Awesome

Supports

KRWatchScroll can easy watching and judging UITableView ( or UIScrollView ) scrolling to top、bottom、left、right motions when it scroll stopped.

So, you can easy use it to implement scrolling to load next or previous page data when scrollview scrolled to side.

How To Get Started

This sample is using with UITableView.

#import "KRWatchScroll.h"

@interface ViewController ()<UITableViewDataSource, UITableViewDelegate>

@property (nonatomic, strong) KRWatchScroll *_krWatchScroll;
@property (nonatomic, strong) NSMutableArray *_datas;
@property (nonatomic, weak) IBOutlet UITableView *outTableView;
@property (nonatomic, weak) IBOutlet UIScrollView *outScrollView;

@end

@implementation ViewController (fixPrivate)

-(void)_makeSubviewsInScrollView
{
    CGFloat _x       = 0.0f;
    CGFloat _y       = 0.0f;
    CGFloat _width   = 80.0f;
    CGFloat _height  = 160.0f;
    CGFloat _offsetX = 10.0f;
    for( int _index=1; _index<20; _index++ )
    {
        UIImageView *_imageView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"sample.png"]];
        [_imageView setFrame:CGRectMake(_x, _y, _width, _height)];
        [self.outScrollView addSubview:_imageView];
        _x += _width + _offsetX;
    }
    [self.outScrollView setContentSize:CGSizeMake(_x, self.outScrollView.frame.size.height)];
    self.outScrollView.scrollEnabled                  = YES;
    self.outScrollView.showsVerticalScrollIndicator   = NO;
    self.outScrollView.showsHorizontalScrollIndicator = NO;
    self.outScrollView.backgroundColor                = [UIColor clearColor];
    self.outScrollView.delegate                       = self;
}

-(void)_watchScrollView
{
    /*
     * If you did set " watchHorizontally " is YES, it will be watching the UIScrollView for scrolling of horizontally.
     * If you did set it to NO, it will be watching Vertically.
     * YES 是監控橫向捲動的 UIScrollView 動作。
     * NO  是監控直向捲動的 UIScrollView 動作。
     */
    self._krWatchScroll.watchHorizontally = YES;
    [self _makeSubviewsInScrollView];
}

-(void)_watchTableView
{
    self._krWatchScroll.watchHorizontally = NO;
    for( int i=1; i<=20; ++i )
    {
        [self._datas addObject:[NSString stringWithFormat:@"%i", i]];
    }
    self.outTableView.dataSource = self;
    self.outTableView.delegate   = self;
}

@end

@implementation ViewController

@synthesize outTableView;
@synthesize outScrollView;

@synthesize _krWatchScroll;
@synthesize _datas;

/*
 * @ This sample is to watch UITableView and UIScrollView.
 */
- (void)viewDidLoad
{
    [super viewDidLoad];
    _krWatchScroll = [[KRWatchScroll alloc] init];
    _datas         = [[NSMutableArray alloc] initWithCapacity:0];
    //If you wanna watch UIScrollView that you can follow this.
    [self _watchScrollView];
    //If you wanna watch UITableView that you can follow this.
    [self _watchTableView];
}

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

#pragma UITableView Delegate
-(NSInteger)numberOfSectionsInTableView:(UITableView *)tableView
{
    return 1;
}

-(NSInteger)tableView:(UITableView *)tableView numberOfRowsInSection:(NSInteger)section
{
    return [self._datas count];
}

-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
    static NSString *cellIdentifier     = @"_someCell";
    static NSString *tempCellIdentifier = @"_tempCell";
    NSInteger row = [indexPath row];
    int dataCount = [self._datas count];
    if (dataCount == 0 && row == 0)
    {
        UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:tempCellIdentifier];
        if (cell == nil){
            cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle
                                          reuseIdentifier:tempCellIdentifier];
            cell.selectionStyle = UITableViewCellSelectionStyleNone;
        }
        cell.detailTextLabel.text = @"Loading ...";
        return cell;
    }
    UITableViewCell *cell = [tableView dequeueReusableCellWithIdentifier:cellIdentifier];
    if ( !cell )
    {
        cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleSubtitle reuseIdentifier:cellIdentifier];
    }
    if( [self._datas count] > 0 )
    {
        cell.textLabel.text = [self._datas objectAtIndex:row];
    }
    return cell;
}

-(void)tableView:(UITableView *)tableView willDisplayCell:(UITableViewCell *)cell forRowAtIndexPath:(NSIndexPath *)indexPath
{
    //...
    
}

-(void)tableView:(UITableView *)tableView didSelectRowAtIndexPath:(NSIndexPath *)indexPath
{
    [tableView deselectRowAtIndexPath:indexPath animated:YES];
}

-(float)tableView:(UITableView *)tableView heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    return 88.0f;
}

#pragma --mark UIScrollViewDelegate
-(void)scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
    KRWatchScrollType _krWatchScrollType = [self._krWatchScroll findScrollingToWhereWithScrollView:scrollView];
    switch (_krWatchScrollType)
    {
        case KRWatchScrollToTop:
            //捲到頂
            NSLog(@"Scrolling to Top.");
            break;
        case KRWatchScrollToBottom:
            //捲到底
            NSLog(@"Scrolling to Bottom.");
            break;
        case KRWatchScrollToLeft:
            //捲到左邊
            NSLog(@"Scrolling to Left.");
            break;
        case KRWatchScrollToRight:
            //捲到右邊
            NSLog(@"Scrolling to Right.");
            break;
        case KRWatchScrollNothing:
        default:
            //Nothing
            NSLog(@"Scrolling Nothing.");
            break;
    }
}

@end

Version

KRWatchScroll now is V0.9.1 beta.

License

KRWatchScroll is available under the MIT license ( or Whatever you wanna do ). See the LICENSE file for more info.