ModalFrameUtil.java Source code

Introduction

Here is the source code for ModalFrameUtil.java

Source

import java.awt.Frame;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

import javax.swing.JFrame;

// @author Santhosh Kumar T - santhosh@in.fiorano.com 
public class ModalFrameUtil {
    static class EventPump implements InvocationHandler {
        Frame frame;

        public EventPump(Frame frame) {
            this.frame = frame;
        }

        public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
            return frame.isShowing();
        }

        // when the reflection calls in this method has to be
        // replaced once Sun provides a public API to pump events.
        public void start() throws Exception {
            Class<?> clazz = Class.forName("java.awt.Conditional");
            Object conditional = Proxy.newProxyInstance(clazz.getClassLoader(), new Class[] { clazz }, this);
            Method pumpMethod = Class.forName("java.awt.EventDispatchThread").getDeclaredMethod("pumpEvents",
                    new Class[] { clazz });
            pumpMethod.setAccessible(true);
            pumpMethod.invoke(Thread.currentThread(), new Object[] { conditional });
        }
    }

    // show the given frame as modal to the specified owner.
    // NOTE: this method returns only after the modal frame is closed.
    public static void showAsModal(final Frame frame, final Frame owner) {
        frame.addWindowListener(new WindowAdapter() {
            public void windowOpened(WindowEvent e) {
                owner.setEnabled(false);
            }

            public void windowClosing(WindowEvent e) {
                owner.setEnabled(true);
                frame.removeWindowListener(this);
            }

            public void windowClosed(WindowEvent e) {
                owner.setEnabled(true);
                frame.removeWindowListener(this);
            }
        });

        owner.addWindowListener(new WindowAdapter() {
            public void windowActivated(WindowEvent e) {
                if (frame.isShowing()) {
                    frame.setExtendedState(JFrame.NORMAL);
                    frame.toFront();
                } else {
                    owner.removeWindowListener(this);
                }
            }
        });

        frame.setVisible(true);
        try {
            new EventPump(frame).start();
        } catch (Throwable throwable) {
            throw new RuntimeException(throwable);
        }
    }
}