treeExpansionListener
Runs onExpansionChange whenever a node of the tree opens or closes. Requires a javax.swing.JTree target.
Return
this chain with the expansion callback declared on it.
Parameters
receives the event, whose path is the node that opened or closed; it is read when the event fires.
See also
Runs onTreeExpanded when a node opens and onTreeCollapsed when one closes. Requires a javax.swing.JTree target. A direction left undeclared reports nowhere.
Each lambda is read when its event fires, so writing a fresh one on every recomposition registers nothing again.
Declaring none at all is refused.
Return
this chain with the expansion callbacks declared on it.
Parameters
runs once the node's children are showing.
runs once they are hidden; the subtree keeps the expansion it had, and shows it again when the node reopens.
See also
Attaches a TreeExpansionListener (addTreeExpansionListener/removeTreeExpansionListener). Requires a javax.swing.JTree target.
Return
this chain with the expansion listener declared on it.
Parameters
attached by identity, so a remembered instance stays put while a fresh one on every pass is detached and re-added.