CameraViewController.m

//
//  CameraViewController.m
//  unnamed
//
//  Created by Bruce Ng on 2/23/15.
//  Copyright (c) 2015 com.yahoo. All rights reserved.
//

#import "CameraViewController.h"
#import "UIColor+AppColor.h"

@interface CameraViewController () <UIImagePickerControllerDelegate, UINavigationControllerDelegate, UIAlertViewDelegate>
@property (weak, nonatomic) IBOutlet UIButton *takePhotoButton;
@property (weak, nonatomic) IBOutlet UIButton *selectPhotoButton;
@property (strong, nonatomic) IBOutlet UIImageView *photoImageView;

@end

@implementation CameraViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    self.view.backgroundColor = [UIColor appBgColor];
    // Do any additional setup after loading the view from its nib.
    if (![UIImagePickerController isSourceTypeAvailable:UIImagePickerControllerSourceTypeCamera]) {
        
        UIAlertView *myAlertView = [[UIAlertView alloc] initWithTitle:@"Error"
                                                              message:@"Device has no camera"
                                                             delegate:self
                                                    cancelButtonTitle:@"OK"
                                                    otherButtonTitles: nil];
        
        [myAlertView show];
        
    }
}

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex {
    self.takePhotoButton.enabled = NO;
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
- (IBAction)onTakePhoto:(UIButton *)sender {
    UIImagePickerController *picker = [[UIImagePickerController alloc] init];
    picker.delegate = self;
    picker.allowsEditing = YES;
    picker.sourceType = UIImagePickerControllerSourceTypeCamera;
    
    [self presentViewController:picker animated:YES completion:NULL];
}

- (IBAction)onSelectPhoto:(UIButton *)sender {
    UIImagePickerController *picker = [[UIImagePickerController alloc] init];
    picker.delegate = self;
    picker.allowsEditing = YES;
    picker.sourceType = UIImagePickerControllerSourceTypePhotoLibrary;
    
    [self presentViewController:picker animated:YES completion:NULL];
}

- (void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info {
    
    UIImage *chosenImage = info[UIImagePickerControllerEditedImage];
    self.photoImageView.image = chosenImage;
    
    [picker dismissViewControllerAnimated:YES completion:NULL];
    
    [self.delegate cameraViewController:self didSelectPhoto:[self image:chosenImage ByScalingAndCroppingForSize:CGSizeMake(400,400)]];
}

- (void)imagePickerControllerDidCancel:(UIImagePickerController *)picker {
    
    [picker dismissViewControllerAnimated:YES completion:NULL];
    
}

- (UIImage*)image:(UIImage *)sourceImage ByScalingAndCroppingForSize:(CGSize)targetSize
{
    UIImage *newImage = nil;
    CGSize imageSize = sourceImage.size;
    CGFloat width = imageSize.width;
    CGFloat height = imageSize.height;
    CGFloat targetWidth = targetSize.width;
    CGFloat targetHeight = targetSize.height;
    CGFloat scaleFactor = 0.0;
    CGFloat scaledWidth = targetWidth;
    CGFloat scaledHeight = targetHeight;
    CGPoint thumbnailPoint = CGPointMake(0.0,0.0);
    
    if (CGSizeEqualToSize(imageSize, targetSize) == NO)
    {
        CGFloat widthFactor = targetWidth / width;
        CGFloat heightFactor = targetHeight / height;
        
        if (widthFactor > heightFactor)
            scaleFactor = widthFactor; // scale to fit height
        else
            scaleFactor = heightFactor; // scale to fit width
        scaledWidth  = width * scaleFactor;
        scaledHeight = height * scaleFactor;
        
        // center the image
        if (widthFactor > heightFactor)
        {
            thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
        }
        else
            if (widthFactor < heightFactor)
            {
                thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
            }
    }
    
    UIGraphicsBeginImageContext(targetSize); // this will crop
    
    CGRect thumbnailRect = CGRectZero;
    thumbnailRect.origin = thumbnailPoint;
    thumbnailRect.size.width  = scaledWidth;
    thumbnailRect.size.height = scaledHeight;
    
    [sourceImage drawInRect:thumbnailRect];
    
    newImage = UIGraphicsGetImageFromCurrentImageContext();
    if(newImage == nil) 
        NSLog(@"could not scale image");
    
    //pop the context to get back to the default
    UIGraphicsEndImageContext();
    return newImage;
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/

@end