Test1.java
Download: java1.zip.
Class Test1
is an example of a simple Java program
that provides the starting-point for demonstrating graphics
applications. The class provides a JFrame
application
with a custom client window derived from JPanel
.
In this example, the custom JPanel
displays the width
and height of the client area, centered in the screen. It illustrates
the use of FontMetrics
to obtain the graphical extent of
a text string in Java.
// Test1.java import java.awt.Graphics; import java.awt.FontMetrics; import java.awt.geom.Rectangle2D; import javax.swing.JPanel; import javax.swing.JFrame; public class Test1 extends JPanel { public void paintComponent(Graphics g) { super.paintComponent( g ); int width = getWidth(); int height = getHeight(); String str = String.format("width %d height %d",width,height); FontMetrics fm = g.getFontMetrics(); Rectangle2D rect = fm.getStringBounds(str,g); width -= rect.getWidth(); height -= rect.getHeight(); g.drawString(str,width/2,height/2); } public static void main( String args[] ) { Test1 panel = new Test1(); JFrame application = new JFrame("Test1"); application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); application.add(panel); application.setSize(200,200); application.setVisible(true); } }
Maintained by John Loomis, updated Sun Jan 28 14:20:56 2007