org.eclipse.jface.viewers

Interface ITreeContentProvider

All Superinterfaces:

IContentProvider, IStructuredContentProvider

All Known Subinterfaces:

ICommonContentProvider, IPipelinedTreeContentProvider, IPipelinedTreeContentProvider2

All Known Implementing Classes:

AbstractSynchronizationContentProvider, BaseWorkbenchContentProvider, ObservableListTreeContentProvider, ObservableSetTreeContentProvider, PreferenceContentProvider, RefactoringHistoryContentProvider, SynchronizationContentProvider, TreeNodeContentProvider, WorkbenchContentProvider

public interface ITreeContentProvider
extends IStructuredContentProvider

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

See Also:

AbstractTreeViewer

Method Summary

Modifier and Type	Method and Description
Object[]	getChildren(Object parentElement) Returns the child elements of the given parent element.
Object[]	getElements(Object inputElement) Returns the elements to display in the viewer when its input is set to the given 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.IContentProvider

dispose, inputChanged

Method Detail

getElements

Object[] getElements(Object inputElement)

Returns the elements to display in the viewer when its input is set to the given element. These elements can be presented as rows in a table, items in a list, etc. The result is not modified by the viewer.

NOTE: The returned array must not contain the given inputElement, since this leads to recursion issues in AbstractTreeViewer (see bug 9262).

Specified by:

getElements in interface IStructuredContentProvider

Parameters:

inputElement - the input element

Returns:

the array of elements to display in the viewer

getChildren

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

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

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