ilog.views

Class IlvBufferedGraphicEnumeration

java.lang.Object

ilog.views.IlvBufferedGraphicEnumeration

All Implemented Interfaces:

IlvGraphicEnumeration

public class IlvBufferedGraphicEnumeration
extends Object
implements IlvGraphicEnumeration

A class used to enumerate graphic objects (IlvGraphic) in a buffered way. Unless explicitly specified, all graphic enumerations delivered by JViews classes are unbuffered, hence they do not allow concurrent modifications. For instance, if you enumerate the objects contained in a layer while adding or removing objects of the same layer, a ConcurrentModificationException is thrown. By adding or removing objects while enumerating, the enumeration itself would reach an undefined state. For instance, the following example is incorrect:

 IlvGraphicEnumeration e = manager.getObjects();
 while (e.hasMoreElements()) {
   // it is not allowed to remove objects while enumerating in unbuffered way
   manager.removeObject(e.nextElement(), true);
 }
 

However, if you use a buffered enumeration, all objects are first copied into a buffer, and you enumerate only over the objects in the buffer. In this case, you can add and remove objects safely while enumerating. The following example is correct:

 IlvGraphicEnumeration e = new IlvBufferedGraphicEnumeration(manager.getObjects());
 while (e.hasMoreElements()) {
   // it is safe to remove objects while enumerating in buffered way
   manager.removeObject(e.nextElement(), true);
 }
 

Note that when using IlvBufferedGraphicEnumeration, you enumerate the objects that were present at the time point when the enumeration was allocated. If you add an object later while enumerating, the object will not appear in the enumeration because it was not present in the enumeration when the enumeration was allocated.

Since:

JViews 8.5

See Also:

IlvGraphicEnumeration

Constructor Summary

Constructors

Constructor and Description
IlvBufferedGraphicEnumeration(IlvGraphicEnumeration e) Creates a new IlvBufferedGraphicEnumeration.

Method Summary

Modifier and Type	Method and Description
boolean	hasMoreElements() Tests if the enumeration contains more elements.
IlvGraphic	nextElement() Returns the next graphic object of the enumeration.

Methods inherited from class java.lang.Object

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

Constructor Detail

IlvBufferedGraphicEnumeration

public IlvBufferedGraphicEnumeration(IlvGraphicEnumeration e)

Creates a new IlvBufferedGraphicEnumeration.

Parameters:

e - The graphic enumeration you want to be buffered.

Method Detail

hasMoreElements

public boolean hasMoreElements()

Tests if the enumeration contains more elements.

Specified by:

hasMoreElements in interface IlvGraphicEnumeration

nextElement

public IlvGraphic nextElement()

Returns the next graphic object of the enumeration. Calling this method will enumerate successive elements.

Specified by:

nextElement in interface IlvGraphicEnumeration

Throws:

NoSuchElementException - if there are no more existing elements.