/*

Copyright (C) 2015 Apple Inc. All Rights Reserved.

See LICENSE.txt for this sample’s licensing information

Abstract:

The primary view controller for this app.

*/

#import "ViewController.h"

#import "Cell.h"

NSString * const cellIdentifier = @"MY_CELL";

@interface ViewController ()

@property (nonatomic, assign) NSInteger cellCount;

@end

@implementation ViewController

-(void)viewDidLoad

{

    [super viewDidLoad];

    self.cellCount = 20;

    UITapGestureRecognizer* tapRecognizer = [[UITapGestureRecognizer alloc] initWithTarget:self action:@selector(handleTapGesture:)];

    [self.collectionView addGestureRecognizer:tapRecognizer];

    [self.collectionView registerClass:[Cell class] forCellWithReuseIdentifier:cellIdentifier];

    [self.collectionView reloadData];

    self.collectionView.backgroundColor = [UIColor whiteColor];

}

- (NSInteger)collectionView:(UICollectionView *)view numberOfItemsInSection:(NSInteger)section;

{

    return self.cellCount;

}

- (UICollectionViewCell *)collectionView:(UICollectionView *)cv cellForItemAtIndexPath:(NSIndexPath *)indexPath;

{

    Cell *cell = [cv dequeueReusableCellWithReuseIdentifier:cellIdentifier forIndexPath:indexPath];

    return cell;

}

- (void)handleTapGesture:(UITapGestureRecognizer *)sender {

    if (sender.state == UIGestureRecognizerStateEnded)

    {

        CGPoint initialPinchPoint = [sender locationInView:self.collectionView];

        NSIndexPath* tappedCellPath = [self.collectionView indexPathForItemAtPoint:initialPinchPoint];

        if (tappedCellPath!=nil)

        {

            self.cellCount = self.cellCount - 1;

            [self.collectionView performBatchUpdates:^{

                [self.collectionView deleteItemsAtIndexPaths:@[tappedCellPath]];

            } completion:nil];

        }

        else

        {

            self.cellCount = self.cellCount + 1;

            [self.collectionView performBatchUpdates:^{

                [self.collectionView insertItemsAtIndexPaths:@[[NSIndexPath indexPathForItem:0 inSection:0]]];

            } completion:nil];

        }

    }

}

@end