LineExample.java Source code

Introduction

Here is the source code for LineExample.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.*;
import org.eclipse.swt.events.*;
import org.eclipse.swt.widgets.*;
import org.eclipse.swt.layout.*;

/**
 * This class demonstrates drawing lines
 */
public class LineExample {
    /**
     * Runs the application
     */
    public void run() {
        Display display = new Display();
        Shell shell = new Shell(display);
        shell.setText("Line 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 to draw on
        Canvas canvas = new Canvas(shell, SWT.NONE);

        // Add a handler to do the drawing
        canvas.addPaintListener(new PaintListener() {
            public void paintControl(PaintEvent e) {
                // Get the canvas and its size
                Canvas canvas = (Canvas) e.widget;
                int maxX = canvas.getSize().x;
                int maxY = canvas.getSize().y;

                // Calculate the middle
                int halfX = (int) maxX / 2;
                int halfY = (int) maxY / 2;

                // Set the drawing color to blue
                e.gc.setForeground(e.display.getSystemColor(SWT.COLOR_BLUE));

                // Set the width of the lines to draw
                e.gc.setLineWidth(10);

                // Draw a vertical line halfway across the canvas
                e.gc.drawLine(halfX, 0, halfX, maxY);

                // Draw a horizontal line halfway down the canvas
                e.gc.drawLine(0, halfY, maxX, halfY);
            }
        });
    }

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