The Viewer sample

Drawing of the graph from the sample

The code snippet demonstrates the basic usage of the viewer.

using System;
using System.Collections.Generic;
using System.Windows.Forms;

class ViewerSample {
    public static void Main() {
        //create a form
        System.Windows.Forms.Form form = new
                System.Windows.Forms.Form();
        //create a viewer object
        Microsoft.Msagl.GraphViewerGdi.GViewer viewer = 
                new Microsoft.Msagl.GraphViewerGdi.GViewer();

        //create a graph object
        Microsoft.Msagl.Drawing.Graph graph = new 
                Microsoft.Msagl.Drawing.Graph("graph");
        //create the graph content
        graph.AddEdge("A", "B");
        graph.AddEdge("B", "C");
        graph.AddEdge("A", "C").EdgeAttr.Color = 
                Microsoft.Msagl.Drawing.Color.Green;
        graph.FindNode("A").Attr.Fillcolor =
                Microsoft.Msagl.Drawing.Color.Magenta;
        graph.FindNode("B").Attr.Fillcolor = 
                Microsoft.Msagl.Drawing.Color.MistyRose;
        Microsoft.Msagl.Drawing.Node c = graph.FindNode("C");
        c.Attr.Fillcolor = Microsoft.Msagl.Drawing.Color.PaleGreen;
        c.Attr.Shape = Microsoft.Msagl.Drawing.Shape.Diamond;
        //bind the graph to the viewer
        viewer.Graph = graph;

        //associate the viewer with the form
        form.SuspendLayout();
        viewer.Dock = System.Windows.Forms.DockStyle.Fill;
        form.Controls.Add(viewer);
        form.ResumeLayout();

        //show the form
        form.ShowDialog();
    }
}

Rendering an image sample

The image from the sample

This sample shows how to render an image by using class Microsoft.Msagl.GraphViewerGDI.GraphRenderer.

Microsoft.Msagl.Drawing.Graph graph = new 
                Microsoft.Msagl.Drawing.Graph("");
        graph.AddEdge("A", "B");
        graph.AddEdge("A", "B");
        graph.FindNode("A").Attr.Fillcolor = 
                Microsoft.Msagl.Drawing.Color.Red;
        graph.FindNode("B").Attr.Fillcolor = 
                Microsoft.Msagl.Drawing.Color.Blue;
        Microsoft.Msagl.GraphViewerGdi.GraphRenderer renderer = 
            new Microsoft.Msagl.GraphViewerGdi.GraphRenderer(graph);
        renderer.CalculateLayout();
        int width = 50;
        Bitmap bitmap = new Bitmap(width, (int)(graph.Height *
                 (width / graph.Width)), PixelFormat.Format32bppPArgb);
        renderer.Render(bitmap);
        bitmap.Save("test.png");

Alternatively, if you have a System.Drawing.Graphics object available, you can draw by using method public void Render(Graphics graphics, Rectangle rect) taking a System.Drawing.Graphics object as an argument.

Sample of using the engine directly

This sample bypasses the layer of the Microsoft.Msagl.Drawing.dll, and Microsoft.Msagl.GraphViewerGDI.dll, and works directly with Microsoft.Msagl.dll. Notice, that in this case the user code is responsible for creation of curves of node boundaries.

using Microsoft.Msagl;
using Microsoft.Msagl.Splines;

class GLEETester
{
    static void Main(string[] args)
    {
        double w = 10;
        double h = 10;
        MsaglGraph graph = new MsaglGraph();
        Node a = new Node("a", new Ellipse(w, h, new Point()));
        Node b = new Node("b", CurveFactory.CreateBox(w, h, new Point()));
        graph.AddNode(a);
        graph.AddNode(b);
        Edge e = new Edge(a, b);
        graph.AddEdge(e);
        graph.CalculateLayout();
    }
}

Please also pay attention to sample WindowsApplication which comes with the distribution and that can serve as a starting point. Comments and bugs should be e-mailed to Lev Nachmanson.

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