VEX-5682: iOS Swift Conversion (#11)

Converts ios implementation from objective-c to swift.

ios/Video/Features/RCTPlayerOperations.swift

@@ -0,0 +1,160 @@
+import AVFoundation
+import MediaAccessibility
+
+let RCTVideoUnset = -1
+
+/*!
+ * Collection of mutating functions
+ */
+enum RCTPlayerOperations {
+    
+    static func setSideloadedText(player:AVPlayer?, textTracks:[TextTrack]?, criteria:SelectedTrackCriteria?) {
+        let type = criteria?.type
+        let textTracks:[TextTrack]! = textTracks ?? RCTVideoUtils.getTextTrackInfo(player)
+        
+        // The first few tracks will be audio & video track
+        let firstTextIndex:Int = 0
+        for firstTextIndex in 0..<(player?.currentItem?.tracks.count ?? 0) {
+            if player?.currentItem?.tracks[firstTextIndex].assetTrack?.hasMediaCharacteristic(.legible) ?? false {
+                break
+            }
+        }
+        
+        var selectedTrackIndex:Int = RCTVideoUnset
+        
+        if (type == "disabled") {
+            // Do nothing. We want to ensure option is nil
+        } else if (type == "language") {
+            let selectedValue = criteria?.value as? String
+            for i in 0..<textTracks.count {
+                let currentTextTrack = textTracks[i]
+                if (selectedValue == currentTextTrack.language) {
+                    selectedTrackIndex = i
+                    break
+                }
+            }
+        } else if (type == "title") {
+            let selectedValue = criteria?.value as? String
+            for i in 0..<textTracks.count {
+                let currentTextTrack = textTracks[i]
+                if (selectedValue == currentTextTrack.title) {
+                    selectedTrackIndex = i
+                    break
+                }
+            }
+        } else if (type == "index") {
+            if let value = criteria?.value, let index = value as? Int {
+                if textTracks.count > index {
+                    selectedTrackIndex = index
+                }
+            }
+        }
+        
+        // in the situation that a selected text track is not available (eg. specifies a textTrack not available)
+        if (type != "disabled") && selectedTrackIndex == RCTVideoUnset {
+            let captioningMediaCharacteristics = MACaptionAppearanceCopyPreferredCaptioningMediaCharacteristics(.user) as! CFArray
+            let captionSettings = captioningMediaCharacteristics as? [AnyHashable]
+            if ((captionSettings?.contains(AVMediaCharacteristic.transcribesSpokenDialogForAccessibility)) != nil) {
+                selectedTrackIndex = 0 // If we can't find a match, use the first available track
+                let systemLanguage = NSLocale.preferredLanguages.first
+                for i in 0..<textTracks.count {
+                    let currentTextTrack = textTracks[i]
+                    if systemLanguage == currentTextTrack.language {
+                        selectedTrackIndex = i
+                        break
+                    }
+                }
+            }
+        }
+        
+        for i in firstTextIndex..<(player?.currentItem?.tracks.count ?? 0) {
+            var isEnabled = false
+            if selectedTrackIndex != RCTVideoUnset {
+                isEnabled = i == selectedTrackIndex + firstTextIndex
+            }
+            player?.currentItem?.tracks[i].isEnabled = isEnabled
+        }
+    }
+    
+    // UNUSED
+    static func setStreamingText(player:AVPlayer?, criteria:SelectedTrackCriteria?) {
+        let type = criteria?.type
+        let group:AVMediaSelectionGroup! = player?.currentItem?.asset.mediaSelectionGroup(forMediaCharacteristic: AVMediaCharacteristic.legible)
+        var mediaOption:AVMediaSelectionOption!
+        
+        if (type == "disabled") {
+            // Do nothing. We want to ensure option is nil
+        } else if (type == "language") || (type == "title") {
+            let value = criteria?.value as? String
+            for i in 0..<group.options.count {
+                let currentOption:AVMediaSelectionOption! = group.options[i]
+                var optionValue:String!
+                if (type == "language") {
+                    optionValue = currentOption.extendedLanguageTag
+                } else {
+                    optionValue = currentOption.commonMetadata.map(\.value)[0] as! String
+                }
+                if (value == optionValue) {
+                    mediaOption = currentOption
+                    break
+                }
+            }
+            //} else if ([type isEqualToString:@"default"]) {
+            //  option = group.defaultOption; */
+        } else if (type == "index") {
+            if let value = criteria?.value, let index = value as? Int {
+                if group.options.count > index {
+                    mediaOption = group.options[index]
+                }
+            }
+        } else { // default. invalid type or "system"
+            player?.currentItem?.selectMediaOptionAutomatically(in: group)
+            return
+        }
+        
+        // If a match isn't found, option will be nil and text tracks will be disabled
+        player?.currentItem?.select(mediaOption, in:group)
+    }
+    
+    static func setMediaSelectionTrackForCharacteristic(player:AVPlayer?, characteristic:AVMediaCharacteristic, criteria:SelectedTrackCriteria?) {
+        let type = criteria?.type
+        let group:AVMediaSelectionGroup! = player?.currentItem?.asset.mediaSelectionGroup(forMediaCharacteristic: characteristic)
+        var mediaOption:AVMediaSelectionOption!
+        
+        if (type == "disabled") {
+            // Do nothing. We want to ensure option is nil
+        } else if (type == "language") || (type == "title") {
+            let value = criteria?.value as? String
+            for i in 0..<group.options.count {
+                let currentOption:AVMediaSelectionOption! = group.options[i]
+                var optionValue:String!
+                if (type == "language") {
+                    optionValue = currentOption.extendedLanguageTag
+                } else {
+                    optionValue = currentOption.commonMetadata.map(\.value)[0] as? String
+                }
+                if (value == optionValue) {
+                    mediaOption = currentOption
+                    break
+                }
+            }
+            //} else if ([type isEqualToString:@"default"]) {
+            //  option = group.defaultOption; */
+        } else if type == "index" {
+            if let value = criteria?.value, let index = value as? Int {
+                if group.options.count > index {
+                    mediaOption = group.options[index]
+                }
+            }
+        } else if let group = group { // default. invalid type or "system"
+            player?.currentItem?.selectMediaOptionAutomatically(in: group)
+            return
+        }
+        
+        if let group = group {
+            // If a match isn't found, option will be nil and text tracks will be disabled
+            player?.currentItem?.select(mediaOption, in:group)
+        }
+        
+    }
+}