UICollectionView

#import "HomeViewController.h"
#import <Parse/Parse.h>

@interface HomeViewController ()

@end

@implementation HomeViewController

-(instancetype) init {
    UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];

    layout.itemSize = CGSizeMake(106.0, 106.0);
    layout.minimumInteritemSpacing = 100.0;
    layout.minimumLineSpacing = 1.0;
    return (self = [super initWithCollectionViewLayout:layout]);
}

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.collectionView.backgroundColor = [UIColor whiteColor];
    [self.collectionView registerClass:[UICollectionViewCell class] forCellWithReuseIdentifier:@"photo"];

    PFUser *currentUser = [PFUser currentUser];
    if (currentUser) {
        NSLog(@"Current User: %@", currentUser.username);
    }
    else {
        [self performSegueWithIdentifier:@"showLogin" sender:self];
    }


}

-(void) prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {

    if ([segue.identifier isEqualToString:@"showLogin"]) {

        [segue.destinationViewController setHidesBottomBarWhenPushed:YES];
    }
}

-(NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return 20;
}

- (UICollectionViewCell *) collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    static NSString *CellIdentifier = @"photo";
    UICollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:CellIdentifier forIndexPath:indexPath];

    cell.backgroundColor = [UIColor lightGrayColor];

    return cell;
}

@end