Element: treenode.contract { }
Element: treenode.contract { }callback
A callback procedure invoked after treenode has been contracted. Contraction is done by double clicking on a node’s label, by single clicking on its contract symbol (a - sign), or by pressing the left arrow key when the node is selected. The - symbol changes to a + after contraction.
This procedure is a class procedure so can only be set via a treenode class name not via a treenode instance name, e.g. if a treenode "mynode" is of class "database_t", then database_t.contract can be set, but mynode.contract may not.
<treenode>.contract(<treenode>)