/**
* Collapse the given fold if it's expanded and expand it if it's collapsed.
*
* <p><b>Note:</b> The hierarchy must be locked prior using of this method.
*
* @param f fold which state should be toggled.
*/
public void toggle(Fold f) {
if (f.isCollapsed()) {
expand(f);
} else { // expanded
collapse(f);
}
}
/**
* Expand the given fold. <br>
* Nothing is done if the fold is already expanded.
*
* <p><b>Note:</b> The hierarchy must be locked prior using of this method.
*
* @param f fold to be expanded.
*/
public void expand(Fold f) {
expand(Collections.singletonList(f));
}