mobile-app/lib/presentation/custom_widgets/widget_media_helper.dart

import 'dart:io';
import 'dart:async';

import 'package:farm_tpf/utils/const_color.dart';
import 'package:farm_tpf/utils/const_string.dart';
import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:video_player/video_player.dart';

class WidgetMediaHelper extends StatefulWidget {
  @override
  _WidgetMediaHelperState createState() => _WidgetMediaHelperState();
}

class _WidgetMediaHelperState extends State<WidgetMediaHelper> {
  PickedFile _imageFile;
  dynamic _pickImageError;
  bool isVideo = false;
  VideoPlayerController _controller;
  VideoPlayerController _toBeDisposed;
  String _retrieveDataError;

  final ImagePicker _picker = ImagePicker();

  @override
  Widget build(BuildContext context) {
    return Container(
        child: Column(
      children: <Widget>[
        _actionButton(),
        1 == 1
            ? FutureBuilder<void>(
                future: retrieveLostData(),
                builder: (BuildContext context, AsyncSnapshot<void> snapshot) {
                  switch (snapshot.connectionState) {
                    case ConnectionState.none:
                    case ConnectionState.waiting:
                      return const Text(
                        'You have not yet picked an image.',
                        textAlign: TextAlign.center,
                      );
                    case ConnectionState.done:
                      return isVideo ? _previewVideo() : _previewImage();
                    default:
                      if (snapshot.hasError) {
                        return Text(
                          'Pick image/video error: ${snapshot.error}}',
                          textAlign: TextAlign.center,
                        );
                      } else {
                        return const Text(
                          'You have not yet picked an image.',
                          textAlign: TextAlign.center,
                        );
                      }
                  }
                },
              )
            : (isVideo ? _previewVideo() : _previewImage()),
      ],
    ));
  }

  Widget viewResult() {
    FutureBuilder<void>(
      future: retrieveLostData(),
      builder: (BuildContext context, AsyncSnapshot<void> snapshot) {
        switch (snapshot.connectionState) {
          case ConnectionState.none:
          case ConnectionState.waiting:
            return const Text(
              'You have not yet picked an image.',
              textAlign: TextAlign.center,
            );
          case ConnectionState.done:
            return isVideo ? _previewVideo() : _previewImage();
          default:
            if (snapshot.hasError) {
              return Text(
                'Pick image/video error: ${snapshot.error}}',
                textAlign: TextAlign.center,
              );
            } else {
              return const Text(
                'You have not yet picked an image.',
                textAlign: TextAlign.center,
              );
            }
        }
      },
    );
  }

  Widget multipleChoice() {
    return CupertinoAlertDialog(
      title: Text(label_title_select_media),
      actions: <Widget>[
        CupertinoDialogAction(
            child: const Text(label_select_image_from_library),
            onPressed: () {
              Navigator.pop(context, 'Discard');
              isVideo = false;
              _onImageButtonPressed(ImageSource.gallery, context: context);
            }),
        CupertinoDialogAction(
            child: const Text(label_take_photo),
            onPressed: () {
              Navigator.pop(context, 'Discard');
              isVideo = false;
              _onImageButtonPressed(ImageSource.camera, context: context);
            }),
        CupertinoDialogAction(
            child: const Text(label_select_video_from_library),
            onPressed: () {
              Navigator.pop(context, 'Discard');
              isVideo = true;
              _onImageButtonPressed(ImageSource.gallery);
            }),
        CupertinoDialogAction(
            child: const Text(label_record_video),
            onPressed: () {
              Navigator.pop(context, 'Discard');
              isVideo = true;
              _onImageButtonPressed(ImageSource.camera);
            }),
        CupertinoDialogAction(
            child: const Text(label_cancel),
            textStyle: TextStyle(fontWeight: FontWeight.bold),
            isDefaultAction: true,
            onPressed: () {
              Navigator.pop(context, 'Cancel');
            }),
      ],
    );
  }

  Widget _actionButton() {
    return SizedBox(
      width: double.infinity,
      height: 55,
      child: FlatButton(
        onPressed: () {
          showDialog(
              context: context,
              barrierDismissible: true,
              builder: (context) => Opacity(
                    child: multipleChoice(),
                    opacity: 1,
                  ));
        },
        color: COLOR_CONST.DEFAULT,
        shape: RoundedRectangleBorder(
          borderRadius: new BorderRadius.circular(7.0),
        ),
        child: Row(
          children: <Widget>[
            Icon(Icons.image),
            Text(
              button_add_media,
              style: TextStyle(
                  fontWeight: FontWeight.bold, color: COLOR_CONST.WHITE),
            )
          ],
        ),
      ),
    );
  }

  Future<void> _playVideo(PickedFile file) async {
    if (file != null && mounted) {
      await _disposeVideoController();
      _controller = VideoPlayerController.file(File(file.path));
      await _controller.setVolume(1.0);
      await _controller.initialize();
      await _controller.setLooping(true);
      await _controller.play();
      setState(() {});
    }
  }

  void _onImageButtonPressed(ImageSource source, {BuildContext context}) async {
    if (_controller != null) {
      await _controller.setVolume(0.0);
    }
    if (isVideo) {
      final PickedFile file = await _picker.getVideo(
          source: source, maxDuration: const Duration(seconds: 10));
      await _playVideo(file);
    } else {
      await _displayPickImageDialog(context,
          (double maxWidth, double maxHeight, int quality) async {
        try {
          final pickedFile = await _picker.getImage(
            source: source,
            maxWidth: maxWidth,
            maxHeight: maxHeight,
            imageQuality: quality,
          );
          setState(() {
            _imageFile = pickedFile;
          });
        } catch (e) {
          setState(() {
            _pickImageError = e;
          });
        }
      });
    }
  }

  @override
  void deactivate() {
    if (_controller != null) {
      _controller.setVolume(0.0);
      _controller.pause();
    }
    super.deactivate();
  }

  @override
  void dispose() {
    _disposeVideoController();
    super.dispose();
  }

  Future<void> _disposeVideoController() async {
    if (_toBeDisposed != null) {
      await _toBeDisposed.dispose();
    }
    _toBeDisposed = _controller;
    _controller = null;
  }

  Widget _previewVideo() {
    final Text retrieveError = _getRetrieveErrorWidget();
    if (retrieveError != null) {
      return retrieveError;
    }
    if (_controller == null) {
      return const Text(
        'You have not yet picked a video',
        textAlign: TextAlign.center,
      );
    }
    return Padding(
      padding: const EdgeInsets.all(10.0),
      child: AspectRatioVideo(_controller),
    );
  }

  Widget _previewImage() {
    final Text retrieveError = _getRetrieveErrorWidget();
    if (retrieveError != null) {
      return retrieveError;
    }
    if (_imageFile != null) {
      return Image.file(File(_imageFile.path), width: 100, height: 100);
    } else if (_pickImageError != null) {
      return Text(
        'Pick image error: $_pickImageError',
        textAlign: TextAlign.center,
      );
    } else {
      return const Text(
        'You have not yet picked an image.',
        textAlign: TextAlign.center,
      );
    }
  }

  Future<void> retrieveLostData() async {
    final LostData response = await _picker.getLostData();
    if (response.isEmpty) {
      return;
    }
    if (response.file != null) {
      if (response.type == RetrieveType.video) {
        isVideo = true;
        await _playVideo(response.file);
      } else {
        isVideo = false;
        setState(() {
          _imageFile = response.file;
        });
      }
    } else {
      _retrieveDataError = response.exception.code;
    }
  }

  Text _getRetrieveErrorWidget() {
    if (_retrieveDataError != null) {
      final Text result = Text(_retrieveDataError);
      _retrieveDataError = null;
      return result;
    }
    return null;
  }

  Future<void> _displayPickImageDialog(
      BuildContext context, OnPickImageCallback onPick) async {
    onPick(null, null, null);
  }
}

typedef void OnPickImageCallback(
    double maxWidth, double maxHeight, int quality);

class AspectRatioVideo extends StatefulWidget {
  AspectRatioVideo(this.controller);

  final VideoPlayerController controller;

  @override
  AspectRatioVideoState createState() => AspectRatioVideoState();
}

class AspectRatioVideoState extends State<AspectRatioVideo> {
  VideoPlayerController get controller => widget.controller;
  bool initialized = false;

  void _onVideoControllerUpdate() {
    if (!mounted) {
      return;
    }
    if (initialized != controller.value.initialized) {
      initialized = controller.value.initialized;
      setState(() {});
    }
  }

  @override
  void initState() {
    super.initState();
    controller.addListener(_onVideoControllerUpdate);
  }

  @override
  void dispose() {
    controller.removeListener(_onVideoControllerUpdate);
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    if (initialized) {
      return Container(
        width: 100,
        height: 100,
        child: AspectRatio(
          aspectRatio: controller.value?.aspectRatio,
          child: VideoPlayer(controller),
        ),
      );
    } else {
      return Container();
    }
  }
}