import java.awt.Toolkit;
import java.awt.AWTEvent;
import java.awt.event.AWTEventListener;

import java.awt.event.MouseListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;

import javax.swing.SwingUtilities;
import javax.swing.SwingUtilities as SU;

/*
	Laurence Toenjes 2011-03-13
	
	This is a "crude" global JButton fix click solution, because:
		
		Sometimes when using internal frames, it takes
		two clicks on a button to get the actionPerformed
		code to fire.
		
	How to use (one call in app startup code):
		FixButtonClick.init()
*/

/*
	development settings to relax java security
	
	file: ${user.home}/.java.policy
	
		grant codeBase "file:///-" { permission java.security.AllPermission "java.security.AllPermission.*"; };
		grant codeBase "http://localhost/-" { permission java.security.AllPermission "java.security.AllPermission.*"; };

*/

class FixButtonClick {

	static private initialized = false;

	static synchronized def fixButtonClick( aButton ) {
		def sKey = 'has_fixButtonClick';
		def getValue = {
			if ( aButton.getClientProperty( sKey ) == null)
				aButton.putClientProperty( sKey, false );
			aButton.getClientProperty( sKey )
		}
		def hasFix = getValue() == true;
		if (hasFix)
			return;
		
		aButton.addMouseListener(
		
			new MouseAdapter() {
				void	 mousePressed(MouseEvent e) {
					if ( e.source.hasFocus() == false ) {
						e.source.doClick()
					}
				}	// end mousePressed
			} 	// end MouseAdapter
			
		);
		
		aButton.putClientProperty( sKey, true );
	}
	
	static synchronized def init() {
	
		if ( FixButtonClick.initialized == true )
			return;
		
		FixButtonClick.initialized = true;
		
		// Global Event Listener
		def gel = new AWTEventListener() {
			
			void eventDispatched(AWTEvent event) {
			
				def isJButton    = event.source instanceof javax.swing.JButton;
				def isMouseEvent = event instanceof java.awt.event.MouseEvent;
						
				if (isJButton && isMouseEvent) {
					
					def MOUSE_EN   = java.awt.event.MouseEvent.MOUSE_ENTERED
					def isMouseEntered = event.getID() == MOUSE_EN;
					
					if ( isMouseEntered ) {
						
						def r = new Runnable() {
								public void run() {
									FixButtonClick.fixButtonClick( event.source );
								}
						};
						
						if ( SU.isEventDispatchThread() ) {
							r.run();
						} 
						else {
							SU.invokeAndWait( r );
						}
						
					} // isMouseEntered
					
				} // isJButton && isMouseEvent
			}
		}
		
		def tk = Toolkit.getDefaultToolkit();
		def long mask
		// mask = Long.MAX_VALUE; // all events
		mask = AWTEvent.MOUSE_EVENT_MASK;
		tk.addAWTEventListener( gel, mask as long );
		
	} 	// end init
	
} 	// end class

Groovy Swing Fix Button Click : Ensure a single click fires actionPerformed

Groovy