Swing Hacks

Mirror an Application #97

Chapter 12, Miscellany

|

489

HACK

AWTEvent.ACTION_EVENT_MASK |

AWTEvent.MOUSE_EVENT_MASK

);

}

First,

openSender( )

creates a new

ObjectOutputStream

around the socket’s

output stream. Next, it creates a new

AWTEventListener

that takes each event

and tests if it is a mouse event; if so, this method writes it to the output

stream. Notice that the second argument of

addAWTEventListener( ) is two

event masks ORed together (using the

| operator).

Receive Mouse Events

Receiving events is the reverse of sending them. You must open a server

socket for the (sending) instance to connect to, and then pull the events off

of the network one by one and repost them to the system event queue:

public void openReceiver( ) throws Exception {

// receive events

ServerSocket server = new ServerSocket(6754);

Socket sock = server.accept( );

EventQueue eq = Toolkit.getDefaultToolkit().getSystemEventQueue( );

ObjectInputStream in = new ObjectInputStream(sock.getInputStream( ));

while(true ) {

AWTEvent evt = (AWTEvent) in.readObject( );

if(evt instanceof MouseEvent) {

MouseEvent me = (MouseEvent)evt;

MouseEvent me2 = new MouseEvent(

me.getComponent( ),

me.getID( ),

me.getWhen( ),

me.getModifiers( ),

me.getX( ),

me.getY( ),

me.getClickCount( ),

me.isPopupTrigger( ),

me.getButton( )

);

eq.postEvent(me2);

}

}

}

Notice that the events are not posted directly to the event queue. Since the

objects really belong to the other instance, they won’t work in this instance

properly—all of the internal object references will be wrong. However, you

can make an exact copy of the event just by creating a new one with the

arguments from the old one. Then the new event will work fine in this sec-

ond instance.