Chapter 19
java.awt Reference

EventQueue

Name

EventQueue (New)

[Graphic: Figure from the text]

Description

The EventQueue class is a facility for queuing Java 1.1 AWT events, either for the system or for some other purpose. You rarely need to create your own event queue; for most purposes, you will want to work with the system's event queue, which you acquire using the Toolkit.

Class Definition

public class EventQueue extends Object {
  // Constructor
  public EventQueue();
  // Instance Methods
  public synchronized AWTEvent getNextEvent() throws InterruptedException;
  public synchronized AWTEvent peekEvent();
  public synchronized AWTEvent peekEvent (int id);
  public synchronized void postEvent (AWTEvent theEvent);
}

Constructor

EventQueue

public EventQueue()

Description: Creates an EventQueue for your own use.

Instance Methods

getNextEvent

public synchronized AWTEvent getNextEvent() throws InterruptedException

Throws

InterruptedException: If the thread is interrupted before an event is posted to the queue.

Returns

AWTEvent taken from the event queue.

Description

Removes the next event from the event queue and returns it. If there are no events in the queue, this method will block until another thread posts one.

peekEvent

public synchronized AWTEvent peekEvent()

Returns

Next AWTEvent on the event queue.

Description

Returns a reference to the next event on the queue without removing it from the queue.

public synchronized AWTEvent peekEvent (int id)

Parameters

id: Type of event to find.

Returns

AWTEvent with the given type id; null if no event with the given type is currently in the queue.

Description

Returns an event with the given type if one exists, but doesn't remove the event from the queue.