Package org.eclipse.ui.model

Class BaseWorkbenchContentProvider

java.lang.Object

org.eclipse.ui.model.BaseWorkbenchContentProvider

All Implemented Interfaces:

IContentProvider, IStructuredContentProvider, ITreeContentProvider

Direct Known Subclasses:

WorkbenchContentProvider

public class BaseWorkbenchContentProvider
extends Object
implements ITreeContentProvider

Tree content provider for objects that can be adapted to the interface IWorkbenchAdapter.

This class may be instantiated, or subclassed.

Since:

3.0

See Also:

• IWorkbenchAdapter

Constructor Summary

Constructors

Constructor	Description
BaseWorkbenchContentProvider()	Creates a new workbench content provider.

Method Summary

Modifier and Type	Method	Description
void	dispose()	Disposes of this content provider.
protected IWorkbenchAdapter	getAdapter(Object element)	Returns the implementation of IWorkbenchAdapter for the given object.
Object[]	getChildren(Object element)	Returns the child elements of the given parent element.
Object[]	getElements(Object element)	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.
void	inputChanged(Viewer viewer, Object oldInput, Object newInput)	Notifies this content provider that the given viewer's input has been switched to a different element.

Methods inherited from class java.lang.Object

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

Constructor Details

BaseWorkbenchContentProvider

public BaseWorkbenchContentProvider()

Creates a new workbench content provider.

Method Details

dispose

public void dispose()

Description copied from interface: IContentProvider

Disposes of this content provider. This is called by the viewer when it is disposed.

The viewer should not be updated during this call, as it is in the process of being disposed.

The default implementation does nothing.

Specified by:

dispose in interface IContentProvider

getAdapter

protected IWorkbenchAdapter getAdapter(Object element)

Returns the implementation of IWorkbenchAdapter for the given object. Returns null if the adapter is not defined or the object is not adaptable.

Parameters:

element - the element

Returns:

the corresponding workbench adapter object

getChildren

public Object[] getChildren(Object element)

Description copied from interface: ITreeContentProvider

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.

Specified by:

getChildren in interface ITreeContentProvider

Parameters:

element - the parent element

Returns:

an array of child elements

getElements

public Object[] getElements(Object element)

Description copied from interface: ITreeContentProvider

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

Specified by:

getElements in interface ITreeContentProvider

Parameters:

element - the input element

Returns:

the array of elements to display in the viewer

getParent

public Object getParent(Object element)

Description copied from interface: ITreeContentProvider

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.

Specified by:

getParent in interface ITreeContentProvider

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)

Description copied from interface: ITreeContentProvider

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.

Specified by:

hasChildren in interface ITreeContentProvider

Parameters:

element - the element

Returns:

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

inputChanged

public void inputChanged(Viewer viewer,
 Object oldInput,
 Object newInput)

Description copied from interface: IContentProvider

Notifies this content provider that the given viewer's input has been switched to a different element.

A typical use for this method is registering the content provider as a listener to changes on the new input (using model-specific means), and deregistering the viewer from the old input. In response to these change notifications, the content provider should update the viewer (see the add, remove, update and refresh methods on the viewers).

The viewer should not be updated during this call, as it might be in the process of being disposed.

The default implementation does nothing.

Specified by:

inputChanged in interface IContentProvider

Parameters:

viewer - the viewer

oldInput - the old input element, or null if the viewer did not previously have an input

newInput - the new input element, or null if the viewer does not have an input