[image-picker][ios] Fix Animated GIF support

packages/expo-image-picker/CHANGELOG.md

@@ -8,6 +8,8 @@
 
 ### 🐛 Bug fixes
 
+- Fix support for animated GIFs on iOS. ([#20034](https://github.com/expo/expo/pull/20034) by [@barthap](https://github.com/barthap))
+
 ### 💡 Others
 
 ## 14.0.1 - 2022-11-08

packages/expo-image-picker/ios/ImagePickerOptions.swift

@@ -5,6 +5,8 @@ import MobileCoreServices
 import PhotosUI
 
 internal let DEFAULT_QUALITY = 0.2
+internal let MAXIMUM_QUALITY = 1.0
+
 internal let UNLIMITED_SELECTION = 0
 internal let SINGLE_SELECTION = 1
 

packages/expo-image-picker/ios/MediaHandler.swift

@@ -126,6 +126,7 @@ internal struct MediaHandler {
         }
 
         let (imageData, fileExtension) = try ImageUtils.readDataAndFileExtension(image: image,
+                                                                                 rawData: rawData,
                                                                                  itemProvider: itemProvider,
                                                                                  options: self.options)
 
@@ -345,11 +346,17 @@ private struct ImageUtils {
       return (nil, ".bmp")
 
     case .some(let s) where s.contains("ext=GIF"):
+      var rawData: Data?
+      if let imgUrl = mediaInfo[.imageURL] as? URL {
+         rawData = try? Data(contentsOf: imgUrl)
+      }
+      let inputData = rawData ?? image.jpegData(compressionQuality: compressionQuality)
       let metadata = mediaInfo[.mediaMetadata] as? [String: Any]
-      let gifData = try getGifDataFrom(image: image,
+      let cropRect = mediaInfo[.cropRect] as? CGRect
+      let gifData = try processGifData(inputData: inputData,
                                        compressionQuality: options.quality,
-                                       initialMetadata: metadata)
-
+                                       initialMetadata: metadata,
+                                       cropRect: cropRect)
       return (gifData, ".gif")
     default:
       let data = image.jpegData(compressionQuality: compressionQuality)
@@ -360,6 +367,7 @@ private struct ImageUtils {
   @available(iOS 14, *)
   static func readDataAndFileExtension(
     image: UIImage,
+    rawData: Data,
     itemProvider: NSItemProvider,
     options: ImagePickerOptions
   ) throws -> (imageData: Data?, fileExtension: String) {
@@ -371,7 +379,7 @@ private struct ImageUtils {
       let data = image.pngData()
       return (data, ".png")
     case UTType.gif.identifier:
-      let gifData = try getGifDataFrom(image: image,
+      let gifData = try processGifData(inputData: rawData,
                                        compressionQuality: options.quality,
                                        initialMetadata: nil)
       return (gifData, ".gif")
@@ -508,37 +516,52 @@ private struct ImageUtils {
     return exif
   }
 
-  static func getGifDataFrom(image: UIImage,
+  static func processGifData(inputData: Data?,
                              compressionQuality quality: Double?,
-                             initialMetadata: [String: Any]?) throws -> Data? {
-    guard let data = image.jpegData(compressionQuality: quality ?? DEFAULT_QUALITY) else {
-      throw FailedToReadImageDataException()
+                             initialMetadata: [String: Any]?,
+                             cropRect: CGRect? = nil) throws -> Data? {
+    // for uncropped, maximum quality image we can just pass through the raw data
+    if cropRect == nil,
+       quality == nil || quality == MAXIMUM_QUALITY {
+      return inputData
     }
 
-    let destinationData = NSMutableData()
-    guard let imageDestination = CGImageDestinationCreateWithData(destinationData, kUTTypeGIF, 1, nil),
-          let cgImage = image.cgImage
+    guard let sourceData = inputData,
+          let imageSource = CGImageSourceCreateWithData(sourceData as CFData, nil)
     else {
-      throw FailedToCreateGifException()
+      throw FailedToReadImageException()
     }
 
-    var metadata: [String: Any] = initialMetadata ?? [:]
-    if initialMetadata == nil,
-       let cgImageSource = CGImageSourceCreateWithData(data as CFData, nil),
-       let properties = CGImageSourceCopyPropertiesAtIndex(cgImageSource, 0, nil) as? [String: Any] {
-      metadata = properties
+    let gifProperties = CGImageSourceCopyProperties(imageSource, nil) as? [String: Any]
+    let frameCount = CGImageSourceGetCount(imageSource)
+
+    let destinationData = NSMutableData()
+    guard let imageDestination = CGImageDestinationCreateWithData(destinationData, kUTTypeGIF, frameCount, nil)
+    else {
+      throw FailedToCreateGifException()
     }
 
-    if quality != nil {
-      metadata[kCGImageDestinationLossyCompressionQuality as String] = quality
+    let gifMetadata = initialMetadata ?? gifProperties
+    CGImageDestinationSetProperties(imageDestination, gifMetadata as CFDictionary?);
+
+    for frameIndex in 0 ..< frameCount {
+      guard var cgImage = CGImageSourceCreateImageAtIndex(imageSource, frameIndex, nil),
+            var frameProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, frameIndex, nil) as? [String: Any]
+      else {
+        throw FailedToCreateGifException()
+      }
+      if cropRect != nil {
+        cgImage = cgImage.cropping(to: cropRect!)!
+      }
+      if quality != nil {
+        frameProperties[kCGImageDestinationLossyCompressionQuality as String] = quality
+      }
+      CGImageDestinationAddImage(imageDestination, cgImage, frameProperties as CFDictionary)
     }
 
-    CGImageDestinationAddImage(imageDestination, cgImage, metadata as CFDictionary)
-
     if !CGImageDestinationFinalize(imageDestination) {
       throw FailedToExportGifException()
     }
-
     return destinationData as Data
   }
 }

packages/expo-image-picker/src/ImagePicker.ts

@@ -225,10 +225,12 @@ export async function launchCameraAsync(
  * Requires `Permissions.MEDIA_LIBRARY` on iOS 10 only. On mobile web, this must be     called
  * immediately in a user interaction like a button press, otherwise the browser will block the
  * request without a warning.
- * **Animated GIFs support** If the selected image is an animated GIF, the result image will be an
- * animated GIF too if and only if `quality` is set to `undefined` and `allowsEditing` is set to `false`.
+ *
+ * **Animated GIFs support:** On Android, if the selected image is an animated GIF, the result image will be an
+ * animated GIF too if and only if `quality` is explicitly set to `1.0` and `allowsEditing` is set to `false`.
  * Otherwise compression and/or cropper will pick the first frame of the GIF and return it as the
- * result (on Android the result will be a PNG, on iOS — GIF).
+ * result (on Android the result will be a PNG). On iOS, both quality and cropping are supported.
+ *
  * > **Notes for Web:** The system UI can only be shown after user activation (e.g. a `Button` press).
  * Therefore, calling `launchImageLibraryAsync` in `componentDidMount`, for example, will **not**
  * work as intended. The `cancelled` event will not be returned in the browser due to platform