Class TreeStructureAdvisor<E>

java.lang.Object
org.eclipse.jface.databinding.viewers.TreeStructureAdvisor<E>
Type Parameters:
E - type of the elements in the tree

public abstract class TreeStructureAdvisor<E> 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 Details

    • TreeStructureAdvisor

      public TreeStructureAdvisor()
  • Method Details

    • getParent

      public E getParent(E 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(E 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 the given element never has children, or null if the children collection should be consulted.