Swiftgram/examples/CustomCollectionView/Sample/ViewController.m

/* This file provided by Facebook is for non-commercial testing and evaluation
 * purposes only.  Facebook reserves all rights not expressly granted.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * FACEBOOK BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 */

#import "ViewController.h"

#import <AsyncDisplayKit/AsyncDisplayKit.h>
#import "MosaicCollectionViewLayout.h"
#import "SupplementaryNode.h"
#import "ImageCellNode.h"

static NSUInteger kNumberOfImages = 14;

@interface ViewController () <ASCollectionViewDataSource, MosaicCollectionViewLayoutDelegate>
{
  NSMutableArray *_sections;
  ASCollectionView *_collectionView;
  MosaicCollectionViewLayoutInspector *_layoutInspector;
}

@end

@implementation ViewController

#pragma mark -
#pragma mark UIViewController.

- (instancetype)init
{
  if (!(self = [super init]))
    return nil;
  
  _sections = [NSMutableArray array];
  [_sections addObject:[NSMutableArray array]];
  for (NSUInteger idx = 0, section = 0; idx < kNumberOfImages; idx++) {
    NSString *name = [NSString stringWithFormat:@"image_%lu.jpg", (unsigned long)idx];
    [_sections[section] addObject:[UIImage imageNamed:name]];
    if ((idx + 1) % 5 == 0 && idx < kNumberOfImages - 1) {
      section++;
      [_sections addObject:[NSMutableArray array]];
    }
  }
  
  MosaicCollectionViewLayout *layout = [[MosaicCollectionViewLayout alloc] init];
  layout.numberOfColumns = 2;
  layout.headerHeight = 44.0;
  
  _layoutInspector = [[MosaicCollectionViewLayoutInspector alloc] init];
  
  _collectionView = [[ASCollectionView alloc] initWithFrame:CGRectZero collectionViewLayout:layout];
  _collectionView.asyncDataSource = self;
  _collectionView.asyncDelegate = self;
  _collectionView.layoutInspector = _layoutInspector;
  _collectionView.backgroundColor = [UIColor whiteColor];
  
  [_collectionView registerSupplementaryNodeOfKind:UICollectionElementKindSectionHeader];
  
  return self;
}

- (void)dealloc
{
  _collectionView.asyncDataSource = nil;
  _collectionView.asyncDelegate = nil;
}

- (void)viewDidLoad
{
  [super viewDidLoad];
  
  [self.view addSubview:_collectionView];
}

- (void)viewWillLayoutSubviews
{
  _collectionView.frame = self.view.bounds;
}

- (BOOL)prefersStatusBarHidden
{
  return YES;
}

- (void)reloadTapped
{
  [_collectionView reloadData];
}

#pragma mark -
#pragma mark ASCollectionView data source.

- (ASCellNodeBlock)collectionView:(ASCollectionView *)collectionView nodeBlockForItemAtIndexPath:(NSIndexPath *)indexPath
{
  UIImage *image = _sections[indexPath.section][indexPath.item];
  return ^{
    return [[ImageCellNode alloc] initWithImage:image];
  };
}


- (ASCellNode *)collectionView:(ASCollectionView *)collectionView nodeForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
{
  NSString *text = [NSString stringWithFormat:@"Section %zd", indexPath.section + 1];
  return [[SupplementaryNode alloc] initWithText:text];
}

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView
{
  return _sections.count;
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
  return [_sections[section] count];
}

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout originalItemSizeAtIndexPath:(NSIndexPath *)indexPath
{
  return [(UIImage *)_sections[indexPath.section][indexPath.item] size];
}

@end