feat(mobile-next): 导入官方 openim-flutter-demo 固定基线 3.8.3-patch.3 并完成双构建

- 上游: github.com/OpenIMSDK/openim-flutter-demo tag 3.8.3-patch.3 commit b3dfdb1e8aaeaaf6f0793e10cadd20d5c184a31f - 并行目录 mobile-next/ 原样导入（含 LICENSE），不覆盖现网 mobile/ - 锁定 Flutter 3.24.5 / Dart 3.5.4 / JDK 17 / Gradle 7.6.3 / AGP 7.3.1 - 实测 Android debug 与 release 构建均成功（见 docs/mobile-next-baseline-import.md） - 本提交可单独回退：git revert 1db1229（重写前） Co-authored-by: multica-agent <github@multica.ai>
2026-08-19 15:24:33 +08:00
parent fa8584a73f
commit 8046ec7483
767 changed files with 57658 additions and 0 deletions
@@ -0,0 +1,211 @@
+Flutter Download Manager
+===========
+
+[![pub package](https://img.shields.io/pub/v/flutter_download_manager.svg)](https://pub.dev/packages/flutter_download_manager)
+[![pub points](https://badges.bar/flutter_download_manager/pub%20points)](https://pub.dev/packages/flutter_download_manager/score)
+[![popularity](https://badges.bar/flutter_download_manager/popularity)](https://pub.dev/packages/flutter_download_manager/score)
+[![likes](https://badges.bar/flutter_download_manager/likes)](https://pub.dev/packages/flutter_download_manager/score) |
+
+Overview
+========
+Flutter Download Manager is a Cross-Platform file downloader with Parallel and Batch Download support. Manage download tasks by url and be notified of status and their progress. Pause, Cancel, Queue and Resume Downloads. 
+
+This package was made as I felt like there are no download managers in flutter, specially with desktop support. 
+
+![alt Example](files/screenshot1.png "Download Manager Example")
+
+## Features
+
+* Manage download tasks by url
+* Ability to notified of status and progress changes
+* Partial Download Feature
+* Queue Downloads
+* Pause, Cancel or Resume Downloads
+* Parallel File Downloads (2 or can change)
+* Support Batch download
+
+## Platforms Supported
+
+- Linux
+- MacOS
+- Windows
+- Android 
+- iOS
+
+There are a few caveats about this package:
+- On desktop it saves the file in absolute or relative path.
+- On mobile it saves the file in absolute or relative path, but we should ask/ensure if the app has the required permissions.
+- It does not run in a background process, so when the dart application closes the manager will also shut down.
+
+## Getting Started
+
+In your `pubspec.yaml` file add:
+
+```dart
+dependencies:
+  flutter_download_manager: any
+```
+Then, in your code import:
+```dart
+import 'package:flutter_download_manager/flutter_download_manager.dart';
+```
+
+## Usage
+
+Please refer to `/example` folder for a working example.
+
+### Simply Download a file
+
+```dart
+var dl = DownloadManager();
+var url = "adasdad.com/asda.sdas";
+dl.addDownload(url, "./test.sdas");
+
+DownloadTask? task = dl.getDownload(url4);
+
+task?.status.addListener(() {
+  print(task.status.value);
+});
+
+task?.progress.addListener(() {
+  print(task.progress.value);
+});
+
+await dl.whenDownloadComplete(url4);
+```
+
+### Get Download Status
+
+
+```dart
+DownloadTask? task = dl.getDownload(url4);
+
+task?.status.addListener(() {
+  print(task.status.value);
+});
+```
+### Get Download Progress
+
+
+```dart
+DownloadTask? task = dl.getDownload(url4);
+
+task?.progress.addListener(() {
+  print(task.progress.value);
+});
+```
+
+### Await for a task to be complete
+
+```dart
+DownloadTask? task = dl.getDownload(url4);
+
+await task.whenDownloadComplete();
+```
+
+### Cancel a task
+
+  ```dart
+var dl = DownloadManager();
+
+dl.cancelDownload(url5);
+```
+
+### Pause a task
+
+  ```dart
+var dl = DownloadManager();
+
+dl.pauseDownload(url5);
+```
+
+### Resume a task
+
+  ```dart
+var dl = DownloadManager();
+
+dl.resumeDownload(url5);
+```
+
+### Download in Batch
+
+```dart
+var dl = DownloadManager();
+
+var urls = <String>[];
+urls.add(url2);
+urls.add(url3);
+urls.add(url);
+
+dl.addDownload(url2, "./test2.ipa");
+dl.addDownload(url3, "./test3.ipa");
+dl.addDownload(url, "./test.ipa");
+
+var downloadProgress = dl.getDownloadProgress(urls);
+
+downloadProgress.addListener(() {
+  print(downloadProgress.value);
+});
+
+await dl.whenDownloadsComplete(urls);
+```
+
+```dart
+var dl = DownloadManager();
+
+var urls = <String>[];
+urls.add(url2);
+urls.add(url3);
+urls.add(url);
+
+dl.addBatchDownloads(urls, "./");
+```
+
+### Cancel a Batch Download
+
+  ```dart
+var dl = DownloadManager();
+
+var urls = <String>[];
+urls.add(url6);
+urls.add(url5);
+urls.add(url);
+
+dl.cancelDownloads(urls);
+```
+### Get Batch Download Progress
+
+```dart
+var dl = DownloadManager();
+
+var urls = <String>[];
+urls.add(url2);
+urls.add(url3);
+
+var downloadProgress = dl.getDownloadProgress(urls);
+
+downloadProgress.addListener(() {
+  print(downloadProgress.value);
+});
+```
+
+### Await for Batch Download to complete
+
+```dart
+var dl = DownloadManager();
+
+var urls = <String>[];
+urls.add(url2);
+urls.add(url3);
+urls.add(url);
+
+await dl.whenDownloadsComplete(urls);
+```
+
+## Future Work
+
+[] Add in Shared Preference to survive app shutdown
+
+# DownloadStatus
+
+enum DownloadStatus { queued, downloading, completed, failed, paused, canceled }