desktop_drop 0.5.0

A plugin which allows user dragging files to your flutter desktop applications.

example/lib/main.dart

import 'dart:convert';
import 'dart:io';

import 'package:desktop_drop/desktop_drop.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:cross_file/cross_file.dart';
import 'package:shared_preferences/shared_preferences.dart';

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

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

  void loadFile(BuildContext context, bool bookmarkEnable) async {
    final SharedPreferences prefs = await SharedPreferences.getInstance();
    String? jsonStr = prefs.getString("apple-bookmark");
    if (jsonStr == null) return;
    print(jsonStr);
    Map<String, dynamic> data = json.decode(jsonStr);
    String path = data["path"]! as String;
    String appleBookmarkStr = data["apple-bookmark"]! as String;
    Uint8List appleBookmark = base64.decode(appleBookmarkStr);

    // var file = XFile(path);
    // var fileSize = await file.length();

    try {
      if (bookmarkEnable) {
        bool grantedPermission = await DesktopDrop.instance
            .startAccessingSecurityScopedResource(bookmark: appleBookmark);

        ScaffoldMessenger.of(context).showSnackBar(SnackBar(
            content: Text(
          "file permission :" + grantedPermission.toString(),
        )));
      }

      var file = File('$path');

      var contents = await file.readAsBytes();
      var fileSize = contents.length;

      if (bookmarkEnable) {
        await DesktopDrop.instance
            .stopAccessingSecurityScopedResource(bookmark: appleBookmark);
      }

      final snackBar =
          SnackBar(content: Text('file size:' + fileSize.toString()));
      ScaffoldMessenger.of(context).showSnackBar(snackBar);
    } catch (e) {
      final snackBar = SnackBar(content: Text('error:' + e.toString()));
      ScaffoldMessenger.of(context).showSnackBar(snackBar);
    }
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Plugin example app'),
        ),
        body: Wrap(
          direction: Axis.horizontal,
          runSpacing: 8,
          spacing: 8,
          children: [
            ExampleDragTarget(),
            ExampleDragTarget(),
            ExampleDragTarget(),
            ExampleDragTarget(),
            ExampleDragTarget(),
            ExampleDragTarget(),
            if (Platform.isMacOS)
              StatefulBuilder(builder: (context, setState) {
                return Column(
                  children: [
                    Text(
                      "Test Apple Bookmark\n1 drag file \n2 save the bookmark,\n3 restart app\n4 choice test button",
                    ),
                    TextButton(
                      onPressed: () async {
                        loadFile(context, true);
                        return;
                      },
                      child: Text(
                        "with applemark, suc",
                      ),
                    ),
                    TextButton(
                      onPressed: () async {
                        loadFile(context, false);
                        return;
                      },
                      child: Text(
                        "without applemark, err",
                      ),
                    ),
                  ],
                );
              }),
          ],
        ),
      ),
    );
  }
}

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

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

class _ExampleDragTargetState extends State<ExampleDragTarget> {
  final List<XFile> _list = [];
  final List<DropItem> drop_files = [];

  bool _dragging = false;

  Offset? offset;

  Future<void> printFiles(List<DropItem> files, [int depth = 0]) async {
    debugPrint('  |' * depth);
    for (final file in files) {
      debugPrint('  |' * depth +
          '> ${file.path} ${file.name}'
              '  ${await file.lastModified()}'
              '  ${await file.length()}'
              '  ${file.mimeType}');
      if (file is DropItemDirectory) {
        printFiles(file.children, depth + 1);
      }
    }
  }

  @override
  Widget build(BuildContext context) {
    return DropTarget(
      onDragDone: (detail) async {
        setState(() {
          _list.addAll(detail.files);
          drop_files.addAll(detail.files);
        });

        debugPrint('onDragDone:');
        await printFiles(detail.files);
      },
      onDragUpdated: (details) {
        setState(() {
          offset = details.localPosition;
        });
      },
      onDragEntered: (detail) {
        setState(() {
          _dragging = true;
          offset = detail.localPosition;
        });
      },
      onDragExited: (detail) {
        setState(() {
          _dragging = false;
          offset = null;
        });
      },
      child: Container(
        height: 200,
        width: 200,
        color: _dragging ? Colors.blue.withOpacity(0.4) : Colors.black26,
        child: Stack(
          children: [
            if (_list.isEmpty)
              Center(child: Text("Drop here"))
            else
              Text(_list.map((e) => e.path).join("\n")),
            if (offset != null)
              Align(
                alignment: Alignment.topRight,
                child: Text(
                  '$offset',
                  style: Theme.of(context).textTheme.bodySmall,
                ),
              ),
            if (!_list.isEmpty && Platform.isMacOS)
              Align(
                alignment: Alignment.bottomRight,
                child: TextButton(
                  onPressed: () async {
                    Map<String, String> data = Map();
                    data["path"] = drop_files[0].path;

                    String bookmark =
                        base64.encode(drop_files[0].extraAppleBookmark!);
                    data["apple-bookmark"] = bookmark;

                    String jsonStr = json.encode(data);
                    print(jsonStr);
                    final SharedPreferences prefs =
                        await SharedPreferences.getInstance();
                    prefs.setString("apple-bookmark", jsonStr);

                    ScaffoldMessenger.of(context).showSnackBar(SnackBar(
                        content: Text(
                            'Save Suc, restart app, and Test Apple Bookmark')));
                  },
                  child: Text(
                    'save bookmark',
                    style: TextStyle(fontSize: 14),
                  ),
                ),
              )
          ],
        ),
      ),
    );
  }
}