GKLParallaxPictures

This component allows you to display an image gallery on top of a simple UIView or UIWebView. Scroll and you will see a nice parallax effect.

Install

The easiest way to install this component is via CocoaPods.

Add the following line to your podfile:

pod 'GKLParallaxPictures'

Then run the pod install command and import GKLParallaxPicturesViewController.h where you plan to use this.

You can also install it manually. Just drag GKLParallaxPicturesViewController.h and GKLParallaxPicturesViewController.m in your project and import the .h file where you want to use this component.

How To Use

GKLParallaxPicturesViewController *paralaxViewController = [[GKLParallaxPicturesViewController alloc] initWithImages:imagesArray andContentView:contentView];

Where contentView is the detailed view you want below your images.

You can always add more images after the view controller is instantiated by calling:

[paralaxViewController addImages:moreImagesArray];

Image arrays can contain both istances of UIImage and NSString. In the latter case those will be URLs of those images which will be loaded asynchronously.

Displaying a web view

This is the reason I forked for. It was not possible to display an UIWebView as the contentView.

UIWebView *testWebView = [[UIWebView alloc] init];
[testWebView loadRequest:[NSURLRequest requestWithURL:[NSURL URLWithString:@"http://nshipster.com/"]]];

UIImage *testImage = [UIImage imageNamed:@"shovel"];
NSArray *images = @[testImage, testImage, testImage];

GKLParallaxPicturesViewController *paralaxViewController = [[GKLParallaxPicturesViewController alloc] initWithImages:images
                                                                                                      andContentWebView:testWebView];

Result:

URL Image Loading

GKLParallaxPictures accepts both UIImages and NSStrings (of an image URL) for adding UIImageViews into the top gallery. By default it uses dispatch_queue to load images asynchronously, but you can subclass GKLParallaxPictures and overwrite this method to handle image loading however you choose.

Default image loading:

-(void)loadImageFromURLString:(NSString*)urlString forImageView:(UIImageView*)imageView{
	dispatch_queue_t queue = dispatch_get_global_queue(DISPATCH_QUEUE_PRIORITY_HIGH, 0ul);
	dispatch_async(queue, ^{
    	NSData *imageData = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:urlString]];
    	dispatch_sync(dispatch_get_main_queue(), ^{
        	UIImage *downloadedImage = [[UIImage alloc] initWithData:imageData];
        	[imageView setImage:downloadedImage];
    	});
	});
}