added cargo files

PinePods-0.8.2/mobile/lib/services/download/mobile_download_manager.dart

@@ -0,0 +1,119 @@
+// Copyright 2020 Ben Hills and the project contributors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+import 'dart:async';
+import 'dart:isolate';
+import 'dart:ui';
+
+import 'package:pinepods_mobile/core/environment.dart';
+import 'package:pinepods_mobile/entities/downloadable.dart';
+import 'package:pinepods_mobile/services/download/download_manager.dart';
+import 'package:flutter_downloader/flutter_downloader.dart';
+import 'package:logging/logging.dart';
+
+/// A [DownloadManager] for handling downloading of podcasts on a mobile device.
+@pragma('vm:entry-point')
+class MobileDownloaderManager implements DownloadManager {
+  static const portName = 'downloader_send_port';
+  final log = Logger('MobileDownloaderManager');
+  final ReceivePort _port = ReceivePort();
+  final downloadController = StreamController<DownloadProgress>();
+  var _lastUpdateTime = 0;
+
+  @override
+  Stream<DownloadProgress> get downloadProgress => downloadController.stream;
+
+  MobileDownloaderManager() {
+    _init();
+  }
+
+  Future _init() async {
+    log.fine('Initialising download manager');
+
+    await FlutterDownloader.initialize();
+    IsolateNameServer.removePortNameMapping(portName);
+
+    IsolateNameServer.registerPortWithName(_port.sendPort, portName);
+
+    var tasks = await FlutterDownloader.loadTasks();
+
+    // Update the status of any tasks that may have been updated whilst
+    // Pinepods was close or in the background.
+    if (tasks != null && tasks.isNotEmpty) {
+      for (var t in tasks) {
+        _updateDownloadState(id: t.taskId, progress: t.progress, status: t.status);
+
+        /// If we are not queued or running we can safely clean up this event
+        if (t.status != DownloadTaskStatus.enqueued && t.status != DownloadTaskStatus.running) {
+          FlutterDownloader.remove(taskId: t.taskId, shouldDeleteContent: false);
+        }
+      }
+    }
+
+    _port.listen((dynamic data) {
+      final id = (data as List<dynamic>)[0] as String;
+      final status = DownloadTaskStatus.fromInt(data[1] as int);
+      final progress = data[2] as int;
+
+      _updateDownloadState(id: id, progress: progress, status: status);
+    });
+
+    FlutterDownloader.registerCallback(downloadCallback);
+  }
+
+  @override
+  Future<String?> enqueueTask(String url, String downloadPath, String fileName) async {
+    return await FlutterDownloader.enqueue(
+      url: url,
+      savedDir: downloadPath,
+      fileName: fileName,
+      showNotification: true,
+      openFileFromNotification: false,
+      headers: {
+        'User-Agent': Environment.userAgent(),
+      },
+    );
+  }
+
+  @override
+  void dispose() {
+    IsolateNameServer.removePortNameMapping(portName);
+    downloadController.close();
+  }
+
+  void _updateDownloadState({required String id, required int progress, required DownloadTaskStatus status}) {
+    var state = DownloadState.none;
+    var updateTime = DateTime.now().millisecondsSinceEpoch;
+
+    if (status == DownloadTaskStatus.enqueued) {
+      state = DownloadState.queued;
+    } else if (status == DownloadTaskStatus.canceled) {
+      state = DownloadState.cancelled;
+    } else if (status == DownloadTaskStatus.complete) {
+      state = DownloadState.downloaded;
+    } else if (status == DownloadTaskStatus.running) {
+      state = DownloadState.downloading;
+    } else if (status == DownloadTaskStatus.failed) {
+      state = DownloadState.failed;
+    } else if (status == DownloadTaskStatus.paused) {
+      state = DownloadState.paused;
+    }
+
+    /// If we are running, we want to limit notifications to 1 per second. Otherwise,
+    /// small downloads can cause a flood of events. Any other status we always want
+    /// to push through.
+    if (status != DownloadTaskStatus.running ||
+        progress == 0 ||
+        progress == 100 ||
+        updateTime > _lastUpdateTime + 1000) {
+      downloadController.add(DownloadProgress(id, progress, state));
+      _lastUpdateTime = updateTime;
+    }
+  }
+
+  @pragma('vm:entry-point')
+  static void downloadCallback(String id, int status, int progress) {
+    IsolateNameServer.lookupPortByName('downloader_send_port')?.send([id, status, progress]);
+  }
+}