iOSテストインタフェースのスムーズさ

他の人のdemoから引き出されたコードの1つは,現在のインタフェースのフレームフローを検出することができ,インタフェースのスムーズさに高い要求がある場合にこのコードで検出することができる.

// .h 
#import 

@interface GGFPSLabel : UILabel

@end

// .m 
#import "GGFPSLabel.h"

#define kSize CGSizeMake(100, 20)

/***   */
@implementation GGFPSLabel{
    CADisplayLink *_link;
    NSUInteger _count;
    NSTimeInterval _lastTime;
    UIFont *_font;
    UIFont *_subFont;
    
    NSTimeInterval _llll;
}

- (instancetype)initWithFrame:(CGRect)frame {
    if (frame.size.width == 0 && frame.size.height == 0) {
        frame.size = kSize;
        
    }
    self = [super initWithFrame:frame];
    
    self.layer.cornerRadius = 5;
    self.clipsToBounds = YES;
    self.textAlignment = NSTextAlignmentCenter;
    self.userInteractionEnabled = NO;
    self.backgroundColor = [UIColor colorWithWhite:0.000 alpha:0.700];
    
    _font = [UIFont fontWithName:@"Menlo" size:14];
    if (_font) {
        _subFont = [UIFont fontWithName:@"Menlo" size:4];
    } else {
        _font = [UIFont fontWithName:@"Courier" size:14];
        _subFont = [UIFont fontWithName:@"Courier" size:4];
    }
    
    _link = [CADisplayLink displayLinkWithTarget:self selector:@selector(tick:)];
    [_link addToRunLoop:[NSRunLoop mainRunLoop] forMode:NSRunLoopCommonModes];
    return self;
}

- (void)dealloc {
    [_link invalidate];
}

- (CGSize)sizeThatFits:(CGSize)size {
    return kSize;
}

- (void)tick:(CADisplayLink *)link {
    if (_lastTime == 0) {
        _lastTime = link.timestamp;
        return;
    }
    
    _count++;
    NSTimeInterval delta = link.timestamp - _lastTime;
    if (delta < 1) return;
    _lastTime = link.timestamp;
    float fps = _count / delta;
    _count = 0;
    
    CGFloat progress = fps / 60.0;
    UIColor *color = [UIColor colorWithHue:0.27 * (progress - 0.2) saturation:1 brightness:0.9 alpha:1];
    
    NSMutableAttributedString *text = [[NSMutableAttributedString alloc] initWithString:[NSString stringWithFormat:@"%.2f FPS", fps]];
    [text setAttributes:@{NSForegroundColorAttributeName : color} range:NSMakeRange(0, text.length - 3)];
    [text setAttributes:@{NSForegroundColorAttributeName : [UIColor whiteColor]} range:NSMakeRange(text.length - 3, 3)];
    self.attributedText = text;
}