JHChainableAnimations 源码阅读

JHChainableAnimations 源码阅读（2）

JHChainableAnimations 支持链式编程。链式编程 在OC中的实现就是，函数返回一个Block,并且在外面调用这个block,传入block计算所需要的参数。并且block返回对象本身，这样子就可以继续调用了

链式编程特点：方法的返回值是block,block必须有返回值（本身对象），block参数（需要操作的值）

Masonry 自动布局的框架也是链式编程有空继续分析

UIView (UIView_JHChainableAnimations)

定义了一些

UIView

的常用操作

改变大小OR位移

- (JHChainableRect) makeFrame;

- (JHChainableRect) makeBounds;

- (JHChainableSize) makeSize;

- (JHChainablePoint) makeOrigin;

- (JHChainablePoint) makeCenter;

- (JHChainableFloat) makeX;

- (JHChainableFloat) makeY;

- (JHChainableFloat) makeWidth;

- (JHChainableFloat) makeHeight;

- (JHChainableFloat) makeOpacity;

- (JHChainableColor) makeBackground;

- (JHChainableColor) makeBorderColor;

- (JHChainableFloat) makeBorderWidth;

- (JHChainableFloat) makeCornerRadius;

- (JHChainableFloat) makeScale;

- (JHChainableFloat) makeScaleX;

- (JHChainableFloat) makeScaleY;

- (JHChainablePoint) makeAnchor;

[/code]

……

接下来分析一个具体的实现看看比如

makeFrame

-(JHChainableRect)makeFrame {
JHChainableRect chainable = JHChainableRect(rect){
return self.makeOrigin(rect.origin.x, rect.origin.y).makeBounds(rect);
};
return chainable;
}

>

JHChainableRect

block 传入参数

CGRect

rect 然后调用

self.makeOrigin

修改Origin 再调用makeBounds 修改大小

-(JHChainablePoint)makeOrigin {
JHChainablePoint chainable = JHChainablePoint(x, y) {
//修改position
[self addAnimationCalculationAction:^(UIView *weakSelf) {
JHKeyframeAnimation *positionAnimation = [weakSelf basicAnimationForKeyPath:@"position"];
CGPoint newPosition = [weakSelf newPositionFromNewOrigin:CGPointMake(x, y)];
positionAnimation.fromValue = [NSValue valueWithCGPoint:weakSelf.layer.position];
positionAnimation.t
4000
oValue = [NSValue valueWithCGPoint:newPosition];
[weakSelf addAnimationFromCalculationBlock:positionAnimation];
}];
//动画结束结束之后，修改最终的结果
[self addAnimationCompletionAction:^(UIView *weakSelf) {
CGPoint newPosition = [weakSelf newPositionFromNewOrigin:CGPointMake(x, y)];
weakSelf.layer.position = newPosition;
}];

return self;
};
return chainable;}

-(JHChainableRect)makeBounds {
JHChainableRect chainable = JHChainableRect(rect) {
//修改大小
return self.makeSize(rect.size.width, rect.size.height);
};
return chainable;
}

- (JHChainableSize) makeSize {
JHChainableSize chainable = JHChainableSize(width, height){

[self addAnimationCalculationAction:^(UIView *weakSelf) {
//动画核心编程
//keyPath bounds.size
JHKeyframeAnimation *sizeAnimation = [weakSelf basicAnimationForKeyPath:@"bounds.size"];
sizeAnimation.fromValue = [NSValue valueWithCGSize:weakSelf.layer.bounds.size];
sizeAnimation.toValue = [NSValue valueWithCGSize:CGSizeMake(width, height)];
//加入动画数组
[weakSelf addAnimationFromCalculationBlock:sizeAnimation];
}];
//执行完了的结果添加到当前的Layer上，不然会返回初始状态
[self addAnimationCompletionAction:^(UIView *weakSelf) {
CGRect bounds = CGRectMake(0, 0, width, height);
weakSelf.layer.bounds = bounds;
weakSelf.bounds = bounds;
}];
[code]//返回当前对象，可以链式调用

return self;
};
return chainable;
}
[/code]

把动画加入到动画数组

-(void) addAnimationCalculationAction:(JHAnimationCalculationAction)action {
NSMutableArray *actions = [self.JHAnimationCalculationActions lastObject];
[actions addObject:action];
}

把动画结果加入到结果的数组中

-(void) addAnimationCompletionAction:(JHAnimationCompletionAction)action {
NSMutableArray *actions = [self.JHAnimationCompletionActions lastObject];
[actions addObject:action];
}

JHAnimationCalculationActions

通过关联把数组设置为当前对象的属性 其他数组一样。

如何调用的呢？

比如：

self.myView.moveX(50).animate(.25);

通过moveX 把动画 过程添加到动画数组，之后通过animate 调用，把动画添加到

CAAnimationGroup

对象中，然后，再加入到当前的layer

-(JHChainableAnimation)animate {
JHChainableAnimation chainable = JHChainableAnimation(duration) {
//从 CAAnimationGroup 数组中拿出最后一个CAAnimationGroup对象
CAAnimationGroup *group = [self.JHAnimationGroups lastObject];
//设置动画需要的时间
group.duration = duration;
[self animateChain];

return self;
};
return chainable;
}

-(void) animateChain {
[self sanityCheck];
//提交事务
[CATransaction begin];
[CATransaction setDisableActions:YES];
[CATransaction setCompletionBlock:^{ //一组动画完成之后的事情
[self.layer removeAnimationForKey:@"AnimationChain"];
[self chainLinkDidFinishAnimating];
}];
//执行动画
[self animateChainLink];

[CATransaction commit];

[self executeCompletionActions];
}

-(void) animateChainLink {
[self makeAnchorFromX:0.5 Y:0.5];
//动画过程传入参数
NSMutableArray *actionCluster = [self.JHAnimationCalculationActions firstObject];
for (JHAnimationCalculationAction action in actionCluster) {
//防止循环引用
__weak UIView *weakSelf = self;
action(weakSelf);
}
CAAnimationGroup *group = [self.JHAnimationGroups firstObject];
NSMutableArray *animationCluster = [self.JHAnimations firstObject];
for (JHKeyframeAnimation *animation in animationCluster) {
animation.duration = group.duration;
[animation calculate];
}
//把一组动画加入到CAAnimationGroup 来
group.animations = animationCluster;
//添加动画
[self.layer addAnimation:group forKey:@"AnimationChain"];

// 自动布局属性的
NSTimeInterval delay = MAX(group.beginTime - CACurrentMediaTime(), 0.0);
[self.class animateWithDuration:group.duration
delay:delay
options:0
animations:^{
[self updateConstraints];
} completion:nil];
}

执行过程大概就是这样子！睡了，明天有空继续分析。分析完这个库，核心动画编程会了一大半了。