Control interaction in VSTGUI4

Developer VSTGUI
3

Does not work as i’d expect it todo. I did the following:

// from EOSXController.h
class EOSXController : public EditController, VSTGUI::VST3EditorDelegate,
	IController
{
	// … //
	virtual IController* createSubController(UTF8StringPtr name,
		const IUIDescription* description, VST3Editor* editor) SMTG_OVERRIDE
		{return this;}
	virtual void valueChanged(CControl* pControl) SMTG_OVERRIDE;
}

My controller now derives from VST3EditorDelegate and IController. I implemented valueChanged like this:

// from EOSXController.cpp
void EOSXController::valueChanged(CControl* pControl)
{
	COnOffButton* pBtn = dynamic_cast<COnOffButton*>(pControl);
	if (pBtn == nullptr)
		return;
	pBtn->setBackground(pBtn->getDisabledBackground());
	pBtn->setDirty(true);
}

So when clicking on the button, the bitmap should change to DisabledBackground. But nothing happens.