You can track this using each control SetOnTouchs methods if they have one, otherwise you can wrap your control in a spy layout that will capture the touch events:
function OnStart() {
var lay = app.CreateLayout( "Linear", "FillXY,VCenter" );
var laySpy = app.AddLayout( lay, "Linear", "TouchSpy" );
laySpy.SetOnTouchDown( laySpy_OnTouchDown );
var spin = app.AddSpinner( laySpy, "one,two,three", 0.5 );
spin.SetOnChange( spin_OnChange );
app.AddLayout( lay );
}
function laySpy_OnTouchDown() {
app.ShowPopup( "spinner touched down!", "Short" );
}
function spin_OnChange( item ) {
app.Alert( item, "Spinner item" );
}