ios/Timi/Class/AppController/ChatRoom/ChatRoomMain/XYChatRoomScrollCollectionViewController.m

//
//  XYChatRoomScrollCollectionViewController.m
//  Starbuds
//
//  Created by 翟玉磊 on 2020/6/28.
//  Copyright © 2020 翟玉磊. All rights reserved.
//

#import "XYChatRoomScrollCollectionViewController.h"

@interface XYChatRoomScrollCollectionViewController ()

@property (nonatomic,assign) CGFloat lastOffset;

@end

@implementation XYChatRoomScrollCollectionViewController

- (void)viewDidLoad {
    [super viewDidLoad];
    // Do any additional setup after loading the view.
}

- (void)setIsCloseScrollSwitch:(BOOL)isCloseScrollSwitch {
    _isCloseScrollSwitch = isCloseScrollSwitch;
    if (isCloseScrollSwitch) {
        self.canScroll = YES;
    }
}

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

-(void)scrollViewDidScroll:(UIScrollView *)scrollView{
    
//    NSLog(@"collectionView >>>>>>> 滚动 == %.2F",scrollView.contentOffset.y);

    if (self.isCloseScrollSwitch) {
        return;
    }
    if (!self.canScroll) {
        scrollView.contentOffset = CGPointZero;
    }
    if (scrollView.contentOffset.y < 0 ) {
        self.canScroll = NO;
        scrollView.contentOffset = CGPointZero;
        [[NSNotificationCenter defaultCenter] postNotificationName:@"chatroom_controller_leave_top" object:nil];//到顶通知父视图改变状态
    }
    scrollView.showsVerticalScrollIndicator = self.canScroll?YES:NO;
}

/*
#pragma mark - Navigation

// In a storyboard-based application, you will often want to do a little preparation before navigation
- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender {
    // Get the new view controller using [segue destinationViewController].
    // Pass the selected object to the new view controller.
}
*/
@end