/*
 *  File: CenterText.java
 *  Author: Java, Java, Java, 2E
 *  Description: This Swing application centers a string of
 *   text in its top-level window. When the window is resized 
 *   and then closed and reopened, the text is recentered. 
 *   Note that it is necessary to clear the window before
 *   repainting it. 
 */

import java.awt.*;
import javax.swing.*;

public class CenterText extends JFrame {
    /**
     *  paint() is invoked automatically whenever the frame's
     *   window is resized. It gets a random font and 
     *   and the applet's current size, and displays a text string
     *   centered in the applet window.
     */
    public void paint(Graphics g) {
        String str = "Hello World!";
        g.setFont(new Font("Random", Font.PLAIN, 24));    // Create a random font
        FontMetrics metrics = g.getFontMetrics();         //  And get its metrics

        Dimension d = getSize();                          // Get the frame's size

        g.setColor(getBackground());
        g.fillRect(0, 0, d.width, d.height);              // Clear the frame
        g.setColor(Color.black);

        int x = (d.width - metrics.stringWidth(str)) / 2; // Calculate coordinates
        int y = (d.height + metrics.getHeight()) / 2;

        g.drawString(str, x, y);                          // Draw the string
    } // paint()
   
    /**  main() creates the top-level window and sizes and displays it.
     */
    public static void main(String args[]) {
        CenterText ct = new CenterText();
        ct.setSize(400,400);
        ct.setVisible(true);
    } // main()
} // CenterText