feat: add some plugins.

app/3rd_party/path_provider_linux/lib/path_provider_linux.dart

@@ -0,0 +1,49 @@
+// Copyright 2013 The Flutter Authors. 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:io';
+
+import 'package:path/path.dart' as path;
+import 'package:path_provider_platform_interface/path_provider_platform_interface.dart';
+import 'package:xdg_directories/xdg_directories.dart';
+
+XDGDirectories xdg = XDGDirectories();
+
+/// The linux implementation of [PathProviderPlatform]
+///
+/// This class implements the `package:path_provider` functionality for linux
+class PathProviderLinux extends PathProviderPlatform {
+  /// Registers this class as the default instance of [PathProviderPlatform]
+  static void registerWith() {
+    PathProviderPlatform.instance = PathProviderLinux();
+  }
+
+  @override
+  Future<String?> getTemporaryPath() {
+    return Future<String?>.value('/tmp');
+  }
+
+  @override
+  Future<String?> getApplicationSupportPath() async {
+    final String processName = path.basenameWithoutExtension(
+        await File('/proc/self/exe').resolveSymbolicLinks());
+    final Directory directory =
+        Directory(path.join(xdg.dataHome.path, processName));
+    // Creating the directory if it doesn't exist, because mobile implementations assume the directory exists
+    if (!directory.existsSync()) {
+      await directory.create(recursive: true);
+    }
+    return directory.path;
+  }
+
+  @override
+  Future<String?> getApplicationDocumentsPath() {
+    return Future<String?>.value(xdg.getUserDirectory('DOCUMENTS')?.path);
+  }
+
+  @override
+  Future<String?> getDownloadsPath() {
+    return Future<String?>.value(xdg.getUserDirectory('DOWNLOAD')?.path);
+  }
+}