数字の６がくるっと回る。というiPhoneアプリのサンプルコードを描いてみます。
#import “ViewController.h”
@interface ViewController ()
@property (nonatomic, weak) UIView *six;
@property (nonatomic) NSUInteger counter;
@end
@implementation ViewController
– (void)viewDidLoad
{
[super viewDidLoad];
self.view.backgroundColor = [UIColor brownColor];
[self create6:[UIColor lightGrayColor]];
[self createDial];
self.six = [self create6:[UIColor whiteColor]];
}
– (UIView *)create6:(UIColor *)color
{
UIView *v = [[UIView alloc] initWithFrame:CGRectMake(10, 80, 300, 300)];
v.backgroundColor = [UIColor clearColor];
[self.view addSubview:v];
float r1 = 300.0 / 3.0;
UIView *circle = [[UIView alloc] initWithFrame:CGRectMake(0, 0, r1, r1)];
circle.layer.cornerRadius = r1/2.0;
circle.backgroundColor = color;
circle.center = CGPointMake(150, 150);
[v addSubview:circle];
UIView *bar = [[UIView alloc] initWithFrame:CGRectMake(100, 40, 30, 120)];
bar.layer.cornerRadius = 15;
bar.backgroundColor = circle.backgroundColor;
[v addSubview:bar];
float r2 = 300 / 7.2;
UIView *hole = [[UIView alloc] initWithFrame:CGRectMake(0, 0, r2, r2)];
hole.center = circle.center;
hole.backgroundColor = self.view.backgroundColor;
hole.layer.cornerRadius = r2/2.0;
[v addSubview:hole];
return v;
}
– (void)createDial
{
CGPoint o = CGPointMake(160, 230);
for (int i=0; i<6; i++) {
float angle = i * M_PI/3.0 – M_PI/6.0;
float x = 110 * cos(angle) + o.x;
float y = 110 * sin(angle) + o.y;
UILabel *l = [[UILabel alloc] init];
l.text = [@(i+1) stringValue];
l.font = [UIFont boldSystemFontOfSize:20];
l.textColor = [UIColor whiteColor];
[l sizeToFit];
l.center = CGPointMake(x, y);
l.backgroundColor = [UIColor clearColor];
[self.view addSubview:l];
}
}
#define mInterval 0.05
– (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
[NSTimer scheduledTimerWithTimeInterval:mInterval target:self selector:@selector(tick:) userInfo:nil repeats:YES];
}
– (void)tick:(NSTimer *)sender
{
self.counter++;
float boundary = 6.0 / mInterval;
if (self.counter > boundary) {
[sender invalidate];
self.counter = 0;
return;
}
float dAngle = mInterval * M_PI/3.0;
self.six.transform = CGAffineTransformRotate(self.six.transform, dAngle);
}
@end