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WPF Diagram Designer - Part 4

, 26 Mar 2008
A Frankenbuild
diagramdesignerpart4.zip
DiagramDesigner
Controls
DiagramDesigner.csproj.user
Properties
Settings.settings
Resources
Images
AlignObjectsBottom.png
AlignObjectsCenteredHorizontal.png
AlignObjectsCenteredVertical.png
AlignObjectsLeft.png
AlignObjectsRight.png
AlignObjectsTop.png
BringForward.png
BringToFront.png
Copy.png
Cut.png
Delete.png
DistributeObjectsHorizontal.png
DistributeObjectsVertical.png
GenericDocument.png
Group.png
OpenFolder.png
Paste.png
PasteBig.png
Print.png
Save.png
SendBackward.png
SendToBack.png
Ungroup.png
Stencils
Styles
using System.Collections.Generic;
using System.ComponentModel;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Controls.Primitives;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;

namespace DiagramDesigner
{
    public class ConnectionAdorner : Adorner
    {
        private DesignerCanvas designerCanvas;
        private Canvas adornerCanvas;
        private Connection connection;
        private PathGeometry pathGeometry;
        private Connector fixConnector, dragConnector;
        private Thumb sourceDragThumb, sinkDragThumb;
        private Pen drawingPen;

        private DesignerItem hitDesignerItem;
        private DesignerItem HitDesignerItem
        {
            get { return hitDesignerItem; }
            set
            {
                if (hitDesignerItem != value)
                {
                    if (hitDesignerItem != null)
                        hitDesignerItem.IsDragConnectionOver = false;

                    hitDesignerItem = value;

                    if (hitDesignerItem != null)
                        hitDesignerItem.IsDragConnectionOver = true;
                }
            }
        }

        private Connector hitConnector;
        private Connector HitConnector
        {
            get { return hitConnector; }
            set
            {
                if (hitConnector != value)
                {
                    hitConnector = value;
                }
            }
        }

        private VisualCollection visualChildren;
        protected override int VisualChildrenCount
        {
            get
            {
                return this.visualChildren.Count;
            }
        }

        protected override Visual GetVisualChild(int index)
        {
            return this.visualChildren[index];
        }

        public ConnectionAdorner(DesignerCanvas designer, Connection connection)
            : base(designer)
        {
            this.designerCanvas = designer;
            adornerCanvas = new Canvas();
            this.visualChildren = new VisualCollection(this);
            this.visualChildren.Add(adornerCanvas);

            this.connection = connection;
            this.connection.PropertyChanged += new PropertyChangedEventHandler(AnchorPositionChanged);

            InitializeDragThumbs();

            drawingPen = new Pen(Brushes.LightSlateGray, 1);
            drawingPen.LineJoin = PenLineJoin.Round;

            base.Unloaded += new RoutedEventHandler(ConnectionAdorner_Unloaded);
        }
                

        void AnchorPositionChanged(object sender, PropertyChangedEventArgs e)
        {
            if (e.PropertyName.Equals("AnchorPositionSource"))
            {
                Canvas.SetLeft(sourceDragThumb, connection.AnchorPositionSource.X);
                Canvas.SetTop(sourceDragThumb, connection.AnchorPositionSource.Y);
            }

            if (e.PropertyName.Equals("AnchorPositionSink"))
            {
                Canvas.SetLeft(sinkDragThumb, connection.AnchorPositionSink.X);
                Canvas.SetTop(sinkDragThumb, connection.AnchorPositionSink.Y);
            }
        }

        void thumbDragThumb_DragCompleted(object sender, DragCompletedEventArgs e)
        {
            if (HitConnector != null)
            {
                if (connection != null)
                {
                    if (connection.Source == fixConnector)
                        connection.Sink = this.HitConnector;
                    else
                        connection.Source = this.HitConnector;
                }
            }

            this.HitDesignerItem = null;
            this.HitConnector = null;
            this.pathGeometry = null;
            this.connection.StrokeDashArray = null;
            this.InvalidateVisual();
        }

        void thumbDragThumb_DragStarted(object sender, DragStartedEventArgs e)
        {
            this.HitDesignerItem = null;
            this.HitConnector = null;
            this.pathGeometry = null;
            this.Cursor = Cursors.Cross;
            this.connection.StrokeDashArray = new DoubleCollection(new double[] { 1, 2 });

            if (sender == sourceDragThumb)
            {
                fixConnector = connection.Sink;
                dragConnector = connection.Source;
            }
            else if (sender == sinkDragThumb)
            {
                dragConnector = connection.Sink;
                fixConnector = connection.Source;
            }
        }

        void thumbDragThumb_DragDelta(object sender, DragDeltaEventArgs e)
        {
            Point currentPosition = Mouse.GetPosition(this);
            this.HitTesting(currentPosition);
            this.pathGeometry = UpdatePathGeometry(currentPosition);
            this.InvalidateVisual();
        }

        protected override void OnRender(DrawingContext dc)
        {
            base.OnRender(dc);
            dc.DrawGeometry(null, drawingPen, this.pathGeometry);
        }

        protected override Size ArrangeOverride(Size finalSize)
        {
            adornerCanvas.Arrange(new Rect(0, 0, this.designerCanvas.ActualWidth, this.designerCanvas.ActualHeight));
            return finalSize;
        }

        private void ConnectionAdorner_Unloaded(object sender, RoutedEventArgs e)
        {
            sourceDragThumb.DragDelta -= new DragDeltaEventHandler(thumbDragThumb_DragDelta);
            sourceDragThumb.DragStarted -= new DragStartedEventHandler(thumbDragThumb_DragStarted);
            sourceDragThumb.DragCompleted -= new DragCompletedEventHandler(thumbDragThumb_DragCompleted);

            sinkDragThumb.DragDelta -= new DragDeltaEventHandler(thumbDragThumb_DragDelta);
            sinkDragThumb.DragStarted -= new DragStartedEventHandler(thumbDragThumb_DragStarted);
            sinkDragThumb.DragCompleted -= new DragCompletedEventHandler(thumbDragThumb_DragCompleted);
        }

        private void InitializeDragThumbs()
        {
            Style dragThumbStyle = connection.FindResource("ConnectionAdornerThumbStyle") as Style;

            //source drag thumb
            sourceDragThumb = new Thumb();
            Canvas.SetLeft(sourceDragThumb, connection.AnchorPositionSource.X);
            Canvas.SetTop(sourceDragThumb, connection.AnchorPositionSource.Y);
            this.adornerCanvas.Children.Add(sourceDragThumb);
            if (dragThumbStyle != null)
                sourceDragThumb.Style = dragThumbStyle;

            sourceDragThumb.DragDelta += new DragDeltaEventHandler(thumbDragThumb_DragDelta);
            sourceDragThumb.DragStarted += new DragStartedEventHandler(thumbDragThumb_DragStarted);
            sourceDragThumb.DragCompleted += new DragCompletedEventHandler(thumbDragThumb_DragCompleted);

            // sink drag thumb
            sinkDragThumb = new Thumb();
            Canvas.SetLeft(sinkDragThumb, connection.AnchorPositionSink.X);
            Canvas.SetTop(sinkDragThumb, connection.AnchorPositionSink.Y);
            this.adornerCanvas.Children.Add(sinkDragThumb);
            if (dragThumbStyle != null)
                sinkDragThumb.Style = dragThumbStyle;

            sinkDragThumb.DragDelta += new DragDeltaEventHandler(thumbDragThumb_DragDelta);
            sinkDragThumb.DragStarted += new DragStartedEventHandler(thumbDragThumb_DragStarted);
            sinkDragThumb.DragCompleted += new DragCompletedEventHandler(thumbDragThumb_DragCompleted);
        }

        private PathGeometry UpdatePathGeometry(Point position)
        {
            PathGeometry geometry = new PathGeometry();

            ConnectorOrientation targetOrientation;
            if (HitConnector != null)
                targetOrientation = HitConnector.Orientation;
            else
                targetOrientation = dragConnector.Orientation;

            List<Point> linePoints = PathFinder.GetConnectionLine(fixConnector.GetInfo(), position, targetOrientation);

            if (linePoints.Count > 0)
            {
                PathFigure figure = new PathFigure();
                figure.StartPoint = linePoints[0];
                linePoints.Remove(linePoints[0]);
                figure.Segments.Add(new PolyLineSegment(linePoints, true));
                geometry.Figures.Add(figure);
            }

            return geometry;
        }

        private void HitTesting(Point hitPoint)
        {
            bool hitConnectorFlag = false;

            DependencyObject hitObject = designerCanvas.InputHitTest(hitPoint) as DependencyObject;
            while (hitObject != null &&
                   hitObject != fixConnector.ParentDesignerItem &&
                   hitObject.GetType() != typeof(DesignerCanvas))
            {
                if (hitObject is Connector)
                {
                    HitConnector = hitObject as Connector;
                    hitConnectorFlag = true;
                }

                if (hitObject is DesignerItem)
                {
                    HitDesignerItem = hitObject as DesignerItem;
                    if (!hitConnectorFlag)
                        HitConnector = null;
                    return;
                }
                hitObject = VisualTreeHelper.GetParent(hitObject);
            }

            HitConnector = null;
            HitDesignerItem = null;
        }

    }
}

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About the Author

sukram

Austria Austria
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Web01 | 2.8.140916.1 | Last Updated 26 Mar 2008
Article Copyright 2008 by sukram
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