Click here to Skip to main content
12,242,812 members (42,408 online)
Click here to Skip to main content

Stats

231.9K views
15.8K downloads
308 bookmarked
Posted

WPF Diagram Designer - Part 2

, 8 Oct 2008 CPOL
Designer Canvas with Zoombox
using System;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Shapes;

namespace DiagramDesigner
{
    public class RubberbandAdorner : Adorner
    {
        private Point? startPoint, endPoint;
        private Rectangle rubberband;
        private DesignerCanvas designerCanvas;
        private VisualCollection visuals;
        private Canvas adornerCanvas;

        protected override int VisualChildrenCount
        {
            get
            {
                return this.visuals.Count;
            }
        }

        public RubberbandAdorner(DesignerCanvas designerCanvas, Point? dragStartPoint)
            : base(designerCanvas)
        {
            this.designerCanvas = designerCanvas;
            this.startPoint = dragStartPoint;

            this.adornerCanvas = new Canvas();
            this.adornerCanvas.Background = Brushes.Transparent;
            this.visuals = new VisualCollection(this);
            this.visuals.Add(this.adornerCanvas);

            this.rubberband = new Rectangle();
            this.rubberband.Stroke = Brushes.Navy;
            this.rubberband.StrokeThickness = 1;
            this.rubberband.StrokeDashArray = new DoubleCollection(new double[] { 2 });                        
            
            this.adornerCanvas.Children.Add(this.rubberband);
        }

        protected override void OnMouseMove(MouseEventArgs e)
        {
            if (e.LeftButton == MouseButtonState.Pressed)
            {
                if (!this.IsMouseCaptured)
                {
                    this.CaptureMouse();
                }

                this.endPoint = e.GetPosition(this);
                this.UpdateRubberband();
                this.UpdateSelection();
                e.Handled = true;
            }
        }

        protected override void OnMouseUp(MouseButtonEventArgs e)
        {
            if (this.IsMouseCaptured)
            {
                this.ReleaseMouseCapture();
            }

            AdornerLayer adornerLayer = this.Parent as AdornerLayer;
            if (adornerLayer != null)
            {
                adornerLayer.Remove(this);
            }
        }

        protected override Size ArrangeOverride(Size arrangeBounds)
        {
            this.adornerCanvas.Arrange(new Rect(arrangeBounds));
            return arrangeBounds;
        }

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

        private void UpdateRubberband()
        {
            double left = Math.Min(this.startPoint.Value.X, this.endPoint.Value.X);
            double top = Math.Min(this.startPoint.Value.Y, this.endPoint.Value.Y);

            double width = Math.Abs(this.startPoint.Value.X - this.endPoint.Value.X);
            double height = Math.Abs(this.startPoint.Value.Y - this.endPoint.Value.Y);

            this.rubberband.Width = width;
            this.rubberband.Height = height;
            Canvas.SetLeft(this.rubberband, left);
            Canvas.SetTop(this.rubberband, top);
        }

        private void UpdateSelection()
        {
            Rect rubberBand = new Rect(this.startPoint.Value, this.endPoint.Value);
            foreach (DesignerItem item in this.designerCanvas.Children)
            {
                Rect itemRect = VisualTreeHelper.GetDescendantBounds(item);
                Rect itemBounds = item.TransformToAncestor(designerCanvas).TransformBounds(itemRect);

                if (rubberBand.Contains(itemBounds))
                {
                    item.IsSelected = true;
                }
                else
                {
                    item.IsSelected = false;
                }
            }
        }
    }
}

By viewing downloads associated with this article you agree to the Terms of Service and the article's licence.

If a file you wish to view isn't highlighted, and is a text file (not binary), please let us know and we'll add colourisation support for it.

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

Share

About the Author

sukram
Austria Austria
No Biography provided

You may also be interested in...

| Advertise | Privacy | Terms of Use | Mobile
Web02 | 2.8.160426.1 | Last Updated 8 Oct 2008
Article Copyright 2008 by sukram
Everything else Copyright © CodeProject, 1999-2016
Layout: fixed | fluid