Cocos2d-x CCScheduler

在CCNode这个类中定义了定时器，那么这个类的派生类都可以进行使用。那么假如不是继承自CCNode的话，可以使用 CCScheduler 这个类，通过：CCDirector::sharedDirector()->getScheduler() 获取全局定时器，使用需要的定时器功能。

通过这个类的头文件就可以大致可以知道它的用法了。

/** @brief Scheduler is responsible for triggering the scheduled callbacks.
You should not use NSTimer. Instead use this class.

There are 2 different types of callbacks (selectors):

- update selector: the 'update' selector will be called every frame. You can customize the priority.
- custom selector: A custom selector will be called every frame, or with a custom interval of time

The 'custom selectors' should be avoided when possible. It is faster, and consumes less memory to use the 'update selector'.

*/
class CC_DLL CCScheduler : public CCObject
{
public:
    CCScheduler();
    ~CCScheduler(void);

    inline float getTimeScale(void) { return m_fTimeScale; }
    /** Modifies the time of all scheduled callbacks.
    You can use this property to create a 'slow motion' or 'fast forward' effect.
    Default is 1.0. To create a 'slow motion' effect, use values below 1.0.
    To create a 'fast forward' effect, use values higher than 1.0.
    @since v0.8
    @warning It will affect EVERY scheduled selector / action.
    */
    inline void setTimeScale(float fTimeScale) { m_fTimeScale = fTimeScale; }

    /** 'update' the scheduler.
     You should NEVER call this method, unless you know what you are doing.
     */
    void update(float dt);

    /** The scheduled method will be called every 'interval' seconds.
     If paused is YES, then it won't be called until it is resumed.
     If 'interval' is 0, it will be called every frame, but if so, it's recommended to use 'scheduleUpdateForTarget:' instead.
     If the selector is already scheduled, then only the interval parameter will be updated without re-scheduling it again.
     repeat let the action be repeated repeat + 1 times, use kCCRepeatForever to let the action run continuously
     delay is the amount of time the action will wait before it'll start

     @since v0.99.3, repeat and delay added in v1.1
     */
    void scheduleSelector(SEL_SCHEDULE pfnSelector, CCObject *pTarget, float fInterval, unsigned int repeat, float delay, bool bPaused);

    /** calls scheduleSelector with kCCRepeatForever and a 0 delay */
    void scheduleSelector(SEL_SCHEDULE pfnSelector, CCObject *pTarget, float fInterval, bool bPaused);
    /** Schedules the 'update' selector for a given target with a given priority.
     The 'update' selector will be called every frame.
     The lower the priority, the earlier it is called.
     @since v0.99.3
     */
    void scheduleUpdateForTarget(CCObject *pTarget, int nPriority, bool bPaused);

    /** Unschedule a selector for a given target.
     If you want to unschedule the "update", use unscheudleUpdateForTarget.
     @since v0.99.3
     */
    void unscheduleSelector(SEL_SCHEDULE pfnSelector, CCObject *pTarget);

    /** Unschedules the update selector for a given target
     @since v0.99.3
     */
    void unscheduleUpdateForTarget(const CCObject *pTarget);

    /** Unschedules all selectors for a given target.
     This also includes the "update" selector.
     @since v0.99.3
     */
    void unscheduleAllForTarget(CCObject *pTarget);

    /** Unschedules all selectors from all targets.
     You should NEVER call this method, unless you know what you are doing.

     @since v0.99.3
     */
    void unscheduleAll(void);
    
    /** Unschedules all selectors from all targets with a minimum priority.
      You should only call this with kCCPriorityNonSystemMin or higher.
      @since v2.0.0
      */
    void unscheduleAllWithMinPriority(int nMinPriority);

    /** The scheduled script callback will be called every 'interval' seconds.
     If paused is YES, then it won't be called until it is resumed.
     If 'interval' is 0, it will be called every frame.
     return schedule script entry ID, used for unscheduleScriptFunc().
     */
    unsigned int scheduleScriptFunc(unsigned int nHandler, float fInterval, bool bPaused);
    
    /** Unschedule a script entry. */
    void unscheduleScriptEntry(unsigned int uScheduleScriptEntryID);

    /** Pauses the target.
     All scheduled selectors/update for a given target won't be 'ticked' until the target is resumed.
     If the target is not present, nothing happens.
     @since v0.99.3
     */
    void pauseTarget(CCObject *pTarget);

    /** Resumes the target.
     The 'target' will be unpaused, so all schedule selectors/update will be 'ticked' again.
     If the target is not present, nothing happens.
     @since v0.99.3
     */
    void resumeTarget(CCObject *pTarget);

    /** Returns whether or not the target is paused
    @since v1.0.0
    */
    bool isTargetPaused(CCObject *pTarget);

    /** Pause all selectors from all targets.
      You should NEVER call this method, unless you know what you are doing.
     @since v2.0.0
      */
    CCSet* pauseAllTargets();

    /** Pause all selectors from all targets with a minimum priority.
      You should only call this with kCCPriorityNonSystemMin or higher.
      @since v2.0.0
      */
    CCSet* pauseAllTargetsWithMinPriority(int nMinPriority);

    /** Resume selectors on a set of targets.
     This can be useful for undoing a call to pauseAllSelectors.
     @since v2.0.0
      */
    void resumeTargets(CCSet* targetsToResume);

private:
    void removeHashElement(struct _hashSelectorEntry *pElement);
    void removeUpdateFromHash(struct _listEntry *entry);

    // update specific

    void priorityIn(struct _listEntry **ppList, CCObject *pTarget, int nPriority, bool bPaused);
    void appendIn(struct _listEntry **ppList, CCObject *pTarget, bool bPaused);

protected:
    float m_fTimeScale;

    //
    // "updates with priority" stuff
    //
    struct _listEntry *m_pUpdatesNegList;        // list of priority < 0
    struct _listEntry *m_pUpdates0List;            // list priority == 0
    struct _listEntry *m_pUpdatesPosList;        // list priority > 0
    struct _hashUpdateEntry *m_pHashForUpdates; // hash used to fetch quickly the list entries for pause,delete,etc

    // Used for "selectors with interval"
    struct _hashSelectorEntry *m_pHashForTimers;
    struct _hashSelectorEntry *m_pCurrentTarget;
    bool m_bCurrentTargetSalvaged;
    // If true unschedule will not remove anything from a hash. Elements will only be marked for deletion.
    bool m_bUpdateHashLocked;
    CCArray* m_pScriptHandlerEntries;
};

下面简单测试一下用法吧！

① setTimeScale

我们创建一个左右运动的精灵，然后通过一个slide来修改动画速度。

    CCSize screenSize = CCDirector::sharedDirector()->getWinSize();
    CCControlSlider *slider = CCControlSlider::create("sliderTrack2.png","sliderProgress2.png" ,"sliderThumb.png");
    slider->setAnchorPoint(ccp(0.5f, 1.0f));
    slider->setMinimumValue(0.0f); // Sets the min value of range
    slider->setMaximumValue(2.0f); // Sets the max value of range
    slider->setValue(1.0f);
    slider->setPosition(ccp(screenSize.width / 2.0f, screenSize.height / 2.0f + 16));
    slider->setTag(1);
    this->addChild(slider);
    
    // When the value of the slider will change, the given selector will be call
    slider->addTargetWithActionForControlEvents(this, cccontrol_selector(HelloWorld::valueChanged), CCControlEventValueChanged);
    
    
    sprite = CCSprite::create("Icon.png");
    sprite->setPosition(ccp(150, 150));
    this->addChild(sprite);
    
    CCMoveTo* moveTo = CCMoveTo::create(1.0f, ccp(400, 150));
    CCMoveTo* mo = CCMoveTo::create(1.0, ccp(150, 150));
    sprite->runAction(CCRepeatForever::create(CCSequence::create(moveTo,mo,NULL)));

void HelloWorld::valueChanged(CCObject *sender, CCControlEvent controlEvent)
{
    CCControlSlider* pSlider = (CCControlSlider*)sender;
	if(pSlider->getTag() == 1)
    {
        //setTimeScale用于减慢或者快进动画，其默认参数值为1.0，低于此值时计时器会放慢，否则加快
        CCDirector::sharedDirector()->getScheduler()->setTimeScale(pSlider->getValue());
    }
}

② eg：CCDirector::sharedDirector()->getScheduler()->scheduleSelector(SEL_SCHEDULE(&HelloWorld::callBack),sprite,0.1,false);