Summary

AXAnimationChain是一个链式动画库
，可以用来轻松的创建基于CAAnimation
的链式动画。链的组合方式有两种，一种是组合，另一种则是链接，通过以上两种方式创建的动画，既可以同时进行，也可以按时间先后进行，可以使用较少的代码创建出丰富复杂的动画效果：
简单使用:

_transitionView.spring.centerBy(CGPointMake(0, 100)).easeOut.spring.sizeBy(CGSizeMake(100, 100)).spring.cornerRadiusBy(4).animate();

_transitionView.chainAnimator.basic.target(self).complete(@selector(complete:)).property(@"position").toValue([NSValue valueWithCGPoint:CGPointMake(100, self.view.center.y)]).easeInBack.duration(0.5).combineSpring.target(self).complete(@selector(complete:)).property(@"bounds").toValue([NSValue valueWithCGRect:CGRectMake(0, 0, 100, 100)]).duration(0.5).repeatCount(5).autoreverses.combineSpring.target(self).complete(@selector(complete:)).property(@"transform.rotation").toValue(@(M_PI_4)).duration(0.5).repeatCount(3).beginTime(1.0).autoreverses.nextToBasic.property(@"position").toValue([NSValue valueWithCGPoint:self.view.center]).duration(0.5).combineSpring.property(@"bounds").toValue([NSValue valueWithCGRect:CGRectMake(0, 0, 100, 100)]).duration(0.8).nextToBasic.property(@"transform.rotation").toValue(@(M_PI_4)).duration(1.0).completeWithBlock(nil).animate();

看起来比较冗余，但是细读会发现，其实就只有一行代码.

AXChainAnimator
 --AXBasicChainAnimator     ==CABasicAnimation
   --AXSpringChainAnimator ==CASpringAnimation
 --AXKeyframeChainAnimator ==CAKeyframeAnimation
 --AXTransitionChainAnimator==CATransitionAnimation

Next-To

通过链接的方式处理两个animator，被链接的animator将会在前者动画(包含组合的动画)完成之后进行动画, 大概的示例如下：

[former nextTo:nexter];

Next-To方法的原型如下：

- (instancetype)nextTo:(id<AXAnimatorChainDelegate>)animator;

当向former aniamtor发送nextTo:消息之后，返回的是nexter animator作为下次链接或者组合操作的对象，因此AXAnimationChain定义了几种常用的操作：

/// 链接到Basic动画并且返回链接的Basic动画.
- (AXBasicChainAnimator *)nextToBasic;
/// 链接到Spring动画并且放回链接的Spring动画.
- (AXSpringChainAnimator *)nextToSpring;
/// 链接到Keyframe动画并且放回链接的Keyframe动画.
- (AXKeyframeChainAnimator *)nextToKeyframe;
/// 链接到Transition动画并且返回链接的Transition动画.
- (AXTransitionChainAnimator *)nextToTransition;

在发送消息之后分别返回对应类型的可操作对象.

Combine-With

通过组合的方式处理两个animator，被组合的animator将会与前者动画同时进行，完成的时间以时间最长的为准, 示例如下：

[former combineWith:combiner];

Combine-With方法原型如下：

- (instancetype)combineWith:(nonnull AXChainAnimator *)animator;

当向former animator发送combineWith:消息之后，返回的是combiner animator作为下次链接或者组合操作的对象，在AXAnimationChain`中，默认一下几种组合方式：

/// 组合到Basic动画并且返回组合的Basic动画.
- (AXBasicChainAnimator *)combineBasic;
/// 组合到Spring动画并且放回组合的Spring动画.
- (AXSpringChainAnimator *)combineSpring;
/// 组合到Keyframe动画并且放回组合的Keyframe动画.
- (AXKeyframeChainAnimator *)combineKeyframe;
/// 组合到Transition动画并且返回组合的Transition动画.
- (AXTransitionChainAnimator *)combineTransition;

同样的，在向某一操作对象animator发送以上消息之后，将会分别返回对应类型的可操作对象.

Relationship

在AXAnimationChain中，关系的管理采用的是二叉树的理论. 某一个animator对应的类结构中，包含了指向父节点的superAnimator用于表示父animator, 表示此animator为superAnimator所链接的animator, 此时，superAnimator的childAnimator即指向此animator作为一个闭环链将两者的关系锁定起来; 同样的，某一个animator还拥有一个指向兄弟节点的NSArray<AXChainAnimator *>结构:combinedAnimators用于管理所组合的animators，并且，被组合的animator的父节点superAnimator则指向当前animator

- (void)start {
   NSAssert(_animatedView, @"Animation chain cannot be created because animated view is null.");
   AXChainAnimator *superAnimator = _superAnimator;
   AXChainAnimator *superSuperAnimator = _superAnimator;
   while (superAnimator) {
       superAnimator = superAnimator.superAnimator;
       if (superAnimator) {
           superSuperAnimator = superAnimator;
       }
   }
   if (superSuperAnimator) {
       [superSuperAnimator start];
   } else {
       [self _beginAnimating];
       if (!_childAnimator) [self _clear];
   }
}

AXAnimatioChain就是通过这样的关系把所有链接和组合的animator管理起来的，在完成关系的链接或组合之后，需要向最后一个animator发送-start消息动画才能正常进行. animator在接收到-start消息之后，会逐级遍历superAnimator直至superAnimator.superAnimator==nil, 此时获取superSuperAnimator, 从superSuperAnimator
自祖先往下逐级进行动画，组合的动画会同时进行，链接的动画则按顺序进行.

Features

• 轻量级解决方案

• 基于CoreAnimation的封装，安全、高效！

• 一行代码搞定复杂的动画管理，提高代码维护效

TimingControl

时间曲线，时间曲线用于描述动画随时间进行的速度，AXAnimationChain除了包含系统默认的时间曲线之外，还提供了如下的曲线以呈现更漂亮的动画：

AXSpringAnimation

CoreAnimation自iOS2.0就为iOS平台提供了核心动画的支持，但是在iOS9.0之前，一直没有Spring动画，要使用Spring动画要么使用第三方动画库，要么使用系统提供的方法:

+ (void)animateWithDuration:(NSTimeInterval)duration delay:(NSTimeInterval)delay usingSpringWithDamping:(CGFloat)dampingRatio initialSpringVelocity:(CGFloat)velocity options:(UIViewAnimationOptions)options animations:(void (^)(void))animations completion:(void (^ __nullable)(BOOL finished))completion NS_AVAILABLE_IOS(7_0);

但是系统提供的这个方法也是iOS7.0以后才能使用了，并且在控制上并非那么容易. AXSpringAnimation是基于阻尼震动运动模型的Spring动画类，能够完美与CASpringAnimation相通用：

@interface AXSpringAnimation : CAKeyframeAnimation
/* The mass of the object attached to the end of the spring. Must be greater
 than 0. Defaults to one. */


@property(assign, nonatomic) CGFloat mass;
​
/* The spring stiffness coefficient. Must be greater than 0.
 * Defaults to 100. */
​
@property(assign, nonatomic) CGFloat stiffness;
​
/* The damping coefficient. Must be greater than or equal to 0.
 * Defaults to 10. */
​
@property(assign, nonatomic) CGFloat damping;
​
/* The initial velocity of the object attached to the spring. Defaults
 * to zero, which represents an unmoving object. Negative values
 * represent the object moving away from the spring attachment point,
 * positive values represent the object moving towards the spring
 * attachment point. */
​
@property(assign, nonatomic) CGFloat initialVelocity;
​
/* Returns the estimated duration required for the spring system to be
 * considered at rest. The duration is evaluated for the current animation
 * parameters. */
​
@property(readonly, nonatomic) CFTimeInterval settlingDuration;
​
/* The objects defining the property values being interpolated between.
 * All are optional, and no more than two should be non-nil. The object
 * type should match the type of the property being animated (using the
 * standard rules described in CALayer.h). The supported modes of
 * animation are:
 *
 * - both `fromValue' and `toValue' non-nil. Interpolates between
 * `fromValue' and `toValue'.
 *
 * - `fromValue' and `byValue' non-nil. Interpolates between
 * `fromValue' and `fromValue' plus `byValue'.
 *
 * - `byValue' and `toValue' non-nil. Interpolates between `toValue'
 * minus `byValue' and `toValue'. */
​
@property(nullable, strong, nonatomic) id fromValue;
@property(nullable, strong, nonatomic) id toValue;
@property(nullable, strong, nonatomic) id byValue;
@end

Convertable

AXAnimationChain框架还提供了将CABasicAnimation无缝转换为CAKeyframeAnimation的功能：

#import <QuartzCore/QuartzCore.h>
#import <UIKit/UIKit.h>
#import "CAMediaTimingFunction+Extends.h"
​
@interface CAAnimation (Convertable)
@end
​
@interface CAKeyframeAnimation (Convertable)
+ (instancetype)animationWithBasic:(CABasicAnimation *)basicAnimation;
+ (instancetype)animationWithBasic:(CABasicAnimation *)basicAnimation usingValuesFunction:(double (^)(double t, double b, double c, double d))valuesFunction;
@end

Requirements

AXAnimationChain 对系统版本支持到iOS8.0，需要使用到的框架：

• Foundation.framework

• UIKit.framework

• QuartzCore.framework

使用的时候最好使用最新版Xcode.

Adding AXAimationChain To Your Project

CocoaPods

1. CocoaPods is the recommended way to add AXAimationChain to your project.
2. Add a pod entry for AXAimationChain to your Podfile pod 'AXAimationChain', '~> 0.1.0' Install the pod(s) by running pod install
3. Include AXAimationChain wherever you need it with #import "AXAimationChain.h"
4. 若需要单独使用AXSpringAnimation或者Convertable以及TimingControl等特性的话，只需要将podfile里边AXAnimationChain替换为AXAnimationChain/CoreAnimation即可，即：pod 'AXAimationChain/CoreAnimation', '~> 0.1.0'

Source files

1. Alternatively you can directly add all the source files to your project. Download the latest code version or add the repository as a git submodule to your git-tracked project.
2. Open your project in Xcode, then drag and drop the source group onto your project (use the "Product Navigator view"). Make sure to select Copy items when asked if you extracted the code archive outside of your project.
3. Include AXAnimationChain wherever you need it with #import "AXAimationChain.h"
   .4. 如单独使用AXSpringAnimation或者Convertable以及TimingControl等特性，只需要导入#import "AXCoreAnimation.h"
   即可.

License

This code is distributed under the terms and conditions of the MIT license.

使用

请参考示例工程代码以及API.

不足

此项目在开展的时候比较庞大，基础的核心类已经构建好了，基本目标已经达成，但是还有很多需要完善的地方，后边会逐步完善并发布Release版本.

声明

转载需注明出处：http://devedbox.com/AXAnimationChain/