OC, oc Language

OC, oc Language
Overview

• Introduction

  • Core animation provides a very powerful set of animation APIs, which can efficiently achieve most brilliant animation effects.

• Notes

  • Core animation operations are executed in child threads without blocking the main thread
  • The core animation works directly with CALayer objects, not UIView objects.

• Differences between core animation and UIView Animation

  • The core animation does not change the frame attribute of the control, but only displays an illusion.
  • The UIView animation changes the frame attribute of the control, and displays the real frame attribute of the control.

Core Animation

• Relationship Diagram of core animation classes

  • This figure is from the official document. I do not know why CAKeyframeAnimation in the lower right corner is a protocol. Subclass that uses CAKeyframeAnimation as CAPropertyAnimation

• CAAnimation and CAPropertyAnimation

  • They are both abstract classes and cannot be used directly. They must be subclasses.

  • Subclass that can be directly used by CAAnimation,

    • CAAnimationGroup, Group Animation
    • CATransaction, transfer Animation

  • Subclass that can be directly used by CAPropertyAnimation

    • CABasicAnimation, basic animation
    • CAKeyframeAnimation, Key Frame Animation

CAAnimation class

• Three important attributes

  • TimingFunction (CAMediaTimingFunction *), speed control function
  • Delegate (id), animation proxy
  • RemovedOnCompletion (BOOL), whether to remove the animation from the layer after execution

Proxy method of CAAnimation

• Note:

  • The proxy method of CAAnimation is implemented by NSObject classification,

• Proxy Method

  • Call at animation start

  - (void)animationDidStart:(CAAnimation *)anim;

  • Call when animation ends

  - (void)animationDidStop:(CAAnimation *)anim finished:(BOOL)flag;

CAMediaTiming Protocol

• Common attributesMedium attribute

  • BeginTime (CFTimeInterval), start time
  • Duration (CFTimeInterval), the execution time of a single Animation
  • Speed (float), animation speed
  • TimeOffset (CFTimeInterval): starts from the time offset timeOffset to execute the animation, compresses the animation before timeOffset, and concatenates it to the end.
  • RepeatCount (float), repeatCount
  • RepeatDuration (CFTimeInterval), animation repetition time, And repeatCount select the shortest time
  • Autoreverses (BOOL), whether to restore to the animation starting state (in Animation Mode)
  • FillMode (NSString *): animation filling mode

Animation filling mode

• Note:

  • To make the fill mode valid, set the removedOnCompletion attribute of the animation to NO.

• Four modes

  • KCAFillModeForwards: After the animation ends, the layer remains in the animation end state.
  • KCAFillModeBackwards: add the animation to the layer and immediately enter the initial state of the animation. Wait until the animation starts to run.
  • KCAFillModeBoth
  • KCAFillModeRemoved. After the animation ends, the layer will return to its original state.

Animation Speed Control Function

• KCAMediaTimingFunctionLinear, constant speed
• KCAMediaTimingFunctionEaseIn
• KCAMediaTimingFunctionEaseOut, entering at full speed, slowing down to the target location
• KCAMediaTimingFunctionEaseInEaseOut
• KCAMediaTimingFunctionDefault, default speed, that is, kCAMediaTimingFunctionEaseInEaseOut