Add workaround for invalid buffering info on android

README.md

@@ -24,7 +24,8 @@ Chewie uses the `video_player` under the hood and wraps it in a friendly Materia
 8.  🧪 [Example](#-example)
 9.  ⏪ [Migrating from Chewie < 0.9.0](#-migrating-from-chewie--090)
 10. 🗺️ [Roadmap](#%EF%B8%8F-roadmap)
-11. 📱 [iOS warning](#-ios-warning-)
+11. ⚠️ [Android warning](#-android-warning-)
+12. 📱 [iOS warning](#-ios-warning-)
 
 
 ## 🚨 IMPORTANT!!! (READ THIS FIRST)
@@ -286,6 +287,42 @@ final playerWidget = Chewie(
 - [ ] Screen-Mirroring / Casting (Google Chromecast)
 
 
+## ⚠️ Android warning
+
+There is an open [issue](https://github.com/flutter/flutter/issues/165149) that the buffering state of a video is not reported correctly. With this, the loading state is always triggered, hiding controls to play, pause or seek the video. A workaround was implemented until this is fixed, however it can't be perfect and still hides controls if seeking backwards while the video is paused, as a result of lack of correct buffering information (see #912).
+
+Add the following to partly fix this behavior:
+
+```dart
+  // Your init code can be above
+  videoController.addListener(yourListeningMethod);
+
+  // ...
+
+  bool wasPlayingBefore = false;
+  void yourListeningMethod() {
+    if (!videoController.value.isPlaying && !wasPlayingBefore) {
+      // -> Workaround if seekTo another position while it was paused before.
+      //    On Android this might lead to infinite loading, so just play the
+      //    video again.
+      videoController.play();
+    }
+
+    wasPlayingBefore = videoController.value.isPlaying;
+
+  // ...
+  }
+```
+
+You can also disable the loading spinner entirely to fix this problem in a more _complete_ way, however will remove the loading indicator if a video is buffering.
+
+```dart
+_chewieController = ChewieController(
+  videoPlayerController: _videoPlayerController,
+  progressIndicatorDelay: Platform.isAndroid ? const Duration(days: 1) : null,
+);
+```
+
 ## 📱 iOS warning 
 
 The video_player plugin used by chewie will only work in iOS simulators if you are on flutter 1.26.0 or above. You may need to switch to the beta channel `flutter channel beta`

lib/src/cupertino/cupertino_controls.dart

@@ -810,9 +810,11 @@ class _CupertinoControlsState extends State<CupertinoControls>
   void _updateState() {
     if (!mounted) return;
 
+    final bool buffering = getIsBuffering(controller);
+
     // display the progress bar indicator only after the buffering delay if it has been set
     if (chewieController.progressIndicatorDelay != null) {
-      if (controller.value.isBuffering) {
+      if (buffering) {
         _bufferingDisplayTimer ??= Timer(
           chewieController.progressIndicatorDelay!,
           _bufferingTimerTimeout,
@@ -823,7 +825,7 @@ class _CupertinoControlsState extends State<CupertinoControls>
         _displayBufferingIndicator = false;
       }
     } else {
-      _displayBufferingIndicator = controller.value.isBuffering;
+      _displayBufferingIndicator = buffering;
     }
 
     setState(() {

lib/src/helpers/utils.dart

@@ -1,3 +1,7 @@
+import 'dart:io';
+
+import 'package:video_player/video_player.dart';
+
 String formatDuration(Duration position) {
   final ms = position.inMilliseconds;
 
@@ -30,3 +34,30 @@
 
   return formattedTime;
 }
+
+bool getIsBuffering(VideoPlayerController controller) {
+  final VideoPlayerValue value = controller.value;
+
+  if (Platform.isAndroid) {
+    if (value.isBuffering) {
+      // -> Check if we actually buffer, as android has a bug preventing to
+      //    get the correct buffering state from this single bool.
+      final int position = value.position.inMilliseconds;
+
+      // Special case, if the video is finished, we don't want to show the
+      // buffering indicator anymore
+      if (position >= value.duration.inMilliseconds) {
+        return false;
+      } else {
+        final int buffer = value.buffered.lastOrNull?.end.inMilliseconds ?? -1;
+
+        return position >= buffer;
+      }
+    } else {
+      // -> No buffering
+      return false;
+    }
+  }
+
+  return value.isBuffering;
+}

lib/src/material/material_controls.dart

@@ -645,9 +645,11 @@ class _MaterialControlsState extends State<MaterialControls>
   void _updateState() {
     if (!mounted) return;
 
+    final bool buffering = getIsBuffering(controller);
+
     // display the progress bar indicator only after the buffering delay if it has been set
     if (chewieController.progressIndicatorDelay != null) {
-      if (controller.value.isBuffering) {
+      if (buffering) {
         _bufferingDisplayTimer ??= Timer(
           chewieController.progressIndicatorDelay!,
           _bufferingTimerTimeout,
@@ -658,7 +660,7 @@ class _MaterialControlsState extends State<MaterialControls>
         _displayBufferingIndicator = false;
       }
     } else {
-      _displayBufferingIndicator = controller.value.isBuffering;
+      _displayBufferingIndicator = buffering;
     }
 
     setState(() {

lib/src/material/material_desktop_controls.dart

@@ -581,9 +581,11 @@ class _MaterialDesktopControlsState extends State<MaterialDesktopControls>
   void _updateState() {
     if (!mounted) return;
 
+    final bool buffering = getIsBuffering(controller);
+
     // display the progress bar indicator only after the buffering delay if it has been set
     if (chewieController.progressIndicatorDelay != null) {
-      if (controller.value.isBuffering) {
+      if (buffering) {
         _bufferingDisplayTimer ??= Timer(
           chewieController.progressIndicatorDelay!,
           _bufferingTimerTimeout,
@@ -594,7 +596,7 @@ class _MaterialDesktopControlsState extends State<MaterialDesktopControls>
         _displayBufferingIndicator = false;
       }
     } else {
-      _displayBufferingIndicator = controller.value.isBuffering;
+      _displayBufferingIndicator = buffering;
     }
 
     setState(() {