import Foundation import UIKit /// The protocol that view classes need to conform to to enable animated GIF support. public protocol GIFAnimatable: class { /// Responsible for managing the animation frames. var animator: Animator? { get set } /// Notifies the instance that it needs display. var layer: CALayer { get } /// View frame used for resizing the frames. var frame: CGRect { get set } /// Content mode used for resizing the frames. var contentMode: UIViewContentMode { get set } } /// A single-property protocol that animatable classes can optionally conform to. public protocol ImageContainer { /// Used for displaying the animation frames. var image: UIImage? { get set } } extension GIFAnimatable where Self: ImageContainer { /// Returns the intrinsic content size based on the size of the image. public var intrinsicContentSize: CGSize { return image?.size ?? CGSize.zero } } extension GIFAnimatable { /// Total duration of one animation loop public var gifLoopDuration: TimeInterval { return animator?.loopDuration ?? 0 } /// Returns the active frame if available. public var activeFrame: UIImage? { return animator?.activeFrame() } /// Total frame count of the GIF. public var frameCount: Int { return animator?.frameCount ?? 0 } /// Introspect whether the instance is animating. public var isAnimatingGIF: Bool { return animator?.isAnimating ?? false } /// Prepare for animation and start animating immediately. /// /// - parameter imageName: The file name of the GIF in the main bundle. /// - parameter loopCount: Desired number of loops, <= 0 for infinite loop. /// - parameter completionHandler: Completion callback function public func animate(withGIFNamed imageName: String, loopCount: Int = 0, completionHandler: (() -> Void)? = nil) { animator?.animate(withGIFNamed: imageName, size: frame.size, contentMode: contentMode, loopCount: loopCount, completionHandler: completionHandler) } /// Prepare for animation and start animating immediately. /// /// - parameter imageData: GIF image data. /// - parameter loopCount: Desired number of loops, <= 0 for infinite loop. /// - parameter completionHandler: Completion callback function public func animate(withGIFData imageData: Data, loopCount: Int = 0, completionHandler: (() -> Void)? = nil) { animator?.animate(withGIFData: imageData, size: frame.size, contentMode: contentMode, loopCount: loopCount, completionHandler: completionHandler) } /// Prepare for animation and start animating immediately. /// /// - parameter imageURL: GIF image url. /// - parameter loopCount: Desired number of loops, <= 0 for infinite loop. /// - parameter completionHandler: Completion callback function public func animate(withGIFURL imageURL: URL, loopCount: Int = 0, completionHandler: (() -> Void)? = nil) { let session = URLSession.shared let task = session.dataTask(with: imageURL) { (data, response, error) in switch (data, response, error) { case (.none, _, let error?): print("Error downloading gif:", error.localizedDescription, "at url:", imageURL.absoluteString) case (let data?, _, _): DispatchQueue.main.async { self.animate(withGIFData: data, loopCount: loopCount, completionHandler: completionHandler) } default: () } } task.resume() } /// Prepares the animator instance for animation. /// /// - parameter imageName: The file name of the GIF in the main bundle. /// - parameter loopCount: Desired number of loops, <= 0 for infinite loop. public func prepareForAnimation(withGIFNamed imageName: String, loopCount: Int = 0, completionHandler: (() -> Void)? = nil) { animator?.prepareForAnimation(withGIFNamed: imageName, size: frame.size, contentMode: contentMode, loopCount: loopCount, completionHandler: completionHandler) } /// Prepare for animation and start animating immediately. /// /// - parameter imageData: GIF image data. /// - parameter loopCount: Desired number of loops, <= 0 for infinite loop. public func prepareForAnimation(withGIFData imageData: Data, loopCount: Int = 0, completionHandler: (() -> Void)? = nil) { if var imageContainer = self as? ImageContainer { imageContainer.image = UIImage(data: imageData) } animator?.prepareForAnimation(withGIFData: imageData, size: frame.size, contentMode: contentMode, loopCount: loopCount, completionHandler: completionHandler) } /// Prepare for animation and start animating immediately. /// /// - parameter imageURL: GIF image url. /// - parameter loopCount: Desired number of loops, <= 0 for infinite loop. public func prepareForAnimation(withGIFURL imageURL: URL, loopCount: Int = 0, completionHandler: (() -> Void)? = nil) { let session = URLSession.shared let task = session.dataTask(with: imageURL) { (data, response, error) in switch (data, response, error) { case (.none, _, let error?): print("Error downloading gif:", error.localizedDescription, "at url:", imageURL.absoluteString) case (let data?, _, _): DispatchQueue.main.async { self.prepareForAnimation(withGIFData: data, loopCount: loopCount, completionHandler: completionHandler) } default: () } } task.resume() } /// Stop animating and free up GIF data from memory. public func prepareForReuse() { animator?.prepareForReuse() } /// Start animating GIF. public func startAnimatingGIF() { animator?.startAnimating() } /// Stop animating GIF. public func stopAnimatingGIF() { animator?.stopAnimating() } /// Whether the frame images should be resized or not. The default is `false`, which means that the frame images retain their original size. /// /// - parameter resize: Boolean value indicating whether individual frames should be resized. public func setShouldResizeFrames(_ resize: Bool) { animator?.shouldResizeFrames = resize } /// Sets the number of frames that should be buffered. Default is 50. A high number will result in more memory usage and less CPU load, and vice versa. /// /// - parameter frames: The number of frames to buffer. public func setFrameBufferCount(_ frames: Int) { animator?.frameBufferCount = frames } /// Updates the image with a new frame if necessary. public func updateImageIfNeeded() { if var imageContainer = self as? ImageContainer { let container = imageContainer imageContainer.image = activeFrame ?? container.image } else { layer.contents = activeFrame?.cgImage } } } extension GIFAnimatable { /// Calls setNeedsDisplay on the layer whenever the animator has a new frame. Should *not* be called directly. func animatorHasNewFrame() { layer.setNeedsDisplay() } }