Add background download support with notifications and concurrent queue

Add background download support with notifications and concurrent queue

Author: warreth

README.md

@@ -56,6 +56,11 @@ As [Anna’s Archive](https://annas-archive.org/) Doesn't Have An API. The App W
   - Drag-to-reorder priority
   - Enable/disable instances
   - Automatic retry (2x per instance) with seamless fallback
+- **Background Downloads** - Download books in the background with progress notifications
+  - Queue multiple books for simultaneous download
+  - Progress notifications with real-time updates
+  - Downloads continue even when app is in background
+  - Visual download queue in Home, Search, and My Library pages
 - Trending Books
 - Download And Read Books With In-Built Viewer
 - Supports Epub And Pdf Formats
@@ -66,8 +71,6 @@ As [Anna’s Archive](https://annas-archive.org/) Doesn't Have An API. The App W
 ## Roadmap 🎯
 
 - Adding More Book Format supports (cbz,cbr,azw3,etc...)
-- Adding Support For Background Downloads
-- Adding Support For Multiple Downloads
 - Move existing books when changing the storage path
 
 ## Building from Source

android/app/src/main/AndroidManifest.xml

@@ -3,6 +3,9 @@
     >
     <uses-permission android:name="android.permission.INTERNET" />
     <uses-permission android:name="android.permission.WAKE_LOCK" />
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_DATA_SYNC" />
 
     <uses-permission android:name="android.permission.READ_MEDIA_IMAGES" /> 
     <uses-permission android:name="android.permission.READ_MEDIA_VIDEOS" />

lib/main.dart

@@ -20,6 +20,7 @@ import 'package:openlib/ui/themes.dart';
 
 import 'package:openlib/services/files.dart'
     show moveFilesToAndroidInternalStorage;
+import 'package:openlib/services/download_manager.dart';
 import 'package:openlib/state/state.dart'
     show
         selectedIndexProvider,
@@ -38,6 +39,8 @@ void main() async {
   }
 
   MyLibraryDb dataBase = MyLibraryDb.instance;
+
+  await DownloadManager().initialize();
   bool isDarkMode =
       await dataBase.getPreference('darkMode') == 0 ? false : true;
   bool openPdfwithExternalapp = await dataBase