import javax.swing.*;
import javax.swing.event.MouseInputAdapter;
import java.awt.*;
import java.awt.event.*;
public class GlassPaneDemo {
static private MyGlassPane myGlassPane;
public static void main(String[] args) {
JFrame frame = new JFrame("GlassPaneDemo");
frame.addWindowListener(new WindowAdapter() {
public void windowClosing(WindowEvent e) {
System.exit(0);
}
});
JCheckBox changeButton =
new JCheckBox("Glass pane \"visible\"");
changeButton.setSelected(false);
changeButton.addItemListener(new ItemListener() {
public void itemStateChanged(ItemEvent e) {
myGlassPane.setVisible(e.getStateChange()
== ItemEvent.SELECTED);
}
});
//Set up the content pane, where the "main GUI" lives.
Container contentPane = frame.getContentPane();
contentPane.setLayout(new FlowLayout());
contentPane.add(changeButton);
contentPane.add(new JButton("Button 1"));
contentPane.add(new JButton("Button 2"));
//Set up the menu bar, which appears above the content pane.
JMenuBar menuBar = new JMenuBar();
JMenu menu = new JMenu("Menu");
menu.add(new JMenuItem("Do nothing"));
menuBar.add(menu);
frame.setJMenuBar(menuBar);
//Set up the glass pane, which appears over both menu bar
//and content pane.
myGlassPane = new MyGlassPane(changeButton, menuBar,
frame.getContentPane());
frame.setGlassPane(myGlassPane);
frame.pack();
frame.setVisible(true);
}
}
/**
* We have to provide our own glass pane so that it can paint.
*/
class MyGlassPane extends JComponent {
Point point;
public void paint(Graphics g) {
if (point != null) {
g.setColor(Color.red);
g.fillOval(point.x - 10, point.y - 10, 20, 20);
}
}
public void setPoint(Point p) {
point = p;
}
public MyGlassPane(AbstractButton aButton,
JMenuBar menuBar,
Container contentPane) {
CBListener listener = new CBListener(aButton, menuBar,
this, contentPane);
addMouseListener(listener);
addMouseMotionListener(listener);
}
}
/**
* Listen for all events that our check box is likely to be
* interested in. Redispatch them to the check box.
*/
class CBListener extends MouseInputAdapter {
Toolkit toolkit;
Component liveButton;
JMenuBar menuBar;
MyGlassPane glassPane;
Container contentPane;
boolean inDrag = false;
public CBListener(Component liveButton, JMenuBar menuBar,
MyGlassPane glassPane, Container contentPane) {
toolkit = Toolkit.getDefaultToolkit();
this.liveButton = liveButton;
this.menuBar = menuBar;
this.glassPane = glassPane;
this.contentPane = contentPane;
}
public void mouseMoved(MouseEvent e) {
redispatchMouseEvent(e, false);
}
/*
* We must forward at least the mouse drags that started
* with mouse presses over the check box. Otherwise,
* when the user presses the check box then drags off,
* the check box isn't disarmed -- it keeps its dark
* gray background or whatever its L&F uses to indicate
* that the button is currently being pressed.
*/
public void mouseDragged(MouseEvent e) {
redispatchMouseEvent(e, false);
}
public void mouseClicked(MouseEvent e) {
redispatchMouseEvent(e, false);
}
public void mouseEntered(MouseEvent e) {
redispatchMouseEvent(e, false);
}
public void mouseExited(MouseEvent e) {
redispatchMouseEvent(e, false);
}
public void mousePressed(MouseEvent e) {
redispatchMouseEvent(e, false);
}
public void mouseReleased(MouseEvent e) {
redispatchMouseEvent(e, true);
inDrag = false;
}
private void redispatchMouseEvent(MouseEvent e,
boolean repaint) {
boolean inButton = false;
boolean inMenuBar = false;
Point glassPanePoint = e.getPoint();
Component component = null;
Container container = contentPane;
Point containerPoint = SwingUtilities.convertPoint(
glassPane,
glassPanePoint,
contentPane);
int eventID = e.getID();
if (containerPoint.y < 0) {
inMenuBar = true;
container = menuBar;
containerPoint = SwingUtilities.convertPoint(
glassPane,
glassPanePoint,
menuBar);
testForDrag(eventID);
}
//XXX: If the event is from a component in a popped-up menu,
//XXX: then the container should probably be the menu's
//XXX: JPopupMenu, and containerPoint should be adjusted
//XXX: accordingly.
component = SwingUtilities.getDeepestComponentAt(
container,
containerPoint.x,
containerPoint.y);
if (component == null) {
return;
}
if (component.equals(liveButton)) {
inButton = true;
testForDrag(eventID);
}
if (inMenuBar || inButton || inDrag) {
Point componentPoint = SwingUtilities.convertPoint(
glassPane,
glassPanePoint,
component);
component.dispatchEvent(new MouseEvent(component,
eventID,
e.getWhen(),
e.getModifiers(),
componentPoint.x,
componentPoint.y,
e.getClickCount(),
e.isPopupTrigger()));
}
if (repaint) {
toolkit.beep();
glassPane.setPoint(glassPanePoint);
glassPane.repaint();
}
}
private void testForDrag(int eventID) {
if (eventID == MouseEvent.MOUSE_PRESSED) {
inDrag = true;
}
}
}
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