NJKScrollFullSrceen

NJKScrollFullSrceen is Facebook App like scroll to full screen library.

This repository consists of full screen delegate and full screen UI behaivior module.

• NJKScrollFullScreen
• Simple UIScrollViewDelegate wrapper. It called delegate methods when full screen wanted.
• UIViewController+NJKFullScreenSupport
• Add full screen behaivior to UIViewController.

These modules are individual. You can implement your own customized full screen behavior without UIViewController+NJKFullScreenSupport. NJKScrollFullSrceen can apply not only UIScrollView but also UIWebView and UITableView.

Requirements

• iOS 5.0 or later
• ARC

Install

CocoaPods

pod 'NJKScrollFullScreen'

Usage

1. Instance NJKScrollFullScreen

Instance and set UIScrollViewDelegate on your view controller. If you set scrollViewDelegate, NJKScrollFullScreen suould perform as a proxy object.

- (void)viewDidLoad
{
    [super viewDidLoad];

    _scrollProxy = [[NJKScrollFullScreen alloc] initWithForwardTarget:self]; // UIScrollViewDelegate and UITableViewDelegate methods proxy to ViewController
    self.tableView.delegate = (id)_scrollProxy; // cast for surpress incompatible warnings
    _scrollProxy.delegate = self;
}

2. Implement delegate methods

- (void)scrollFullScreen:(NJKScrollFullScreen *)proxy scrollViewDidScrollUp:(CGFloat)deltaY
{
    [self moveNavigationBar:deltaY animated:YES];
}

- (void)scrollFullScreen:(NJKScrollFullScreen *)proxy scrollViewDidScrollDown:(CGFloat)deltaY
{
    [self moveNavigationBar:deltaY animated:YES];
}

- (void)scrollFullScreenScrollViewDidEndDraggingScrollUp:(NJKScrollFullScreen *)proxy
{
    [self hideNavigationBar:YES];
}

- (void)scrollFullScreenScrollViewDidEndDraggingScrollDown:(NJKScrollFullScreen *)proxy
{
    [self showNavigationBar:YES];
}

3. Implement full screen behavior

You can choose UIViewController+NJKFullScreenSupport or your own view management code.

Use UIViewController+NJKFullScreenSupport.h.

#import "UIViewController+NJKFullScreenSupport.h"

Or you can implement own full screen behavior like below.

- (void)showNavigationBar:(BOOL)animated
{
    CGFloat statusBarHeight = [UIApplication sharedApplication].statusBarFrame.size.height;
    [self setNavigationBarOriginY:statusBarHeight animated:animated];
}

- (void)hideNavigationBar:(BOOL)animated
{
    [self setNavigationBarOriginY:0 animated:animated];
}

- (void)moveNavigationBar:(CGFloat)deltaY animated:(BOOL)animated
{
    CGRect frame = self.navigationController.navigationBar.frame;
    CGFloat nextY = frame.origin.y + deltaY;
    [self setNavigationBarOriginY:nextY animated:animated];
}

- (void)setNavigationBarOriginY:(CGFloat)y animated:(BOOL)animated
{
    CGFloat statusBarHeight = [UIApplication sharedApplication].statusBarFrame.size.height;
    CGRect frame = self.navigationController.navigationBar.frame;
    CGFloat navigationBarHeight = frame.size.height;

    frame.origin.y = fmin(fmax(y, navigationBarHeight), statusBarHeight); // limit over moving

    [UIView animateWithDuration:animated ? 0.1 : 0 animations:^{
        self.navigationController.navigationBar.frame = frame;
    }];
}

License

MIT license.