Adds animated GIF support to UIKit. For the Japanese prefecture, click here.

Why?

Because Apple's +animatedImage* sucks, and the few third party implementations that got it right (see Credits) still require you to use a UIImageView subclass.

How?

Gifu is a UIImage subclass and UIImageView extension written in Swift. It uses CADisplayLink to animate the view and only keeps a limited number of frames in-memory, which exponentially minimizes memory usage for large GIF files (+300 frames).

The figure below summarizes how this works in practice. Given an image containing 10 frames, Gifu will load the current frame (red), pre-load the next two frames (orange), and nullify all the other frames to free up memory (gray):

Usage

Use git submodules or drag-and-drop the files in your Xcode project. I can't believe I'm saying this in 2014.

Once done, you can call setAnimatableImage(named:) or setAnimatableImage(data:) on your UIImageView (or its subclass):

let imageView = UIImageView(...)

imageView.setAnimatableImage(named: "computer-kid.gif")
// or
imageView.setAnimatableImage(data: NSData(...))

You can find a demo app here.

To-do

The usual suspects:

• Add documentation.
• Write some basic tests.

Nice-to-haves:

• Use Reactive Cocoa instead of (sloppy) delegation.
• Remove side effects from the private functions.

Credits

• The animation technique described above was originally spotted on OLImageView, then improved in YLGIFImage.

• The font used in the logo is Azuki

• Kudos to my colleague Tony DiPasquale for helping out with the factory methods.

License

See LICENSE.