How to make an image blink in a random position?
I have an image inside the JApplet
and I want it to appear in a random position. It will disappear after 1 second and appear again, in another random position.
How do I impleme开发者_如何学Gont 'blinking in a random position'?
import javax.imageio.ImageIO;
import javax.swing.*;
import java.awt.*;
import java.net.URL;
public class Random extends JApplet
{
Image ball;
public void init()
{
try
{
URL pic = new URL(getDocumentBase(), "ball.gif");
ball = ImageIO.read(pic);
}
catch (Exception e)
{
e.printStackTrace();
}
}
public void paint(Graphics g)
{
if (ball != null)
{
g.drawImage(ball,50,50,50,50,this);
}
}
}
import java.awt.*;
import java.awt.event.*;
import java.awt.image.*;
import javax.swing.*;
import java.util.Random;
class ImageBlinker extends JComponent {
BufferedImage image;
boolean showImage;
int x = -1;
int y = -1;
Random r;
ImageBlinker() {
// put your image reading code here..
image = new BufferedImage(32,32,BufferedImage.TYPE_INT_ARGB);
Graphics g = image.createGraphics();
g.setColor(Color.ORANGE);
g.fillOval(0,0,32,32);
// END - image read
r = new Random();
ActionListener listener = new ActionListener(){
public void actionPerformed(ActionEvent ae) {
if (image!=null) {
if (!showImage) {
int w = image.getWidth();
int h = image.getHeight();
int rx = getWidth()-w;
int ry = getHeight()-h;
if (rx>-1 && ry>-1) {
x = r.nextInt(rx);
y = r.nextInt(ry);
}
}
showImage = !showImage;
repaint();
}
}
};
Timer timer = new Timer(600,listener);
timer.start();
setPreferredSize(new Dimension(150,100));
JOptionPane.showMessageDialog(null, this);
timer.stop();
}
public void paintComponent(Graphics g) {
g.setColor(Color.BLUE);
g.fillRect(0,0,getWidth(),getHeight());
if (showImage && image!=null) {
g.drawImage(image,x,y,this);
}
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
new ImageBlinker();
}
});
}
}
For my money, I'd put the Image in an ImageIcon, the ImageIcon in a JLabel, and then use a Swing Timer and a Random object to randomly move the JLabel about. You'd have to move it in a container (the contentPane will do) whose layout has been set to null, and you'll have to specify the size of the JLabel as its preferredSize for this to work.
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