org.eclipse.jface.viewers
Interface ITreeContentProvider

All Superinterfaces:

IContentProvider, IStructuredContentProvider

All Known Implementing Classes:

WorkbenchContentProvider

public interface ITreeContentProvider

extends IStructuredContentProvider

An interface to content providers for tree-structure-oriented viewers.

See Also:

AbstractTreeViewer

Method Summary

Object[]	getChildren(Object parentElement) Returns the child elements of the given parent element.
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.

Methods inherited from interface org.eclipse.jface.viewers.IStructuredContentProvider

getElements

Methods inherited from interface org.eclipse.jface.viewers.IContentProvider

dispose, inputChanged

Method Detail

getChildren

public Object[] getChildren(Object parentElement)

Returns the child elements of the given parent element.

The difference between this method and IStructuredContentProvider.getElements is that getElements is called to obtain the tree viewer's root elements, whereas getChildren is used to obtain the children of a given parent element in the tree (including a root).

The result is not modified by the viewer.

Parameters:

parentElement - the parent element

Returns:

an array of child elements

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.

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.

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:

true if the given element has children, and false if it has no children