Tree Events: View Changes

The TreeExpansionListener Class lets us catch:

changes in Tree expansion/collapse

Useful methods include:

public TreePath getPath();

TreeWillExpandListener interface:

* new to JDK 1.2 Beta 4

* allows access to events before

they take place

* allows one to prep the tree before

expansion/collapse

ExpandVetoException Class

-- blocks impending TreeExpansionEvent

The TreeModelListener interface imposes two methods:

public void treeExpanded

(TreeExpansionEvent e);

public void treeCollapsed

(TreeExpansionEvent e);