Vaani/lib/features/player/view/widgets/speed_selector.dart

import 'package:flutter/material.dart';
import 'package:flutter_hooks/flutter_hooks.dart';
import 'package:hooks_riverpod/hooks_riverpod.dart';
import 'package:list_wheel_scroll_view_nls/list_wheel_scroll_view_nls.dart';
import 'package:vaani/features/player/providers/audiobook_player.dart';
import 'package:vaani/settings/app_settings_provider.dart';

class SpeedSelector extends HookConsumerWidget {
  const SpeedSelector({
    super.key,
    required this.onSpeedSelected,
  });

  final void Function(double speed) onSpeedSelected;

  @override
  Widget build(BuildContext context, WidgetRef ref) {
    final appSettings = ref.watch(appSettingsProvider);
    final speeds = appSettings.playerSettings.speedOptions;
    final currentSpeed = ref.watch(audiobookPlayerProvider).speed;
    final speedState = useState(currentSpeed);

    // hook the onSpeedSelected function to the state
    useEffect(
      () {
        onSpeedSelected(speedState.value);
        return null;
      },
      [speedState.value],
    );

    // the speed options
    const minSpeed = 0.1;
    const maxSpeed = 4.0;
    const speedIncrement = 0.05;
    final availableSpeeds = ((maxSpeed - minSpeed) / speedIncrement).ceil();
    final availableSpeedsList = List.generate(
      availableSpeeds,
      (index) {
        // need to round to 2 decimal place to avoid floating point errors
        return double.parse(
          (minSpeed + index * speedIncrement).toStringAsFixed(2),
        );
      },
    );

    final scrollController = FixedExtentScrollController(
      initialItem: availableSpeedsList.indexOf(currentSpeed),
    );
    const double itemExtent = 25;
    return Padding(
      padding: const EdgeInsets.all(8.0),
      child: Column(
        children: [
          Expanded(
            child: Padding(
              padding: const EdgeInsets.all(8.0),
              child: Center(
                child: Text(
                  'Playback Speed: ${speedState.value}x',
                  style: Theme.of(context).textTheme.titleLarge,
                ),
              ),
            ),
          ),
          Flexible(
            child: Row(
              crossAxisAlignment: CrossAxisAlignment.center,
              mainAxisAlignment: MainAxisAlignment.spaceBetween,
              children: [
                // a minus button to decrease the speed
                IconButton.filledTonal(
                  icon: const Icon(Icons.remove),
                  onPressed: () {
                    // animate to index - 1
                    final index = availableSpeedsList.indexOf(speedState.value);
                    if (index > 0) {
                      scrollController.animateToItem(
                        index - 1,
                        duration: const Duration(milliseconds: 300),
                        curve: Curves.easeInOut,
                      );
                    }
                  },
                ),
                Expanded(
                  child: ListWheelScrollViewX(
                    controller: scrollController,
                    scrollDirection: Axis.horizontal,
                    itemExtent: itemExtent,
                    diameterRatio: 1.5, squeeze: 1.2,
                    // useMagnifier: true,
                    // magnification: 1.5,
                    physics: const FixedExtentScrollPhysics(),
                    children: availableSpeedsList
                        .map(
                          (speed) => Column(
                            children: [
                              // a vertical line
                              Container(
                                height: itemExtent * 2,
                                // thick if multiple of 1, thin if multiple of 0.5 and transparent if multiple of 0.05
                                width: speed % 0.5 == 0
                                    ? 3
                                    : speed % 0.25 == 0
                                        ? 2
                                        : 0.5,
                                color:
                                    Theme.of(context).colorScheme.onSurface,
                              ),
                              // the speed text but only at .5 increments of speed
                              if (speed % 0.25 == 0)
                                Text(
                                  speed.toString(),
                                  style: TextStyle(
                                    color: Theme.of(context)
                                        .colorScheme
                                        .onSurface,
                                  ),
                                ),
                            ],
                          ),
                        )
                        .toList(),
                    onSelectedItemChanged: (index) {
                      speedState.value = availableSpeedsList[index];
                      // onSpeedSelected(availableSpeedsList[index]);
                      // call after 500ms to avoid the scrollview from scrolling to the selected speed
                      // Future.delayed(
                      //   const Duration(milliseconds: 100),
                      //   () => onSpeedSelected(availableSpeedsList[index]),
                      // );
                    },
                  ),
                ),
                // a plus button to increase the speed
                IconButton.filledTonal(
                  icon: const Icon(Icons.add),
                  onPressed: () {
                    // animate to index + 1
                    final index = availableSpeedsList.indexOf(speedState.value);
                    if (index < availableSpeedsList.length - 1) {
                      scrollController.animateToItem(
                        index + 1,
                        duration: const Duration(milliseconds: 300),
                        curve: Curves.easeInOut,
                      );
                    }
                  },
                ),
              ],
            ),
          ),
          Row(
            mainAxisAlignment: MainAxisAlignment.spaceBetween,
            children: speeds
                .map(
                  (speed) => Flexible(
                    // the text button should be highlighted if the speed is selected
                    child: TextButton(
                      style: speed == speedState.value
                          ? TextButton.styleFrom(
                              backgroundColor: Theme.of(context)
                                  .colorScheme
                                  .primaryContainer,
                              foregroundColor: Theme.of(context)
                                  .colorScheme
                                  .onPrimaryContainer,
                            )
                          : null,
                      onPressed: () async {
                        // animate the wheel to the selected speed
                        var index = availableSpeedsList.indexOf(speed);
                        // if the speed is not in the list
                        if (index == -1) {
                          // find the nearest speed
                          final nearestSpeed = availableSpeedsList.firstWhere(
                            (element) => element > speed,
                            orElse: () => availableSpeedsList.last,
                          );
                          index = availableSpeedsList.indexOf(nearestSpeed);
                        }
                        await scrollController.animateToItem(
                          index,
                          duration: const Duration(milliseconds: 300),
                          curve: Curves.easeInOut,
                        );

                        // call the onSpeedSelected function
                        speedState.value = speed;
                      },
                      child: Text('$speed'),
                    ),
                  ),
                )
                .toList(),
          ),
          const SizedBox(
            height: 8,
          ),
        ],
      ),
    );
  }
}