clock number

ViewController.m

//
//  ViewController.m
//  clockNumber
//
//  Created by MizushimaYusuke on 9/21/15.
//  Copyright © 2015 MizushimaYusuke. All rights reserved.
//

#import "ViewController.h"

@interface ShapeLayerHitCustom : CAShapeLayer
@end

@implementation ShapeLayerHitCustom
- (BOOL)containsPoint:(CGPoint)p
{
    return CGPathContainsPoint(self.path, NULL, p, false);
}
@end

@interface ViewController ()
@property (nonatomic, weak) CALayer *selected;
@end

@implementation ViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor orangeColor];
    
    [self createClock];
}

- (void)createClock {
    
    CGPoint o = CGPointMake(CGRectGetMidX(self.view.bounds), CGRectGetMidY(self.view.bounds));
    
    float s = CGRectGetMaxX(self.view.bounds) * 0.84;
    UIView *v = [[UIView alloc] initWithFrame:CGRectMake(0, 0, s, s)];
    v.center = o;
    v.backgroundColor = [UIColor whiteColor];
    v.layer.cornerRadius = s * 0.5;
    [self.view addSubview:v];

    UIBezierPath *path = [UIBezierPath bezierPath];
    [path moveToPoint:o];
    [path addLineToPoint:CGPointMake(o.x + s * 0.5, o.y)];
    [path addArcWithCenter:o radius:s * 0.5 startAngle:0 endAngle:M_PI / 6.0 clockwise:YES];
    [path closePath];
    
    float dw = M_PI / 6.0;
    
    NSMutableArray *numbers = [NSMutableArray array];
    for (int i=1; i<=12; i++) [numbers addObject:@(i)];
    
    for (int i=1; i<=12; i++) {
        
        float w = i * dw - dw * 3.5;
        int n = [[numbers objectAtIndex:(arc4random() % (int)numbers.count)] intValue];
        [numbers removeObject:@(n)];
        
        CAShapeLayer *l = [ShapeLayerHitCustom layer];
        l.name = [NSString stringWithFormat:@"%d", n];
        l.frame = self.view.bounds;
        l.path = path.CGPath;
        l.fillColor = [UIColor colorWithHue:0.3 saturation:0.8 brightness:0.7 alpha:1].CGColor;
        l.transform = CATransform3DMakeRotation(w, 0, 0, 1);
        l.masksToBounds = YES;
        [self.view.layer addSublayer:l];
        
        CATextLayer *t = [CATextLayer layer];
        t.bounds = CGRectMake(0, 0, 40, 40);
        t.fontSize = 30;
        t.backgroundColor = [UIColor clearColor].CGColor;
        t.alignmentMode = kCAAlignmentCenter;
        t.string = [NSString stringWithFormat:@"%d", n];
        t.position = CGPointMake(o.x + s * 0.4, o.y + 30);
        t.transform = CATransform3DMakeRotation(-w, 0, 0, 1);
        [l addSublayer:t];
    }
}

- (void)touchesBegan:(NSSet<UITouch *> *)touches withEvent:(UIEvent *)event {
    CGPoint p = [[touches anyObject] locationInView:self.view];
    CALayer *l = [self.view.layer hitTest:p];
    
    if ([l isKindOfClass:[CATextLayer class]]) {
        l = l.superlayer;
    }
    
    if (l.name) {
        if (!self.selected) {
            self.selected = l;
            ((CAShapeLayer*)l).fillColor = [UIColor colorWithHue:0.7 saturation:0.8 brightness:0.7 alpha:1].CGColor;
        } else {
            CATextLayer *a = (CATextLayer *)self.selected.sublayers[0];
            CATextLayer *b = (CATextLayer *)l.sublayers[0];
            NSString *aText = a.string;
            a.string = b.string;
            b.string = aText;
            
            ((CAShapeLayer*)self.selected).fillColor = [UIColor colorWithHue:0.3 saturation:0.8 brightness:0.7 alpha:1].CGColor;
            ((CAShapeLayer*)l).fillColor = [UIColor colorWithHue:0.7 saturation:0.8 brightness:0.7 alpha:1].CGColor;
            dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.2 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
                ((CAShapeLayer*)l).fillColor = [UIColor colorWithHue:0.3 saturation:0.8 brightness:0.7 alpha:1].CGColor;
            });
            
            self.selected = nil;
        }
    }
}

@end

http://lepetit-prince.net/ios/?p=4376