freezer/lib/ui/player_bar.dart

import 'dart:async';

import 'package:audio_service/audio_service.dart';
import 'package:flutter/material.dart';
import 'package:freezer/settings.dart';
import 'package:freezer/translations.i18n.dart';
import 'package:rxdart/rxdart.dart';

import '../api/player/audio_handler.dart';
import 'cached_image.dart';

class PlayerBar extends StatelessWidget {
  final VoidCallback? onTap;
  final bool shouldHaveHero;
  final Color? backgroundColor;
  final FocusNode? focusNode;
  const PlayerBar({
    Key? key,
    this.onTap,
    this.shouldHaveHero = true,
    this.backgroundColor,
    this.focusNode,
  }) : super(key: key);

  final double iconSize = 28;

  double parsePosition(Duration position) {
    if (audioHandler.mediaItem.value == null) return 0.0;
    if (audioHandler.mediaItem.value!.duration!.inSeconds == 0) {
      return 0.0; //Division by 0
    }
    return position.inSeconds /
        audioHandler.mediaItem.value!.duration!.inSeconds;
  }

  Color? get _backgroundColor => backgroundColor;

  @override
  Widget build(BuildContext context) {
    return SizedBox(
      height: 68.0,
      child: Column(mainAxisSize: MainAxisSize.max, children: <Widget>[
        Expanded(
          child: StreamBuilder<MediaItem?>(
              stream: audioHandler.mediaItem,
              initialData: audioHandler.mediaItem.valueOrNull,
              builder: (context, snapshot) {
                if (snapshot.data == null) {
                  // lazy way to prevent dragging up
                  return GestureDetector(
                    behavior: HitTestBehavior.opaque,
                    onVerticalDragEnd: (_) {},
                    onVerticalDragUpdate: (_) {},
                    child: Material(
                      child: ListTile(
                        dense: true,
                        visualDensity: VisualDensity.standard,
                        contentPadding: const EdgeInsets.symmetric(
                            horizontal: 16.0, vertical: 6.0),
                        leading: Image.asset(
                          'assets/cover_thumb.jpg',
                          width: 48.0,
                          height: 48.0,
                        ),
                        title: Text('Nothing is currently playing'.i18n),
                      ),
                    ),
                  );
                }
                final currentMediaItem = snapshot.data!;
                final image = CachedImage(
                  width: 50,
                  height: 50,
                  url: currentMediaItem.extras!['thumb'] ??
                      currentMediaItem.artUri.toString(),
                );
                final leadingWidget = shouldHaveHero
                    ? Hero(tag: currentMediaItem.id, child: image)
                    : image;
                return Material(
                    type: MaterialType.transparency,
                    child: ListTile(
                        dense: true,
                        tileColor: _backgroundColor,
                        focusNode: focusNode,
                        visualDensity: VisualDensity.standard,
                        contentPadding: const EdgeInsets.symmetric(
                            horizontal: 16.0, vertical: 0.0),
                        onTap: onTap,
                        leading: AnimatedSwitcher(
                            key: const ValueKey('player_bar_art_switcher'),
                            duration: const Duration(milliseconds: 250),
                            child: leadingWidget),
                        title: Text(
                          currentMediaItem.displayTitle!,
                          overflow: TextOverflow.clip,
                          maxLines: 1,
                        ),
                        subtitle: Text(
                          currentMediaItem.displaySubtitle ?? '',
                          overflow: TextOverflow.clip,
                          maxLines: 1,
                        ),
                        trailing: IconTheme(
                          data: IconThemeData(
                              color: settings.isDark
                                  ? Colors.white
                                  : Colors.grey[600]),
                          child: Row(
                            mainAxisSize: MainAxisSize.min,
                            children: <Widget>[
                              PrevNextButton(
                                iconSize,
                                prev: true,
                              ),
                              PlayPauseButton(iconSize),
                              PrevNextButton(iconSize)
                            ],
                          ),
                        )));
              }),
        ),
        SizedBox(
          height: 3.0,
          child: StreamBuilder<Duration>(
              stream: AudioService.position,
              builder: (context, snapshot) {
                return LinearProgressIndicator(
                  value: parsePosition(snapshot.data ?? Duration.zero),
                );
              }),
        ),
      ]),
    );
  }
}

class PrevNextButton extends StatelessWidget {
  final double size;
  final bool prev;
  final bool hidePrev;
  const PrevNextButton(this.size,
      {super.key, this.prev = false, this.hidePrev = false});

  @override
  Widget build(BuildContext context) {
    // Listens to both mediaItem updates (a.k.a. when the song changes)
    // and queue updates (so for example, in SmartTrackLists, when the songs are fetched, it's updated with the new items)
    return StreamBuilder<bool>(
      stream: Rx.combineLatest2<MediaItem?, List<MediaItem>, bool>(
          audioHandler.mediaItem,
          audioHandler.queue,
          (_, queue) => playerHelper.queueIndex < queue.length - 1),
      builder: (context, snapshot) {
        if (!prev) {
          return IconButton(
            splashRadius: size * 2.0,
            icon: Icon(
              Icons.skip_next,
              semanticLabel: "Play next".i18n,
            ),
            iconSize: size,
            onPressed:
                snapshot.data == true ? () => audioHandler.skipToNext() : null,
          );
        }
        final canGoPrev = playerHelper.queueIndex > 0;

        if (!canGoPrev && hidePrev) return const SizedBox.shrink();

        return IconButton(
          splashRadius: size * 2.0,
          icon: Icon(
            Icons.skip_previous,
            semanticLabel: "Play previous".i18n,
          ),
          iconSize: size,
          onPressed: canGoPrev ? () => audioHandler.skipToPrevious() : null,
        );
      },
    );
  }
}

class PlayPauseButton extends StatefulWidget {
  final double size;
  final bool filled;
  final Color? iconColor;

  /// The color of the card if [filled] is true
  final Color? color;
  const PlayPauseButton(
    this.size, {
    Key? key,
    this.filled = false,
    this.color,
    this.iconColor,
  }) : super(key: key);

  @override
  State<PlayPauseButton> createState() => _PlayPauseButtonState();
}

class _PlayPauseButtonState extends State<PlayPauseButton>
    with SingleTickerProviderStateMixin {
  late final AnimationController _controller;
  late final Animation<double> _animation;
  late StreamSubscription _subscription;
  late bool _canPlay = audioHandler.playbackState.value.processingState ==
          AudioProcessingState.ready ||
      audioHandler.playbackState.value.processingState ==
          AudioProcessingState.idle;

  @override
  void initState() {
    _controller = AnimationController(
        vsync: this, duration: const Duration(milliseconds: 200));
    _animation = CurvedAnimation(parent: _controller, curve: Curves.easeInOut);

    _subscription = audioHandler.playbackState.listen((playbackState) {
      if (playbackState.processingState == AudioProcessingState.ready ||
          audioHandler.playbackState.value.processingState ==
              AudioProcessingState.idle) {
        if (playbackState.playing) {
          _controller.forward();
        } else {
          _controller.reverse();
        }
        if (!_canPlay) setState(() => _canPlay = true);
        return;
      }
      setState(() => _canPlay = false);
    });
    super.initState();
  }

  @override
  void dispose() {
    _subscription.cancel();
    _controller.dispose();
    super.dispose();
  }

  void _playPause() {
    if (audioHandler.playbackState.value.playing) {
      audioHandler.pause();
    } else {
      audioHandler.play();
    }
  }

  @override
  Widget build(BuildContext context) {
    final Widget? child;
    if (_canPlay) {
      final icon = AnimatedIcon(
        icon: AnimatedIcons.play_pause,
        progress: _animation,
        semanticLabel: audioHandler.playbackState.value.playing
            ? 'Pause'.i18n
            : 'Play'.i18n,
      );
      if (!widget.filled) {
        return IconButton(
            color: widget.iconColor,
            icon: icon,
            iconSize: widget.size,
            onPressed: _playPause);
      } else {
        child = Material(
          type: MaterialType.transparency,
          child: InkWell(
              customBorder: const CircleBorder(),
              onTap: _playPause,
              child: IconTheme.merge(
                  child: Center(child: icon),
                  data: IconThemeData(
                      size: widget.size / 2, color: widget.iconColor))),
        );
      }
    } else {
      switch (audioHandler.playbackState.value.processingState) {
        //Stopped/Error
        case AudioProcessingState.error:
          child = null;
          break;
        //Loading, connecting, rewinding...
        default:
          child = const Center(child: CircularProgressIndicator());
          break;
      }
    }
    if (widget.filled) {
      return SizedBox.square(
          dimension: widget.size,
          child: AnimatedContainer(
              duration: const Duration(seconds: 1),
              decoration:
                  BoxDecoration(shape: BoxShape.circle, color: widget.color),
              child: child));
    } else {
      return SizedBox.square(dimension: widget.size, child: child);
    }
  }
}