TreeExpansionListener (Java Platform SE 8 )

All Superinterfaces:

EventListener

All Known Implementing Classes:

BasicTreeUI.TreeExpansionHandler, JTree.AccessibleJTree
```
public interface TreeExpansionListener
extends EventListener
```
The listener that's notified when a tree expands or collapses a node. For further documentation and examples see How to Write a Tree Expansion Listener, a section in The Java Tutorial.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method and Description
`void`	`treeCollapsed(TreeExpansionEvent event)` Called whenever an item in the tree has been collapsed.
`void`	`treeExpanded(TreeExpansionEvent event)` Called whenever an item in the tree has been expanded.

- Method Detail
  - treeExpanded
```
void treeExpanded(TreeExpansionEvent event)
```
    Called whenever an item in the tree has been expanded.
  - treeCollapsed
```
void treeCollapsed(TreeExpansionEvent event)
```
    Called whenever an item in the tree has been collapsed.

Submit a bug or feature
For further API reference and developer documentation, see Java SE Documentation. That documentation contains more detailed, developer-targeted descriptions, with conceptual overviews, definitions of terms, workarounds, and working code examples.
Copyright © 1993, 2025, Oracle and/or its affiliates. All rights reserved. Use is subject to license terms. Also see the documentation redistribution policy.

Interface TreeExpansionListener

Method Summary

Method Detail

treeExpanded

treeCollapsed