MSAGL: Microsoft Automatic Graph Layout

MSAGL is a .NET tool for graph layout and viewing. It was developed in Microsoft Research by Lev Nachmanson. MSAGL is built on the principle of the Sugiyama scheme; it produces so called layered, or hierarchical layouts. This kind of a layout naturally applies to graphs with some flow of information. The graph could represent a control flow graph of a program, a state machine, a C++ class hierarchy, etc.

Purchase

The Microsoft Automatic Graph Layout (MSAGL) tool can be purchased at Windows Marketplace.

The Distribution Content and Important Features

The package contains the following DLLs:

• Microsoft.MSAGL.dll is the layout engine. The core layout functionality is implemented in this DLL. One would directly use Microsoft.MSAGL.dll mainly in cases when visualization is handled by some other tool than MSAGL.
• Microsoft.MSAGL.Drawing.dll contains definitions of different drawing attributes like colors, line styles, etc. It also contains definitions of a node class, an edge class, and a graph class. By using these classes a user can create a graph object and use it later for layout, and rendering.
• Microsoft.MSAGL.GraphViewerGDIGraph.dll contains a viewer control, and provides some other rendering functionality.

The most important features of the viewer are:

• Zoom and pan abilities.
• Event SelectedObjectChanged. A better name for this event would be “AnObjectUnderMouseCursorHasChanged”, but it is a too long name. The event can be used for configuring of the tooltip, and the graph entities highlighting.
• Backward and forward navigation.
• Methods CenterToPoint, CenterToObject, etc can be used for graph entities search.

Code Samples

The code snippet demonstrates the basic usage of the viewer. It uses the C# language.

The Viewer sample

Drawing of the graph from the sample

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();
    }
}

More code samples…

Layouts Created by MSAGL

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People

Primary Contact: Lev Nachmanson
Nachmanson, Lev