How to display a tickertape?

I'm sure there are better ways, but here's a rudimentary late-night attempt:

package yawmark.jdc.marquee;

import java.awt.BorderLayout;

import java.awt.Font;

import java.awt.FontMetrics;

import java.awt.Graphics;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import java.awt.geom.Rectangle2D;

import javax.swing.JFrame;

import javax.swing.JPanel;

import javax.swing.Timer;

public class MarqueeDemo {

public static void main(String[] args) {

String message = "All work and no play makes Jack a dull boy. ";

MarqueePanel panel = new MarqueePanel(message, 5);

JFrame f = new JFrame("MarqueeDemo");

f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

f.setLocationRelativeTo(null);

f.add(panel, BorderLayout.CENTER);

f.setSize(300, 300);

f.setVisible(true);

panel.start();

}

}

class MarqueePanel extends JPanel {

private String message;

private Timer timer;

private int delay;

private int x;

private int y;

public MarqueePanel(String message, int delay) {

this.message = message;

this.delay = delay;

}

public void start() {

this.x = getWidth();

if (this.timer == null) {

this.timer = new Timer(this.delay, new ActionListener() {

public void actionPerformed(ActionEvent arg0) {

MarqueePanel.this.update();

MarqueePanel.this.repaint();

}

});

this.timer.start();

}

}

@Override

protected void paintComponent(Graphics g) {

super.paintComponent(g);

g.drawString(this.message, this.x, this.y);

}

void update() {

updateXposition();

updateYposition();

}

private void updateYposition() {

final int panelHeight = getHeight();

this.y = panelHeight / 2;

}

private void updateXposition() {

this.x--;

if ((offRightSideOfPanel()) || (offLeftSideOfPanel())) {

this.x = getWidth();

}

}

private boolean offLeftSideOfPanel() {

final Font font = getFont();

final FontMetrics metrics = getFontMetrics(font);

final Graphics graphics = getGraphics();

final Rectangle2D stringBounds = metrics.getStringBounds(this.message, graphics);

final double messageWidth = stringBounds.getWidth();

return (this.x + messageWidth) < 0;

}

private boolean offRightSideOfPanel() {

return this.x > getWidth();

}

}

~

yawmarka at 2007-7-12 10:21:38 >