Additive属性动画

Additive属性动画

参考

http://ronnqvi.st/multiple-animations/

效果

源码

https://github.com/YouXianMing/Animations

//
//  AdditiveAnimationController.m
//  Animations
//
//  Created by YouXianMing on 16/1/21.
//  Copyright © 2016年 YouXianMing. All rights reserved.
//

#import "AdditiveAnimationController.h"
#import "UIView+SetRect.h"

@interface AdditiveAnimationController ()

@property (nonatomic, strong) CALayer  *layer;

@end

@implementation AdditiveAnimationController

- (void)setup {

    [super setup];

    // http://ronnqvi.st/multiple-animations/

    self.layer                 = [CALayer layer];
    self.layer.frame           = CGRectMake(, , , );
    self.layer.backgroundColor = [UIColor redColor].CGColor;
    self.layer.cornerRadius    = .f;
    self.layer.position        = self.contentView.middlePoint;
    [self.contentView.layer addSublayer:self.layer];

    UITapGestureRecognizer *tap = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(tapEvent:)];
    [self.contentView addGestureRecognizer:tap];
}

- (void)tapEvent:(UITapGestureRecognizer *)tapGesture {

    CGPoint touchPoint      = [tapGesture locationInView:tapGesture.view];
    CGPoint differencePoint = CGPointMake(self.layer.position.x - touchPoint.x,
                                          self.layer.position.y - touchPoint.y);

    CALayer *presentationLayer = self.layer.presentationLayer;
    NSLog(@"%@", presentationLayer);

    CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"position"];
    animation.duration          = .f;
    animation.timingFunction    = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionEaseInEaseOut];
    animation.additive          = true;
    animation.fromValue         = [NSValue valueWithCGPoint:differencePoint];
    animation.toValue           = [NSValue valueWithCGPoint:CGPointZero];

    [CATransaction begin];
    [CATransaction setDisableActions:YES];
    self.layer.position = touchPoint;
    [CATransaction commit];

    [self.layer addAnimation:animation forKey:nil];
}

@end

细节