ConsumptionViewController.m

//
//  ANConsumptionViewController.m
//  Futruy
//
//  Created by Milan Vít on 31.01.14.
//  Copyright (c) 2014 AiNeuron. All rights reserved.
//

#import "ANConsumptionViewController.h"

@interface ANConsumptionViewController ()
@property (nonatomic, strong) UIView *highlightView;
@property (nonatomic, strong) AVCaptureSession *session;
@property (nonatomic, strong) AVCaptureDevice *device;
@property (nonatomic, strong) AVCaptureDeviceInput *input;
@property (nonatomic, strong) AVCaptureMetadataOutput *output;
@property (nonatomic, strong) AVCaptureVideoPreviewLayer *previousLayer;
@end

@implementation ANConsumptionViewController
#pragma mark Initialisation methods
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];

    if (self)
    {
    }

    return self;
}

#pragma mark Superclass methods
- (void)viewDidLoad
{
    NSError *error = nil;

    [super viewDidLoad];

    [[UIDevice currentDevice] beginGeneratingDeviceOrientationNotifications];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(orientationChanged:) name:UIDeviceOrientationDidChangeNotification object:nil];

    [self setHighlightView:[[UIView alloc] init]];
    [[self highlightView] setAutoresizingMask:UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | UIViewAutoresizingFlexibleBottomMargin];
    [[[self highlightView] layer] setBorderColor:[[UIColor colorWithRed:227/255.0 green:0 blue:24/255.0 alpha:1] CGColor]];
    [[[self highlightView] layer] setBorderWidth:3];
    [[self view] addSubview:[self highlightView]];

    [self setSession:[[AVCaptureSession alloc] init]];
    [self setDevice:[AVCaptureDevice defaultDeviceWithMediaType:AVMediaTypeVideo]];
    [self setInput:[AVCaptureDeviceInput deviceInputWithDevice:[self device] error:&error]];

    if ([self input])
    {
        [[self session] addInput:self.input];
    }
    else
    {
        NSLog(@"Error: %@", error);
    }

    [self setOutput:[[AVCaptureMetadataOutput alloc] init]];
    [[self output] setMetadataObjectsDelegate:self queue:dispatch_get_main_queue()];
    [[self session] addOutput:[self output]];
    [[self output] setMetadataObjectTypes:[[self output] availableMetadataObjectTypes]];

    [self setPreviousLayer:[AVCaptureVideoPreviewLayer layerWithSession:[self session]]];
    [[self previousLayer] setFrame:[[self view] bounds]];
    [[self previousLayer] setVideoGravity:AVLayerVideoGravityResizeAspectFill];
    [[[self view] layer] addSublayer:[self previousLayer]];

    [[self session] startRunning];
    [[self view] bringSubviewToFront:[self highlightView]];
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
}

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
    [touches enumerateObjectsUsingBlock:^(id obj, BOOL *stop)
    {
        UITouch *touch = obj;
        CGPoint touchPoint = [touch locationInView:[touch view]];
        CGRect screenRect = [[UIScreen mainScreen] bounds];
        CGFloat focusX, focusY;

        if (UIDeviceOrientationIsPortrait([[UIDevice currentDevice] orientation]))
        {
            focusX = touchPoint.x / screenRect.size.width;
            focusY = touchPoint.y / screenRect.size.height;
        }
        else
        {
            focusX = touchPoint.x / screenRect.size.height;
            focusY = touchPoint.y / screenRect.size.width;
        }

        CGPoint focusPoint = CGPointMake(focusX, focusY);

        if ([[self device] isFocusPointOfInterestSupported])
        {
            NSError *error;

            if ([[self device] lockForConfiguration:&error])
            {
                [[self device] setFocusPointOfInterest:focusPoint];
                [[self device] setExposurePointOfInterest:focusPoint];
                [[self device] setFocusMode:AVCaptureFocusModeAutoFocus];

                if ([[self device] isExposureModeSupported:AVCaptureExposureModeAutoExpose])
                {
                    [[self device] setExposureMode:AVCaptureExposureModeAutoExpose];
                }

                [[self device] unlockForConfiguration];
            }
        }
    }];
}

#pragma mark Private methods
- (void)orientationChanged:(NSNotification *)notification
{

}

#pragma mark AVCaptureMetadataOutputObjects delegate methods
- (void)captureOutput:(AVCaptureOutput *)captureOutput didOutputMetadataObjects:(NSArray *)metadataObjects fromConnection:(AVCaptureConnection *)connection
{
    CGRect highlightViewRect = CGRectZero;
    AVMetadataMachineReadableCodeObject *barCodeObject;
    NSString *detectionString = nil;
    NSArray *barCodeTypes = @[AVMetadataObjectTypeEAN8Code, AVMetadataObjectTypeEAN13Code, AVMetadataObjectTypeQRCode];

    for (AVMetadataObject *metadata in metadataObjects)
    {
        for (NSString *type in barCodeTypes)
        {
            if ([[metadata type] isEqualToString:type])
            {
                barCodeObject = (AVMetadataMachineReadableCodeObject *)[[self previousLayer] transformedMetadataObjectForMetadataObject:(AVMetadataMachineReadableCodeObject *) metadata];
                highlightViewRect = [barCodeObject bounds];
                detectionString = [(AVMetadataMachineReadableCodeObject *)metadata stringValue];

                break;
            }
        }

        if (detectionString != nil)
        {
            // TODO: uncomment when you are ready to pass the value to next view controller
            //[[self session] stopRunning];
            break;
        }
        else
        {
        }
    }

    [[self highlightView] setFrame:highlightViewRect];
}
@end