Make JLabel background transparent again
I have a JLa开发者_运维问答bel that changes its background color when the mouse enters it. The problem I have is that I want the JLabel to become transparent after the mouse exits.
Is there a statement I can use to accomplish this?
It's a lazy holiday here in Germany, so combining the two answers:
final JLabel label = new JLabel("some label with a nice text");
label.setBackground(Color.YELLOW);
MouseAdapter adapter = new MouseAdapter() {
/**
* @inherited <p>
*/
@Override
public void mouseEntered(MouseEvent e) {
label.setOpaque(true);
label.repaint();
}
/**
* @inherited <p>
*/
@Override
public void mouseExited(MouseEvent e) {
label.setOpaque(false);
label.repaint();
}
};
label.addMouseListener(adapter);
The problem (actually, I tend to regard it as a bug) is that setting the opaque property doesn't trigger a repaint as would be appropriate. JComponent fires a change event, but seems like nobody is listening:
public void setOpaque(boolean isOpaque) {
boolean oldValue = getFlag(IS_OPAQUE);
setFlag(IS_OPAQUE, isOpaque);
setFlag(OPAQUE_SET, true);
firePropertyChange("opaque", oldValue, isOpaque);
}
JLabel
is by default transparent and non-opaque, if you want to change background on mouse exit, then you have to:
setBackground()
for both states, enter and exitchange to
JPanel
or anotherJComponent
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