/**
 * File: Ticker.java
 * Author: Brian Borowski
 * Date created: May 1999
 * Date last modified: January 30, 2011
 */
import java.awt.Color;
import java.awt.Font;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JComponent;
import javax.swing.Timer;

public class Ticker extends JComponent {
    private static final long serialVersionUID = 1L;
    private int xPos;
    private final int strWidth, fontHeight, fontDescent;
    private final String text;
    private Color textColor, backColor;
    private final Font font = new Font("SansSerif", Font.PLAIN, 24);
    private final Timer timer;

    public Ticker(final String text, final Color textColor, final Color backColor) {
        this.text = text;
        this.textColor = textColor;
        this.backColor = backColor;
        final FontMetrics fontMetrics = getFontMetrics(font);
        fontHeight = fontMetrics.getHeight();
        fontDescent = fontMetrics.getDescent();
        strWidth = fontMetrics.stringWidth(text);
        xPos = Integer.MAX_VALUE;
        setDoubleBuffered(true);
        timer = new Timer(25, new ActionListener() {
            public void actionPerformed(final ActionEvent ae) {
                --xPos;
                repaint();
            }
        });
        timer.setInitialDelay(0);
    }

    public void setTextColor(final Color textColor) {
        this.textColor = textColor;
    }

    public void setBackgroundColor(final Color backColor) {
        this.backColor = backColor;
    }

    public void start() {
        timer.restart();
    }

    public void stop() {
        timer.stop();
    }

    public void paintComponent(Graphics g) {
        final int canvasWidth = getSize().width,
                  canvasHeight = getSize().height,
                  yPos = (canvasHeight - fontHeight) / 2 + fontHeight - fontDescent;
        g.setColor(backColor);
        g.fillRect(0, 0, canvasWidth, canvasHeight);
        g.setColor(textColor);
        g.setFont(font);
        if (xPos > canvasWidth) {
            xPos = canvasWidth;
        }
        if (xPos < 0) {
            if (xPos <= -strWidth) {
                xPos = canvasWidth - strWidth;
            } else {
                g.drawString(text, canvasWidth + xPos, yPos);
            }
        }
        g.drawString(text, xPos, yPos);
    }
}