org.apache.velocity.tools.generic
Class LoopTool.ManagedIterator

java.lang.Object
  extended by org.apache.velocity.tools.generic.LoopTool.ManagedIterator
All Implemented Interfaces:
java.util.Iterator
Enclosing class:
LoopTool

public static class LoopTool.ManagedIterator
extends java.lang.Object
implements java.util.Iterator

Iterator implementation that wraps a standard Iterator and allows it to be prematurely stopped, skipped ahead, and associated with a name for advanced nested loop control. This also allows a arbitrary LoopTool.ActionConditions to be added in order to have it automatically skip over or stop before certain elements in the iterator.


Field Summary
private  java.util.List<LoopTool.ActionCondition> conditions
           
private  int count
           
private  java.lang.Boolean first
           
private  java.util.Iterator iterator
           
private  java.lang.String name
           
private  java.lang.Object next
           
private  LoopTool owner
           
private  boolean stopped
           
private  java.util.Map<java.lang.String,LoopTool.SyncedIterator> synced
           
 
Constructor Summary
LoopTool.ManagedIterator(java.lang.String name, java.util.Iterator iterator, LoopTool owner)
           
 
Method Summary
private  boolean cacheNext(boolean popWhenDone)
           
 LoopTool.ManagedIterator condition(LoopTool.ActionCondition condition)
          Adds a new LoopTool.ActionCondition for this instance to check against the elements in the iterator being managed.
 LoopTool.ManagedIterator exclude(java.lang.Object compare)
          Directs this instance to completely exclude any elements equal to the specified Object.
 java.lang.Object get(java.lang.String name)
          Returns the parallel value from the specified sync'ed iterator.
 int getCount()
          Returns the number of elements returned by next() so far.
 java.lang.String getName()
          Returns the name of this instance.
 boolean hasNext()
          Returns true if there are more elements in the iterator being managed by this instance which satisfy all the LoopTool.ActionConditions set for this instance.
private  boolean hasNext(boolean popWhenDone)
           
 boolean isFirst()
          Returns true if either 0 or 1 elements have been returned by next().
 boolean isLast()
          Returns true if the last element returned by next() is the last element available in the iterator being managed which satisfies any/all LoopTool.ActionConditions set for this instance.
 boolean isSyncedWith(java.lang.String name)
          Returns true if this ManagedIterator has a sync'ed iterator with the specified name.
 java.lang.Object next()
          Returns the next element that meets the set LoopTool.ActionConditions (if any) in the iterator being managed.
 void remove()
          This operation is unsupported.
private  void shiftSynced()
           
 void stop()
          Stops this iterator from doing any further iteration.
 LoopTool.ManagedIterator stop(java.lang.Object compare)
          Directs this instance to stop iterating immediately prior to any element equal to the specified Object.
 LoopTool.ManagedIterator sync(java.lang.Object iterable)
          Adds another iterator to be kept in sync with the one being managed by this instance.
 LoopTool.ManagedIterator sync(java.lang.Object iterable, java.lang.String name)
          Adds another iterator to be kept in sync with the one being managed by this instance.
 java.lang.String toString()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 

Field Detail

name

private java.lang.String name

iterator

private java.util.Iterator iterator

owner

private LoopTool owner

stopped

private boolean stopped

first

private java.lang.Boolean first

count

private int count

next

private java.lang.Object next

conditions

private java.util.List<LoopTool.ActionCondition> conditions

synced

private java.util.Map<java.lang.String,LoopTool.SyncedIterator> synced
Constructor Detail

LoopTool.ManagedIterator

public LoopTool.ManagedIterator(java.lang.String name,
                                java.util.Iterator iterator,
                                LoopTool owner)
Method Detail

getName

public java.lang.String getName()
Returns the name of this instance.


isFirst

public boolean isFirst()
Returns true if either 0 or 1 elements have been returned by next().


isLast

public boolean isLast()
Returns true if the last element returned by next() is the last element available in the iterator being managed which satisfies any/all LoopTool.ActionConditions set for this instance. Otherwise, returns false.


hasNext

public boolean hasNext()
Returns true if there are more elements in the iterator being managed by this instance which satisfy all the LoopTool.ActionConditions set for this instance. Returns false if there are no more valid elements available.

Specified by:
hasNext in interface java.util.Iterator

hasNext

private boolean hasNext(boolean popWhenDone)

cacheNext

private boolean cacheNext(boolean popWhenDone)

shiftSynced

private void shiftSynced()

isSyncedWith

public boolean isSyncedWith(java.lang.String name)
Returns true if this ManagedIterator has a sync'ed iterator with the specified name.


get

public java.lang.Object get(java.lang.String name)
Returns the parallel value from the specified sync'ed iterator. If no sync'ed iterator exists with that name or that iterator is finished, this will return null.


getCount

public int getCount()
Returns the number of elements returned by next() so far.


next

public java.lang.Object next()
Returns the next element that meets the set LoopTool.ActionConditions (if any) in the iterator being managed. If there are none left, then this will throw a NoSuchElementException.

Specified by:
next in interface java.util.Iterator

remove

public void remove()
This operation is unsupported.

Specified by:
remove in interface java.util.Iterator

stop

public void stop()
Stops this iterator from doing any further iteration.


exclude

public LoopTool.ManagedIterator exclude(java.lang.Object compare)
Directs this instance to completely exclude any elements equal to the specified Object.

Returns:
This same LoopTool.ManagedIterator instance

stop

public LoopTool.ManagedIterator stop(java.lang.Object compare)
Directs this instance to stop iterating immediately prior to any element equal to the specified Object.

Returns:
This same LoopTool.ManagedIterator instance

condition

public LoopTool.ManagedIterator condition(LoopTool.ActionCondition condition)
Adds a new LoopTool.ActionCondition for this instance to check against the elements in the iterator being managed.

Returns:
This same LoopTool.ManagedIterator instance

sync

public LoopTool.ManagedIterator sync(java.lang.Object iterable)

Adds another iterator to be kept in sync with the one being managed by this instance. The values of the parallel iterator can be retrieved from the LoopTool under the name s"synced" (e.g. $loop.synched or $loop.get('synced')) and are automatically updated for each iteration by this instance.

NOTE: if you are sync'ing multiple iterators with the same managed iterator, you must use sync(Object,String) or else your the later iterators will simply replace the earlier ones under the default 'synced' key.

Returns:
This same LoopTool.ManagedIterator instance
See Also:
LoopTool.SyncedIterator, get(String)

sync

public LoopTool.ManagedIterator sync(java.lang.Object iterable,
                                     java.lang.String name)
Adds another iterator to be kept in sync with the one being managed by this instance. The values of the parallel iterator can be retrieved from the LoopTool under the name specified here (e.g. $loop.name or $loop.get('name')) and are automatically updated for each iteration by this instance.

Returns:
This same LoopTool.ManagedIterator instance
See Also:
LoopTool.SyncedIterator, get(String)

toString

public java.lang.String toString()
Overrides:
toString in class java.lang.Object


Copyright (c) 2003-2007 Apache Software Foundation