SVIndefiniteAnimatedView.m

//
//  SVIndefiniteAnimatedView.m
//  SVProgressHUD
//
//  Created by Guillaume Campagna on 2014-12-05.
//
//

#import "SVIndefiniteAnimatedView.h"

#pragma mark SVIndefiniteAnimatedView

@interface SVIndefiniteAnimatedView ()

@property (nonatomic, strong) CAShapeLayer *indefiniteAnimatedLayer;

@end

@implementation SVIndefiniteAnimatedView

- (void)willMoveToSuperview:(UIView *)newSuperview {
    if (newSuperview) {
        [self layoutAnimatedLayer];
    } else {
        [_indefiniteAnimatedLayer removeFromSuperlayer];
        _indefiniteAnimatedLayer = nil;
    }
}

- (void)layoutAnimatedLayer {
    CALayer *layer = self.indefiniteAnimatedLayer;
    [self.layer addSublayer:layer];
    layer.position = CGPointMake(CGRectGetWidth(self.bounds) - CGRectGetWidth(layer.bounds) / 2, CGRectGetHeight(self.bounds) - CGRectGetHeight(layer.bounds) / 2);
}

- (CAShapeLayer*)indefiniteAnimatedLayer {
    if(!_indefiniteAnimatedLayer) {
        CGPoint arcCenter = CGPointMake(self.radius+self.strokeThickness/2+5, self.radius+self.strokeThickness/2+5);
        CGRect rect = CGRectMake(0.0f, 0.0f, arcCenter.x*2, arcCenter.y*2);
        
        UIBezierPath* smoothedPath = [UIBezierPath bezierPathWithArcCenter:arcCenter
                                                                    radius:self.radius
                                                                startAngle:M_PI*3/2
                                                                  endAngle:M_PI/2+M_PI*5
                                                                 clockwise:YES];
        
        _indefiniteAnimatedLayer = [CAShapeLayer layer];
        _indefiniteAnimatedLayer.contentsScale = [[UIScreen mainScreen] scale];
        _indefiniteAnimatedLayer.frame = rect;
        _indefiniteAnimatedLayer.fillColor = [UIColor clearColor].CGColor;
        _indefiniteAnimatedLayer.strokeColor = self.strokeColor.CGColor;
        _indefiniteAnimatedLayer.lineWidth = self.strokeThickness;
        _indefiniteAnimatedLayer.lineCap = kCALineCapRound;
        _indefiniteAnimatedLayer.lineJoin = kCALineJoinBevel;
        _indefiniteAnimatedLayer.path = smoothedPath.CGPath;
        
        CALayer *maskLayer = [CALayer layer];
        
        NSBundle *bundle = [NSBundle bundleForClass:self.class];
        NSURL *url = [bundle URLForResource:@"SVProgressHUD" withExtension:@"bundle"];
        NSBundle *imageBundle = [NSBundle bundleWithURL:url];
        NSString *path = [imageBundle pathForResource:@"angle-mask" ofType:@"png"];
        
        maskLayer.contents = (id)[[UIImage imageWithContentsOfFile:path] CGImage];;
        maskLayer.frame = _indefiniteAnimatedLayer.bounds;
        _indefiniteAnimatedLayer.mask = maskLayer;
        
        NSTimeInterval animationDuration = 1;
        CAMediaTimingFunction *linearCurve = [CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear];
        
        CABasicAnimation *animation = [CABasicAnimation animationWithKeyPath:@"transform.rotation"];
        animation.fromValue = 0;
        animation.toValue = [NSNumber numberWithFloat:M_PI*2];
        animation.duration = animationDuration;
        animation.timingFunction = linearCurve;
        animation.removedOnCompletion = NO;
        animation.repeatCount = INFINITY;
        animation.fillMode = kCAFillModeForwards;
        animation.autoreverses = NO;
        [_indefiniteAnimatedLayer.mask addAnimation:animation forKey:@"rotate"];
        
        CAAnimationGroup *animationGroup = [CAAnimationGroup animation];
        animationGroup.duration = animationDuration;
        animationGroup.repeatCount = INFINITY;
        animationGroup.removedOnCompletion = NO;
        animationGroup.timingFunction = linearCurve;
        
        CABasicAnimation *strokeStartAnimation = [CABasicAnimation animationWithKeyPath:@"strokeStart"];
        strokeStartAnimation.fromValue = @0.015;
        strokeStartAnimation.toValue = @0.515;
        
        CABasicAnimation *strokeEndAnimation = [CABasicAnimation animationWithKeyPath:@"strokeEnd"];
        strokeEndAnimation.fromValue = @0.485;
        strokeEndAnimation.toValue = @0.985;
        
        animationGroup.animations = @[strokeStartAnimation, strokeEndAnimation];
        [_indefiniteAnimatedLayer addAnimation:animationGroup forKey:@"progress"];
        
    }
    return _indefiniteAnimatedLayer;
}

- (void)setFrame:(CGRect)frame {
    if(!CGRectEqualToRect(frame, super.frame)){
        [super setFrame:frame];
        
        if (self.superview) {
            [self layoutAnimatedLayer];
        }
    }
    
}

- (void)setRadius:(CGFloat)radius {
    if(radius != _radius){
        _radius = radius;
        
        [_indefiniteAnimatedLayer removeFromSuperlayer];
        _indefiniteAnimatedLayer = nil;
        
        if (self.superview) {
            [self layoutAnimatedLayer];
        }
    }
}

- (void)setStrokeColor:(UIColor *)strokeColor {
    _strokeColor = strokeColor;
    _indefiniteAnimatedLayer.strokeColor = strokeColor.CGColor;
}

- (void)setStrokeThickness:(CGFloat)strokeThickness {
    _strokeThickness = strokeThickness;
    _indefiniteAnimatedLayer.lineWidth = _strokeThickness;
}

- (CGSize)sizeThatFits:(CGSize)size {
    return CGSizeMake((self.radius+self.strokeThickness/2+5)*2, (self.radius+self.strokeThickness/2+5)*2);
}

@end