Package org.apache.tapestry5.tree

# Interface TreeExpansionModel<T>

All Known Implementing Classes:
  `DefaultTreeExpansionModel`

public interface TreeExpansionModel<T>
Tracks which nodes of a `TreeModel` are currently expanded. The default implementation simply stores a set of unique node ids to identify expanded nodes. The expansion model is updated whenever folders are expanded or collapsed on the client side.

Since:
  5.3
See Also:
  - `Tree`

- ## Method Summary

  Modifier and Type
  Method
  Description
  `void`
  `clear()`
  Marks all nodes as collapsed.
  `boolean`
  `isExpanded(TreeNode<T> node)`
  Returns true if the node has been previously expanded.
  `void`
  `markCollapsed(TreeNode<T> node)`
  Marks the node as collapsed (not expanded).
  `void`
  `markExpanded(TreeNode<T> node)`
  Marks the node as expanded.

- ## Method Details

  - ### isExpanded

    boolean isExpanded(TreeNode<T> node)
    Returns true if the node has been previously expanded.
    Parameters:
      `node` - node to check for expansion
    Returns:
      true if expanded

  - ### markExpanded

    void markExpanded(TreeNode<T> node)
    Marks the node as expanded.

  - ### markCollapsed

    void markCollapsed(TreeNode<T> node)
    Marks the node as collapsed (not expanded).

  - ### clear

    void clear()
    Marks all nodes as collapsed.