Attachment menu improvements

submodules/MediaPickerUI/Sources/FetchAssets.swift

@@ -0,0 +1,61 @@
+import Foundation
+import UIKit
+import Photos
+import SwiftSignalKit
+
+private let imageManager = PHCachingImageManager()
+
+func assetImage(fetchResult: PHFetchResult<PHAsset>, index: Int, targetSize: CGSize, exact: Bool) -> Signal<UIImage?, NoError> {
+    let asset = fetchResult[index]
+    return assetImage(asset: asset, targetSize: targetSize, exact: exact)
+}
+
+func assetImage(asset: PHAsset, targetSize: CGSize, exact: Bool) -> Signal<UIImage?, NoError> {
+    return Signal { subscriber in        
+        let options = PHImageRequestOptions()
+        if exact {
+            options.resizeMode = .exact
+        }
+        let token = imageManager.requestImage(for: asset, targetSize: targetSize, contentMode: .aspectFill, options: options) { (image, info) in
+            var degraded = false
+            
+            if let info = info {
+                if let cancelled = info[PHImageCancelledKey] as? Bool, cancelled {
+                    return
+                }
+                if let degradedValue = info[PHImageResultIsDegradedKey] as? Bool, degradedValue {
+                    degraded = true
+                }
+            }
+            
+            if let image = image {
+                subscriber.putNext(image)
+                if !degraded {
+                    subscriber.putCompletion()
+                }
+            }
+        }
+        return ActionDisposable {
+            imageManager.cancelImageRequest(token)
+        }
+    }
+}
+
+func assetVideo(fetchResult: PHFetchResult<PHAsset>, index: Int) -> Signal<AVAsset?, NoError> {
+    return Signal { subscriber in
+        let asset = fetchResult[index]
+        
+        let options = PHVideoRequestOptions()
+        
+        let token = imageManager.requestAVAsset(forVideo: asset, options: options) { (avAsset, _, info) in
+            if let avAsset = avAsset {
+                subscriber.putNext(avAsset)
+                subscriber.putCompletion()
+            }
+        }
+    
+        return ActionDisposable {
+            imageManager.cancelImageRequest(token)
+        }
+    }
+}