Load GIFs progressively using stills.

// FREEBIE

Signal/src/ViewControllers/GifPicker/GifPickerCell.swift

@@ -25,8 +25,10 @@ class GifPickerCell: UICollectionViewCell {
         }
     }
 
-    var assetRequest: GiphyAssetRequest?
-    var asset: GiphyAsset?
+    var stillAssetRequest: GiphyAssetRequest?
+    var stillAsset: GiphyAsset?
+    var fullAssetRequest: GiphyAssetRequest?
+    var fullAsset: GiphyAsset?
     var imageView: YYAnimatedImageView?
 
     // MARK: Initializers
@@ -46,16 +48,29 @@ class GifPickerCell: UICollectionViewCell {
 
         imageInfo = nil
         shouldLoad = false
-        asset = nil
-        assetRequest?.cancel()
-        assetRequest = nil
+        stillAsset = nil
+        stillAssetRequest?.cancel()
+        stillAssetRequest = nil
+        fullAsset = nil
+        fullAssetRequest?.cancel()
+        fullAssetRequest = nil
         imageView?.removeFromSuperview()
         imageView = nil
     }
 
+    private func clearStillAssetRequest() {
+        stillAssetRequest?.cancel()
+        stillAssetRequest = nil
+    }
+
+    private func clearFullAssetRequest() {
+        fullAssetRequest?.cancel()
+        fullAssetRequest = nil
+    }
+
     private func clearAssetRequest() {
-        assetRequest?.cancel()
-        assetRequest = nil
+        clearStillAssetRequest()
+        clearFullAssetRequest()
     }
 
     private func ensureLoad() {
@@ -67,31 +82,60 @@ class GifPickerCell: UICollectionViewCell {
             clearAssetRequest()
             return
         }
-        guard self.assetRequest == nil else {
+        guard self.fullAsset == nil else {
+            return
+        }
+        guard let fullRendition = imageInfo.pickGifRendition() else {
+            Logger.warn("\(TAG) could not pick gif rendition: \(imageInfo.giphyId)")
+//            imageInfo.log()
+            clearAssetRequest()
             return
         }
-        guard let rendition = imageInfo.pickGifRendition() else {
-            Logger.warn("\(TAG) could not pick rendition")
+        guard let stillRendition = imageInfo.pickStillRendition() else {
+            Logger.warn("\(TAG) could not pick still rendition: \(imageInfo.giphyId)")
+//            imageInfo.log()
             clearAssetRequest()
             return
         }
-//        Logger.verbose("\(TAG) picked rendition: \(rendition.name)")
+//        Logger.verbose("picked full: \(fullRendition.name)")
+//        Logger.verbose("picked still: \(stillRendition.name)")
 
-        assetRequest = GifDownloader.sharedInstance.downloadAssetAsync(rendition:rendition,
+        if stillAsset == nil && fullAsset == nil && stillAssetRequest == nil {
+            stillAssetRequest = GifDownloader.sharedInstance.downloadAssetAsync(rendition:stillRendition,
+                                                                                priority:.high,
                                                                                 success: { [weak self] asset in
+//                                                                                    Logger.verbose("downloaded still")
+                                                                                    guard let strongSelf = self else { return }
+                                                                                    strongSelf.clearStillAssetRequest()
+                                                                                    strongSelf.stillAsset = asset
+                                                                                    strongSelf.tryToDisplayAsset()
+                },
+                                                                                failure: { [weak self] in
+//                                                                                    Logger.verbose("failed to download still")
+                                                                                    guard let strongSelf = self else { return }
+                                                                                    strongSelf.clearStillAssetRequest()
+            })
+        }
+        if fullAsset == nil && fullAssetRequest == nil {
+            fullAssetRequest = GifDownloader.sharedInstance.downloadAssetAsync(rendition:fullRendition,
+                                                                               priority:.low,
+                                                                               success: { [weak self] asset in
+//                                                                                Logger.verbose("downloaded full")
                                                                                 guard let strongSelf = self else { return }
                                                                                 strongSelf.clearAssetRequest()
-                                        strongSelf.asset = asset
+                                                                                strongSelf.fullAsset = asset
                                                                                 strongSelf.tryToDisplayAsset()
                 },
                                                                                failure: { [weak self] in
+//                                                                                Logger.verbose("failed to download full")
                                                                                 guard let strongSelf = self else { return }
                                                                                 strongSelf.clearAssetRequest()
             })
         }
+    }
 
     private func tryToDisplayAsset() {
-        guard let asset = asset else {
+        guard let asset = pickBestAsset() else {
             owsFail("\(TAG) missing asset.")
             return
         }
@@ -99,11 +143,27 @@ class GifPickerCell: UICollectionViewCell {
             owsFail("\(TAG) could not load asset.")
             return
         }
+        if imageView == nil {
             let imageView = YYAnimatedImageView()
             self.imageView = imageView
-        imageView.image = image
             self.contentView.addSubview(imageView)
             imageView.autoPinWidthToSuperview()
             imageView.autoPinHeightToSuperview()
         }
+        guard let imageView = imageView else {
+            owsFail("\(TAG) missing imageview.")
+            return
+        }
+        imageView.image = image
+    }
+
+    private func pickBestAsset() -> GiphyAsset? {
+        if let fullAsset = fullAsset {
+            return fullAsset
+        }
+        if let stillAsset = stillAsset {
+            return stillAsset
+        }
+        return nil
+    }
 }

Signal/src/ViewControllers/GifPicker/GifPickerViewController.swift

@@ -164,7 +164,7 @@ class GifPickerViewController: OWSViewController, UISearchBarDelegate, UICollect
             owsFail("\(TAG) unexpected cell.")
             return
         }
-        guard let asset = cell.asset else {
+        guard let asset = cell.fullAsset else {
             Logger.info("\(TAG) unload cell selected.")
             return
         }

Signal/src/network/GifDownloader.swift

@@ -5,20 +5,27 @@
 import Foundation
 import ObjectiveC
 
+enum GiphyRequestPriority {
+    case low, high
+}
+
 @objc class GiphyAssetRequest: NSObject {
     static let TAG = "[GiphyAssetRequest]"
 
     let rendition: GiphyRendition
+    let priority: GiphyRequestPriority
     let success: ((GiphyAsset) -> Void)
     let failure: (() -> Void)
     var wasCancelled = false
     var assetFilePath: String?
 
     init(rendition: GiphyRendition,
+         priority: GiphyRequestPriority,
          success:@escaping ((GiphyAsset) -> Void),
          failure:@escaping (() -> Void)
         ) {
         self.rendition = rendition
+        self.priority = priority
         self.success = success
         self.failure = failure
     }
@@ -121,6 +128,7 @@ extension URLSessionTask {
     // The success and failure handlers are always called on main queue.
     // The success and failure handlers may be called synchronously on cache hit.
     public func downloadAssetAsync(rendition: GiphyRendition,
+                                   priority: GiphyRequestPriority,
                               success:@escaping ((GiphyAsset) -> Void),
                               failure:@escaping (() -> Void)) -> GiphyAssetRequest? {
         AssertIsOnMainThread()
@@ -132,6 +140,7 @@ extension URLSessionTask {
 
         var hasRequestCompleted = false
         let assetRequest = GiphyAssetRequest(rendition:rendition,
+                                             priority:priority,
                                              success : { asset in
                                                 DispatchQueue.main.async {
                                                     // Ensure we call success or failure exactly once.
@@ -171,14 +180,9 @@ extension URLSessionTask {
             guard !self.isDownloading else {
                 return
             }
-            guard self.assetRequestQueue.count > 0 else {
-                return
-            }
-            guard let assetRequest = self.assetRequestQueue.first else {
-                owsFail("\(GiphyAsset.TAG) could not pop asset requests")
+            guard let assetRequest = self.popNextAssetRequest() else {
                 return
             }
-            self.assetRequestQueue.removeFirst()
             guard !assetRequest.wasCancelled else {
                 DispatchQueue.main.async {
                     self.downloadIfNecessary()
@@ -206,6 +210,22 @@ extension URLSessionTask {
         }
     }
 
+    private func popNextAssetRequest() -> GiphyAssetRequest? {
+        AssertIsOnMainThread()
+
+//        var result : GiphyAssetRequest?
+        for priority in [GiphyRequestPriority.high, GiphyRequestPriority.low] {
+            for (assetRequestIndex, assetRequest) in assetRequestQueue.enumerated() {
+                if assetRequest.priority == priority {
+                    assetRequestQueue.remove(at:assetRequestIndex)
+                    return assetRequest
+                }
+            }
+        }
+
+        return nil
+    }
+
     // MARK: URLSessionDataDelegate
 
     @nonobjc

Signal/src/network/GifManager.swift

@@ -7,7 +7,7 @@ import ObjectiveC
 
 // There's no UTI type for webp!
 enum GiphyFormat {
-    case gif, mp4
+    case gif, mp4, jpg
 }
 
 @objc class GiphyRendition: NSObject {
@@ -38,6 +38,8 @@ enum GiphyFormat {
             return "gif"
         case .mp4:
             return "mp4"
+        case .jpg:
+            return "jpg"
         }
     }
 
@@ -47,8 +49,14 @@ enum GiphyFormat {
             return kUTTypeGIF as String
         case .mp4:
             return kUTTypeMPEG4 as String
+        case .jpg:
+            return kUTTypeJPEG as String
         }
     }
+
+    public func log() {
+        Logger.verbose("\t \(format), \(name), \(width), \(height), \(fileSize)")
+    }
 }
 
 @objc class GiphyImageInfo: NSObject {
@@ -69,21 +77,48 @@ enum GiphyFormat {
     let kMinDimension = UInt(101)
     let kMaxFileSize = UInt(3 * 1024 * 1024)
 
+    public func log() {
+        Logger.verbose("giphyId: \(giphyId), \(renditions.count)")
+        for rendition in renditions {
+            rendition.log()
+        }
+    }
+
+    public func pickStillRendition() -> GiphyRendition? {
+        return pickRendition(isStill:true)
+    }
+
     public func pickGifRendition() -> GiphyRendition? {
+        return pickRendition(isStill:false)
+    }
+
+    private func pickRendition(isStill: Bool) -> GiphyRendition? {
         var bestRendition: GiphyRendition?
 
         for rendition in renditions {
-            guard rendition.format == .gif else {
+            if isStill {
+                guard [.gif, .jpg].contains(rendition.format) else {
                     continue
                 }
-            guard !rendition.name.hasSuffix("_still")
-                else {
+                guard rendition.name.hasSuffix("_still") else {
                         continue
                 }
-            guard !rendition.name.hasSuffix("_downsampled")
+                guard rendition.width >= kMinDimension &&
+                    rendition.height >= kMinDimension &&
+                    rendition.fileSize <= kMaxFileSize
                     else {
                         continue
                 }
+            } else {
+                guard rendition.format == .gif else {
+                    continue
+                }
+                guard !rendition.name.hasSuffix("_still") else {
+                        continue
+                }
+                guard !rendition.name.hasSuffix("_downsampled") else {
+                        continue
+                }
                 guard rendition.width >= kMinDimension &&
                     rendition.width <= kMaxDimension &&
                     rendition.height >= kMinDimension &&
@@ -92,11 +127,18 @@ enum GiphyFormat {
                     else {
                         continue
                 }
+            }
 
             if let currentBestRendition = bestRendition {
+                if isStill {
+                    if rendition.width < currentBestRendition.width {
+                        bestRendition = rendition
+                    }
+                } else {
                     if rendition.width > currentBestRendition.width {
                         bestRendition = rendition
                     }
+                }
             } else {
                 bestRendition = rendition
             }
@@ -191,6 +233,8 @@ enum GiphyFormat {
     // MARK: Parse API Responses
 
     private func parseGiphyImages(responseJson:Any?) -> [GiphyImageInfo]? {
+//        Logger.verbose("\(responseJson)")
+
         guard let responseJson = responseJson else {
             Logger.error("\(GifManager.TAG) Missing response.")
             return nil
@@ -292,14 +336,27 @@ enum GiphyFormat {
             Logger.warn("\(GifManager.TAG) Rendition url missing file extension.")
             return nil
         }
-        guard fileExtension.lowercased() == "gif" else {
-//            Logger.verbose("\(GifManager.TAG) Rendition has invalid type: \(fileExtension).")
+        var format = GiphyFormat.gif
+        if fileExtension.lowercased() == "gif" {
+            format = .gif
+        } else if fileExtension.lowercased() == "jpg" {
+            format = .jpg
+        } else if fileExtension.lowercased() == "mp4" {
+            format = .mp4
+        } else if fileExtension.lowercased() == "webp" {
+            return nil
+        } else {
+            Logger.warn("\(GifManager.TAG) Invalid file extension: \(fileExtension).")
             return nil
         }
+//        guard fileExtension.lowercased() == "gif" else {
+////            Logger.verbose("\(GifManager.TAG) Rendition has invalid type: \(fileExtension).")
+//            return nil
+//        }
 
 //        Logger.debug("\(GifManager.TAG) Rendition successfully parsed.")
         return GiphyRendition(
-            format : .gif,
+            format : format,
             name : renditionName,
             width : width,
             height : height,