Swing Action with JTree

Question

As developing a Swing application I use Action rather than Listener. I have an action which is usually triggered from AbstractButtons but now I need to trigger it as well when selecting a JTree node.

Since the TreeSelectionModel does not support Actions I am wondering what the best practice would be to archive this.

Until now I just came up with the idea to implement a generalized method which is invoked from actionPerformed(ActionEvent) and as well from addTreeSelectionListener(TreeSelectListener).

Anyone who has a better idea?

Answer 1

This seems like it might increase coupling between your TreeModel and its view component, JTree. As Action instances are often used in key bindings, it may help to review the existing actions defined for common Look & Feel implementations, as shown in @camickr's article Key Bindings. These actions can be evoked from your TreeSelectionListener, as shown in this example that leverages scroll pane actions.

Addendum: For reference, javax.swing.plaf.metal.MetalLookAndFeel defines these JTree actions and bindings.

Action                        Focused                                             Ancestor
------                        ------                                              -------
addToSelection                SPACE
cancel                                                                            ESCAPE
clearSelection                ctrl BACK_SLASH
collapse                      SUBTRACT
copy                          ctrl INSERT, ctrl C, COPY
cut                           CUT, shift DELETE, ctrl X
expand                        ADD
extendTo                      shift SPACE
moveSelectionTo               shift ctrl SPACE
moveSelectionToParent
paste                         shift INSERT, ctrl V, PASTE
scrollDownChangeLead          ctrl PAGE_DOWN
scrollDownChangeSelection     PAGE_DOWN
scrollDownExtendSelection     shift ctrl PAGE_DOWN, shift PAGE_DOWN
scrollLeft                    ctrl LEFT, ctrl KP_LEFT
scrollLeftChangeLead
scrollLeftExtendSelection
scrollRight                   ctrl RIGHT, ctrl KP_RIGHT
scrollRightChangeLead
scrollRightExtendSelection
scrollUpChangeLead            ctrl PAGE_UP
scrollUpChangeSelection       PAGE_UP
scrollUpExtendSelection       shift PAGE_UP, shift ctrl PAGE_UP
selectAll                     ctrl SLASH, ctrl A
selectChild                   RIGHT, KP_RIGHT
selectChildChangeLead
selectFirst                   HOME
selectFirstChangeLead         ctrl HOME
selectFirstExtendSelection    shift HOME, shift ctrl HOME
selectLast                    END
selectLastChangeLead          ctrl END
selectLastExtendSelection     shift END, shift ctrl END
selectNext                    DOWN, KP_DOWN
selectNextChangeLead          ctrl DOWN, ctrl KP_DOWN
selectNextExtendSelection     shift ctrl DOWN, shift DOWN, shift ctrl KP_DOWN, shift KP_DOWN
selectParent                  LEFT, KP_LEFT
selectParentChangeLead
selectPrevious                KP_UP, UP
selectPreviousChangeLead      ctrl UP, ctrl KP_UP
selectPreviousExtendSelection shift UP, shift KP_UP, shift ctrl UP, shift ctrl KP_UP
startEditing                  F2
toggle
toggleAndAnchor               ctrl SPACE