValue(GridMarginSizeProperty);
+            }
+            set
+            {
+                SetValue(GridMarginSizeProperty, value);
+            }
         }
 
         #endregion
@@ -204,7 +256,10 @@ namespace AIStudio.Wpf.DiagramDesigner
         private Connector sourceConnector;
         public Connector SourceConnector
         {
-            get { return sourceConnector; }
+            get
+            {
+                return sourceConnector;
+            }
             set
             {
                 if (sourceConnector != value)
@@ -218,7 +273,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                     Point point = new Point(rectangleBounds.Left + (rectangleBounds.Width / 2),
                                             rectangleBounds.Bottom + (rectangleBounds.Height / 2));
                     partialConnection = new ConnectionViewModel(_viewModel, sourceDataItem, new PartCreatedConnectorInfo(point.X, point.Y), DrawMode, RouterMode);
-                
+
                     _viewModel.DirectAddItemCommand.Execute(partialConnection);
                 }
             }
@@ -227,7 +282,10 @@ namespace AIStudio.Wpf.DiagramDesigner
         private FullyCreatedConnectorInfo sourceConnectorInfo;
         public FullyCreatedConnectorInfo SourceConnectorInfo
         {
-            get { return sourceConnectorInfo; }
+            get
+            {
+                return sourceConnectorInfo;
+            }
             set
             {
                 if (sourceConnectorInfo != value)
@@ -288,7 +346,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                     {
                         if (connectorsHit.Count == 0)
                         {
-                            LinkPointDesignerItemViewModel pointItemView = new LinkPointDesignerItemViewModel(rubberbandSelectionStartPoint.Value);                        
+                            LinkPointDesignerItemViewModel pointItemView = new LinkPointDesignerItemViewModel(rubberbandSelectionStartPoint.Value);
                             _viewModel.DirectAddItemCommand.Execute(pointItemView);
                             SourceConnectorInfo = pointItemView.TopConnector;
                         }
@@ -311,8 +369,7 @@ namespace AIStudio.Wpf.DiagramDesigner
 
             if (_service.DrawModeViewModel.CursorMode == CursorMode.Move)
             {
-                _viewModel.SelectedItems.OfType<DesignerItemViewModelBase>().ToList().ForEach(p =>
+                _viewModel.SelectedItems.OfType<DesignerItemViewModelBase>().ToList().ForEach(p => {
-                {
                     p.Left = currentPoint.X;
                     p.Top = currentPoint.Y;
                 });
@@ -325,6 +382,19 @@ namespace AIStudio.Wpf.DiagramDesigner
                 {
                     partialConnection.SinkConnectorInfo = new PartCreatedConnectorInfo(currentPoint.X, currentPoint.Y);
                     HitTesting(currentPoint);
+
+                    if (EnableSnapping)
+                    {
+                        var nearPort = FindNearPortToAttachTo();
+                        if (nearPort != null || partialConnection.SinkConnectorInfoFully != null)
+                        {
+                            //var oldPort = _ongoingLink.TargetPort;
+                            //_ongoingLink.SetTargetPort(nearPort);
+                            //oldPort?.Refresh();
+                            //nearPort?.Refresh();
+                            partialConnection.SinkConnectorInfo = nearPort;
+                        }
+                    }
                 }
             }
             else
@@ -377,6 +447,10 @@ namespace AIStudio.Wpf.DiagramDesigner
                     sinkDataItem.DataItem.Root.DirectRemoveItemCommand.Execute(
                         sinkDataItem.DataItem.Root.Items[indexOfLastTempConnection]);
                     sinkDataItem.DataItem.Root.AddItemCommand.Execute(new ConnectionViewModel(_viewModel, sourceDataItem, sinkDataItem, DrawMode, RouterMode));
+                }
+                else if (partialConnection.IsFullConnection)
+                {
+
                 }
                 else if (_service.DrawModeViewModel.GetDrawMode() == DrawMode.DirectLine && connectorsHit.Count() == 1)
                 {
@@ -403,7 +477,7 @@ namespace AIStudio.Wpf.DiagramDesigner
 
                 }
             }
-     
+
             connectorsHit = new List<Connector>();
             sourceConnector = null;
             sourceConnectorInfo = null;
@@ -508,7 +582,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                     itemBase.Suffix = System.IO.Path.GetExtension(itemBase.Icon).ToLower();
                     itemBase.InitWidthAndHeight();
                     itemBase.AutoSize();
-                    
+
                     itemBase.Left = Math.Max(0, position.X - itemBase.ItemWidth / 2);
                     itemBase.Top = Math.Max(0, position.Y - itemBase.ItemHeight / 2);
                     (DataContext as IDiagramViewModel).AddItemCommand.Execute(itemBase);
@@ -516,5 +590,17 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
             e.Handled = true;
         }
+
+        public FullyCreatedConnectorInfo FindNearPortToAttachTo()
+        {
+            foreach (var port in _viewModel.Items.OfType<DesignerItemViewModelBase>().ToList().SelectMany(n => n.Connectors))
+            {
+                if (partialConnection.OnGoingPosition.DistanceTo(port.Position) < SnappingRadius &&
+                    partialConnection.SourceConnectorInfo.CanAttachTo(port))
+                    return port;
+            }
+
+            return null;
+        }
     }
-}
+}

AIStudio.Wpf.DiagramDesigner/UserControls/LineControl.xaml

@@ -44,8 +44,7 @@
             </Path>
 
             <Path x:Name="rightarrow" 
-                Data="{Binding ShapeViewModel.SinkMarker.Path}"
+                Data="{Binding ShapeViewModel.SinkMarker.Path}"              
-                Visibility="{Binding Path=IsFullConnection, Converter={x:Static s:BoolToVisibilityConverter.Instance}}"
                 Width="{Binding ShapeViewModel.SinkMarker.Width}"
                 Stretch="UniformToFill"   
                 HorizontalAlignment="Left"
@@ -61,8 +60,7 @@
             </Path>
 
             <Path x:Name="leftarrow" 
-                Data="{Binding ShapeViewModel.SourceMarker.Path}"
+                Data="{Binding ShapeViewModel.SourceMarker.Path}"               
-                Visibility="{Binding Path=IsFullConnection, Converter={x:Static s:BoolToVisibilityConverter.Instance}}"                                                       
                 Width="{Binding ShapeViewModel.SourceMarker.Width}"
                 Canvas.Left="{Binding StartPoint.X}"
                 Canvas.Top="{Binding StartPoint.Y}"

AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/Connector/FullyCreatedConnectorInfo.cs

@@ -13,7 +13,7 @@ namespace AIStudio.Wpf.DiagramDesigner
         public FullyCreatedConnectorInfo(DesignerItemViewModelBase dataItem, ConnectorOrientation orientation, bool isInnerPoint = false, ValueTypePoint valueTypePoint = 0)
             : base(orientation)
         {
-            this.DataItem = dataItem;
+            this.Parent = dataItem;
             this.IsInnerPoint = isInnerPoint;
             this.ValueTypePoint = valueTypePoint;
             if (IsInnerPoint == true)
@@ -24,7 +24,7 @@ namespace AIStudio.Wpf.DiagramDesigner
 
         public FullyCreatedConnectorInfo(IDiagramViewModel root, DesignerItemViewModelBase dataItem, SelectableItemBase designer) : base(root, designer)
         {
-            this.DataItem = dataItem;
+            this.Parent = dataItem;
             if (IsInnerPoint == true)
             {
                 BuildMenuOptions();
@@ -33,7 +33,7 @@ namespace AIStudio.Wpf.DiagramDesigner
 
         public FullyCreatedConnectorInfo(IDiagramViewModel root, DesignerItemViewModelBase dataItem, SerializableItem serializableItem, string serializableType) : base(root, serializableItem, serializableType)
         {
-            this.DataItem = dataItem;
+            this.Parent = dataItem;
             if (IsInnerPoint == true)
             {
                 BuildMenuOptions();
@@ -88,7 +88,10 @@ namespace AIStudio.Wpf.DiagramDesigner
 
         public DesignerItemViewModelBase DataItem
         {
-            get; private set;
+            get
+            {
+                return Parent as DesignerItemViewModelBase;
+            }
         }
 
         private bool _showConnectors = false;
@@ -257,6 +260,8 @@ namespace AIStudio.Wpf.DiagramDesigner
                 }
             }
         }
+
+        public virtual bool CanAttachTo(FullyCreatedConnectorInfo port) => port != this && !port.IsReadOnly && DataItem != port.DataItem;
     }
 
 

AIStudio.Wpf.DiagramDesigner/ViewModels/BaseViewModel/DiagramViewModel.cs

@@ -366,6 +366,31 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
+        private bool _enableSnapping;
+        public bool EnableSnapping
+        {
+            get
+            {
+                return _enableSnapping;
+            }
+            set
+            {
+                SetProperty(ref _enableSnapping, value);
+            }
+        }
+
+        private double _snappingRadius = 50;
+        public double SnappingRadius
+        {
+            get
+            {
+                return _snappingRadius;
+            }
+            set
+            {
+                SetProperty(ref _snappingRadius, value);
+            }
+        }
 
         private bool _isEditName;
         [Browsable(false)]
@@ -1089,7 +1114,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                 });
             }
         }
-     
+
 
         private void ExecuteBringForwardCommand(object parameter)
         {
@@ -1391,7 +1416,7 @@ namespace AIStudio.Wpf.DiagramDesigner
            SelectedItems.OfType<DesignerItemViewModelBase>().ToList();
 
             List<ConnectionViewModel> selectedConnections =
-                SelectedItems.OfType<ConnectionViewModel>().ToList();     
+                SelectedItems.OfType<ConnectionViewModel>().ToList();
 
             foreach (ConnectionViewModel connection in Items.OfType<ConnectionViewModel>())
             {
@@ -1444,7 +1469,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                     foreach (var diagramItemData in copyitem.DesignerItems)
                     {
                         DesignerItemViewModelBase newItem = null;
-                
+
                         Type type = TypeHelper.GetType(diagramItemData.ModelTypeName);
 
                         DesignerItemViewModelBase itemBase = Activator.CreateInstance(type, this, diagramItemData, ".json") as DesignerItemViewModelBase;
@@ -1460,7 +1485,7 @@ namespace AIStudio.Wpf.DiagramDesigner
                         {
                             items.Add(newItem);
                         }
-                    }      
+                    }
 
                     DirectAddItemCommand.Execute(items);
                     OffsetX += 10;
@@ -1751,7 +1776,7 @@ namespace AIStudio.Wpf.DiagramDesigner
         {
 
         }
- 
+
 
 
 

AIStudio.Wpf.DiagramDesigner/ViewModels/IDiagramViewModel.cs

@@ -228,6 +228,14 @@ namespace AIStudio.Wpf.DiagramDesigner
         {
             get; set;
         }
+        bool EnableSnapping
+        {
+            get; set;
+        }
+        double SnappingRadius
+        {
+            get; set;
+        }
         Size GridMarginSize
         {
             get; set;