public abstract void onHeightChange(Component component, double existingValue, double newValue, Object eOpts);
// Called from JSNI
private final void fireOnEvent(Component component, double existingValue, double newValue, Object eOpts) {
UncaughtExceptionHandler handler = GWT.getUncaughtExceptionHandler();
if (handler != null) {
fireOnEventAndCatch(component, existingValue, newValue, eOpts, handler);
} else {
onHeightChange(component, existingValue, newValue, eOpts);
}