benmy--tlchat/TLChat/TLKitExtensions/Components/TLPictureCarouselView/TLPictureCarouselView.m

//
//  TLPictureCarouselView.m
//  TLChat
//
//  Created by 李伯坤 on 16/4/20.
//  Copyright © 2016年 李伯坤. All rights reserved.
//

#import "TLPictureCarouselView.h"
#import "TLPictureCarouselViewCell.h"
#import "UIScrollView+Pages.h"

@interface TLPictureCarouselView () <UICollectionViewDelegate, UICollectionViewDataSource, UICollectionViewDelegateFlowLayout>

@property (nonatomic, strong) NSArray *data;

@property (nonatomic, strong) NSTimer *timer;

@property (nonatomic, strong) UICollectionView *collectionView;

@end

@implementation TLPictureCarouselView

- (id)initWithFrame:(CGRect)frame
{
    if (self = [super initWithFrame:frame]) {
        _timeInterval = DEFAULT_TIMEINTERVAL;
        [self.collectionView setFrame:self.bounds];
        [self addSubview:self.collectionView];
        
        [self.collectionView registerClass:[TLPictureCarouselViewCell class] forCellWithReuseIdentifier:@"TLPictureCarouselViewCell"];
    }
    return self;
}

- (void)layoutSubviews
{
    [super layoutSubviews];
    if (!CGRectEqualToRect(self.bounds, self.collectionView.frame)) {
        [self.collectionView setFrame:self.bounds];
        [self.collectionView reloadData];
    }
}

- (void)setData:(NSArray *)data
{
    if (data.count > 1) {
        NSMutableArray *tempData = data.mutableCopy;
        [tempData insertObject:data.lastObject atIndex:0];
        [tempData addObject:data.firstObject];
        _data = tempData;
    }
    else {
        _data = data;
    }
    [self.collectionView reloadData];
    [self.collectionView setPageX:1 animated:NO];
    
    [self restartTimerIfNeed];
}

- (void)setTimeInterval:(NSTimeInterval)timeInterval
{
    if (_timeInterval != timeInterval) {
        _timeInterval = timeInterval;
        [self restartTimerIfNeed];
    }
}

- (void)restartTimerIfNeed
{
    if (self.data.count > 1) {
        [self.timer invalidate];
        self.timer = [NSTimer scheduledTimerWithTimeInterval:self.timeInterval target:self selector:@selector(scrollToNextPage) userInfo:nil repeats:YES];
        [[NSRunLoop currentRunLoop] addTimer:_timer forMode:NSRunLoopCommonModes];
    }
}

- (void)dealloc
{
    [self.timer invalidate];
    self.timer = nil;
}

#pragma mark - # Delegate
- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section
{
    return self.data.count;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath
{
    id<TLPictureCarouselProtocol> model = self.data[indexPath.row];
    TLPictureCarouselViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:@"TLPictureCarouselViewCell" forIndexPath:indexPath];
    [cell setModel:model];
    return cell;
}

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath
{
    id<TLPictureCarouselProtocol> model = self.data[indexPath.row];
    if (self.didSelectItem) {
        self.didSelectItem(self, model);
    }
    if (self.delegate && [self.delegate respondsToSelector:@selector(pictureCarouselView:didSelectItem:)]) {
        [self.delegate pictureCarouselView:self didSelectItem:model];
    }
}

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout sizeForItemAtIndexPath:(NSIndexPath *)indexPath
{
    return collectionView.frame.size;
}

//MARK: UIScrollViewDelegate
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
    [self.timer invalidate];
}

- (void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
    if (!decelerate) {
        [self scrollViewDidEndDecelerating:scrollView];
    }
}

- (void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    // 轮播实现
    if (scrollView.pageX == 0) {
        [scrollView setPageX:self.data.count - 2 animated:NO];
    }
    else if (scrollView.pageX == self.data.count - 1) {
        [scrollView setPageX:1 animated:NO];
    }

    [self restartTimerIfNeed];
}

- (void)scrollViewDidEndScrollingAnimation:(UIScrollView *)scrollView
{
    [self scrollViewDidEndDecelerating:scrollView];
}

#pragma mark - # Event Response
- (void)scrollToNextPage
{
    NSInteger nextPage;
    if (self.collectionView.pageX == self.data.count) {
        [self.collectionView setPageX:0 animated:NO];
        nextPage = 1;
    }
    else {
        nextPage = self.collectionView.pageX + 1;
    }
    [self.collectionView setPageX:nextPage animated:YES];
}

#pragma mark - # Getter
- (UICollectionView *)collectionView
{
    if (_collectionView == nil) {
        UICollectionViewFlowLayout *layout = [[UICollectionViewFlowLayout alloc] init];
        [layout setScrollDirection:UICollectionViewScrollDirectionHorizontal];
        [layout setMinimumLineSpacing:0];
        [layout setMinimumInteritemSpacing:0];
        [layout setSectionInset:UIEdgeInsetsZero];
        _collectionView = [[UICollectionView alloc] initWithFrame:CGRectZero collectionViewLayout:layout];
        [_collectionView setBackgroundColor:[UIColor whiteColor]];
        [_collectionView setShowsVerticalScrollIndicator:NO];
        [_collectionView setShowsHorizontalScrollIndicator:NO];
        [_collectionView setPagingEnabled:YES];
        [_collectionView setScrollsToTop:NO];
        [_collectionView setDelegate:self];
        [_collectionView setDataSource:self];
    }
    return _collectionView;
}

@end