# Animator Development ## When to Use A UI animator is implemented by calling the callback function you set for each tick using the task processing mechanism. The following classes are provided for you to implement an animator: - **AnimatorManager**: Manages Animator instances. This is a singleton class, which is registered with the system task callback when the **Init** function is executed. The system task mechanism ensures that each tick invokes the callback function of **AnimatorManager**. - **Animator**: Represents animator-related attributes, including the start and end time of an animator. It also provides animator-specific functions, for example, to start and stop an animator, to set the animator state, and to obtain the animator. - **AnimatorCallback**: Implements the content of each tick. You need to implement your own logic in this callback class so that the desired operation is executed upon the corresponding callback is invoked. ## Available APIs **Table 1** Available functions for an animator

Module	Function	Description
Animator	void Start ()	Starts an animator.
Animator	void Stop ()	Stops the animator.
Animator	void Pause ()	Pauses the animator.
Animator	void Resume ()	Resumes the animator.
Animator	uint8_t GetState () const	Obtains the current state of the animator.
Animator	void SetState (uint8_t state)	Sets the current state for the animator.
Animator	uint32_t GetTime () const	Obtains the total duration of the animator.
Animator	void SetTime (uint32_t time)	Sets the total duration for the animator.
Animator	uint32_t GetRunTime () const	Obtains the running time of the animator.
Animator	void SetRunTime (uint32_t runTime)	Sets the running time for the animator.
Animator	bool IsRepeat () const	Checks whether the animator is repeated.
AnimatorCallback	virtual void Callback (UIView *view)=0	Represents the animator callback. You can implement your own logic in this callback.
AnimatorCallback	virtual void OnStop(UIView& view) {}	Called after the animator stops. You can implement your own logic in this callback.
AnimatorManager	static AnimatorManager* GetInstance()	Obtains an AnimatorManager instance.
AnimatorManager	void Add (Animator *animator)	Adds an animator.
AnimatorManager	void Remove(const Animator* animator);	Removes the animator.

## How to Develop 1. Implement the callback in **AnimatorCallback**. ``` class AnimatorCallbackDemo : public OHOS::AnimatorCallback { public: AnimatorCallbackDemo(int16_t startPos, int16_t endPos, uint16_t time) : start_(startPos), end_(endPos), time_(time), curTime_(0) {} virtual void Callback(OHOS::UIView* view) { curTime_++; int16_t pos = EasingEquation::CubicEaseIn(start_, end_, curTime_, time_); view->Invalidate(); view->SetPosition(pos, view->GetY()); view->Invalidate(); } protected: int16_t start_; int16_t end_; uint16_t time_; uint16_t curTime_; }; ``` 2. Register **AnimatorCallback** to the animator. ``` UIImageView* image = new UIImageView(); image->SetSrc("..\\config\\images\\A021_001.bin"); image->SetPosition(0, 50); AnimatorCallbackDemo* callback = new AnimatorCallbackDemo(0, 338, 60); Animator* animator = new Animator(callback, image, 0, true); ``` 3. Add the animator to **AnimatorManager**. ``` AnimatorManager::GetInstance()->Add(animator); ``` 4. Click the buttons in the lower part of the following figure to verify that the animation effects are as expected. **Figure 1** Animator effect ![](figures/animator-effect.gif "animator-effect")