Swiftgram/examples/ASViewController/Sample/DetailRootNode.m

//
//  DetailRootNode.m
//  Sample
//
//  Copyright (c) 2014-present, Facebook, Inc.  All rights reserved.
//  This source code is licensed under the BSD-style license found in the
//  LICENSE file in the root directory of this source tree. An additional grant
//  of patent rights can be found in the PATENTS file in the same directory.
//
//  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 "DetailRootNode.h"
#import <AsyncDisplayKit/AsyncDisplayKit.h>

#import "DetailCellNode.h"

static const NSInteger kImageHeight = 200;

@interface DetailRootNode () <ASCollectionViewDataSource, ASCollectionViewDelegate>
@property (nonatomic, copy) NSString *imageCategory;
@property (nonatomic, strong) ASCollectionNode *collectionNode;
@end

@implementation DetailRootNode

#pragma mark - Lifecycle

- (instancetype)initWithImageCategory:(NSString *)imageCategory
{
    self = [super init];
    if (self == nil) { return self; }
    
    _imageCategory = imageCategory;

    // Create ASCollectionView. We don't have to add it explicitly as subnode as we will set usesImplicitHierarchyManagement to YES
    UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
    _collectionNode = [[ASCollectionNode alloc] initWithCollectionViewLayout:layout];
    _collectionNode.delegate = self;
    _collectionNode.dataSource = self;
    _collectionNode.backgroundColor = [UIColor whiteColor];
    
    // Enable usesImplicitHierarchyManagement so the first time the layout pass of the node is happening all nodes that are referenced
    // in layouts within layoutSpecThatFits: will be added automatically
    self.usesImplicitHierarchyManagement = YES;
    
    return self;
}

- (void)dealloc
{
    _collectionNode.delegate = nil;
    _collectionNode.dataSource = nil;
}

#pragma mark - ASDisplayNode

- (ASLayoutSpec *)layoutSpecThatFits:(ASSizeRange)constrainedSize
{
    self.collectionNode.position = CGPointZero;
    self.collectionNode.sizeRange = ASRelativeSizeRangeMakeWithExactCGSize(constrainedSize.max);
    return [ASStaticLayoutSpec staticLayoutSpecWithChildren:@[self.collectionNode]];
}

#pragma mark - ASCollectionDataSource

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return 10;
}

- (ASCellNodeBlock)collectionView:(ASCollectionView *)collectionView nodeBlockForItemAtIndexPath:(NSIndexPath *)indexPath
{
    NSString *imageCategory = self.imageCategory;
    return ^{
        DetailCellNode *node = [[DetailCellNode alloc] init];
        node.row = indexPath.row;
        node.imageCategory = imageCategory;
        return node;
    };
}

- (ASSizeRange)collectionView:(ASCollectionView *)collectionView constrainedSizeForNodeAtIndexPath:(NSIndexPath *)indexPath
{
    CGSize imageSize = CGSizeMake(CGRectGetWidth(collectionView.frame), kImageHeight);
    return ASSizeRangeMake(imageSize, imageSize);
}

@end