/** Do the last entry that was undone again. */
public void redo() {
if (canRedo()) {
final HistoryAction entry = redoList.removeLast();
entry.redo();
undoList.addLast(entry);
}
}
/** Undo the last entry that was added to this history. */
public void undo() {
if (canUndo()) {
final HistoryAction entry = undoList.removeLast();
entry.undo();
redoList.addLast(entry);
}
}
/** Executes the action-list and changes the status */
public void execute() {
if (_actions.size() == 0) return;
int type = ((HistoryAction) _actions.get(0))._actionType;
if (type == HistoryAction.UNDO) {
// we have to walk backwards because the actions have to be undone in
// the opposite order
ListIterator it = _actions.listIterator(_actions.size());
while (it.hasPrevious()) {
HistoryAction action = (HistoryAction) it.previous();
action.performAction();
}
} else {
Iterator it = _actions.iterator();
while (it.hasNext()) {
HistoryAction action = (HistoryAction) it.next();
action.performAction();
}
}
}