QueueListener

Type Parameters:

T - The type of object stored in this queue.

All Known Implementing Classes:

QueueListener.Adapter, QueueListener.Listeners
```
public interface QueueListener<T>
```
Queue listener interface.

Nested Class Summary

Nested Classes
Modifier and Type	Interface	Description
`static class`	`QueueListener.Adapter<T>`	Deprecated. Since 2.1 and Java 8 the interface itself has default implementations.
`static class`	`QueueListener.Listeners<T>`	Queue listeners.

Method Summary

All Methods Instance Methods Default Methods
Modifier and Type	Method	Description
`default void`	`comparatorChanged(Queue<T> queue, java.util.Comparator<T> previousComparator)`	Called when a queue's comparator has changed.
`default void`	`itemDequeued(Queue<T> queue, T item)`	Called when an item has been removed from the head of a queue.
`default void`	`itemEnqueued(Queue<T> queue, T item)`	Called when an item has been inserted into the tail of a queue.
`default void`	`queueCleared(Queue<T> queue)`	Called when a queue has been cleared.

- Method Detail
  - itemEnqueued
```
default void itemEnqueued(Queue<T> queue,
                          T item)
```
    Called when an item has been inserted into the tail of a queue.
    
    Parameters:
    
    queue - The queue that has been modified.
    
    item - The item that was just added to the queue.
  - itemDequeued
```
default void itemDequeued(Queue<T> queue,
                          T item)
```
    Called when an item has been removed from the head of a queue.
    
    Parameters:
    
    queue - The queue in question.
    
    item - The item that was just removed from the head of the queue.
  - queueCleared
```
default void queueCleared(Queue<T> queue)
```
    Called when a queue has been cleared.
    
    Parameters:
    
    queue - The newly cleared queue object.
  - comparatorChanged
```
default void comparatorChanged(Queue<T> queue,
                               java.util.Comparator<T> previousComparator)
```
    Called when a queue's comparator has changed.
    
    Parameters:
    
    queue - The queue that changed.
    
    previousComparator - Previous value of the queue's comparator (if any).