void () { if (myTargetOperation != null) { if (myContext.isMove()) { setExecuteEnabled(myContext.isMoveEnabled() && myTargetOperation.canExecute()); } else if (myContext.isAdd()) { setExecuteEnabled(myContext.isAddEnabled() && myTargetOperation.canExecute()); } else { setExecuteEnabled(false); } } else { setExecuteEnabled(false); } }