TTKuaiBaoProject/YouHuiProject/YouHui/NineNine/ViewController/KBNineNineSc...

//
//  KBNineNineScrollChildViewController.m
//  YouHuiProject
//
//  Created by xiaoxi on 2018/1/29.
//  Copyright © 2018年 kuxuan. All rights reserved.
//

#import "KBNineNineScrollChildViewController.h"
#import "KBCollectionView.h"
#import "KBScrollChildCollectionViewCell.h"
#import "KBNineNineScrollChannelModel.h"
#import "KBNineNineRequestViewModel.h"
#import "KBGoodCollectionCell.h"
#import "KBCollectionView.h"
#import "KBNineCollectionView.h"

static NSString *const cellID = @"KBScrollChildCollectionViewCell";
static NSInteger page = 1;

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

@property (nonatomic, strong) NSMutableArray *dataSource;
@property (nonatomic, strong) UIButton *toTopButton;
@end

@implementation KBNineNineScrollChildViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    
    [self initNavBar];
    [self initSubviews];
    [self request];
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(changedSexRequest) name:ChangeSex object:nil];
}

- (void)didReceiveMemoryWarning {
    [super didReceiveMemoryWarning];
}

- (void)initNavBar {
    self.navigationBar.hidden = YES;
}

- (void)initSubviews {
    [self.view addSubview:self.collectionView];
    
    UIButton *button = [[UIButton alloc] initWithFrame:CGRectMake(SCREEN_WIDTH-50, self.collectionView.height-100, 40, 40)];
    button.backgroundColor = [UIColor grayColor];
    button.layer.cornerRadius = 20;
    [self.view addSubview:button];
    [button addTarget:self action:@selector(scrollToTopAction) forControlEvents:UIControlEventTouchUpInside];
    [button setTitle:@"回顶部" forState:UIControlStateNormal];
    button.titleLabel.font = [UIFont systemFontOfSize:12];
    self.toTopButton = button;
    self.toTopButton.alpha = .0;
}

- (void)scrollToTopAction {
    [self.collectionView scrollToTop];
}

#pragma mark - request

- (void)request {
    [KBNineNineRequestViewModel requestNineNineCategoryGoodsParamPage:page scid:self.model.Id type:@"1" stype:@"1" success:^(NSArray *array) {
        if (array.count > 0) {
            [self.dataSource addObjectsFromArray:array];
            [self.collectionView reloadData];
        }
        [self.collectionView.mj_footer endRefreshing];
    } failure:^(NSError *error) {
        [self.collectionView.mj_footer endRefreshing];
    }];
}

- (void)changedSexRequest {
    [self.dataSource removeAllObjects];
    page = 1;
    [self request];
}

#pragma mark - collectionview

- (NSInteger)numberOfSectionsInCollectionView:(UICollectionView *)collectionView {
    return 1;
}

- (NSInteger)collectionView:(UICollectionView *)collectionView numberOfItemsInSection:(NSInteger)section {
    return self.dataSource.count;
}

- (UICollectionViewCell *)collectionView:(UICollectionView *)collectionView cellForItemAtIndexPath:(NSIndexPath *)indexPath {
    KBScrollChildCollectionViewCell *cell = [collectionView dequeueReusableCellWithReuseIdentifier:cellID forIndexPath:indexPath];
    cell.backgroundColor = [UIColor whiteColor];
    cell.backgroundView.backgroundColor = [UIColor whiteColor];
    cell.contentView.backgroundColor = [UIColor whiteColor];
    KBChildGoodModel *model = self.dataSource[indexPath.item];
    cell.model = model;
    return cell;
}

- (CGSize)collectionView:(UICollectionView *)collectionView layout:(UICollectionViewLayout *)collectionViewLayout referenceSizeForFooterInSection:(NSInteger)section {
    return CGSizeZero;
}

- (void)collectionView:(UICollectionView *)collectionView didSelectItemAtIndexPath:(NSIndexPath *)indexPath {
    
    if ([self.delegate respondsToSelector:@selector(yh_NineNineScrollChildViewControllerDidSelectItem:)]) {
        KBChildGoodModel *model = self.dataSource[indexPath.item];
        [self.delegate yh_NineNineScrollChildViewControllerDidSelectItem:model];
    }
}


- (void)setCanScroll:(BOOL)canScroll {
    _canScroll = canScroll;
    self.collectionView.canScroll = canScroll;
}


#pragma mark - scrollView

- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
    if (!self.canScroll) {
        scrollView.contentOffset = CGPointZero;
    }
    if (scrollView.contentOffset.y <= 0) {
        //        if (!self.fingerIsTouch) {//这里的作用是在手指离开屏幕后也不让显示主视图，具体可以自己看看效果
        //            return;
        //        }
        self.canScroll = NO;
        scrollView.contentOffset = CGPointZero;
        [[NSNotificationCenter defaultCenter] postNotificationName:@"leaveTop" object:nil];//到顶通知父视图改变状态
    }
    
    
    [self setScrollToTopView:scrollView changeHeight:SCREEN_HEIGHT];
}

- (void)setScrollToTopView:(UIScrollView *)scrollView changeHeight:(CGFloat)height{
    
    CGFloat offY = scrollView.contentOffset.y;
    
    if (offY >= height-1) {
        UIPanGestureRecognizer *pan = scrollView.panGestureRecognizer;
        //获取到拖拽的速度 >0 向下拖动 <0 向上拖动
        CGFloat velocity = [pan velocityInView:scrollView].y;
        if (velocity <- 10) {
            //向上拖动，隐藏
            [UIView animateWithDuration:0.35 animations:^{
                self.toTopButton.alpha = 0.0;
            }];
        }else if (velocity > 10) {
            //向下拖动，显示
            [UIView animateWithDuration:0.35 animations:^{
                self.toTopButton.alpha = 1.0;
            }];
            
        }else if(velocity == 0){
            //停止拖拽
        }
    }else {
        [UIView animateWithDuration:0.35 animations:^{
            self.toTopButton.alpha = 0.0;
        }];
    }
    
}

#pragma mark - lazy

- (UICollectionView *)collectionView {
    if (!_collectionView) {
        UICollectionViewFlowLayout *flowLayout = [[UICollectionViewFlowLayout alloc] init];
        flowLayout.itemSize = CGSizeMake(FITSIZE(184.9), FITSIZE(287));
        flowLayout.scrollDirection = UICollectionViewScrollDirectionVertical;
        flowLayout.minimumLineSpacing = FITSIZE(5);
        flowLayout.minimumInteritemSpacing = FITSIZE(5);
        
        _collectionView = [[KBNineCollectionView alloc] initWithFrame:CGRectMake(0, 0, kScreenWidth, kScreenHeight-NavBarHeight-FITSIZE(40)) collectionViewLayout:flowLayout];
        _collectionView.backgroundView.backgroundColor = [UIColor clearColor];
        _collectionView.backgroundColor = [UIColor clearColor];
        _collectionView.bounces = YES;
        _collectionView.delegate = self;
        _collectionView.dataSource = self;
        _collectionView.backgroundColor = [UIColor clearColor];
        [_collectionView registerClass:[KBScrollChildCollectionViewCell class] forCellWithReuseIdentifier:cellID];
        if (@available(iOS 11.0, *)) {
            _collectionView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;
        }
        kWeak(self);
        _collectionView.mj_footer = [MJRefreshAutoNormalFooter footerWithRefreshingBlock:^{
            page ++;
            [selfWeak request];
        }];
    }
    return _collectionView;
}

- (NSMutableArray *)dataSource {
    if (!_dataSource) {
        _dataSource = [NSMutableArray array];
    }
    return _dataSource;
}

@end