Element: treenode.expand { }
Element: treenode.expand { }callback
A callback procedure invoked after treenode has been expanded. Expansion is done by double clicking on a node’s label, by single clicking on its expand symbol (a + sign), or by pressing the right arrow key when the node is selected. The + symbol changes to a - after expansion.
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.expand can be set, but mynode.expand may not.
<treenode>.expand(<treenode>)