Eclipse Platform
Release 3.4

org.eclipse.jface.databinding.viewers
Class TreeStructureAdvisor

java.lang.Object
  extended byorg.eclipse.jface.databinding.viewers.TreeStructureAdvisor

public abstract class TreeStructureAdvisor
extends Object

Instances of this class can be used to improve accuracy and performance of an ObservableListTreeContentProvider or an ObservableSetTreeContentProvider. This class is intended to be subclassed by clients.

Since:
1.2

Constructor Summary
TreeStructureAdvisor()
           
 
Method Summary
 Object getParent(Object element)
          Returns the parent for the given element, or null indicating that the parent can't be computed.
 Boolean hasChildren(Object element)
          Returns whether the given element has children, or null if the actual children collection should be consulted.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

TreeStructureAdvisor

public TreeStructureAdvisor()
Method Detail

getParent

public Object getParent(Object element)
Returns the parent for the given element, or null indicating that the parent can't be computed. In this case the tree-structured viewer can't expand a given node correctly if requested. The default implementation returns null; clients should override.

Parameters:
element - the element
Returns:
the parent element, or null if it has none or if the parent cannot be computed

hasChildren

public Boolean hasChildren(Object element)
Returns whether the given element has children, or null if the actual children collection should be consulted. The default implementation returns null; clients should override.

Intended as an optimization for when the viewer does not need the actual children. Clients may be able to implement this more efficiently than getChildren.

Parameters:
element - the element
Returns:
Boolean.TRUE if the given element has children, Boolean.FALSE if it has no children, or null if the children collection should be consulted.

Eclipse Platform
Release 3.4

Guidelines for using Eclipse APIs.

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