net.sourceforge.jsh3modtool.gui.imagetable.cache
Class Queue

java.lang.Object
  net.sourceforge.jsh3modtool.gui.imagetable.cache.Queue

public class Queue
extends java.lang.Object

Active queue that threads can listen on item addition and/or removal of items.

Author:

erma

Field Summary

protected java.util.Vector	listeners
protected int	numberOfAvailablePlaces
protected java.util.Vector	queueItems

Constructor Summary

Queue()
Creates a new instance of Queue

Queue(int numberOfPlaces)
Creates a new instance of Queue

Method Summary

boolean	add(QueueItem item) Adds the specified item to the queue.
protected boolean	add(QueueItem item, int index)
boolean	addFirst(QueueItem item) Adds the specified item to the end of the queue.
boolean	addLast(QueueItem item) Adds the specified item to the end of the queue.
void	addListener(QueueListener listener) Add a QueueListener to this object
protected void	fireAdditionEvent() Fire event that there is a new item in the queue
protected void	fireItemAdded(QueueItem item) Notify all listeners that an item has been added
protected void	fireItemRemoved(QueueItem item) Notify all listeners that an item has been removed
protected void	fireRemovalEvent() Fire event that there is one less item in the queue
QueueItem	getFirst() Returns the first item in the queue
QueueItem	getLast() Returns the last item in the queue
boolean	isEmpty() Returns if the queue is empty.
protected QueueItem	remove(int index) Remove the item at the specified index and return it.
QueueItem	remove(QueueItem item) Removes the queueitem from the queue
void	removeAll() Removes all items in the queue
QueueItem	removeFirst() Removes the first item and returns it.
QueueItem	removeLast() Removes the last item and returns it.
void	removeListener(QueueListener listener) Remove a QueueListener from this object
int	size() Returns the size of the queue
boolean	waitForEmptyQueue() Waits until the queue is empty for the specified timeout time This method behaves exactly as if it simply performs the call waitForEmptyQueue(0)
boolean	waitForEmptyQueue(long timeout) Waits until the queue is empty for the specified timeout time
boolean	waitForEmptySpace() Waits until there is an available place in the queue.
boolean	waitForEmptySpace(long timeout) Waits until there is an available place in the queue for the specified timeout time
boolean	waitForFirstObject() Waits until there is an object in the queue
boolean	waitForFirstObject(long timeout) Waits until there is an object in the queue for the specified timeout time

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

listeners

protected java.util.Vector listeners

numberOfAvailablePlaces

protected int numberOfAvailablePlaces

queueItems

protected java.util.Vector queueItems

Constructor Detail

Queue

public Queue()

Creates a new instance of Queue

Queue

public Queue(int numberOfPlaces)

Creates a new instance of Queue

Parameters:

numberOfPlaces - Maximum capacity

Method Detail

waitForFirstObject

public boolean waitForFirstObject()

Waits until there is an object in the queue

Returns:

false if this wait() (thread) was interrupted; true otherwise

waitForFirstObject

public boolean waitForFirstObject(long timeout)

Waits until there is an object in the queue for the specified timeout time

Parameters:

timeout - the maximum time to wait in milliseconds.

Returns:

false if this wait() (thread) was interrupted; true otherwise

waitForEmptySpace

public boolean waitForEmptySpace()

Waits until there is an available place in the queue. This method behaves exactly as if it simply performs the call waitForEmptySpace(0)

Returns:

false if this wait() (thread) was interrupted; true otherwise

waitForEmptySpace

public boolean waitForEmptySpace(long timeout)

Waits until there is an available place in the queue for the specified timeout time

Parameters:

timeout - the maximum time to wait in milliseconds.

Returns:

false if this wait() (thread) was interrupted; true otherwise

waitForEmptyQueue

public boolean waitForEmptyQueue()

Waits until the queue is empty for the specified timeout time This method behaves exactly as if it simply performs the call waitForEmptyQueue(0)

Returns:

false if this wait() (thread) was interrupted; true otherwise

waitForEmptyQueue

public boolean waitForEmptyQueue(long timeout)

Waits until the queue is empty for the specified timeout time

Parameters:

timeout - the maximum time to wait in milliseconds.

Returns:

false if this wait() (thread) was interrupted; true otherwise

fireAdditionEvent

protected void fireAdditionEvent()

Fire event that there is a new item in the queue

fireRemovalEvent

protected void fireRemovalEvent()

Fire event that there is one less item in the queue

add

public boolean add(QueueItem item)

Adds the specified item to the queue.

Parameters:

item - the item to add

Returns:

true if it was sucessfully added; false if there was no place.

addLast

public boolean addLast(QueueItem item)

Adds the specified item to the end of the queue.

Parameters:

item - the item to add

Returns:

true if it was sucessfully added; false if there was no place.

addFirst

public boolean addFirst(QueueItem item)

Adds the specified item to the end of the queue.

Parameters:

item - the item to add

Returns:

true if it was sucessfully added; false if there was no place.

add

protected boolean add(QueueItem item,
                      int index)

removeAll

public void removeAll()

Removes all items in the queue

remove

protected QueueItem remove(int index)

Remove the item at the specified index and return it.

Parameters:

index - the item index to remove

Returns:

the removed item

remove

public QueueItem remove(QueueItem item)

Removes the queueitem from the queue

Parameters:

item - the item to remove from the queue

Returns:

the removed item; null if there wasnt such item in the queue

removeFirst

public QueueItem removeFirst()

Removes the first item and returns it.

Returns:

the removed item; null if there was no items in the queue

removeLast

public QueueItem removeLast()

Removes the last item and returns it.

Returns:

the removed item; null if there was no items in the queue

getFirst

public QueueItem getFirst()

Returns the first item in the queue

Returns:

the first item; null if the queue was empty

getLast

public QueueItem getLast()

Returns the last item in the queue

Returns:

the last item; null if the queue was empty

size

public int size()

Returns the size of the queue

Returns:

the size of the queue

isEmpty

public boolean isEmpty()

Returns if the queue is empty.

Returns:

if the queue is empty.

addListener

public void addListener(QueueListener listener)

Add a QueueListener to this object

Parameters:

listener - the listener

removeListener

public void removeListener(QueueListener listener)

Remove a QueueListener from this object

Parameters:

listener - the listener

fireItemAdded

protected void fireItemAdded(QueueItem item)

Notify all listeners that an item has been added

Parameters:

item - the item

fireItemRemoved

protected void fireItemRemoved(QueueItem item)

Notify all listeners that an item has been removed

Parameters:

item - the item