Rotate an imageTag(s): AWT
The following snippet rotates an image (90 degrees). The applet assumes the dimension 32x32 for the image. You may want to grap this image
import java.applet.Applet;
import java.awt.*;
import java.awt.image.*;
import java.net.*;
public class RotateGumby extends Applet {
Image img = null;
Image rot = null;
int buffer[] = new int[32 * 32];
int rotate[] = new int[32 * 32];
public void init() {
try {
MediaTracker tracker = new MediaTracker (this);
img = getImage(new URL(getDocumentBase(), "gumby.gif"));
tracker.addImage (img, 0);
tracker.waitForAll();
PixelGrabber grabber =
new PixelGrabber(img, 0, 0, 32, 32, buffer, 0, 32);
try {
grabber.grabPixels();
}
catch(InterruptedException e) {
e.printStackTrace();
}
for(int y = 0; y < 32; y++) {
for(int x = 0; x < 32; x++) {
rotate[((32-x-1)*32)+y] = buffer[(y*32)+x];
}
}
rot = createImage(new MemoryImageSource(32, 32, rotate, 0, 32));
}
catch (Exception e) {
e.printStackTrace();
}
}
public void update( Graphics g) {
paint(g);
}
public void paint(Graphics g) {
g.drawImage(img, 0, 0,this);
g.drawImage(rot,0, 40, this);
}
}import java.awt.*;
import java.awt.event.*;
import java.awt.geom.*;
import javax.swing.*;
public class RotatePanel extends JPanel {
private Image image;
private double currentAngle;
public RotatePanel(Image image) {
this.image = image;
MediaTracker mt = new MediaTracker(this);
mt.addImage(image, 0);
try {
mt.waitForID(0);
}
catch (Exception e) {
e.printStackTrace();
}
}
public void rotate() {
//rotate 5 degrees at a time
currentAngle+=5.0;
if (currentAngle >= 360.0) {
currentAngle = 0;
}
repaint();
}
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2d = (Graphics2D)g;
AffineTransform origXform = g2d.getTransform();
AffineTransform newXform = (AffineTransform)(origXform.clone());
//center of rotation is center of the panel
int xRot = this.getWidth()/2;
int yRot = this.getHeight()/2;
newXform.rotate(Math.toRadians(currentAngle), xRot, yRot);
g2d.setTransform(newXform);
//draw image centered in panel
int x = (getWidth() - image.getWidth(this))/2;
int y = (getHeight() - image.getHeight(this))/2;
g2d.drawImage(image, x, y, this);
g2d.setTransform(origXform);
}
public Dimension getPreferredSize() {
return new Dimension (image.getWidth(this), image.getHeight(this));
}
public static void main(String[] args) {
JFrame f = new JFrame();
Container cp = f.getContentPane();
cp.setLayout(new BorderLayout());
Image testImage =
Toolkit.getDefaultToolkit().getImage("c:/temp/gumby.gif");
final RotatePanel rotatePanel = new RotatePanel(testImage);
JButton b = new JButton ("Rotate");
b.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent ae) {
rotatePanel.rotate();
}
});
cp.add(rotatePanel, BorderLayout.CENTER);
cp.add(b, BorderLayout.SOUTH);
f.pack();
f.setVisible(true);
}
}
mail_outline
Send comment, question or suggestion to howto@rgagnon.com
Send comment, question or suggestion to howto@rgagnon.com