Package org.eclipse.jface.databinding.viewers

Class TreeStructureAdvisor<E>

  • Type Parameters:
    E - type of the elements in the tree
    public abstract class TreeStructureAdvisor<E>
extends java.lang.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

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      E getParent​(E element)
      Returns the parent for the given element, or null indicating that the parent can't be computed.
      java.lang.Boolean hasChildren​(E element)
      Returns whether the given element has children, or null if the actual children collection should be consulted.

      • Methods inherited from class java.lang.Object

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

    • Constructor Detail

      • TreeStructureAdvisor

        public TreeStructureAdvisor()

    • Method Detail

      • 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 java.lang.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.