SimpleCanvas.java Source code

Introduction

Here is the source code for SimpleCanvas.java

Source

//Send questions, comments, bug reports, etc. to the authors:

//Rob Warner (rwarner@interspatial.com)
//Robert Harris (rbrt_harris@yahoo.com)

import org.eclipse.swt.SWT;
import org.eclipse.swt.events.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.layout.*;
import org.eclipse.swt.widgets.*;

/**
 * This class demonstrates a Canvas
 */
public class SimpleCanvas {
    /**
     * Runs the application
     */
    public void run() {
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("Canvas Example");
        createContents(shell);
        shell.open();
        while (!shell.isDisposed()) {
            if (!display.readAndDispatch()) {
                display.sleep();
            }
        }
        display.dispose();
    }

    /**
     * Creates the main window's contents
     * 
     * @param shell the main window
     */
    private void createContents(Shell shell) {
        shell.setLayout(new FillLayout());

        // Create a canvas
        Canvas canvas = new Canvas(shell, SWT.NONE);

        // Create a button on the canvas
        Button button = new Button(canvas, SWT.PUSH);
        button.setBounds(10, 10, 300, 40);
        button.setText("You can place widgets on a canvas");

        // Create a paint handler for the canvas
        canvas.addPaintListener(new PaintListener() {
            public void paintControl(PaintEvent e) {
                // Do some drawing
                Rectangle rect = ((Canvas) e.widget).getBounds();
                e.gc.setForeground(e.display.getSystemColor(SWT.COLOR_RED));
                e.gc.drawFocus(5, 5, rect.width - 10, rect.height - 10);
                e.gc.drawText("You can draw text directly on a canvas", 60, 60);
            }
        });
    }

    /**
     * The application entry point
     * 
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        new SimpleCanvas().run();
    }
}