source: release-kits/shared/launch4j/src/net/sf/launch4j/formimpl/GlassPane.java@ 15024

package net.sf.launch4j.formimpl;

import java.awt.AWTEvent;
import java.awt.Component;
import java.awt.Cursor;
import java.awt.Toolkit;
import java.awt.Window;
import java.awt.event.AWTEventListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;

import javax.swing.JComponent;
import javax.swing.SwingUtilities;

/**
 * This is the glass pane class that intercepts screen interactions during
 * system busy states.
 * 
 * Based on JavaWorld article by Yexin Chen.
 */
public class GlassPane extends JComponent implements AWTEventListener {
    private final Window _window;

    public GlassPane(Window w) {
        _window = w;
        addMouseListener(new MouseAdapter() {});
        addKeyListener(new KeyAdapter() {});
        setCursor(Cursor.getPredefinedCursor(Cursor.WAIT_CURSOR));
    }

    /**
     * Receives all key events in the AWT and processes the ones that originated
     * from the current window with the glass pane.
     * 
     * @param event
     *            the AWTEvent that was fired
     */
    public void eventDispatched(AWTEvent event) {
        Object source = event.getSource();
        if (event instanceof KeyEvent
                && source instanceof Component) {
            /*
             * If the event originated from the window w/glass pane,
             * consume the event.
             */
            if ((SwingUtilities.windowForComponent((Component) source) == _window)) {
                ((KeyEvent) event).consume();
            }
        }
    }

    /**
     * Sets the glass pane as visible or invisible. The mouse cursor will be set
     * accordingly.
     */
    public void setVisible(boolean visible) {
        if (visible) {
            // Start receiving all events and consume them if necessary
            Toolkit.getDefaultToolkit().addAWTEventListener(this, AWTEvent.KEY_EVENT_MASK);
        } else {
            // Stop receiving all events
            Toolkit.getDefaultToolkit().removeAWTEventListener(this);
        }
        super.setVisible(visible);
    }
}