cocos2dx中的调度器

cocos2dx中的调度器
cocos2dx提供了多种调度器，通常我们使用其中常见的3种：

1. 默认调度器：void scheduleUpdate(void);
2. 自定义调度器：void schedule(SEL_SCHEDULE selector, float interval, unsigned int repeat, float delay);
3. 单次调度器：void scheduleOnce(SEL_SCHEDULE selector, float delay);

CCNode类中提供了调度器相关的函数。

     * Sets a Scheduler object that is used to schedule all "updates" and timers.       设置一个调度对象，用来调度所有updates和计时器
     *
     * @warning If you set a new Scheduler, then previously created timers/update are going to be removed.      警告：如果你设置一个新的调度器，那么以前创建的计数器和update将被删除
     * @param scheduler     A Shdeduler object that is used to schedule all "update" and timers.
     */
    virtual void setScheduler(Scheduler* scheduler);
    /**
     * Gets a Sheduler object.      获得一个调度器对象
     *
     * @see setScheduler(Scheduler*)
     * @return A Scheduler object.
     */
    virtual Scheduler* getScheduler() { return _scheduler; }
    virtual const Scheduler* getScheduler() const { return _scheduler; }


    /**
     * Checks whether a selector is scheduled.      判断调度器是否被调度中
     *
     * @param selector      A function selector
     * @return Whether the funcion selector is scheduled.
     * @js NA
     * @lua NA
     */
    bool isScheduled(SEL_SCHEDULE selector);

    /**
     * Schedules the "update" method.       （默认的调度器）调度update方法
     *
     * It will use the order number 0. This method will be called every frame.      它将使用优先级为0，该方法每帧都会被调用
     * Scheduled methods with a lower order value will be called before the ones that have a higher order value.        调度值较小的调度函数会比调度值较高的函数优先被调用
     * Only one "update" method could be scheduled per node.        每个节点只能有一个update被调度
     * @js NA
     * @lua NA
     */
    void scheduleUpdate(void);

    /**
     * Schedules the "update" method with a custom priority.        自定义优先级的调度update方法
     *
     * This selector will be called every frame.        这个选择器每帧都会被调用
     * Scheduled methods with a lower priority will be called before the ones that have a higher value.     调度值较小的调度函数会比调度值较高的函数优先被调用
     * Only one "update" selector could be scheduled per node (You can't have 2 'update' selectors).
     * @js NA
     * @lua NA
     */
    void scheduleUpdateWithPriority(int priority);

    /*
     * Unschedules the "update" method.     停止调度update方法
     * @see scheduleUpdate();
     */
    void unscheduleUpdate(void);

    /**
     * Schedules a custom selector.     自定义调度器
     *
     * If the selector is already scheduled, then the interval parameter will be updated without scheduling it again.
     @code
     // firstly, implement a schedule function
     void MyNode::TickMe(float dt);
     // wrap this function into a selector via schedule_selector marco.
     this->schedule(schedule_selector(MyNode::TickMe), 0, 0, 0);
     @endcode
     *
     * @param selector  The SEL_SCHEDULE selector to be scheduled.      调度函数
     * @param interval  Tick interval in seconds. 0 means tick every frame. If interval = 0, it's recommended to use scheduleUpdate() instead.      调度时间。0表示每帧都被调度。如果为0，相反应该推荐使用scheduleUpdate
     * @param repeat    The selector will be excuted (repeat + 1) times, you can use kRepeatForever for tick infinitely.        调度函数将被调度repeat+1次，你可以使用参数kRepeatForever表示永远调用
     * @param delay     The amount of time that the first tick will wait before execution.      执行第一次调度之前等待的延迟时间
     * @lua NA
     */
    void schedule(SEL_SCHEDULE selector, float interval, unsigned int repeat, float delay);

    /**
     * Schedules a custom selector with an interval time in seconds.        调度一个有时间间隔的自定义调度器
     * @see `schedule(SEL_SCHEDULE, float, unsigned int, float)`
     *
     * @param selector      The SEL_SCHEDULE selector to be scheduled.
     * @param interval      Callback interval time in seconds. 0 means tick every frame,
     * @lua NA
     */
    void schedule(SEL_SCHEDULE selector, float interval);

    /**
     * Schedules a selector that runs only once, with a delay of 0 or larger        调度一个带有延迟时间的单次调度器
     * @see `schedule(SEL_SCHEDULE, float, unsigned int, float)`
     *
     * @param selector      The SEL_SCHEDULE selector to be scheduled.
     * @param delay         The amount of time that the first tick will wait before execution.
     * @lua NA
     */
    void scheduleOnce(SEL_SCHEDULE selector, float delay);

    /**
     * Schedules a custom selector, the scheduled selector will be ticked every frame
     * @see schedule(SEL_SCHEDULE, float, unsigned int, float)
     *
     * @param selector      A function wrapped as a selector
     * @lua NA
     */
    void schedule(SEL_SCHEDULE selector);

    /**
     * Unschedules a custom selector.       停止调度一个自定义的调度器
     * @see `schedule(SEL_SCHEDULE, float, unsigned int, float)`
     *
     * @param selector      A function wrapped as a selector
     * @lua NA
     */
    void unschedule(SEL_SCHEDULE selector);

    /**
     * Unschedule all scheduled selectors: custom selectors, and the 'update' selector.     停止调度所有调度器：包括自定义调度器和默认调度器update
     * Actions are not affected by this method.     这个方法不影响动作
     * @lua NA
     */
    void unscheduleAllSelectors(void);

    /**
     * Resumes all scheduled selectors, actions and event listeners.        恢复启动所有调度器，动作和事件监听器
     * This method is called internally by onEnter      该方法在内部被onEnter方法调用
     */
    void resume(void);
    /**
     * Pauses all scheduled selectors, actions and event listeners..        暂停所有调度器，动作和事件监听器
     * This method is called internally by onExit       该方法在内部被onExit方法调用
     */
    void pause(void);

    /**
     * Resumes all scheduled selectors, actions and event listeners.        同resume方法，不再推荐使用
     * This method is called internally by onEnter
     */
    CC_DEPRECATED_ATTRIBUTE void resumeSchedulerAndActions();
    /**
     * Pauses all scheduled selectors, actions and event listeners..        同pause方法，不再推荐使用
     * This method is called internally by onExit
     */
    CC_DEPRECATED_ATTRIBUTE void pauseSchedulerAndActions();

    /*
     * Update method will be called automatically every frame if "scheduleUpdate" is called, and the node is "live"
     */     //update方法每帧都会被调用，当scheduleUpdate被调用而且节点node还存活的时候
    virtual void update(float delta);

默认调度器scheduleUpdate
该方法在内部调用了节点node的update方法，update方法在每帧都会被调用一次。通过重载该update方法，在update方法内部实现我们的逻辑代码。
可以通过 void unscheduleUpdate(void);方法来停止调度该调度器。

自定义调度器schedule
void schedule(SEL_SCHEDULE selector, float interval, unsigned int repeat, float delay);
如果要指定间隔多少时间调度一次，可以使用自定义调度器。
不需要该调度器的时候可以通过void unschedule(SEL_SCHEDULE selector);方法来停止该调度器。

单次调度器scheduleOnce
void scheduleOnce(SEL_SCHEDULE selector, float delay);
对于只执行一次调度的时候可以用单次调度器。
同样可以用void unschedule(SEL_SCHEDULE selector);方法来停止该调度器。