typedef Signal< bool (const KeyEvent&) > KeyEventGeneratedSignalType;
typedef Signal< void (const TouchData&) > TouchSignalType;
typedef Signal< void (const WheelEvent&) > WheelEventSignalType;
typedef Signal< bool (const KeyEvent&) > KeyEventGeneratedSignalType;
typedef Signal< void (const TouchData&) > TouchSignalType;
typedef Signal< void (const WheelEvent&) > WheelEventSignalType;