问使用objective-c的无限旋转木马

EN

#import "ViewController.h"

@interface ViewController () {

@private NSInteger index;
@private NSInteger iterations;
@private UIButton* buttons[6];
@private CGPoint centers[6];
@private CGRect bounds[6];
@private CGFloat opacities[6];
@private CGFloat opacitieOffsets[6];
@private CGPoint centerOffsets[6];
@private CGRect boundOffsets[6];
@private NSString* titles[6];

}

@property (strong, nonatomic) NSTimer *timer;

@end

@implementation ViewController

@synthesize Button1;
@synthesize Button2;
@synthesize Button3;
@synthesize Button4;
@synthesize Button5;
@synthesize Button6;
@synthesize TitleLabel;

- (void)viewDidLoad
{
    [super viewDidLoad];

    buttons[0] = Button1;
    titles[0] = @"btnTitle1";
    buttons[1] = Button2;
    titles[1] = @"btnTitle2";
    buttons[2] = Button3;
    titles[2] = @"btnTitle3";
    buttons[3] = Button4;
    titles[3] = @"btnTitle4";
    buttons[4] = Button5;
    titles[4] = @"btnTitle5";
    buttons[5] = Button6;
    titles[5] = @"btnTitle6";

    for (NSInteger i = 0; i < 6; i++)
    {
        centers[i] = buttons[i].center;
        bounds[i] = buttons[i].bounds;
        opacities[i] = buttons[i].alpha;
    }
}

- (void)viewDidUnload
{
    [self stopAnimation];
    [self setButton1:nil];
    [self setButton2:nil];
    [self setButton3:nil];
    [self setButton4:nil];
    [self setButton5:nil];
    [self setButton6:nil];
    [self setTitleLabel:nil];

    [super viewDidUnload];
}

/////////////////////////////////////////////////////
- (IBAction)swipeLeft:(UISwipeGestureRecognizer *)sender {
    [self stopAnimation];
    buttons[index].enabled = NO;
    {
        TitleLabel.text = @"";
        index = [self next:index];
        [self startAnimation];
    }
}

- (IBAction)swipeRight:(UISwipeGestureRecognizer *)sender { 
    [self stopAnimation];
    buttons[index].enabled = NO;
    {
        TitleLabel.text = @"";
        index = [self back:index];
        [self startAnimation];
    }
}
///////////////////////////////////////////////////
- (void)startAnimation
{
    [self prepareForUpdate];
    [self.timer invalidate];
    self.timer = [NSTimer scheduledTimerWithTimeInterval:0 target:self selector:@selector(update) userInfo:nil repeats:YES];
}

- (void)stopAnimation
{
    [self.timer invalidate];
    [self finalizeUpdate];
    self.timer = nil;
}

- (void)prepareForUpdate
{
    NSInteger i = 0;
    NSInteger iter = index;

    do
    {
        centerOffsets[iter] = CGPointMake
        (
         (centers[i].x - buttons[iter].center.x) / 30,
         (centers[i].y - buttons[iter].center.y) / 30
         );
        boundOffsets[iter] = CGRectMake
        (
         (bounds[i].origin.x - buttons[iter].bounds.origin.x) / 30,
         (bounds[i].origin.y - buttons[iter].bounds.origin.y) / 30,
         (bounds[i].size.width - buttons[iter].bounds.size.width) / 30,
         (bounds[i].size.height - buttons[iter].bounds.size.height) / 30
         );
        opacitieOffsets[iter] = (opacities[i] - buttons[iter].alpha) / 30;

        i++;
        iter = [self next:iter];
    }
    while ( iter != index);
    iterations = 30;
}

- (void)update
{
    if (iterations <= 1)
    {

    }
    if (iterations > 0)
    {
        for (NSInteger i = 0; i < 6; i++)
        {
            buttons[i].center = CGPointMake
            (
             centerOffsets[i].x + buttons[i].center.x,
             centerOffsets[i].y + buttons[i].center.y
             );
            buttons[i].bounds = CGRectMake
            (
             boundOffsets[i].origin.x + buttons[i].bounds.origin.x,
             boundOffsets[i].origin.y + buttons[i].bounds.origin.y,
             boundOffsets[i].size.width + buttons[i].bounds.size.width,
             boundOffsets[i].size.height + buttons[i].bounds.size.height
             );
            buttons[i].alpha = buttons[i].alpha + opacitieOffsets[i];
        }
        iterations--;
    }
    else [self stopAnimation];
}

- (void)finalizeUpdate
{
    NSInteger i = 0;
    NSInteger iter = index;

    do
    {
        buttons[iter].center = centers[i];
        buttons[iter].bounds = bounds[i];
        buttons[iter].alpha = opacities[i];

        i++;
        iter = [self next:iter];
    }
    while ( iter != index);
    iterations = 0;
    buttons[index].enabled = YES;

    TitleLabel.text = titles[index];
}

- (NSInteger)back:(NSInteger) i
{
    return i == 0 ? 5 : i - 1;
}

- (NSInteger)next:(NSInteger) i
{
    return i == 5 ? 0 : i + 1;
}