Last post demonstrate a simple way to
draw scaled image using Graphics.drawImage(Image img, int x, int y, int width, int height, ImageObserver observer) method. We can also use drawImage(Image img, int dx1, int dy1, int dx2, int dy2, int sx1, int sy1, int sx2, int sy2, ImageObserver observer) method to draw part of the image.
drawImage(Image img, int dx1, int dy1, int dx2, int dy2, int sx1, int sy1, int sx2, int sy2, ImageObserver observer)Where:
img - the specified image to be drawn. This method does nothing if img is null.
dx1 - the x coordinate of the first corner of the destination rectangle.
dy1 - the y coordinate of the first corner of the destination rectangle.
dx2 - the x coordinate of the second corner of the destination rectangle.
dy2 - the y coordinate of the second corner of the destination rectangle.
sx1 - the x coordinate of the first corner of the source rectangle.
sy1 - the y coordinate of the first corner of the source rectangle.
sx2 - the x coordinate of the second corner of the source rectangle.
sy2 - the y coordinate of the second corner of the source rectangle.
observer - object to be notified as more of the image is scaled and converted.
 |
| Draw partial scaled image using Graphics.drawImage() |
package javaswing;
import java.awt.Graphics;
import java.awt.Image;
import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.imageio.ImageIO;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.SwingUtilities;
/**
*
* @web http://java-buddy.blogspot.com/
*/
public class JavaTestSwing {
static JFrameWin jFrameWindow;
public static class MyComponent extends JComponent{
@Override
protected void paintComponent(Graphics g) {
try {
//prepare a original Image source
Image image = ImageIO.read(this.getClass().getResource("duke.png"));
int w = image.getWidth(null);
int h = image.getHeight(null);
g.drawImage(image, 0, 0, w, h, null);
g.drawImage(image,
0, //dx1
h, //dy1
w, //dx2
h + h, //dy2
0, //sx1
0, //sy1
w/2, //sx2
h/2, //sy2
null); //ImageObserver
} catch (IOException ex) {
Logger.getLogger(JavaTestSwing.class.getName()).log(Level.SEVERE, null, ex);
}
}
}
public static class JFrameWin extends JFrame{
public JFrameWin(){
this.setTitle("java-buddy.blogspot.com");
this.setSize(300, 300);
this.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
MyComponent myComponent = new MyComponent();
this.add(myComponent);
}
}
public static void main(String[] args){
Runnable doSwingLater = new Runnable(){
@Override
public void run() {
jFrameWindow = new JFrameWin();
jFrameWindow.setVisible(true);
}
};
SwingUtilities.invokeLater(doSwingLater);
}
}
