Animating dashed-line with java.awt.BasicStroke
Is there a way to produce animated dashed line using BasicStroke from java.awt? My desire is to have a running dashed-line in the same way that photoshop's rectangle marque tool has its line animated.
Use a dashed line, a Thread
(or a Swing Timer
) & combine them with repaint()
and some tweaking of where the dashes start and end - and there you have it.
Example
package test;
import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.Shape;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.geom.Rectangle2D;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.IOException;
import javax.imageio.ImageIO;
import javax.swing.ImageIcon;
import javax.swing.JLabel;
import javax.swing.JOptionPane;
import javax.swing.SwingUtilities;
import javax.swing.Timer;
public class AnimatedStroke {
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
BasicStroke dashedStroke;
final int width = 100;
final int height = 30;
final BufferedImage image = new BufferedImage(
width,height,BufferedImage.TYPE_INT_ARGB);
final JLabel label = new JLabel(new ImageIcon(image));
int pad = 5;
final Shape rectangle = new Rectangle2D.Double(
(double)pad,(double)pad,
(double)(width-2*pad),
(double)(height-2*pad));
ActionListener listener = new ActionListener() {
float dashPhase = 0f;
float dash[] = {5.0f,5.0f};
@Override
public void actionPerformed(ActionEvent ae) {
dashPhase += 9.0f;
BasicStroke dashedStroke = new BasicStroke(
1.5f,
BasicStroke.CAP_ROUND,
BasicStroke.JOIN_MITER,
1.5f, //miter limit
dash,
dashPhase
);
Graphics2D g = image.createGraphics();
g.setColor(Color.WHITE);
g.fillRect(0,0,width,height);
g.setColor(Color.BLACK);
g.setStroke(dashedStroke);
g.draw(rectangle);
g.dispose();
label.repaint();
/*
if (dashPhase<100f) {
try {
ImageIO.write(
image,
"PNG",
new File("img" + dashPhase + ".png"));
} catch(IOException ioe) {
// we tried
}
}*/
}
};
Timer timer = new Timer(40, listener);
timer.start();
JOptionPane.showMessageDialog(null, label);
}
});
}
}