果冻效果

果冻效果

说明

参考源码 https://github.com/Resory/RYCuteView

效果

源码

https://github.com/YouXianMing/Animations

//
//  SpringEffectController.m
//  Animations
//
//  Created by YouXianMing on 16/1/17.
//  Copyright  2016年 YouXianMing. All rights reserved.
//

#import "SpringEffectController.h"
#import "WxHxD.h"
#import "UIView+SetRect.h"

@interface SpringEffectController (){

    CGPoint  _centerPoint;
}

@property (nonatomic, strong) UIView         *pointView;
@property (nonatomic, strong) CAShapeLayer   *shapeLayer;
@property (nonatomic, strong) CADisplayLink  *displayLink;

@end

@implementation SpringEffectController

- (void)setup {

    [super setup];

    _centerPoint = self.contentView.center;

    self.shapeLayer           = [CAShapeLayer layer];
    self.shapeLayer.frame     = self.contentView.bounds;
    self.shapeLayer.fillColor = [UIColor redColor].CGColor;
    self.shapeLayer.path      = [self calculatePathWithPoint:CGPointMake(Width / 2.f, Height / 2.f)].CGPath;
    [self.contentView.layer addSublayer:self.shapeLayer];

    self.pointView                   = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 4, 4)];
    self.pointView.center            = self.contentView.center;
    [self.contentView addSubview:self.pointView];

    self.displayLink = [CADisplayLink displayLinkWithTarget:self selector:@selector(displayLinkEvent)];
    [self.displayLink addToRunLoop:[NSRunLoop currentRunLoop] forMode:NSDefaultRunLoopMode];

    UIPanGestureRecognizer *panGesture = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(panGestureEvent:)];
    [self.contentView addGestureRecognizer:panGesture];

}

- (UIBezierPath *)calculatePathWithPoint:(CGPoint)point {

    UIBezierPath *path = [UIBezierPath bezierPath];

    [path moveToPoint:CGPointMake(0, Height / 2.f)];
    [path addLineToPoint:CGPointMake(0, Height)];
    [path addLineToPoint:CGPointMake(Width, Height)];
    [path addLineToPoint:CGPointMake(Width, Height / 2.f)];
    [path addQuadCurveToPoint:CGPointMake(0, Height / 2.f)
                 controlPoint:point];

    return path;
}

- (void)panGestureEvent:(UIPanGestureRecognizer *)panGesture {

    CGPoint point          = [panGesture locationInView:panGesture.view];
    CGPoint calculatePoint = CGPointMake((point.x + _centerPoint.x) / 2.f, (point.y + _centerPoint.y) / 2.f);

    if (panGesture.state == UIGestureRecognizerStateChanged) {

        self.shapeLayer.path  = [self calculatePathWithPoint:calculatePoint].CGPath;
        self.pointView.center = calculatePoint;

    } else if (panGesture.state == UIGestureRecognizerStateCancelled ||
               panGesture.state == UIGestureRecognizerStateEnded ||
               panGesture.state == UIGestureRecognizerStateFailed) {

        [UIView animateWithDuration:1.0 delay:0.0 usingSpringWithDamping:0.25f initialSpringVelocity:0
                            options:UIViewAnimationOptionCurveEaseInOut
                         animations:^{

                             self.pointView.center = self.contentView.center;

                         } completion:nil];
    }
}

- (void)displayLinkEvent {

    CALayer *layer       = self.pointView.layer.presentationLayer;
    self.shapeLayer.path = [self calculatePathWithPoint:layer.position].CGPath;
}

@end