支持添加中间节点

AIStudio.Wpf.DiagramDesigner/Controls/PointDragThumb.cs

@@ -33,19 +33,8 @@ namespace AIStudio.Wpf.DiagramDesigner.Controls
         {
             if (this.DataContext is ConnectorPoint point)
             {
-                double minLeft = double.MaxValue;
+                point.X += e.HorizontalChange;
-                double minTop = double.MaxValue;
+                point.Y += e.VerticalChange;
-
-                double left = point.X;
-                double top = point.Y;
-                minLeft = double.IsNaN(left) ? 0 : Math.Min(left, minLeft);
-                minTop = double.IsNaN(top) ? 0 : Math.Min(top, minTop);
-
-                double deltaHorizontal = Math.Max(-minLeft, e.HorizontalChange);
-                double deltaVertical = Math.Max(-minTop, e.VerticalChange);
-
-                point.X += deltaHorizontal;
-                point.Y += deltaVertical;
             }
         }
 

AIStudio.Wpf.DiagramDesigner/PathGenerators/PathGenerators.Smooth.cs

@@ -32,7 +32,12 @@ namespace AIStudio.Wpf.DiagramDesigner
             double targetAngle = TargetMarkerAdjustement(route, link.ColorViewModel.RightArrowSize);
 
             BezierSpline.GetCurveControlPoints(route, out var firstControlPoints, out var secondControlPoints);
-            var paths = new string[firstControlPoints.Length];
+
+            DoShift(route, link);
+            DoShift(firstControlPoints, link);
+            DoShift(secondControlPoints, link);
+
+            var paths = new string[firstControlPoints.Length];       
 
             for (var i = 0; i < firstControlPoints.Length; i++)
             {

AIStudio.Wpf.DiagramDesigner/Routers/Routers.Normal.cs

@@ -7,7 +7,7 @@ namespace AIStudio.Wpf.DiagramDesigner
     {
         public static PointBase[] Normal(IDiagramViewModel _, ConnectorViewModel link)
         {
-            return link.Vertices.Select(v => (PointBase)v).ToArray();
+            return link.Vertices.Select(v => v.MiddlePosition).ToArray();
         }
     }
 }

AIStudio.Wpf.DiagramDesigner/UserControls/DiagramControl.xaml

@@ -542,7 +542,7 @@
                                                 <MouseBinding MouseAction="LeftDoubleClick" Command="{Binding EditCommand}" CommandParameter="{Binding }" />
                                             </Canvas.InputBindings>
                                             <!--<Polyline x:Name="poly"                                                  
-                                                        Points="{Binding Path=ConnectionPoints, Converter={x:Static s:ConnectionPointConverter.Instance}}"
+                                                        Points="{Binding Path=Vertices, Converter={x:Static s:ConnectionPointConverter.Instance}}"
                                                         Stroke="{Binding ColorViewModel.LineColor,Converter={StaticResource ColorBrushConverter}}"
                                                         StrokeThickness="{Binding ColorViewModel.LineWidth}"  
                                                         StrokeDashArray="{Binding ColorViewModel.LineDashStyle,Converter={StaticResource LineDashConverter}}" />-->
@@ -600,7 +600,7 @@
                                             </c:DragThumb.InputBindings>                                 
                                         </c:DragThumb>
 
-                                        <s:PointContainer x:Name="PART_PointContainer" Style="{StaticResource innerConnectorContainer}" ItemsSource="{Binding ConnectionPoints}" Visibility="Collapsed">
+                                        <s:PointContainer x:Name="PART_PointContainer" Style="{StaticResource innerConnectorContainer}" ItemsSource="{Binding Vertices}" Visibility="Collapsed">
                                             <s:PointContainer.ItemTemplate>
                                                 <DataTemplate>
                                                     <Grid>
@@ -616,6 +616,7 @@
                                                 </Style>
                                             </s:PointContainer.Resources>
                                         </s:PointContainer>
+                                        
                                         <Rectangle Fill="#7F243859" Opacity="0.5" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" Visibility="{Binding ShouldInsertAnchor, Converter={StaticResource BooleanToVisibilityConverter}}">
                                             <i:Interaction.Behaviors>
                                                 <s:ControlMouseLeftButtonDownCommandBehavior Command="{Binding AddVertexCommand}" />

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

@@ -91,14 +91,14 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
-        public PointBase Position
+        public virtual PointBase Position
         {
             get
             {
                 return new PointBase(Left, Top);
             }
         }
-        public PointBase MiddlePosition => new PointBase(Left + ConnectorWidth / 2, Top + ConnectorHeight / 2);
+        public virtual PointBase MiddlePosition => new PointBase(Left + ConnectorWidth / 2, Top + ConnectorHeight / 2);
 
         private double connectorWidth = 8;
         public double ConnectorWidth

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

@@ -46,7 +46,8 @@ namespace AIStudio.Wpf.DiagramDesigner
             {
                 this.ColorViewModel.RightArrowPathStyle = ArrowPathStyle.None;
             }
-            ColorViewModel.PropertyChanged += ColorViewModel_PropertyChanged;
+            ColorViewModel.PropertyChanged += ConnectorViewModel_PropertyChanged;
+            this.PropertyChanged += ConnectorViewModel_PropertyChanged;
 
             var routetype = GlobalType.AllTypes.Where(p => typeof(IRouter).IsAssignableFrom(p)).FirstOrDefault(p => p.Name == RouterMode);
             Router = routetype != null ? (System.Activator.CreateInstance(routetype) as IRouter) : new RouterNormal();
@@ -57,18 +58,12 @@ namespace AIStudio.Wpf.DiagramDesigner
             this.SourceConnectorInfo = sourceConnectorInfo;
             this.SinkConnectorInfo = sinkConnectorInfo;
             DeleteConnectionCommand = new SimpleCommand(DeleteConnection);
-            AddVertexCommand = new SimpleCommand(AddVertex);
+            AddVertexCommand = new SimpleCommand(AddVertex);     
         }
 
-        private void ColorViewModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
+        private void ConnectorViewModel_PropertyChanged1(object sender, PropertyChangedEventArgs e)
         {
-            if (e.PropertyName == nameof(ColorViewModel.LeftArrowPathStyle) ||
+            throw new NotImplementedException();
-                e.PropertyName == nameof(ColorViewModel.LeftArrowSizeStyle) ||
-                e.PropertyName == nameof(ColorViewModel.RightArrowPathStyle) ||
-                e.PropertyName == nameof(ColorViewModel.RightArrowSizeStyle))
-            {
-                UpdatePathGeneratorResult();
-            }
         }
 
         public override SelectableDesignerItemBase ToXmlObject()
@@ -90,6 +85,7 @@ namespace AIStudio.Wpf.DiagramDesigner
             return typeof(ConnectionItem);
         }
 
+        #region 属性
         private PointBase _sourceA;
         public PointBase SourceA
         {
@@ -99,10 +95,7 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
             set
             {
-                if (SetProperty(ref _sourceA, value))
+                SetProperty(ref _sourceA, value);
-                {
-                    UpdateArea();
-                }
             }
         }
 
@@ -115,37 +108,7 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
             set
             {
-                if (SetProperty(ref _sourceB, value))
+                SetProperty(ref _sourceB, value);     
-                {
-                    UpdateArea();
-                }
-            }
-        }
-
-        private ObservableCollection<ConnectorPoint> _connectionPoints = new ObservableCollection<ConnectorPoint>();
-        public ObservableCollection<ConnectorPoint> ConnectionPoints
-        {
-            get
-            {
-                return _connectionPoints;
-            }
-            private set
-            {
-                if (_connectionPoints != null)
-                {
-                    foreach (var connectionPoint in _connectionPoints)
-                    {
-                        connectionPoint.PropertyChanged -= new WeakINPCEventHandler(ConnectionPoint_PropertyChanged).Handler;
-                    }
-                }
-                SetProperty(ref _connectionPoints, value);
-                if (_connectionPoints != null)
-                {
-                    foreach (var connectionPoint in _connectionPoints)
-                    {
-                        connectionPoint.PropertyChanged += new WeakINPCEventHandler(ConnectionPoint_PropertyChanged).Handler;
-                    }
-                }
             }
         }
 
@@ -210,12 +173,7 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
             private set
             {
-                RectangleBase oldarea = _area;
+                SetProperty(ref _area, value); 
-                if (SetProperty(ref _area, value))
-                {
-                    UpdatePathGeneratorResult();
-                    OutTextItemLocation(oldarea, value);
-                }
             }
         }
 
@@ -266,7 +224,19 @@ namespace AIStudio.Wpf.DiagramDesigner
         }
 
         //待完善这两处
-        public List<LinkVertexModel> Vertices { get; } = new List<LinkVertexModel>();
+        private ObservableCollection<LinkVertexModel> _vertices = new ObservableCollection<LinkVertexModel>();
+        public ObservableCollection<LinkVertexModel> Vertices
+        {
+            get
+            {
+                return _vertices;
+            }
+            private set
+            {
+                SetProperty(ref _vertices, value);
+            }
+        }
+
         public List<LinkLabelModel> Labels { get; set; } = new List<LinkLabelModel>();
 
         public virtual Dictionary<string, string> PropertiesSetting
@@ -289,11 +259,7 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
             set
             {
-                if (SetProperty(ref _sourceConnectorInfo, value))
+                SetProperty(ref _sourceConnectorInfo, value);
-                {
-                    SourceA = PointHelper.GetPointForConnector(_sourceConnectorInfo);
-                    (_sourceConnectorInfo.DataItem as INotifyPropertyChanged).PropertyChanged += new WeakINPCEventHandler(ConnectorViewModel_PropertyChanged).Handler;
-                }
             }
         }
 
@@ -306,14 +272,8 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
             set
             {
-                if (SetProperty(ref _sinkConnectorInfo, value))
+                SetProperty(ref _sinkConnectorInfo, value);
-                {
+                
-                    SourceB = _sinkConnectorInfo.Position;
-                    if (_sinkConnectorInfo is FullyCreatedConnectorInfo)
-                    {
-                        (((FullyCreatedConnectorInfo)_sinkConnectorInfo).DataItem as INotifyPropertyChanged).PropertyChanged += new WeakINPCEventHandler(ConnectorViewModel_PropertyChanged).Handler;
-                    }
-                }
             }
         }
 
@@ -350,6 +310,95 @@ namespace AIStudio.Wpf.DiagramDesigner
         }
 
         public bool IsPortless => SourceConnectorInfo?.DataItem?.Connectors?.Count() == 0;
+        #endregion
+
+        #region 方法
+        public SimpleCommand DeleteConnectionCommand
+        {
+            get; set;
+        }
+
+        public SimpleCommand AddVertexCommand
+        {
+            get; set;
+        }
+        #endregion
+
+        private void ConnectorViewModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
+        {
+            if (sender is ConnectorViewModel)
+            {
+                switch (e.PropertyName)
+                {
+                    case nameof(SourceA):
+                    case nameof(SourceB):
+                        UpdateArea();
+                        break;
+                    case nameof(Area):
+                        UpdatePathGeneratorResult();
+                        if (e is ValuePropertyChangedEventArgs valuePropertyChangedEventArgs)
+                        {
+                            OutTextItemLocation((RectangleBase)valuePropertyChangedEventArgs.OldValue, (RectangleBase)valuePropertyChangedEventArgs.NewValue);
+                        }
+                        break;
+                    case nameof(Vertices):
+                        foreach (var vertice in Vertices)
+                        {
+                            vertice.PropertyChanged += new WeakINPCEventHandler(ConnectorViewModel_PropertyChanged).Handler;
+                        }
+                        break;
+                    case nameof(SourceConnectorInfo):
+                        SourceA = PointHelper.GetPointForConnector(SourceConnectorInfo);
+                        (SourceConnectorInfo.DataItem as INotifyPropertyChanged).PropertyChanged += new WeakINPCEventHandler(ConnectorViewModel_PropertyChanged).Handler;
+                        break;
+                    case nameof(SinkConnectorInfo):
+                        SourceB = SinkConnectorInfo.Position;
+                        if (SinkConnectorInfo is FullyCreatedConnectorInfo)
+                        {
+                            (((FullyCreatedConnectorInfo)SinkConnectorInfo).DataItem as INotifyPropertyChanged).PropertyChanged += new WeakINPCEventHandler(ConnectorViewModel_PropertyChanged).Handler;
+                        }
+                        break;
+
+                }
+            }
+            else if (sender is ColorViewModel)
+            {
+                if (e.PropertyName == nameof(ColorViewModel.LeftArrowPathStyle) ||
+                   e.PropertyName == nameof(ColorViewModel.LeftArrowSizeStyle) ||
+                   e.PropertyName == nameof(ColorViewModel.RightArrowPathStyle) ||
+                   e.PropertyName == nameof(ColorViewModel.RightArrowSizeStyle))
+                {
+                    UpdatePathGeneratorResult();
+                }
+            }
+            else if (sender is DesignerItemViewModelBase)
+            {
+                switch (e.PropertyName)
+                {
+                    case nameof(DesignerItemViewModelBase.ItemHeight):
+                    case nameof(DesignerItemViewModelBase.ItemWidth):
+                    case nameof(DesignerItemViewModelBase.Left):
+                    case nameof(DesignerItemViewModelBase.Top):
+                        SourceA = PointHelper.GetPointForConnector(this.SourceConnectorInfo);
+                        if (IsFullConnection)
+                        {
+                            SourceB = PointHelper.GetPointForConnector(this.SinkConnectorInfoFully);
+                        }
+                        break;
+                }
+            }
+            else if (sender is LinkVertexModel)
+            {
+                switch (e.PropertyName)
+                {
+                    case nameof(ConnectorPoint.Left):
+                    case nameof(ConnectorPoint.Top):
+                        UpdatePathGeneratorResult();
+                        break;
+
+                }
+            }
+        }
 
         private void UpdateArea()
         {
@@ -405,18 +454,19 @@ namespace AIStudio.Wpf.DiagramDesigner
                 case ConnectorOrientation.Left:
                     {
                         EndPoint = new PointBase(PathGeneratorResult.TargetMarkerPosition.X, PathGeneratorResult.TargetMarkerPosition.Y - ColorViewModel.RightArrowSize / 2);
-                        break;                    }
+                        break;
-                
+                    }
+
                 case ConnectorOrientation.Top:
                     {
                         EndPoint = new PointBase(PathGeneratorResult.TargetMarkerPosition.X - ColorViewModel.RightArrowSize / 2, PathGeneratorResult.TargetMarkerPosition.Y);
                         break;
-                    }                   
+                    }
                 case ConnectorOrientation.Right:
                     {
                         EndPoint = new PointBase(PathGeneratorResult.TargetMarkerPosition.X - ColorViewModel.RightArrowSize, PathGeneratorResult.TargetMarkerPosition.Y - ColorViewModel.RightArrowSize / 2);
                         break;
-                    }                   
+                    }
                 case ConnectorOrientation.Bottom:
                     {
                         EndPoint = new PointBase(PathGeneratorResult.TargetMarkerPosition.X - ColorViewModel.RightArrowSize / 2, PathGeneratorResult.TargetMarkerPosition.Y - ColorViewModel.RightArrowSize);
@@ -433,48 +483,6 @@ namespace AIStudio.Wpf.DiagramDesigner
             EndAngle = PathGeneratorResult.TargetMarkerAngle;
         }
 
-
-
-        private void ConnectorViewModel_PropertyChanged(object sender, PropertyChangedEventArgs e)
-        {
-            switch (e.PropertyName)
-            {
-                case "ItemHeight":
-                case "ItemWidth":
-                case "Left":
-                case "Top":
-                    SourceA = PointHelper.GetPointForConnector(this.SourceConnectorInfo);
-                    if (IsFullConnection)
-                    {
-                        SourceB = PointHelper.GetPointForConnector(this.SinkConnectorInfoFully);
-                    }
-                    break;
-
-            }
-        }
-
-        private void ConnectionPoint_PropertyChanged(object sender, PropertyChangedEventArgs e)
-        {
-            switch (e.PropertyName)
-            {
-                case "Left":
-                case "Top":
-                    RaisePropertyChanged(nameof(ConnectionPoints));
-                    break;
-
-            }
-        }
-
-        public SimpleCommand DeleteConnectionCommand
-        {
-            get; set;
-        }
-
-        public SimpleCommand AddVertexCommand
-        {
-            get; set;
-        }
-
         private void DeleteConnection(object args)
         {
             if (this.Parent is IDiagramViewModel)
@@ -489,7 +497,10 @@ namespace AIStudio.Wpf.DiagramDesigner
             MouseButtonEventArgs mosueArg = ((EventToCommandArgs)parameter).EventArgs as MouseButtonEventArgs;
             var position = mosueArg.GetPosition(((EventToCommandArgs)parameter).Sender as IInputElement);
 
-            ConnectionPoints.Add(new ConnectorPoint(position.X, position.Y));
+            var vertice = new LinkVertexModel(this, new PointBase(position.X, position.Y));
+            vertice.PropertyChanged += new WeakINPCEventHandler(ConnectorViewModel_PropertyChanged).Handler;
+            Vertices.Add(vertice);
+            UpdatePathGeneratorResult();
 
             if (!((Keyboard.Modifiers & ModifierKeys.Control) == ModifierKeys.Control))
             {
@@ -497,58 +508,6 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
-        protected override void ExecuteEditCommand(object param)
-        {
-            if (this.OutTextItem != null) return;
-            AddText("");
-        }
-
-        public void AddText(string text)
-        {
-            if (this.Parent is IDiagramViewModel)
-            {
-                var diagramVM = this.Parent as IDiagramViewModel;
-
-                TextDesignerItemViewModel textitem = new TextDesignerItemViewModel();
-                textitem.ItemWidth = Double.NaN;
-                textitem.ItemHeight = double.NaN;
-                //if (this.PathMode == DrawMode.ConnectingLineBoundary.ToString())
-                //{
-                //    var mid = (int)(ConnectionPoints.Count / 2);
-                //    var p = PathGenerators.SegmentMiddlePoint(ConnectionPoints[mid - 1], ConnectionPoints[mid]);
-                //    textitem.Left = this.Area.Left + p.X + 2;
-                //    textitem.Top = this.Area.Top + p.Y - 15;
-                //}
-                //else
-                {
-                    textitem.Left = this.Area.Left + this.Area.Width / 2 - 16;
-                    textitem.Top = this.Area.Top + this.Area.Height / 2 - 5;
-                }
-                textitem.Watermark = null;
-                textitem.ZIndex = diagramVM.Items.Count;
-                textitem.ParentId = this.Id;
-                textitem.ParentItem = this;
-                textitem.ColorViewModel.FillColor = new ColorObject() { Color = Colors.White };
-                textitem.Text = text;
-
-                diagramVM.DirectAddItemCommand.Execute(textitem);
-
-                this.OutTextItem = textitem;
-            }
-        }
-
-        public void OutTextItemLocation(RectangleBase oldArea, RectangleBase newArea)
-        {
-            if (this.OutTextItem is TextDesignerItemViewModel text)
-            {
-                var oldpoint = new PointBase(oldArea.Left + oldArea.Width / 2, oldArea.Top + oldArea.Height / 2);
-                var newpoint = new PointBase(newArea.Left + newArea.Width / 2, newArea.Top + newArea.Height / 2);
-
-                text.Left = text.Left + newpoint.X - oldpoint.X;
-                text.Top = text.Top + newpoint.Y - oldpoint.Y;
-            }
-        }
-
         private (PointBase? source, PointBase? target) FindConnectionPoints(PointBase[] route)
         {
             if (IsPortless) // Portless
@@ -624,7 +583,58 @@ namespace AIStudio.Wpf.DiagramDesigner
             return minPoint;
         }
 
+        #region 双击添加
+        protected override void ExecuteEditCommand(object param)
+        {
+            if (this.OutTextItem != null) return;
+            AddText("");
+        }
 
+        public void AddText(string text)
+        {
+            if (this.Parent is IDiagramViewModel)
+            {
+                var diagramVM = this.Parent as IDiagramViewModel;
 
+                TextDesignerItemViewModel textitem = new TextDesignerItemViewModel();
+                textitem.ItemWidth = Double.NaN;
+                textitem.ItemHeight = double.NaN;
+                //if (this.PathMode == DrawMode.ConnectingLineBoundary.ToString())
+                //{
+                //    var mid = (int)(ConnectionPoints.Count / 2);
+                //    var p = PathGenerators.SegmentMiddlePoint(ConnectionPoints[mid - 1], ConnectionPoints[mid]);
+                //    textitem.Left = this.Area.Left + p.X + 2;
+                //    textitem.Top = this.Area.Top + p.Y - 15;
+                //}
+                //else
+                {
+                    textitem.Left = this.Area.Left + this.Area.Width / 2 - 16;
+                    textitem.Top = this.Area.Top + this.Area.Height / 2 - 5;
+                }
+                textitem.Watermark = null;
+                textitem.ZIndex = diagramVM.Items.Count;
+                textitem.ParentId = this.Id;
+                textitem.ParentItem = this;
+                textitem.ColorViewModel.FillColor = new ColorObject() { Color = Colors.White };
+                textitem.Text = text;
+
+                diagramVM.DirectAddItemCommand.Execute(textitem);
+
+                this.OutTextItem = textitem;
+            }
+        }
+
+        public void OutTextItemLocation(RectangleBase oldArea, RectangleBase newArea)
+        {
+            if (this.OutTextItem is TextDesignerItemViewModel text)
+            {
+                var oldpoint = new PointBase(oldArea.Left + oldArea.Width / 2, oldArea.Top + oldArea.Height / 2);
+                var newpoint = new PointBase(newArea.Left + newArea.Width / 2, newArea.Top + newArea.Height / 2);
+
+                text.Left = text.Left + newpoint.X - oldpoint.X;
+                text.Top = text.Top + newpoint.Y - oldpoint.Y;
+            }
+        }
+        #endregion
     }
 }

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

@@ -16,5 +16,15 @@ namespace AIStudio.Wpf.DiagramDesigner
             get;
         }
 
+        public override PointBase Position
+        {
+            get
+            {
+                return new PointBase(Parent.Area.Left + Left, Parent.Area.Top + Top);
+            }
+        }
+
+        public override PointBase MiddlePosition => new PointBase(Parent.Area.Left + Left + ConnectorWidth / 2, Parent.Area.Top + Top + ConnectorHeight / 2);
+
     }
 }

AIStudio.Wpf.DiagramDesigner/ViewModels/BindableBase.cs

@@ -17,40 +17,6 @@ namespace AIStudio.Wpf.DiagramDesigner
         /// </summary>
         public event PropertyChangedEventHandler PropertyChanged;
 
-        /// <summary>
-        /// Checks if a property already matches a desired value. Sets the property and
-        /// notifies listeners only when necessary.
-        /// </summary>
-        /// <typeparam name="T">Type of the property.</typeparam>
-        /// <param name="storage">Reference to a property with both getter and setter.</param>
-        /// <param name="value">Desired value for the property.</param>
-        /// <param name="propertyName">Name of the property used to notify listeners. This
-        /// value is optional and can be provided automatically when invoked from compilers that
-        /// support CallerMemberName.</param>
-        /// <returns>True if the value was changed, false if the existing value matched the
-        /// desired value.</returns>
-        protected virtual bool SetProperty<T>(ref T storage, T value, [CallerMemberName] string propertyName = null)
-        {
-            if (EqualityComparer<T>.Default.Equals(storage, value))
-                return false;
-
-            if (propertyName == "IsSelected")
-            {
-
-            }
-            else if (this.ContainsProperty("IsReadOnly"))
-            {
-                if (object.Equals(this.GetPropertyValue("IsReadOnly"), true))
-                    return false;
-            }
-
-            var old = storage;
-            storage = value;
-            RaisePropertyChanged(propertyName, old, value);
-
-            return true;
-        }
-
         private Dictionary<string, object> _oldDic = new Dictionary<string, object>();
         public void SetOldValue<T>(T value, string propertyName, string guid = null)
         {
@@ -78,6 +44,44 @@ namespace AIStudio.Wpf.DiagramDesigner
             }
         }
 
+        /// <summary>
+        /// Checks if a property already matches a desired value. Sets the property and
+        /// notifies listeners only when necessary.
+        /// </summary>
+        /// <typeparam name="T">Type of the property.</typeparam>
+        /// <param name="storage">Reference to a property with both getter and setter.</param>
+        /// <param name="value">Desired value for the property.</param>
+        /// <param name="propertyName">Name of the property used to notify listeners. This
+        /// value is optional and can be provided automatically when invoked from compilers that
+        /// support CallerMemberName.</param>
+        /// <returns>True if the value was changed, false if the existing value matched the
+        /// desired value.</returns>
+        protected virtual bool SetProperty<T>(ref T storage, T value, [CallerMemberName] string propertyName = null)
+        {
+            if (EqualityComparer<T>.Default.Equals(storage, value))
+                return false;
+
+            if (propertyName == "IsSelected")
+            {
+
+            }
+            else if (this.ContainsProperty("IsReadOnly"))
+            {
+                if (object.Equals(this.GetPropertyValue("IsReadOnly"), true))
+                    return false;
+            }
+
+            if (propertyName == "Area")
+            {
+            
+            }
+            var old = storage;
+            storage = value;
+            RaisePropertyChanged(propertyName, old, value);
+
+            return true;
+        }
+
         /// <summary>
         /// Checks if a property already matches a desired value. Sets the property and
         /// notifies listeners only when necessary.
@@ -93,11 +97,22 @@ namespace AIStudio.Wpf.DiagramDesigner
         /// desired value.</returns>
         protected virtual bool SetProperty<T>(ref T storage, T value, Action onChanged, [CallerMemberName] string propertyName = null)
         {
-            if (EqualityComparer<T>.Default.Equals(storage, value)) return false;
+            if (EqualityComparer<T>.Default.Equals(storage, value)) return false;          
 
+            if (propertyName == "IsSelected")
+            {
+
+            }
+            else if (this.ContainsProperty("IsReadOnly"))
+            {
+                if (object.Equals(this.GetPropertyValue("IsReadOnly"), true))
+                    return false;
+            }
+
+            var old = storage;
             storage = value;
             onChanged?.Invoke();
-            RaisePropertyChanged(propertyName);
+            RaisePropertyChanged(propertyName, old, value);
 
             return true;
         }