package gve.calc.formula;

public interface ActivationListener {
	
 When deactivate() or activate() want to change the formula
	  tree structure (e.g. call formula.replace()), they first should check
	  if their FormulaView.isReplacing() returns false (indicating that
	  the formula is not in the middle of another replace() operation).
	  See IdentifierView.replace(). 
	public void deactivate();
	public void activate();
}