Click here to Skip to main content
Click here to Skip to main content
 
Add your own
alternative version
Go to top

DSGraphEdit: A Reasonable Facsimile of Microsoft's GraphEdit in .NET

, 19 Dec 2007
A library for adding DirectShow GraphEdit-like abilities to .NET applications.
dsgrapheditdemo.zip
WeifenLuo.WinFormsUI.Docking.dll
DaggerLib.dll
DaggerLib.DSGraphEdit.dll
DaggerLib.UI.Windows.dll
DirectShowLib-2005.dll
DSGraphEdit.exe
MediaFoundation.dll
dsgrapheditsrc.zip
DSGraphEdit
bin
Release
DSIcon.ico
Properties
Settings.settings
Referenced Libs
WeifenLuo.WinFormsUI.Docking.dll
RemoteGraphTile.jpg
DaggerLib
bin
Release
Core
Interfaces
Properties
SetGeneric
UI
DaggerLib.DSGraphEdit
DMOParameterControls
DSFilterTreeView
DSGraphEditControls
lib
Properties
ReferencedLibs
DirectShowLib-2005.dll
MediaFoundation.dll
DaggerLib.UI.Windows
AStar
bin
Debug
DaggerPropertyGrid
PropertyGridEx
Properties
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Data;
using System.Text;
using System.Windows.Forms;

namespace DaggerLib.UI.Windows
{
    public partial class UIGraphNavigator : DoubleBufferedPanel
    {
        private DaggerUIGraph _uigraph;
        private Bitmap _canvasImage;
        private RectangleF _viewPort = new RectangleF(0, 0, 1, 1);
        private Rectangle _viewPortRect;
        private Rectangle _rzoom;
        private Color _puckColor = Color.Red;
        private bool _isMoving = false;
        private Point _dragOffset;

        public UIGraphNavigator()
        {
            InitializeComponent();
            BackgroundImageLayout = ImageLayout.Zoom;
        }

        public Color PuckColor
        {
            get
            {
                return _puckColor;
            }
            set
            {
                _puckColor = value;
                Invalidate();
            }
        }

        public DaggerUIGraph AssociatedUIGraph
        {
            get
            {
                return _uigraph;
            }
            set
            {
                // unhook previous events
                if (_uigraph != null)
                {
                    _uigraph.CanvasImageChanged -= new EventHandler(_uigraph_CanvasImageChanged);
                    _uigraph.ViewportChanged -=new EventHandler(_uigraph_ViewportChanged);
                }

                // clear the existing canvas image
                if (_canvasImage != null)
                {
                    _canvasImage.Dispose();
                    _canvasImage = null;
                }

                _uigraph = value;

                // set up events
                if (_uigraph != null)
                {
                    _uigraph.CanvasImageChanged += new EventHandler(_uigraph_CanvasImageChanged);
                    _uigraph.ViewportChanged += new EventHandler(_uigraph_ViewportChanged);
                }

                // reset the viewport
                _viewPort = new RectangleF(0, 0, 1, 1);

                // refresh the Navigator
                _uigraph_CanvasImageChanged(null, null);
            }
        }

        void _uigraph_ViewportChanged(object sender, EventArgs e)
        {
            _viewPort = _uigraph.ViewPort;
            _viewPortRect = new Rectangle((int)(_rzoom.Width * _viewPort.X + _rzoom.X),
                (int)(_rzoom.Height * _viewPort.Y + _rzoom.Y),
                (int)(_rzoom.Width * _viewPort.Width),
                (int)(_rzoom.Height * _viewPort.Height));

            Invalidate();
        }

        void _uigraph_CanvasImageChanged(object sender, EventArgs e)
        {
            if (_canvasImage != null)
            {
                _canvasImage.Dispose();
            }

            if (_uigraph != null)
            {
                // get the Canvas Image
                Bitmap tempb = _uigraph.CanvasImage;

                // Calculate a new zoom rectangle
                if (((float)tempb.Height / (float)tempb.Width) < ((float)Height / (float)Width))
                {
                    _rzoom = new Rectangle(0, 0, Width, (int)((float)Width * ((float)tempb.Height / (float)tempb.Width)));
                    _rzoom.Y = (Height - _rzoom.Height) / 2;
                }
                else
                {
                    _rzoom = new Rectangle(0, 0, (int)((float)Height * ((float)tempb.Width / (float)tempb.Height)), Height);
                    _rzoom.X = (Width - _rzoom.Width) / 2;
                }

                _rzoom.Width = Math.Max(1, _rzoom.Width);
                _rzoom.Height = Math.Max(1, _rzoom.Height);

                // stretch the image into the zoomed bitmap
                _canvasImage = new Bitmap(_rzoom.Width, _rzoom.Height);
                Graphics g = Graphics.FromImage(_canvasImage);
                g.InterpolationMode = System.Drawing.Drawing2D.InterpolationMode.Bilinear;
                g.DrawImage(tempb, new Rectangle(0, 0, _canvasImage.Width, _canvasImage.Height), new Rectangle(0, 0, tempb.Width, tempb.Height), GraphicsUnit.Pixel);
                g.Dispose();
                tempb.Dispose();

                // update the viewport position
                _uigraph_ViewportChanged(null, null);

                Invalidate(false);
            }
        }

        protected override void OnMouseMove(MouseEventArgs e)
        {
            base.OnMouseMove(e);
            if (_uigraph != null)
            {
                if (!_isMoving)
                {
                    if (_viewPortRect.Contains(e.Location))
                    {
                        Cursor = Cursors.SizeAll;
                    }
                    else
                    {
                        Cursor = Cursors.Default;
                    }
                }
                else
                {
                    int offx = e.Location.X - _rzoom.X + _dragOffset.X;
                    int offy = e.Location.Y - _rzoom.Y + _dragOffset.Y;

                    float scalex = (float)offx / (float)_rzoom.Width;
                    float scaley = (float)offy / (float)_rzoom.Height;

                    _uigraph.ScrollToPosition(new Point((int)(scalex * (float)_uigraph.ActualCanvasSize.Width), (int)(scaley * (float)_uigraph.ActualCanvasSize.Height)));
                }
            }
        }

        protected override void OnMouseDown(MouseEventArgs e)
        {
            base.OnMouseDown(e);
            if (_uigraph != null)
            {
                if (_viewPortRect.Contains(e.Location))
                {
                    Capture = true;
                    _isMoving = true;
                    _dragOffset = new Point(_viewPortRect.X - e.Location.X, _viewPortRect.Y - e.Location.Y);
                }
            }
        }

        protected override void OnMouseCaptureChanged(EventArgs e)
        {
            base.OnMouseCaptureChanged(e);
            if (!Capture)
            {
                _isMoving = false;
                Cursor = Cursors.Default;
            }
        }

        protected override void OnResize(EventArgs eventargs)
        {
            base.OnResize(eventargs);
            _uigraph_CanvasImageChanged(null, null);
        }

        protected override void OnPaintBackground(PaintEventArgs e)
        {
            base.OnPaintBackground(e);
            if (_canvasImage != null)
            {
                e.Graphics.DrawImage(_canvasImage, _rzoom.Location);
            }

            if (_viewPort.X != 0f || _viewPort.Y != 0f || _viewPort.Width != 1f || _viewPort.Height != 1f)
            {
                // overlay the ViewPort Rectangle
                using (Brush pb = new SolidBrush(Color.FromArgb(100, _puckColor)))
                {                    
                    e.Graphics.FillRectangle(pb, _viewPortRect);                    
                }
                using (Pen pp = new Pen(Color.FromArgb(175, _puckColor)))
                {
                    e.Graphics.DrawRectangle(pp, _viewPortRect);
                }
            }
        }
    }
}

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

JohnnyLocust
Software Developer (Senior) Haivision Network Video
United States United States
AKA Rich Insley.
 
I have over 25 years experience in programming, and I'm completely self taught. (Except for one year at California State University Fresno where I had to learn the God awful language Miranda (http://miranda.org.uk/). I've spent 10 years as a Paratrooper in the US Army during the Clinton Administration.
Follow on   LinkedIn

| Advertise | Privacy | Mobile
Web04 | 2.8.140926.1 | Last Updated 20 Dec 2007
Article Copyright 2007 by JohnnyLocust
Everything else Copyright © CodeProject, 1999-2014
Terms of Service
Layout: fixed | fluid