ETPMagnifyingView

ETPMagnifyingView

Custom UIView that supports magnifying paging UIScrollView

How it works

• Place a small UIScrollView inside a custom view. Any subviews added to this UIScrollView needs to be the same size as the UIScrollView, in order to get the paging work
• The container custom view has clipsToBounds = YES and override hitTest:withEvent: to return the UIScrollView
• I use HTDelegateProxy to achieve multicast delegate

How to use it

• Typical usage

(void)setupMagnifyingView
{
    self.magnifyingView.backgroundColor = [UIColor yellowColor];

    for (int i=0; i< NUMBER_OF_PAGES; ++i) {
        NSString *imageName = [NSString stringWithFormat:@"number%d.jpg", i];
        UIImage *image = [UIImage imageNamed:imageName];

        UIImageView *imageView = [[UIImageView alloc] initWithFrame:self.magnifyingView.scrollView.bounds];
        imageView.image = image;

        CGRect imageFrame = CGRectMake(self.magnifyingView.scrollView.bounds.size.width * i, 0,
                                       self.magnifyingView.scrollView.bounds.size.width, self.magnifyingView.scrollView.bounds.size.height);

        imageView.frame = imageFrame;
        
        [self.magnifyingView.scrollView addSubview:imageView];

    }

    self.magnifyingView.scrollView.contentSize = CGSizeMake(self.magnifyingView.scrollView.bounds.size.width * NUMBER_OF_PAGES,
                                                            self.magnifyingView.scrollView.bounds.size.height);

    // This is important
    self.magnifyingView.edgeScale = 0.6;
    self.magnifyingView.scrollViewDelegate = self;
}

• More customization

self.magnifyingView.scrollView.pagingEnabled = NO;
self.magnifyingView.scrollView.showsHorizontalScrollIndicator = YES;

License

This project is released under the MIT license. See LICENSE.md.

Reference

1. Paging UIScrollView in increments smaller than frame size
2. UIScrollView horizontal paging like Mobile Safari tabs
3. HTDelegateProxy
4. A MULTICAST DELEGATE PATTERN FOR IOS CONTROLS