All the constructors in class PlatformKeyboardEvent are platform dependent. It seems inappropriate for naturalization to other platform. Should class PlatformKeyboardEvent need a platform independent constructor like class PlatformMouseEvent ? /////////////////////////////code in PlatformMouseEvent.h/////////////////////////////////// class PlatformMouseEvent { public: PlatformMouseEvent() : m_button(NoButton) , m_eventType(MouseEventMoved) , m_clickCount(0) , m_shiftKey(false) , m_ctrlKey(false) , m_altKey(false) , m_metaKey(false) , m_timestamp(0) , m_modifierFlags(0) { } PlatformMouseEvent(const IntPoint& position, const IntPoint& globalPosition, MouseButton button, MouseEventType eventType, int clickCount, bool shift, bool ctrl, bool alt, bool meta, double timestamp) : m_position(position) , m_globalPosition(globalPosition) , m_button(button) , m_eventType(eventType) , m_clickCount(clickCount) , m_shiftKey(shift) , m_ctrlKey(ctrl) , m_altKey(alt) , m_metaKey(meta) , m_timestamp(timestamp) , m_modifierFlags(0) { } .... } /////////////////////example code for PlatformKeyboardEvent//////////////////////////// PlatformKeyboardEvent(Type type, String text, String unmodifiedText, String keyIdentifier, bool autoRepeat, int windowsVirtualKeyCode, int nativeVirtualKeyCode, bool isKeypad, bool shiftKey, bool ctrlKey, bool altKey, bool metaKey) : m_type(type) , m_text(text) , m_unmodifiedText(unmodifiedText) , m_keyIdentifier(keyIdentifier) , m_autoRepeat(autoRepeat) , m_windowsVirtualKeyCode(windowsVirtualKeyCode) , m_nativeVirtualKeyCode(nativeVirtualKeyCode) , m_isKeypad(isKeypad) , m_shiftKey(shiftKey) , m_ctrlKey(ctrlKey) , m_altKey(altKey) , m_metaKey(metaKey) { }