Add custom collection view layout example project

examples/CustomCollectionView/Sample/ViewController.m

@@ -0,0 +1,117 @@
+/* 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 asyncDataFetching:YES];
+  _collectionView.asyncDataSource = self;
+  _collectionView.asyncDelegate = self;
+  _collectionView.layoutInspector = _layoutInspector;
+  _collectionView.backgroundColor = [UIColor whiteColor];
+  
+  [_collectionView registerSupplementaryNodeOfKind:UICollectionElementKindSectionHeader];
+  
+  return self;
+}
+
+- (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.
+
+- (ASCellNode *)collectionView:(ASCollectionView *)collectionView nodeForItemAtIndexPath:(NSIndexPath *)indexPath
+{
+  return [[ImageCellNode alloc] initWithImage:_sections[indexPath.section][indexPath.item]];
+}
+
+- (ASCellNode *)collectionView:(ASCollectionView *)collectionView nodeForSupplementaryElementOfKind:(NSString *)kind atIndexPath:(NSIndexPath *)indexPath
+{
+  NSString *text = [NSString stringWithFormat:@"Section %d", (int)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