Disable automatic GIF playback in low-power mode

Tusker/Screens/Large Image/LargeImageContentView.swift

@@ -78,6 +78,8 @@ class LargeImageGifvContentView: GifvAttachmentView, LargeImageContentView {
         super.init(asset: asset, gravity: .resizeAspect)
         
         self.animationImage = source.image
+        
+        self.player.play()
     }
     
     required init?(coder: NSCoder) {

Tusker/Views/Attachments/AttachmentView.swift

@@ -21,6 +21,7 @@ class AttachmentView: UIImageView, GIFAnimatable {
     weak var delegate: AttachmentViewDelegate?
 
     var playImageView: UIImageView?
+    var gifvView: GifvAttachmentView?
     
     var attachment: Attachment!
     var index: Int!
@@ -28,6 +29,9 @@ class AttachmentView: UIImageView, GIFAnimatable {
     private var attachmentRequest: ImageCache.Request?
     
     var gifData: Data?
+    private var autoplayGifs: Bool {
+        Preferences.shared.automaticallyPlayGifs && !ProcessInfo.processInfo.isLowPowerModeEnabled
+    }
 
     public lazy var animator: Animator? = Animator(withDelegate: self)
 
@@ -55,17 +59,29 @@ class AttachmentView: UIImageView, GIFAnimatable {
         isUserInteractionEnabled = true
         addGestureRecognizer(UITapGestureRecognizer(target: self, action: #selector(imagePressed)))
         
-        NotificationCenter.default.addObserver(self, selector: #selector(preferencesChanged), name: .preferencesChanged, object: nil)
+        NotificationCenter.default.addObserver(self, selector: #selector(gifPlaybackModeChanged), name: .preferencesChanged, object: nil)
+        NotificationCenter.default.addObserver(self, selector: #selector(gifPlaybackModeChanged), name: .NSProcessInfoPowerStateDidChange, object: nil)
         
         addInteraction(UIContextMenuInteraction(delegate: self))
     }
     
-    @objc func preferencesChanged() {
+    @objc func gifPlaybackModeChanged() {
-        if let gifData = gifData {
+        // NSProcessInfoPowerStateDidChange is sometimes fired on a background thread
-            if Preferences.shared.automaticallyPlayGifs && !isAnimatingGIF {
+        DispatchQueue.main.async {
-                animate(withGIFData: gifData)
+            if self.attachment.kind == .image,
-            } else if !Preferences.shared.automaticallyPlayGifs && isAnimatingGIF {
+               let gifData = self.gifData {
-                stopAnimatingGIF()
+                if self.autoplayGifs && !self.isAnimatingGIF {
+                    self.animate(withGIFData: gifData)
+                } else if !self.autoplayGifs && self.isAnimatingGIF {
+                    self.stopAnimatingGIF()
+                }
+            } else if self.attachment.kind == .gifv,
+                      let gifvView = self.gifvView {
+                if self.autoplayGifs {
+                    gifvView.player.play()
+                } else {
+                    gifvView.player.pause()
+                }
             }
         }
     }
@@ -95,7 +111,7 @@ class AttachmentView: UIImageView, GIFAnimatable {
             DispatchQueue.main.async {
                 if self.attachment.url.pathExtension == "gif" {
                     self.gifData = data
-                    if Preferences.shared.automaticallyPlayGifs {
+                    if self.autoplayGifs {
                         self.animate(withGIFData: data)
                     } else {
                         self.image = UIImage(data: data)
@@ -166,7 +182,11 @@ class AttachmentView: UIImageView, GIFAnimatable {
         }
         
         let gifvView = GifvAttachmentView(asset: asset, gravity: .resizeAspectFill)
+        self.gifvView = gifvView
         gifvView.translatesAutoresizingMaskIntoConstraints = false
+        if autoplayGifs {
+            gifvView.player.play()
+        }
         addSubview(gifvView)
         NSLayoutConstraint.activate([
             gifvView.leadingAnchor.constraint(equalTo: leadingAnchor),

Tusker/Views/Attachments/GifvAttachmentView.swift

@@ -31,7 +31,6 @@ class GifvAttachmentView: UIView {
         playerLayer.player = player
         playerLayer.videoGravity = gravity
         player.isMuted = true
-        player.play()
 
         NotificationCenter.default.addObserver(self, selector: #selector(restartItem), name: .AVPlayerItemDidPlayToEndTime, object: item)
     }