Introduction to Draw2d

Draw2d is a lightweight widget system that is hosted on an SWT Composite.  A Draw2d instance consists of an SWT Composite, a Lightweight System, and its contents: figures.  Figures are the building blocks for Draw2d.  Here is how "Hello World" translates into a draw2d program:

import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Display;
import org.eclipse.swt.SWT;

import org.eclipse.draw2d.*;
import org.eclipse.draw2d.geometry.*;

public class HelloWorld {
	public static void main(String args[]){
		Shell shell = new Shell();
		shell.open();
		shell.setText("Draw2d Hello World");
		LightweightSystem lws = new LightweightSystem(shell);
		IFigure label = new Label("Hello World");
		lws.setContents(label);
		Display display = Display.getDefault();
		while (!shell.isDisposed ()) {
			if (!display.readAndDispatch ())
				display.sleep ();
		}
	}
}

What's going on?

The LightweightSystem is the "glue" for Draw2d.  You provide the SWT composite and the root of the figure hierarchy that you want rendered, and the LightweightSystem sets up the rest with default values.  "The rest" consists of an {@link org.eclipse.draw2d.EventDispatcher EventDispatcher}, which handles SWT events and dispatches them to figures , and an {@link org.eclipse.draw2d.UpdateManager UpdateManager}, which handles layout and repaint requests from the figures in that system.

More Examples

	Demo2 This example shows basic use of a layout manager and how to create some of the provided figures.
		Demo3 This example demonstrates button use and the dynamic laying out of figures.  It also shows how to use a ScrollPane
	Demo 4 This example demonstrates the usage of a Connection Figure.   It demonstrates how to decorate the connection, and simple routing support.