behaviorDelegate and Vivoactive4

Hi all,

I surely miss something but don't find what...

I try to understand what function of a behaviorDelegate is called when I push the upper button of a vivoactive4. So I overload all functions of inputDelegate and behaviorDelegate and put a println.
But when I start the simulator and push the button : nothing in the log !!... Same for holding pressure on screen.

class APICallDelegate extends WatchUi.BehaviorDelegate {

    function initialize() {
        BehaviorDelegate.initialize();
    }

    function onKey(evt) {
        var key = evt.getKey();
        System.println("Evt = " + evt + ", key=" + key);      // e.g. CLICK_TYPE_TAP = 0
        return true;
    }

    function onTap(clickEvent) {
		System.println("arg1");
		if (Application.Properties.getValue("TapLaunch") || selected_action == null) {
			self.onKey(new Toybox.WatchUi.KeyEvent(KEY_ENTER, PRESS_TYPE_ACTION));
		}
        return true;
    }

function onNextMode() {
		System.println("arg3");
		return false;
	}
function onNextPage() {
		System.println("arg4");
		return false;
	}
function onPreviousMode() {
		System.println("arg5");
		return false;
	}
function onPreviousPage() {
		System.println("arg6");
		return false;
	}
function onSelect() {
		System.println("arg7");
		return false;
	}

function onKeyPressed(keyEvent) {
		System.println("arg8");
		return false;
	}
function onKeyReleased(keyEvent) {
		System.println("arg9");
		return false;
	}
function onRelease(clickEvent) {
		System.println("arg10");
		return false;
	}
function onSelectable(selectableEvent) {
		System.println("arg11");
		return false;
	}
function onSwipe(swipeEvent) {
		System.println("arg12");
		return false;
	}


	function onHold(clickEvent) {
		System.println("arg20");
		self.onMenu();

        return true;
	}
	
	function onMenu() {
		System.println("arg21");
        ...

        return true;
    }

	function onBack() {
		System.println("arg22");
    	System.exit();
    }