[file_selector] Add getDirectoryPaths method to the file_selector_platform_interface. (#6572)

* Add getDirectoriesPaths method to the file_selector_platform_interface

* Add getDirectoriesPaths to method channel.

* Increment version to 2.3.0

* apply feedback

* extract assertion method

Co-authored-by: Alejandro Pinola <[email protected]>

Author: eugerossetto

packages/file_selector/file_selector_platform_interface/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.4.0
+
+* Adds `getDirectoryPaths` method to the interface.
+
 ## 2.3.0
 
 * Replaces `macUTIs` with `uniformTypeIdentifiers`. `macUTIs` is available as an alias, but will be deprecated in a future release.

packages/file_selector/file_selector_platform_interface/lib/src/method_channel/method_channel_file_selector.dart

@@ -16,7 +16,6 @@ class MethodChannelFileSelector extends FileSelectorPlatform {
   @visibleForTesting
   MethodChannel get channel => _channel;
 
-  /// Load a file from user's computer and return it as an XFile
   @override
   Future<XFile?> openFile({
     List<XTypeGroup>? acceptedTypeGroups,
@@ -37,7 +36,6 @@ class MethodChannelFileSelector extends FileSelectorPlatform {
     return path == null ? null : XFile(path.first);
   }
 
-  /// Load multiple files from user's computer and return it as an XFile
   @override
   Future<List<XFile>> openFiles({
     List<XTypeGroup>? acceptedTypeGroups,
@@ -58,7 +56,6 @@ class MethodChannelFileSelector extends FileSelectorPlatform {
     return pathList?.map((String path) => XFile(path)).toList() ?? <XFile>[];
   }
 
-  /// Gets the path from a save dialog
   @override
   Future<String?> getSavePath({
     List<XTypeGroup>? acceptedTypeGroups,
@@ -79,7 +76,6 @@ class MethodChannelFileSelector extends FileSelectorPlatform {
     );
   }
 
-  /// Gets a directory path from a dialog
   @override
   Future<String?> getDirectoryPath({
     String? initialDirectory,
@@ -93,4 +89,17 @@ class MethodChannelFileSelector extends FileSelectorPlatform {
       },
     );
   }
+
+  @override
+  Future<List<String>> getDirectoryPaths(
+      {String? initialDirectory, String? confirmButtonText}) async {
+    final List<String>? pathList = await _channel.invokeListMethod<String>(
+      'getDirectoryPaths',
+      <String, dynamic>{
+        'initialDirectory': initialDirectory,
+        'confirmButtonText': confirmButtonText,
+      },
+    );
+    return pathList ?? <String>[];
+  }
 }

packages/file_selector/file_selector_platform_interface/lib/src/platform_interface/file_selector_interface.dart

@@ -36,7 +36,7 @@ abstract class FileSelectorPlatform extends PlatformInterface {
     _instance = instance;
   }
 
-  /// Open file dialog for loading files and return a file path
+  /// Opens a file dialog for loading files and returns a file path.
   /// Returns `null` if user cancels the operation.
   Future<XFile?> openFile({
     List<XTypeGroup>? acceptedTypeGroups,
@@ -46,7 +46,7 @@ abstract class FileSelectorPlatform extends PlatformInterface {
     throw UnimplementedError('openFile() has not been implemented.');
   }
 
-  /// Open file dialog for loading files and return a list of file paths
+  /// Opens a file dialog for loading files and returns a list of file paths.
   Future<List<XFile>> openFiles({
     List<XTypeGroup>? acceptedTypeGroups,
     String? initialDirectory,
@@ -55,7 +55,7 @@ abstract class FileSelectorPlatform extends PlatformInterface {
     throw UnimplementedError('openFiles() has not been implemented.');
   }
 
-  /// Open file dialog for saving files and return a file path at which to save
+  /// Opens a file dialog for saving files and returns a file path at which to save.
   /// Returns `null` if user cancels the operation.
   Future<String?> getSavePath({
     List<XTypeGroup>? acceptedTypeGroups,
@@ -66,12 +66,20 @@ abstract class FileSelectorPlatform extends PlatformInterface {
     throw UnimplementedError('getSavePath() has not been implemented.');
   }
 
-  /// Open file dialog for loading directories and return a directory path
+  /// Opens a file dialog for loading directories and returns a directory path.
   /// Returns `null` if user cancels the operation.
   Future<String?> getDirectoryPath({
     String? initialDirectory,
     String? confirmButtonText,
   }) {
     throw UnimplementedError('getDirectoryPath() has not been implemented.');
   }
+
+  /// Opens a file dialog for loading directories and returns multiple directory paths.
+  Future<List<String>> getDirectoryPaths({
+    String? initialDirectory,
+    String? confirmButtonText,
+  }) {
+    throw UnimplementedError('getDirectoryPaths() has not been implemented.');
+  }
 }

packages/file_selector/file_selector_platform_interface/pubspec.yaml

@@ -4,7 +4,7 @@ repository: https://github.com/flutter/plugins/tree/main/packages/file_selector/
 issue_tracker: https://github.com/flutter/flutter/issues?q=is%3Aissue+is%3Aopen+label%3A%22p%3A+file_selector%22
 # NOTE: We strongly prefer non-breaking changes, even at the expense of a
 # less-clean API. See https://flutter.dev/go/platform-interface-breaking-changes
-version: 2.3.0
+version: 2.4.0
 
 environment:
   sdk: ">=2.12.0 <3.0.0"

packages/file_selector/file_selector_platform_interface/test/file_selector_platform_interface_test.dart

@@ -19,6 +19,16 @@ void main() {
       FileSelectorPlatform.instance = ExtendsFileSelectorPlatform();
     });
   });
+
+  group('#GetDirectoryPaths', () {
+    test('Should throw unimplemented exception', () async {
+      final FileSelectorPlatform fileSelector = ExtendsFileSelectorPlatform();
+
+      await expectLater(() async {
+        return fileSelector.getDirectoryPaths();
+      }, throwsA(isA<UnimplementedError>()));
+    });
+  });
 }
 
 class ExtendsFileSelectorPlatform extends FileSelectorPlatform {}