Updated audio attachments to allow scrubbing.

SignalUtilitiesKit/Media Viewing & Editing/Attachment Approval/AttachmentPrepViewController.swift

@@ -15,7 +15,7 @@ protocol AttachmentPrepViewControllerDelegate: AnyObject {
 
 // MARK: -
 
-public class AttachmentPrepViewController: OWSViewController, PlayerProgressBarDelegate, OWSVideoPlayerDelegate {
+public class AttachmentPrepViewController: OWSViewController, PlayerProgressBarDelegate, OWSVideoPlayerDelegate, MediaMessageViewAudioDelegate {
     // We sometimes shrink the attachment view so that it remains somewhat visible
     // when the keyboard is presented.
     public enum AttachmentViewScale {
@@ -74,6 +74,7 @@ public class AttachmentPrepViewController: OWSViewController, PlayerProgressBarD
     private lazy var mediaMessageView: MediaMessageView = {
         let view: MediaMessageView = MediaMessageView(attachment: attachment, mode: .attachmentApproval)
         view.translatesAutoresizingMaskIntoConstraints = false
+        view.audioDelegate = self
         view.isHidden = (imageEditorView != nil)
         
         return view
@@ -168,12 +169,15 @@ public class AttachmentPrepViewController: OWSViewController, PlayerProgressBarD
             mediaMessageView.videoPlayButton.isHidden = true
             mediaMessageView.addSubview(playerView)
             
-            // we don't want the progress bar to zoom during "pinch-to-zoom"
+            // We don't want the progress bar to zoom during "pinch-to-zoom"
             // but we do want it to shrink with the media content when the user
             // pops the keyboard.
             contentContainerView.addSubview(progressBar)
             contentContainerView.addSubview(playVideoButton)
         }
+        else if attachment.isAudio, mediaMessageView.audioPlayer != nil {
+            contentContainerView.addSubview(progressBar)
+        }
         
         setupLayout()
     }
@@ -268,6 +272,13 @@ public class AttachmentPrepViewController: OWSViewController, PlayerProgressBarD
                 playVideoButton.heightAnchor.constraint(equalToConstant: playButtonSize),
             ])
         }
+        else if attachment.isAudio, mediaMessageView.audioPlayer != nil {
+            NSLayoutConstraint.activate([
+                progressBar.topAnchor.constraint(equalTo: view.topAnchor),
+                progressBar.widthAnchor.constraint(equalTo: contentContainerView.widthAnchor),
+                progressBar.heightAnchor.constraint(equalToConstant: 44)
+            ])
+        }
     }
 
     // MARK: - Navigation Bar
@@ -326,6 +337,11 @@ public class AttachmentPrepViewController: OWSViewController, PlayerProgressBarD
     }
 
     public func playerProgressBarDidStartScrubbing(_ playerProgressBar: PlayerProgressBar) {
+        if attachment.isAudio {
+            mediaMessageView.pauseAudio()
+            return
+        }
+        
         guard let videoPlayer = self.videoPlayer else {
             owsFailDebug("video player was unexpectedly nil")
             return
@@ -335,25 +351,50 @@ public class AttachmentPrepViewController: OWSViewController, PlayerProgressBarD
     }
 
     public func playerProgressBar(_ playerProgressBar: PlayerProgressBar, scrubbedToTime time: CMTime) {
+        if attachment.isAudio {
+            mediaMessageView.setAudioTime(currentTime: CMTimeGetSeconds(time))
+            progressBar.manuallySetValue(CMTimeGetSeconds(time), durationSeconds: mediaMessageView.audioDurationSeconds)
+            return
+        }
+        
         guard let videoPlayer = self.videoPlayer else {
             owsFailDebug("video player was unexpectedly nil")
             return
         }
 
         videoPlayer.seek(to: time)
+        progressBar.updateState()
     }
 
     public func playerProgressBar(_ playerProgressBar: PlayerProgressBar, didFinishScrubbingAtTime time: CMTime, shouldResumePlayback: Bool) {
+        if attachment.isAudio {
+            mediaMessageView.setAudioTime(currentTime: CMTimeGetSeconds(time))
+            progressBar.manuallySetValue(CMTimeGetSeconds(time), durationSeconds: mediaMessageView.audioDurationSeconds)
+            
+            if mediaMessageView.wasPlayingAudio {
+                mediaMessageView.playAudio()
+            }
+            return
+        }
+        
         guard let videoPlayer = self.videoPlayer else {
             owsFailDebug("video player was unexpectedly nil")
             return
         }
 
         videoPlayer.seek(to: time)
+        progressBar.updateState()
+        
         if (shouldResumePlayback) {
             videoPlayer.play()
         }
     }
+    
+    // MARK: - MediaMessageViewAudioDelegate
+    
+    public func progressChanged(_ progressSeconds: CGFloat, durationSeconds: CGFloat) {
+        progressBar.manuallySetValue(progressSeconds, durationSeconds: durationSeconds)
+    }
 
     // MARK: - Helpers
 

SignalUtilitiesKit/Media Viewing & Editing/MediaMessageView.swift

@@ -8,6 +8,10 @@ import YYImage
 import NVActivityIndicatorView
 import SessionUIKit
 
+public protocol MediaMessageViewAudioDelegate: AnyObject {
+    func progressChanged(_ progressSeconds: CGFloat, durationSeconds: CGFloat)
+}
+
 public class MediaMessageView: UIView, OWSAudioPlayerDelegate {
     public enum Mode: UInt {
         case large
@@ -26,8 +30,10 @@ public class MediaMessageView: UIView, OWSAudioPlayerDelegate {
         return OWSAudioPlayer(mediaUrl: dataUrl, audioBehavior: .playback, delegate: self)
     }()
     
+    public var wasPlayingAudio: Bool = false
     public var audioProgressSeconds: CGFloat = 0
     public var audioDurationSeconds: CGFloat = 0
+    public weak var audioDelegate: MediaMessageViewAudioDelegate?
     
     public var playbackState = AudioPlaybackState.stopped {
         didSet {
@@ -354,6 +360,7 @@ public class MediaMessageView: UIView, OWSAudioPlayerDelegate {
                 imageView.isHidden = false
                 audioPlayPauseButton.isHidden = (audioPlayer == nil)
                 setAudioIconToPlay()
+                setAudioProgress(0, duration: (audioPlayer?.duration ?? 0))
                 
                 fileTypeImageView.image = UIImage(named: "table_ic_notification_sound")?
                     .withRenderingMode(.alwaysTemplate)
@@ -561,6 +568,32 @@ public class MediaMessageView: UIView, OWSAudioPlayerDelegate {
             }
             .retainUntilComplete()
     }
+    
+    // MARK: - Functions
+    
+    public func playAudio() {
+        audioPlayer?.play()
+        ensureButtonState()
+    }
+    
+    public func pauseAudio() {
+        wasPlayingAudio = (audioPlayer?.isPlaying == true)
+        
+        // If the 'audioPlayer' has a duration of 0 then we probably haven't played previously which
+        // will result in the audioPlayer having a 'duration' of 0 breaking the progressBar. We play
+        // the audio to get it to properly load the file right before pausing it so the data is
+        // loaded correctly
+        if audioPlayer?.duration == 0 {
+            audioPlayer?.play()
+        }
+        
+        audioPlayer?.pause()
+        ensureButtonState()
+    }
+    
+    public func setAudioTime(currentTime: TimeInterval) {
+        audioPlayer?.setCurrentTime(currentTime)
+    }
 
     // MARK: - Event Handlers
 
@@ -594,8 +627,13 @@ public class MediaMessageView: UIView, OWSAudioPlayerDelegate {
     }
 
     public func setAudioProgress(_ progress: CGFloat, duration: CGFloat) {
+        // Note: When the OWSAudioPlayer stops it sets the duration to 0 (which we want to ignore so
+        // the UI doesn't look buggy)
+        let finalDuration: CGFloat = (duration > 0 ? duration : audioDurationSeconds)
         audioProgressSeconds = progress
-        audioDurationSeconds = duration
+        audioDurationSeconds = finalDuration
+        
+        audioDelegate?.progressChanged(progress, durationSeconds: finalDuration)
     }
 
     private func setAudioIconToPlay() {

SignalUtilitiesKit/Media Viewing & Editing/OWSVideoPlayer.swift

@@ -58,7 +58,7 @@ public class OWSVideoPlayer: NSObject {
 
         if item.currentTime() == item.duration {
             // Rewind for repeated plays, but only if it previously played to end.
-            avPlayer.seek(to: CMTime.zero)
+            avPlayer.seek(to: CMTime.zero, toleranceBefore: .zero, toleranceAfter: .zero)
         }
 
         avPlayer.play()
@@ -67,13 +67,13 @@ public class OWSVideoPlayer: NSObject {
     @objc
     public func stop() {
         avPlayer.pause()
-        avPlayer.seek(to: CMTime.zero)
+        avPlayer.seek(to: CMTime.zero, toleranceBefore: .zero, toleranceAfter: .zero)
         audioSession.endAudioActivity(self.audioActivity)
     }
 
     @objc(seekToTime:)
     public func seek(to time: CMTime) {
-        avPlayer.seek(to: time)
+        avPlayer.seek(to: time, toleranceBefore: .zero, toleranceAfter: .zero)
     }
 
     // MARK: private

SignalUtilitiesKit/Media Viewing & Editing/VideoPlayerView.swift

@@ -88,12 +88,16 @@ public class PlayerProgressBar: UIView {
             let duration: CMTime = item.asset.duration
             slider.maximumValue = Float(CMTimeGetSeconds(duration))
 
-            // OPTIMIZE We need a high frequency observer for smooth slider updates,
+            updateState()
+            
+            // OPTIMIZE We need a high frequency observer for smooth slider updates while playing,
             // but could use a much less frequent observer for label updates
-            progressObserver = player?.addPeriodicTimeObserver(forInterval: CMTime(seconds: 0.01, preferredTimescale: kPreferredTimeScale), queue: nil, using: { [weak self] (_) in
-                self?.updateState()
+            progressObserver = player?.addPeriodicTimeObserver(forInterval: CMTime(seconds: 0.1, preferredTimescale: kPreferredTimeScale), queue: nil, using: { [weak self] _ in
+                // If it is playing update the time
+                if self?.player?.rate != 0 && self?.player?.error == nil {
+                    self?.updateState()
+                }
             }) as AnyObject
-            updateState()
         }
     }
 
@@ -182,7 +186,7 @@ public class PlayerProgressBar: UIView {
 
     // MARK: Render cycle
 
-    private func updateState() {
+    public func updateState() {
         guard let player = player else {
             owsFailDebug("player isn't set.")
             return
@@ -219,4 +223,26 @@ public class PlayerProgressBar: UIView {
         let seconds: Double = Double(slider.value)
         return CMTime(seconds: seconds, preferredTimescale: kPreferredTimeScale)
     }
+    
+    // MARK: - Functions
+    
+    public func manuallySetValue(_ positionSeconds: CGFloat, durationSeconds: CGFloat) {
+        let remainingSeconds = (durationSeconds - positionSeconds)
+        
+        slider.minimumValue = 0
+        slider.maximumValue = Float(durationSeconds)
+        
+        positionLabel.text = formatter.string(from: positionSeconds)
+        
+        guard let remainingString = formatter.string(from: remainingSeconds) else {
+            owsFailDebug("unable to format time remaining")
+            remainingLabel.text = "0:00"
+            return
+        }
+        
+        // show remaining time as negative
+        remainingLabel.text = "-\(remainingString)"
+        
+        slider.setValue(Float(positionSeconds), animated: false)
+    }
 }