Package Summary Overview Summary

class:TreeWillExpandListener [NONE]

All Superinterfaces:

EventListener
```
public interface TreeWillExpandListener
extends EventListener
```
The listener that's notified when a tree expands or collapses a node. For further information and examples see How to Write a Tree-Will-Expand Listener , a section in The Java Tutorial.

method:treeWillExpand(javax.swing.event.TreeExpansionEvent) [NONE]

treeWillExpand
```
void treeWillExpand(TreeExpansionEvent event)
             throws ExpandVetoException
```
Invoked whenever a node in the tree is about to be expanded.

Parameters:

event - a TreeExpansionEvent containing a TreePath object for the node

Throws:

ExpandVetoException - to signify expansion has been canceled

method:treeWillCollapse(javax.swing.event.TreeExpansionEvent) [NONE]

treeWillCollapse
```
void treeWillCollapse(TreeExpansionEvent event)
               throws ExpandVetoException
```
Invoked whenever a node in the tree is about to be collapsed.

Parameters:

event - a TreeExpansionEvent containing a TreePath object for the node

Throws:

ExpandVetoException - to signify collapse has been canceled

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