//
// CKScanManager.m
// iOS7使用原生API进行二维码和条形码的扫描
//

import "CKScanHelper.h"

import <AVFoundation/AVFoundation.h>

@interface CKScanHelper() <AVCaptureMetadataOutputObjectsDelegate>
{
AVCaptureSession _session; //输入输出的中间桥梁
AVCaptureVideoPreviewLayer _layer; //捕捉视频预览层
AVCaptureMetadataOutput _output; //捕获元数据输出
AVCaptureDeviceInput _input; //采集设备输入
UIView *_superView; //图层的父类
}

@end

@implementation CKScanHelper

pragma mark - 生命周期

//第二步：实现声明单例方法 GCD

• (instancetype)manager
  {
  static CKScanHelper *singleton = nil;
  static dispatch_once_t onceToken;
  dispatch_once(&onceToken, ^{
  singleton = [[CKScanHelper alloc] init];
  });
  return singleton;
  }

//初始化-单例，只调用一次

• (id)init
  {
  self = [super init];
  if (self) {
  //初始化链接对象
  _session = [[AVCaptureSession alloc]init];
  //高质量采集率
  [_session setSessionPreset:AVCaptureSessionPresetHigh];

  // 避免模拟器运行崩溃  
  if(!TARGET_IPHONE_SIMULATOR) {  
      //获取摄像设备  
      AVCaptureDevice *device = [AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo];  
      //创建输入流  
      _input = [AVCaptureDeviceInput deviceInputWithDevice:device error:nil];  
      [_session addInput:_input];  
  
      //创建输出流  
      _output = [[AVCaptureMetadataOutput alloc]init];  
      //设置代理 在主线程里刷新  
      [_output setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];  
      [_session addOutput:_output];  
      //设置扫码支持的编码格式(如下设置条形码和二维码兼容)  
      _output.metadataObjectTypes = @[AVMetadataObjectTypeQRCode,  
                                      AVMetadataObjectTypeEAN13Code,  
                                      AVMetadataObjectTypeEAN8Code,  
                                      AVMetadataObjectTypeCode128Code];  
  }  
  _layer = [AVCaptureVideoPreviewLayer layerWithSession:_session];  
  _layer.videoGravity=AVLayerVideoGravityResizeAspectFill;  

  }
  return self;
  }

//销毁对象

• (void)dealloc
  {
  _scanView = nil;
  _scanBlock = nil;
  }

pragma mark - 方法

• (void)startRunning {
  //开始捕获
  [_session startRunning];
  }

• (void)stopRunning {
  //停止捕获
  [_session stopRunning];
  }

/**

• 显示图层
• @param superView 需要在哪个View显示
  */
  • (void)showLayer:(UIView *)superView {
    _superView = superView;
    _layer.frame = superView.layer.frame;
    [superView.layer insertSublayer:_layer atIndex:0];
    }

/**

• 设置扫描范围区域 CGRectMake（y的起点/屏幕的高，x的起点/屏幕的宽，扫描的区域的高/屏幕的高，扫描的区域的宽/屏幕的宽）
• @param scanRect 扫描范围

• @param scanView 扫描框
  */

  • (void)setScanningRect:(CGRect)scanRect scanView:(UIView *)scanView
    {
    CGFloat x,y,width,height;

  x = scanRect.origin.y / _layer.frame.size.height;
  y = scanRect.origin.x / _layer.frame.size.width;
  width = scanRect.size.height / _layer.frame.size.height;
  height = scanRect.size.width / _layer.frame.size.width;

  _output.rectOfInterest = CGRectMake(x, x, width, height);

  self.scanView = scanView;
  if (self.scanView) {
  self.scanView.frame = scanRect;
  if (_superView) {
  [_superView addSubview:self.scanView];
  }
  }
  }

pragma mark - AVCaptureMetadataOutputObjects Delegate

• (void)captureOutput:(AVCaptureOutput )captureOutput didOutputMetadataObjects:(NSArray )metadataObjects fromConnection:(AVCaptureConnection )connection{
  if (metadataObjects.count > 0) {
  //[_session stopRunning];
  AVMetadataMachineReadableCodeObject metadataObject = [metadataObjects objectAtIndex :0];
  if (self.scanBlock) {
  self.scanBlock(metadataObject.stringValue);
  }
  //输出扫描字符串
  NSLog(@"%@",metadataObject.stringValue);
  }
  }

@end