import <Foundation/Foundation.h>

@interface NSTimer (addition)

• (void)pause;
• (void)resume;
• (void)resumeWithTimeInterval:(NSTimeInterval)time;

@end

import "NSTimer+addition.h"

@implementation NSTimer (addition)

• (void)pause {
  if (!self.isValid) return;
  [self setFireDate:[NSDate distantFuture]];
  }

• (void)resume {
  if (!self.isValid) return;
  [self setFireDate:[NSDate date]];
  }

• (void)resumeWithTimeInterval:(NSTimeInterval)time {
  if (!self.isValid) return;
  [self setFireDate:[NSDate dateWithTimeIntervalSinceNow:time]];
  }

@end

@interface RGWebProgressLayer : CAShapeLayer

• (void)finishedLoad;

• (void)startLoad;

• (void)closeTimer;

@end

import "RGWebProgressLayer.h"

import "NSTimer+addition.h"

static NSTimeInterval const kFastTimeInterval = 0.003;

@implementation RGWebProgressLayer{
CAShapeLayer *_layer;

NSTimer *_timer;
CGFloat _plusWidth; ///< 增加点

}

• (instancetype)init {
  if (self = [super init]) {
  [self initialize];
  }
  return self;
  }

• (void)initialize {
  self.lineWidth = 2;
  self.strokeColor = [UIColor greenColor].CGColor;

  _timer = [NSTimer scheduledTimerWithTimeInterval:kFastTimeInterval target:self selector:@selector(pathChanged:) userInfo:nil repeats:YES];
  [_timer pause];

  UIBezierPath *path = [UIBezierPath bezierPath];
  [path moveToPoint:CGPointMake(0, 2)];
  [path addLineToPoint:CGPointMake(KScreen_Width, 2)];

  self.path = path.CGPath;
  self.strokeEnd = 0;
  _plusWidth = 0.01;
  }

• (void)pathChanged:(NSTimer *)timer {
  self.strokeEnd += _plusWidth;

  if (self.strokeEnd > 0.8) {
  _plusWidth = 0.002;
  }
  }

• (void)startLoad {
  [_timer resumeWithTimeInterval:kFastTimeInterval];
  }

• (void)finishedLoad {
  [self closeTimer];

  self.strokeEnd = 1.0;
  dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(0.25 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{
  self.hidden = YES;
  [self removeFromSuperlayer];
  });
  }

• (void)dealloc {
  // NSLog(@"progressView dealloc");
  [self closeTimer];
  }

pragma mark - private

• (void)closeTimer {
  [_timer invalidate];
  _timer = nil;
  }