#import <AsyncDisplayKit/ASPagerNode.h>

#import <AsyncDisplayKit/ASDelegateProxy.h>

#import <AsyncDisplayKit/ASDisplayNode+FrameworkPrivate.h>

#import <AsyncDisplayKit/ASDisplayNode+Subclasses.h>

#import <AsyncDisplayKit/ASPagerFlowLayout.h>

#import <AsyncDisplayKit/ASAssert.h>

#import <AsyncDisplayKit/ASCellNode.h>

#import <AsyncDisplayKit/ASCollectionView+Undeprecated.h>

#import <AsyncDisplayKit/UIResponder+AsyncDisplayKit.h>

@interface ASPagerNode () <ASCollectionDataSource, ASCollectionDelegate, ASCollectionDelegateFlowLayout, ASDelegateProxyInterceptor>

{

ASPagerFlowLayout *_flowLayout;

__weak id <ASPagerDataSource> _pagerDataSource;

ASPagerNodeProxy *_proxyDataSource;

struct {

unsigned nodeBlockAtIndex:1;

unsigned nodeAtIndex:1;

} _pagerDataSourceFlags;

__weak id <ASPagerDelegate> _pagerDelegate;

struct {

unsigned constrainedSizeForNode:1;

} _pagerDelegateFlags;

ASPagerNodeProxy *_proxyDelegate;

}

@implementation ASPagerNode

@dynamic view, delegate, dataSource;

#pragma mark - Lifecycle

- (instancetype)init

{

ASPagerFlowLayout *flowLayout = [[ASPagerFlowLayout alloc] init];

flowLayout.scrollDirection = UICollectionViewScrollDirectionHorizontal;

flowLayout.minimumInteritemSpacing = 0;

flowLayout.minimumLineSpacing = 0;

return [self initWithCollectionViewLayout:flowLayout];

}

- (instancetype)initWithCollectionViewLayout:(ASPagerFlowLayout *)flowLayout;

{

ASDisplayNodeAssert([flowLayout isKindOfClass:[ASPagerFlowLayout class]], @"ASPagerNode requires a flow layout.");

self = [super initWithCollectionViewLayout:flowLayout];

if (self != nil) {

_flowLayout = flowLayout;

}

return self;

}

#pragma mark - ASDisplayNode

- (void)didLoad

{

[super didLoad];

ASCollectionView *cv = self.view;

cv.asyncDataSource = (id<ASCollectionDataSource>)_proxyDataSource ?: self;

cv.asyncDelegate = (id<ASCollectionDelegate>)_proxyDelegate ?: self;

#if TARGET_OS_IOS

cv.pagingEnabled = YES;

cv.scrollsToTop = NO;

#endif

cv.allowsSelection = NO;

cv.showsVerticalScrollIndicator = NO;

cv.showsHorizontalScrollIndicator = NO;

ASRangeTuningParameters minimumRenderParams = { .leadingBufferScreenfuls = 0.0, .trailingBufferScreenfuls = 0.0 };

ASRangeTuningParameters minimumPreloadParams = { .leadingBufferScreenfuls = 1.0, .trailingBufferScreenfuls = 1.0 };

[self setTuningParameters:minimumRenderParams forRangeMode:ASLayoutRangeModeMinimum rangeType:ASLayoutRangeTypeDisplay];

[self setTuningParameters:minimumPreloadParams forRangeMode:ASLayoutRangeModeMinimum rangeType:ASLayoutRangeTypePreload];

ASRangeTuningParameters fullRenderParams = { .leadingBufferScreenfuls = 1.0, .trailingBufferScreenfuls = 1.0 };

ASRangeTuningParameters fullPreloadParams = { .leadingBufferScreenfuls = 2.0, .trailingBufferScreenfuls = 2.0 };

[self setTuningParameters:fullRenderParams forRangeMode:ASLayoutRangeModeFull rangeType:ASLayoutRangeTypeDisplay];

[self setTuningParameters:fullPreloadParams forRangeMode:ASLayoutRangeModeFull rangeType:ASLayoutRangeTypePreload];

}

#pragma mark - Getters / Setters

- (NSInteger)currentPageIndex

{

return (self.view.contentOffset.x / CGRectGetWidth(self.view.bounds));

}

#pragma mark - Helpers

- (void)scrollToPageAtIndex:(NSInteger)index animated:(BOOL)animated

{

NSIndexPath *indexPath = [NSIndexPath indexPathForItem:index inSection:0];

[self scrollToItemAtIndexPath:indexPath atScrollPosition:UICollectionViewScrollPositionLeft animated:animated];

}

- (ASCellNode *)nodeForPageAtIndex:(NSInteger)index

{

return [self nodeForItemAtIndexPath:[NSIndexPath indexPathForItem:index inSection:0]];

}

- (NSInteger)indexOfPageWithNode:(ASCellNode *)node

{

NSIndexPath *indexPath = [self indexPathForNode:node];

if (!indexPath) {

return NSNotFound;

}

return indexPath.row;

}

#pragma mark - ASCollectionDataSource

- (ASCellNodeBlock)collectionNode:(ASCollectionNode *)collectionNode nodeBlockForItemAtIndexPath:(NSIndexPath *)indexPath

{

if (_pagerDataSourceFlags.nodeBlockAtIndex) {

return [_pagerDataSource pagerNode:self nodeBlockAtIndex:indexPath.item];

} else if (_pagerDataSourceFlags.nodeAtIndex) {

ASCellNode *node = [_pagerDataSource pagerNode:self nodeAtIndex:indexPath.item];

return ^{ return node; };

} else {

ASDisplayNodeFailAssert(@"Pager data source must implement either %@ or %@. Data source: %@", NSStringFromSelector(@selector(pagerNode:nodeBlockAtIndex:)), NSStringFromSelector(@selector(pagerNode:nodeAtIndex:)), _pagerDataSource);

return ^{

return [[ASCellNode alloc] init];

};

}

}

- (NSInteger)collectionNode:(ASCollectionNode *)collectionNode numberOfItemsInSection:(NSInteger)section

{

ASDisplayNodeAssert(_pagerDataSource != nil, @"ASPagerNode must have a data source to load nodes to display");

return [_pagerDataSource numberOfPagesInPagerNode:self];

}

#pragma mark - ASCollectionDelegate

- (ASSizeRange)collectionNode:(ASCollectionNode *)collectionNode constrainedSizeForItemAtIndexPath:(NSIndexPath *)indexPath

{

#pragma clang diagnostic push

#pragma clang diagnostic ignored "-Wdeprecated-declarations"

if (_pagerDelegateFlags.constrainedSizeForNode) {

return [_pagerDelegate pagerNode:self constrainedSizeForNodeAtIndex:indexPath.item];

}

#pragma clang diagnostic pop

return ASSizeRangeMake(self.bounds.size);

}

#pragma mark - Data Source Proxy

- (id <ASPagerDataSource>)dataSource

{

return _pagerDataSource;

}

- (void)setDataSource:(id <ASPagerDataSource>)dataSource

{

if (dataSource != _pagerDataSource) {

_pagerDataSource = dataSource;

if (dataSource == nil) {

memset(&_pagerDataSourceFlags, 0, sizeof(_pagerDataSourceFlags));

} else {

_pagerDataSourceFlags.nodeBlockAtIndex = [_pagerDataSource respondsToSelector:@selector(pagerNode:nodeBlockAtIndex:)];

_pagerDataSourceFlags.nodeAtIndex = [_pagerDataSource respondsToSelector:@selector(pagerNode:nodeAtIndex:)];

}

_proxyDataSource = dataSource ? [[ASPagerNodeProxy alloc] initWithTarget:dataSource interceptor:self] : nil;

super.dataSource = (id <ASCollectionDataSource>)_proxyDataSource;

}

}

- (void)setDelegate:(id<ASPagerDelegate>)delegate

{

if (delegate != _pagerDelegate) {

_pagerDelegate = delegate;

if (delegate == nil) {

memset(&_pagerDelegateFlags, 0, sizeof(_pagerDelegateFlags));

} else {

_pagerDelegateFlags.constrainedSizeForNode = [_pagerDelegate respondsToSelector:@selector(pagerNode:constrainedSizeForNodeAtIndex:)];

}

_proxyDelegate = delegate ? [[ASPagerNodeProxy alloc] initWithTarget:delegate interceptor:self] : nil;

super.delegate = (id <ASCollectionDelegate>)_proxyDelegate;

}

}

- (void)proxyTargetHasDeallocated:(ASDelegateProxy *)proxy

{

[self setDataSource:nil];

[self setDelegate:nil];

}

- (void)didEnterVisibleState

{

[super didEnterVisibleState];

// Check that our view controller does not automatically set our content insets

// It would be better to have a -didEnterHierarchy hook to put this in, but

// such a hook doesn't currently exist, and in every use case I can imagine,

// the pager is not hosted inside a range-managed node.

if (_allowsAutomaticInsetsAdjustment == NO) {

UIViewController *vc = [self.view asdk_associatedViewController];

if (vc.automaticallyAdjustsScrollViewInsets) {

NSLog(@"AsyncDisplayKit: ASPagerNode is setting automaticallyAdjustsScrollViewInsets=NO on its owning view controller %@. This automatic behavior will be disabled in the future. Set allowsAutomaticInsetsAdjustment=YES on the pager node to suppress this behavior.", vc);

vc.automaticallyAdjustsScrollViewInsets = NO;

}

}

}