Package org.eclipse.jface.databinding.viewers

Class ObservableSetTreeContentProvider<E>

java.lang.Object
org.eclipse.jface.databinding.viewers.ObservableSetTreeContentProvider<E>
Type Parameters:
E - type of the values that are provided by this object
All Implemented Interfaces:
IContentProvider, IStructuredContentProvider, ITreeContentProvider
public class ObservableSetTreeContentProvider<E> extends Object implements ITreeContentProvider
An ITreeContentProvider for use with an AbstractTreeViewer, which uses the provided set factory to obtain the elements of a tree. Objects of this class listen for changes to each IObservableSet created by the factory, and will insert and remove viewer elements to reflect the observed changes.
Since:
1.2
Restriction:
This class is not intended to be subclassed by clients.

  • Constructor Details

    • ObservableSetTreeContentProvider

      public ObservableSetTreeContentProvider(IObservableFactory<? super E,? extends IObservableSet<E>> setFactory, TreeStructureAdvisor<E> structureAdvisor)
      Constructs an ObservableListTreeContentProvider using the given list factory. Must be called from the display thread.
      Parameters:
      setFactory - observable factory that produces an IObservableSet of children for a given parent element. Observable sets created by this factory must be on the realm of the current display.
      structureAdvisor - an advisor that will be consulted from the implementations of the getParent(Object) and hasChildren(Object) methods, or null if no advisor is available. It is recommended that clients pass a non-null advisor if they can provide additional structural information about the tree.

  • Method Details

    • 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

    • getElements

      public Object[] getElements(Object inputElement)
      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:
      inputElement - the input element
      Returns:
      the array of elements to display in the viewer

    • 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

    • getChildren

      public Object[] getChildren(Object parentElement)
      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:
      parentElement - the parent element
      Returns:
      an array of child elements

    • 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

    • dispose

      public void dispose()
      Disposes of this content provider. This is called by the viewer when a content provider is replaced, or when the viewer itself is disposed.

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

      Note: Data binding content providers become unusable on disposal.

      Specified by:
      dispose in interface IContentProvider

    • getKnownElements

      public IObservableSet<E> getKnownElements()
      Returns the set of elements known to this content provider. Label providers may track this set if they need to be notified about additions before the viewer sees the added element, and notified about removals after the element was removed from the viewer. This is intended for use by label providers, as it will always return the items that need labels.
      Returns:
      readableSet of items that will need labels

    • getRealizedElements

      public IObservableSet<E> getRealizedElements()
      Returns the set of known elements which have been realized in the viewer. Clients may track this set in order to perform custom actions on elements while they are known to be present in the viewer.
      Returns:
      the set of known elements which have been realized in the viewer.
      Since:
      1.3