HelloCanvas.java

/*
 * Copyright © 2011 Nokia Corporation. All rights reserved.
 * Nokia and Nokia Connecting People are registered trademarks of Nokia Corporation.
 * Oracle and Java are trademarks or registered trademarks of Oracle and/or its
 * affiliates. Other product and company names mentioned herein may be trademarks
 * or trade names of their respective owners.
 * See LICENSE.TXT for license information.
 */

import javax.microedition.lcdui.*;

public class HelloCanvas extends Canvas {

    boolean messageVisible = true;

    public HelloCanvas() {
    }

    public void newMessage() {
        messageVisible = !messageVisible;
        repaint();
    }

    public void paint(Graphics g) {
        int w = getWidth();
        int h = getHeight();
        g.setColor(0, 51, 240); // blue
        g.fillRect(0, 0, w, h);
        //display the message
        if (messageVisible) {
            Font font = g.getFont();
            int fontHeight = font.getHeight();
            //set the text color
            g.setColor(255, 255, 255); // white
            //write the strings in the center of the screen
            g.drawString("Hello, world!", w / 2, (h - fontHeight) / 2, Graphics.TOP | Graphics.HCENTER);
        }
    }
}