main.dart

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

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

import 'package:flutter_photokit/flutter_photokit.dart';
import 'package:path_provider/path_provider.dart';

enum _SaveStatus { NONE, SAVING, SAVED }

void main() => runApp(const MyApp());

class MyApp extends StatefulWidget {
  const MyApp({Key key}) : super(key: key);

  @override
  _MyAppState createState() => new _MyAppState();
}

class _MyAppState extends State<MyApp> {
  _SaveStatus _cameraRollStatus = _SaveStatus.NONE;
  _SaveStatus _albumStatus = _SaveStatus.NONE;
  TextEditingController _albumTextController;

  static HttpClient _httpClient = HttpClient();
  static String _sampleImageUrl =
      'https://cdn-images-1.medium.com/max/1200/1*5-aoK8IBmXve5whBQM90GA.png';
  // Use this link to test with a video.
  // static String _sampleVideoUrl = 'https://www.sample-videos.com/video/mp4/720/big_buck_bunny_720p_1mb.mp4';

  @override
  void initState() {
    super.initState();

    _albumTextController = TextEditingController()
      ..addListener(() => setState(() {}));
  }

  Future<File> _downloadFile(String url) async {
    Uri uri = Uri.parse(url);

    HttpClientRequest req = await _httpClient.getUrl(uri);
    HttpClientResponse res = await req.close();

    List<int> bytes = await consolidateHttpClientResponseBytes(res);
    String tempDir = (await getTemporaryDirectory()).path;
    File outputFile = File('$tempDir/${uri.pathSegments.last}');
    await outputFile.writeAsBytes(bytes);

    return outputFile;
  }

  void _saveToCameraRoll() async {
    setState(() => _cameraRollStatus = _SaveStatus.SAVING);

    File file = await _downloadFile(_sampleImageUrl);
    await FlutterPhotokit.saveToCameraRoll(filePath: file.path);

    setState(() => _cameraRollStatus = _SaveStatus.SAVED);
  }

  void _saveToAlbum() async {
    setState(() => _albumStatus = _SaveStatus.SAVING);

    File file = await _downloadFile(_sampleImageUrl);
    await FlutterPhotokit.saveToAlbum(
        filePath: file.path, albumName: _albumTextController.value.text);

    setState(() => _albumStatus = _SaveStatus.SAVED);
  }

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new Scaffold(
          appBar: new AppBar(
            title: const Text('Flutter PhotoKit Example'),
          ),
          body: _appBody()),
    );
  }

  Widget _appBody() {
    if (Platform.isIOS) {
      return SingleChildScrollView(
          child: new Column(
        mainAxisAlignment: MainAxisAlignment.spaceAround,
        children: <Widget>[
          Image.network(_sampleImageUrl),
          SizedBox(height: 16.0),
          _saveToCameraRollRow(),
          SizedBox(height: 16.0),
          _saveToAlbumRow()
        ],
      ));
    } else {
      return Center(
          child: Text('The PhotoKit plugin is only available for iOS!'));
    }
  }

  Widget _saveToCameraRollRow() {
    switch (_cameraRollStatus) {
      case _SaveStatus.NONE:
        return RaisedButton(
            onPressed: _saveToCameraRoll, child: Text('Save to Camera Roll'));
      case _SaveStatus.SAVING:
        return CircularProgressIndicator();
      case _SaveStatus.SAVED:
        return Icon(Icons.check);
    }
  }

  Widget _saveToAlbumRow() {
    switch (_albumStatus) {
      case _SaveStatus.NONE:
        return Row(
          children: <Widget>[
            Expanded(
              child: TextField(
                  controller: _albumTextController,
                  decoration: InputDecoration(labelText: 'Album name')),
            ),
            RaisedButton(
              onPressed: _albumTextController.value.text.trim().isEmpty
                  ? null
                  : _saveToAlbum,
              child: Text('Save to album'),
            )
          ],
        );
      case _SaveStatus.SAVING:
        return CircularProgressIndicator();
      case _SaveStatus.SAVED:
        return Icon(Icons.check);
    }
  }
}