Kingfisher/Sources/ImageView+Kingfisher.swift

//
//  ImageView+Kingfisher.swift
//  Kingfisher
//
//  Created by Wei Wang on 15/4/6.
//
//  Copyright (c) 2016 Wei Wang <onevcat@gmail.com>
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.


#if os(OSX)
import AppKit
typealias ImageView = NSImageView
public typealias IndicatorView = NSProgressIndicator
#else
import UIKit
typealias ImageView = UIImageView
public typealias IndicatorView = UIActivityIndicatorView
#endif

// MARK: - Set Images
/**
*	Set image to use from web.
*/
extension ImageView {
    
    /**
    Set an image with a resource.
    It will ask for Kingfisher's manager to get the image for the `cacheKey` property in `resource`.
    The memory and disk will be searched first. If the manager does not find it, it will try to download the image at the `resource.downloadURL` and store it with `resource.cacheKey` for next use.
    
    - parameter resource: Resource object contains information such as `cacheKey` and `downloadURL`.
    
    - returns: A task represents the retrieving process.
    */
    public func kf_setImageWithResource(resource: Resource) -> RetrieveImageTask
    {
        return kf_setImageWithResource(resource, placeholderImage: nil, optionsInfo: nil, progressBlock: nil, completionHandler: nil)
    }
    
    /**
    Set an image with a URL.
    It will ask for Kingfisher's manager to get the image for the URL.
    The memory and disk will be searched first with `URL.absoluteString` as the cache key. If the manager does not find it, it will try to download the image at this URL and store the image with `URL.absoluteString` as cache key for next use.
    
    If you need to specify the key other than `URL.absoluteString`, please use resource version of these APIs with `resource.cacheKey` set to what you want.
    
    - parameter URL: The URL of image.
    
    - returns: A task represents the retrieving process.
    */
    public func kf_setImageWithURL(URL: NSURL) -> RetrieveImageTask
    {
        return kf_setImageWithURL(URL, placeholderImage: nil, optionsInfo: nil, progressBlock: nil, completionHandler: nil)
    }

    /**
    Set an image with a resource and a placeholder image.
    
    - parameter resource:         Resource object contains information such as `cacheKey` and `downloadURL`.
    - parameter placeholderImage: A placeholder image when retrieving the image at URL.
    
    - returns: A task represents the retrieving process.
    */
    public func kf_setImageWithResource(resource: Resource,
                                placeholderImage: Image?) -> RetrieveImageTask
    {
        return kf_setImageWithResource(resource, placeholderImage: placeholderImage, optionsInfo: nil, progressBlock: nil, completionHandler: nil)
    }
    
    /**
    Set an image with a URL and a placeholder image.
    
    - parameter URL:              The URL of image.
    - parameter placeholderImage: A placeholder image when retrieving the image at URL.
    
    - returns: A task represents the retrieving process.
    */
    public func kf_setImageWithURL(URL: NSURL,
                      placeholderImage: Image?) -> RetrieveImageTask
    {
        return kf_setImageWithURL(URL, placeholderImage: placeholderImage, optionsInfo: nil, progressBlock: nil, completionHandler: nil)
    }
    
    /**
    Set an image with a resource, a placaholder image and options.
    
    - parameter resource:         Resource object contains information such as `cacheKey` and `downloadURL`.
    - parameter placeholderImage: A placeholder image when retrieving the image at URL.
    - parameter optionsInfo:      A dictionary could control some behaviors. See `KingfisherOptionsInfo` for more.
    
    - returns: A task represents the retrieving process.
    */
    public func kf_setImageWithResource(resource: Resource,
                                placeholderImage: Image?,
                                     optionsInfo: KingfisherOptionsInfo?) -> RetrieveImageTask
    {
        return kf_setImageWithResource(resource, placeholderImage: placeholderImage, optionsInfo: optionsInfo, progressBlock: nil, completionHandler: nil)
    }
    
    /**
    Set an image with a URL, a placaholder image and options.
    
    - parameter URL:              The URL of image.
    - parameter placeholderImage: A placeholder image when retrieving the image at URL.
    - parameter optionsInfo:      A dictionary could control some behaviors. See `KingfisherOptionsInfo` for more.
    
    - returns: A task represents the retrieving process.
    */
    public func kf_setImageWithURL(URL: NSURL,
                      placeholderImage: Image?,
                           optionsInfo: KingfisherOptionsInfo?) -> RetrieveImageTask
    {
        return kf_setImageWithURL(URL, placeholderImage: placeholderImage, optionsInfo: optionsInfo, progressBlock: nil, completionHandler: nil)
    }
    
    /**
    Set an image with a resource, a placeholder image, options and completion handler.
    
    - parameter resource:          Resource object contains information such as `cacheKey` and `downloadURL`.
    - parameter placeholderImage:  A placeholder image when retrieving the image at URL.
    - parameter optionsInfo:       A dictionary could control some behaviors. See `KingfisherOptionsInfo` for more.
    - parameter completionHandler: Called when the image retrieved and set.
    
    - returns: A task represents the retrieving process.
     
    - note: `completionHandler` will be invoked in main thread.
     The `CallbackDispatchQueue` specified in `optionsInfo` will not be used in callbacks of this method.
    */
    public func kf_setImageWithResource(resource: Resource,
                                placeholderImage: Image?,
                                     optionsInfo: KingfisherOptionsInfo?,
                               completionHandler: CompletionHandler?) -> RetrieveImageTask
    {
        return kf_setImageWithResource(resource, placeholderImage: placeholderImage, optionsInfo: optionsInfo, progressBlock: nil, completionHandler: completionHandler)
    }
    
    /**
    Set an image with a URL, a placeholder image, options and completion handler.
    
    - parameter URL:               The URL of image.
    - parameter placeholderImage:  A placeholder image when retrieving the image at URL.
    - parameter optionsInfo:       A dictionary could control some behaviors. See `KingfisherOptionsInfo` for more.
    - parameter completionHandler: Called when the image retrieved and set.
    
    - returns: A task represents the retrieving process.
     
    - note: `completionHandler` will be invoked in main thread.
     The `CallbackDispatchQueue` specified in `optionsInfo` will not be used in callbacks of this method.
    */
    public func kf_setImageWithURL(URL: NSURL,
                      placeholderImage: Image?,
                           optionsInfo: KingfisherOptionsInfo?,
                     completionHandler: CompletionHandler?) -> RetrieveImageTask
    {
        return kf_setImageWithURL(URL, placeholderImage: placeholderImage, optionsInfo: optionsInfo, progressBlock: nil, completionHandler: completionHandler)
    }
    
    /**
    Set an image with a URL, a placeholder image, options, progress handler and completion handler.
    
    - parameter resource:          Resource object contains information such as `cacheKey` and `downloadURL`.
    - parameter placeholderImage:  A placeholder image when retrieving the image at URL.
    - parameter optionsInfo:       A dictionary could control some behaviors. See `KingfisherOptionsInfo` for more.
    - parameter progressBlock:     Called when the image downloading progress gets updated.
    - parameter completionHandler: Called when the image retrieved and set.
    
    - returns: A task represents the retrieving process.
     
    - note: Both the `progressBlock` and `completionHandler` will be invoked in main thread. 
     The `CallbackDispatchQueue` specified in `optionsInfo` will not be used in callbacks of this method.
    */
    public func kf_setImageWithResource(resource: Resource,
                                placeholderImage: Image?,
                                     optionsInfo: KingfisherOptionsInfo?,
                                   progressBlock: DownloadProgressBlock?,
                               completionHandler: CompletionHandler?) -> RetrieveImageTask
    {
        let showIndicatorWhenLoading = kf_showIndicatorWhenLoading
        var indicator: IndicatorView? = nil
        if showIndicatorWhenLoading {
            indicator = kf_indicator
            indicator?.hidden = false
            indicator?.kf_startAnimating()
        }
        
        image = placeholderImage
        
        kf_setWebURL(resource.downloadURL)
        
        let task = KingfisherManager.sharedManager.retrieveImageWithResource(resource, optionsInfo: optionsInfo,
            progressBlock: { receivedSize, totalSize in
                if let progressBlock = progressBlock {
                    progressBlock(receivedSize: receivedSize, totalSize: totalSize)
                }
            },
            completionHandler: {[weak self] image, error, cacheType, imageURL in
                
                dispatch_async_safely_to_main_queue {
                    guard let sSelf = self where imageURL == sSelf.kf_webURL else {
                        completionHandler?(image: image, error: error, cacheType: cacheType, imageURL: imageURL)
                        return
                    }
                    
                    sSelf.kf_setImageTask(nil)
                    
                    guard let image = image else {
                        indicator?.kf_stopAnimating()
                        completionHandler?(image: nil, error: error, cacheType: cacheType, imageURL: imageURL)
                        return
                    }
                    
                    if let transitionItem = optionsInfo?.kf_firstMatchIgnoringAssociatedValue(.Transition(.None)),
                        case .Transition(let transition) = transitionItem where cacheType == .None {
                            #if !os(OSX)
                                UIView.transitionWithView(sSelf, duration: 0.0, options: [],
                                    animations: {
                                        indicator?.kf_stopAnimating()
                                    },
                                    completion: { finished in
                                        UIView.transitionWithView(sSelf, duration: transition.duration,
                                            options: [transition.animationOptions, .AllowUserInteraction],
                                            animations: {
                                                transition.animations?(sSelf, image)
                                            },
                                            completion: { finished in
                                                transition.completion?(finished)
                                                completionHandler?(image: image, error: error, cacheType: cacheType, imageURL: imageURL)
                                        })
                                })
                            #endif
                    } else {
                        indicator?.kf_stopAnimating()
                        sSelf.image = image
                        completionHandler?(image: image, error: error, cacheType: cacheType, imageURL: imageURL)
                    }
                }
            })
        
        kf_setImageTask(task)
        
        return task
    }
    
    /**
    Set an image with a URL, a placeholder image, options, progress handler and completion handler.
    
    - parameter URL:               The URL of image.
    - parameter placeholderImage:  A placeholder image when retrieving the image at URL.
    - parameter optionsInfo:       A dictionary could control some behaviors. See `KingfisherOptionsInfo` for more.
    - parameter progressBlock:     Called when the image downloading progress gets updated.
    - parameter completionHandler: Called when the image retrieved and set.
    
    - returns: A task represents the retrieving process.

    - note: Both the `progressBlock` and `completionHandler` will be invoked in main thread.
     The `CallbackDispatchQueue` specified in `optionsInfo` will not be used in callbacks of this method.
    */
    
    public func kf_setImageWithURL(URL: NSURL,
                      placeholderImage: Image?,
                           optionsInfo: KingfisherOptionsInfo?,
                         progressBlock: DownloadProgressBlock?,
                     completionHandler: CompletionHandler?) -> RetrieveImageTask
    {
        return kf_setImageWithResource(Resource(downloadURL: URL),
                            placeholderImage: placeholderImage,
                                 optionsInfo: optionsInfo,
                               progressBlock: progressBlock,
                           completionHandler: completionHandler)
    }
}

extension ImageView {
    /**
     Cancel the image download task bounded to the image view if it is running.
     Nothing will happen if the downloading has already finished.
     */
    public func kf_cancelDownloadTask() {
        kf_imageTask?.downloadTask?.cancel()
    }
}

// MARK: - Associated Object
private var lastURLKey: Void?
private var indicatorKey: Void?
private var showIndicatorWhenLoadingKey: Void?
private var imageTaskKey: Void?

extension ImageView {
    /// Get the image URL binded to this image view.
    public var kf_webURL: NSURL? {
        return objc_getAssociatedObject(self, &lastURLKey) as? NSURL
    }
    
    private func kf_setWebURL(URL: NSURL) {
        objc_setAssociatedObject(self, &lastURLKey, URL, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
    }
    
    /// Whether show an animating indicator when the image view is loading an image or not.
    /// Default is false.
    public var kf_showIndicatorWhenLoading: Bool {
        get {
            if let result = objc_getAssociatedObject(self, &showIndicatorWhenLoadingKey) as? NSNumber {
                return result.boolValue
            } else {
                return false
            }
        }
        
        set {
            if kf_showIndicatorWhenLoading == newValue {
                return
            } else {
                if newValue {
                    
#if os(OSX)
                    let indicator = NSProgressIndicator(frame: CGRect(x: 0, y: 0, width: 16, height: 16))
                    indicator.controlSize = .SmallControlSize
                    indicator.style = .SpinningStyle
#else
    #if os(tvOS)
                    let indicatorStyle = UIActivityIndicatorViewStyle.White
    #else
                    let indicatorStyle = UIActivityIndicatorViewStyle.Gray
    #endif
                    let indicator = UIActivityIndicatorView(activityIndicatorStyle:indicatorStyle)
                    indicator.autoresizingMask = [.FlexibleLeftMargin, .FlexibleRightMargin, .FlexibleBottomMargin, .FlexibleTopMargin]
#endif

                    indicator.kf_center = CGPoint(x: CGRectGetMidX(bounds), y: CGRectGetMidY(bounds))
                    indicator.hidden = true

                    self.addSubview(indicator)
                    
                    kf_setIndicator(indicator)
                } else {
                    kf_indicator?.removeFromSuperview()
                    kf_setIndicator(nil)
                }
                
                objc_setAssociatedObject(self, &showIndicatorWhenLoadingKey, NSNumber(bool: newValue), .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
            }
        }
    }
    
    /// The indicator view showing when loading. This will be `nil` if `kf_showIndicatorWhenLoading` is false.
    /// You may want to use this to set the indicator style or color when you set `kf_showIndicatorWhenLoading` to true.
    public var kf_indicator: IndicatorView? {
        return objc_getAssociatedObject(self, &indicatorKey) as? IndicatorView
    }
    
    private func kf_setIndicator(indicator: IndicatorView?) {
        objc_setAssociatedObject(self, &indicatorKey, indicator, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
    }
    
    private var kf_imageTask: RetrieveImageTask? {
        return objc_getAssociatedObject(self, &imageTaskKey) as? RetrieveImageTask
    }
    
    private func kf_setImageTask(task: RetrieveImageTask?) {
        objc_setAssociatedObject(self, &imageTaskKey, task, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
    }
}


extension IndicatorView {
    func kf_startAnimating() {
        #if os(OSX)
            startAnimation(nil)
        #else
            startAnimating()
        #endif
        hidden = false
    }
    
    func kf_stopAnimating() {
        #if os(OSX)
            stopAnimation(nil)
        #else
            stopAnimating()
        #endif
        hidden = true
    }
    
    #if os(OSX)
    var kf_center: CGPoint {
    get {
    return CGPoint(x: frame.origin.x + frame.size.width / 2.0, y: frame.origin.y + frame.size.height / 2.0 )
    }
    set {
    let newFrame = CGRect(x: newValue.x - frame.size.width / 2.0, y: newValue.y - frame.size.height / 2.0, width: frame.size.width, height: frame.size.height)
    frame = newFrame
    }
    }
    #else
    var kf_center: CGPoint {
        get {
            return center
        }
        set {
            center = newValue
        }
    }
    #endif
}