事件Event

Event类是所有事件类的基类

/**
 *   Base class of all kinds of events.
 */
class Event : public Ref
{
public:
    enum class Type
    {
        TOUCH,
        KEYBOARD,
        ACCELERATION,
        MOUSE,
        CUSTOM
    };

protected:
    /** Constructor */
    Event(Type type);
public:
    /** Destructor */
    virtual ~Event();

    /** Gets the event type */
    inline Type getType() const { return _type; };

    /** Stops propagation for current event */
    inline void stopPropagation() { _isStopped = true; };

    /** Checks whether the event has been stopped */
    inline bool isStopped() const { return _isStopped; };

    /** @brief Gets current target of the event
     *  @return The target with which the event associates.
     *  @note It onlys be available when the event listener is associated with node.
     *        It returns 0 when the listener is associated with fixed priority.
     */
    inline Node* getCurrentTarget() { return _currentTarget; };

protected:
    /** Sets current target */
    inline void setCurrentTarget(Node* target) { _currentTarget = target; };

    Type _type;     ///< Event type

    bool _isStopped;       ///< whether the event has been stopped.
    Node* _currentTarget;  ///< Current target

    friend class EventDispatcher;
};