flutter image picker

gistfile1.txt

// Copyright 2013 The Flutter Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// ignore_for_file: public_member_api_docs

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

import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:image_picker/image_picker.dart';
import 'package:mime/mime.dart';

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({super.key});

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: 'Image Picker Demo',
      home: MyHomePage(title: 'Image Picker Example'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, this.title});

  final String? title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  List<XFile>? _mediaFileList;

  void _setImageFileListFromFile(XFile? value) {
    _mediaFileList = value == null ? null : <XFile>[value];
  }

  dynamic _pickImageError;
  bool isVideo = false;

  String? _retrieveDataError;

  final ImagePicker _picker = ImagePicker();
  final TextEditingController maxWidthController = TextEditingController();
  final TextEditingController maxHeightController = TextEditingController();
  final TextEditingController qualityController = TextEditingController();

  Future<void> _onImageButtonPressed(
    ImageSource source, {
    required BuildContext context,
    bool isMultiImage = false,
    bool isMedia = false,
  }) async {
    if (context.mounted) {
      if (isMultiImage) {
        await _displayPickImageDialog(context,
            (double? maxWidth, double? maxHeight, int? quality) async {
          try {
            final List<XFile> pickedFileList = isMedia
                ? await _picker.pickMultipleMedia(
                    maxWidth: maxWidth,
                    maxHeight: maxHeight,
                    imageQuality: quality,
                  )
                : await _picker.pickMultiImage(
                    maxWidth: maxWidth,
                    maxHeight: maxHeight,
                    imageQuality: quality,
                  );
            setState(() {
              _mediaFileList = pickedFileList;
            });
          } catch (e) {
            setState(() {
              _pickImageError = e;
            });
          }
        });
      } else if (isMedia) {
        await _displayPickImageDialog(context,
            (double? maxWidth, double? maxHeight, int? quality) async {
          try {
            final List<XFile> pickedFileList = <XFile>[];
            final XFile? media = await _picker.pickMedia(
              maxWidth: maxWidth,
              maxHeight: maxHeight,
              imageQuality: quality,
            );
            if (media != null) {
              pickedFileList.add(media);
              setState(() {
                _mediaFileList = pickedFileList;
              });
            }
          } catch (e) {
            setState(() {
              _pickImageError = e;
            });
          }
        });
      } else {
        await _displayPickImageDialog(context,
            (double? maxWidth, double? maxHeight, int? quality) async {
          try {
            final XFile? pickedFile = await _picker.pickImage(
              source: source,
              maxWidth: maxWidth,
              maxHeight: maxHeight,
              imageQuality: quality,
            );
            setState(() {
              _setImageFileListFromFile(pickedFile);
            });
          } catch (e) {
            setState(() {
              _pickImageError = e;
            });
          }
        });
      }
    }
  }

  @override
  void dispose() {
    maxWidthController.dispose();
    maxHeightController.dispose();
    qualityController.dispose();
    super.dispose();
  }

  Widget _previewImages() {
    final Text? retrieveError = _getRetrieveErrorWidget();
    if (retrieveError != null) {
      return retrieveError;
    }
    if (_mediaFileList != null) {
      return Semantics(
        label: 'image_picker_example_picked_images',
        child: ListView.builder(
          key: UniqueKey(),
          itemBuilder: (BuildContext context, int index) {
            final String? mime = lookupMimeType(_mediaFileList![index].path);

            // Why network for web?
            // See https://pub.dev/packages/image_picker_for_web#limitations-on-the-web-platform
            return Semantics(
              label: 'image_picker_example_picked_image',
              child: kIsWeb
                  ? Image.network(_mediaFileList![index].path)
                  : Row(
                      children: [
                        const Padding(padding: EdgeInsets.all(8.0)),
                        Container(
                          width: 300.0,
                          height: 300.0,
                          decoration: const BoxDecoration(
                            borderRadius:
                                BorderRadius.all(Radius.circular(8.0)),
                            color: Colors.redAccent,
                          ),
                          child: Image.file(
                            File(_mediaFileList![index].path),
                            errorBuilder: (BuildContext context, Object error,
                                StackTrace? stackTrace) {
                              return const Center(
                                  child:
                                      Text('This image type is not supported'));
                            },
                          ),
                        ),
                        const Padding(padding: EdgeInsets.all(8.0)),
                      ],
                    ),
            );
          },
          itemCount: _mediaFileList!.length,
        ),
      );
    } 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,
      );
    }
  }

  Widget _handlePreview() {
    return _previewImages();
  }

  Future<void> retrieveLostData() async {
    final LostDataResponse response = await _picker.retrieveLostData();
    if (response.isEmpty) {
      return;
    }
    if (response.file != null) {
      setState(() {
        if (response.files == null) {
          _setImageFileListFromFile(response.file);
        } else {
          _mediaFileList = response.files;
        }
      });
    } else {
      _retrieveDataError = response.exception!.code;
    }
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title!),
      ),
      body: Center(
        child: !kIsWeb && defaultTargetPlatform == TargetPlatform.android
            ? 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 _handlePreview();
                    case ConnectionState.active:
                      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,
                        );
                      }
                  }
                },
              )
            : _handlePreview(),
      ),
      floatingActionButton: Column(
        mainAxisAlignment: MainAxisAlignment.end,
        children: <Widget>[
          Semantics(
            label: 'image_picker_example_from_gallery',
            child: FloatingActionButton(
              onPressed: () {
                isVideo = false;
                _onImageButtonPressed(ImageSource.gallery, context: context);
              },
              heroTag: 'image0',
              tooltip: 'Pick Image from gallery',
              child: const Icon(Icons.photo),
            ),
          ),
          Padding(
            padding: const EdgeInsets.only(top: 16.0),
            child: FloatingActionButton(
              onPressed: () {
                isVideo = false;
                _onImageButtonPressed(
                  ImageSource.gallery,
                  context: context,
                  isMultiImage: true,
                  isMedia: true,
                );
              },
              heroTag: 'multipleMedia',
              tooltip: 'Pick Multiple Media from gallery',
              child: const Icon(Icons.photo_library),
            ),
          ),
          Padding(
            padding: const EdgeInsets.only(top: 16.0),
            child: FloatingActionButton(
              onPressed: () {
                isVideo = false;
                _onImageButtonPressed(
                  ImageSource.gallery,
                  context: context,
                  isMedia: true,
                );
              },
              heroTag: 'media',
              tooltip: 'Pick Single Media from gallery',
              child: const Icon(Icons.photo_library),
            ),
          ),
          Padding(
            padding: const EdgeInsets.only(top: 16.0),
            child: FloatingActionButton(
              onPressed: () {
                isVideo = false;
                _onImageButtonPressed(
                  ImageSource.gallery,
                  context: context,
                  isMultiImage: true,
                );
              },
              heroTag: 'image1',
              tooltip: 'Pick Multiple Image from gallery',
              child: const Icon(Icons.photo_library),
            ),
          ),
          if (_picker.supportsImageSource(ImageSource.camera))
            Padding(
              padding: const EdgeInsets.only(top: 16.0),
              child: FloatingActionButton(
                onPressed: () {
                  isVideo = false;
                  _onImageButtonPressed(ImageSource.camera, context: context);
                },
                heroTag: 'image2',
                tooltip: 'Take a Photo',
                child: const Icon(Icons.camera_alt),
              ),
            ),
          Padding(
            padding: const EdgeInsets.only(top: 16.0),
            child: FloatingActionButton(
              backgroundColor: Colors.red,
              onPressed: () {
                isVideo = true;
                _onImageButtonPressed(ImageSource.gallery, context: context);
              },
              heroTag: 'video0',
              tooltip: 'Pick Video from gallery',
              child: const Icon(Icons.video_library),
            ),
          ),
          if (_picker.supportsImageSource(ImageSource.camera))
            Padding(
              padding: const EdgeInsets.only(top: 16.0),
              child: FloatingActionButton(
                backgroundColor: Colors.red,
                onPressed: () {
                  isVideo = true;
                  _onImageButtonPressed(ImageSource.camera, context: context);
                },
                heroTag: 'video1',
                tooltip: 'Take a Video',
                child: const Icon(Icons.videocam),
              ),
            ),
        ],
      ),
    );
  }

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

  Future<void> _displayPickImageDialog(
      BuildContext context, OnPickImageCallback onPick) async {
    return showDialog(
        context: context,
        builder: (BuildContext context) {
          return AlertDialog(
            title: const Text('Add optional parameters'),
            content: Column(
              mainAxisSize: MainAxisSize.min,
              children: <Widget>[
                TextField(
                  controller: maxWidthController,
                  keyboardType:
                      const TextInputType.numberWithOptions(decimal: true),
                  decoration: const InputDecoration(
                      hintText: 'Enter maxWidth if desired'),
                ),
                TextField(
                  controller: maxHeightController,
                  keyboardType:
                      const TextInputType.numberWithOptions(decimal: true),
                  decoration: const InputDecoration(
                      hintText: 'Enter maxHeight if desired'),
                ),
                TextField(
                  controller: qualityController,
                  keyboardType: TextInputType.number,
                  decoration: const InputDecoration(
                      hintText: 'Enter quality if desired'),
                ),
              ],
            ),
            actions: <Widget>[
              TextButton(
                child: const Text('CANCEL'),
                onPressed: () {
                  Navigator.of(context).pop();
                },
              ),
              TextButton(
                  child: const Text('PICK'),
                  onPressed: () {
                    final double? width = maxWidthController.text.isNotEmpty
                        ? double.parse(maxWidthController.text)
                        : null;
                    final double? height = maxHeightController.text.isNotEmpty
                        ? double.parse(maxHeightController.text)
                        : null;
                    final int? quality = qualityController.text.isNotEmpty
                        ? int.parse(qualityController.text)
                        : null;
                    onPick(width, height, quality);
                    Navigator.of(context).pop();
                  }),
            ],
          );
        });
  }
}

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