Mega Code Archive
Repaint just the affected part of the component
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import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.Image;
import java.awt.Rectangle;
import java.awt.Toolkit;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionListener;
import javax.swing.JComponent;
import javax.swing.JFrame;
public class ClippedDragImage extends DragImage {
int oldX, oldY;
public ClippedDragImage(Image i) {
super(i);
}
public void mouseDragged(MouseEvent e) {
imageX = e.getX();
imageY = e.getY();
Rectangle r = getAffectedArea(oldX, oldY, imageX, imageY, imageWidth, imageHeight);
repaint(r); // repaint just the affected part of the component
oldX = imageX;
oldY = imageY;
}
private Rectangle getAffectedArea(int oldx, int oldy, int newx, int newy, int width, int height) {
int x = Math.min(oldx, newx);
int y = Math.min(oldy, newy);
int w = (Math.max(oldx, newx) + width) - x;
int h = (Math.max(oldy, newy) + height) - y;
return new Rectangle(x, y, w, h);
}
public static void main(String[] args) {
String imageFile = "A.jpg";
Image image = Toolkit.getDefaultToolkit().getImage(
ClippedDragImage.class.getResource(imageFile));
image = image.getScaledInstance(imageWidth, imageHeight, Image.SCALE_DEFAULT);
JFrame frame = new JFrame("ClippedDragImage");
frame.getContentPane().add(new ClippedDragImage(image));
frame.setSize(300, 300);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.setVisible(true);
}
}
class DragImage extends JComponent implements MouseMotionListener {
static int imageWidth = 60, imageHeight = 60;
int grid = 10;
int imageX, imageY;
Image image;
public DragImage(Image i) {
image = i;
addMouseMotionListener(this);
}
public void mouseDragged(MouseEvent e) {
imageX = e.getX();
imageY = e.getY();
repaint();
}
public void mouseMoved(MouseEvent e) {
}
public void paint(Graphics g) {
Graphics2D g2 = (Graphics2D) g;
g2.drawImage(image, imageX, imageY, this);
}
}
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