Fading a JLabel that contains html
I can fade out a normal JLabel using a Timer, as follows:
public static void main(String[] args) {
JFrame frame = new JFrame();
// final JLabel label = new JLabel("<html>开发者_StackOverflow中文版<font color=red>Red</font><font color=blue>Blue</font>");
final JLabel label = new JLabel("Hello");
label.setOpaque(true);
label.setBackground(Color.WHITE);
frame.getContentPane().add(label);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
final Timer timer = new Timer(100, null);
final int steps = 25;
timer.addActionListener(new ActionListener() {
int count = 0;
public void actionPerformed(ActionEvent e) {
if (count <= steps) {
float intensity = count / (float) steps;
label.setForeground(new Color(intensity, intensity, intensity));
count++;
} else {
timer.stop();
}
}
});
timer.start();
}
How can I make this also work with a JLabel that contains html, as per the commented-out line?
final JLabel label = new JLabel("<html><font color=red>Red</font><font color=blue>Blue</font>");
I got out my copy of "Filthy Rich Clients" and read up on using composites. My solution is to make a subclass of JLabel, as follows:
import javax.swing.*;
import java.awt.*;
public class FadeableLabel extends JLabel {
private float intensity = 1.0f;
public FadeableLabel() {
}
public void setIntensity(float intensity) {
this.intensity = intensity;
repaint();
}
@Override
protected void paintComponent(Graphics g) {
super.paintComponent(g);
Graphics2D g2 = (Graphics2D) g;
final Composite oldComposite = g2.getComposite();
g2.setComposite(AlphaComposite.SrcOver);
final Color c = getBackground();
final Color color = new Color(c.getRed(), c.getGreen(), c.getBlue(), (int) (255 * (1.0f - intensity)));
g2.setColor(color);
g2.fillRect(0, 0, getWidth(), getHeight());
g2.setComposite(oldComposite);
}
}
You must fade the HTML:
float intensity = count / (float) steps;
String color = String.format("%02x" % 255*intensity);
label.setText("<html><font color='#FF"+color+color+"'>Red</font>...");
加载中,请稍侯......
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