[file_selector] Migrate FileSelectorApi to Dart

packages/file_selector/file_selector_windows/lib/src/file_selector_api.dart

@@ -0,0 +1,92 @@
+// 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 'package:flutter/cupertino.dart';
+import 'package:win32/win32.dart';
+
+import 'file_selector_dart/dialog_mode.dart';
+import 'file_selector_dart/dialog_wrapper.dart';
+import 'file_selector_dart/dialog_wrapper_factory.dart';
+import 'file_selector_dart/selection_options.dart';
+
+/// File dialog handling for Open and Save operations.
+class FileSelectorApi {
+  /// Creates a new instance of [FileSelectorApi].
+  /// Allows Dependency Injection of a [DialogWrapperFactory] to handle dialog creation.
+  FileSelectorApi(this._dialogWrapperFactory)
+      : _foregroundWindow = GetForegroundWindow();
+
+  /// Creates a fake instance of [FileSelectorApi] for testing purpose where the [_foregroundWindow] handle is set
+  /// from the outside.
+  @visibleForTesting
+  FileSelectorApi.useFakeForegroundWindow(
+      this._dialogWrapperFactory, this._foregroundWindow);
+
+  final DialogWrapperFactory _dialogWrapperFactory;
+
+  final int _foregroundWindow;
+
+  /// Displays a dialog window to open one or more files.
+  List<String?> showOpenDialog(
+    SelectionOptions options,
+    String? initialDirectory,
+    String? confirmButtonText,
+  ) =>
+      _showDialog(_foregroundWindow, DialogMode.Open, options, initialDirectory,
+          null, confirmButtonText);
+
+  /// Displays a dialog used to save a file.
+  List<String?> showSaveDialog(
+    SelectionOptions options,
+    String? initialDirectory,
+    String? suggestedName,
+    String? confirmButtonText,
+  ) =>
+      _showDialog(_foregroundWindow, DialogMode.Save, options, initialDirectory,
+          suggestedName, confirmButtonText);
+
+  List<String?> _showDialog(
+      int parentWindow,
+      DialogMode mode,
+      SelectionOptions options,
+      String? initialDirectory,
+      String? suggestedName,
+      String? confirmLabel) {
+    final DialogWrapper dialogWrapper =
+        _dialogWrapperFactory.createInstance(mode);
+    if (!SUCCEEDED(dialogWrapper.lastResult)) {
+      throw WindowsException(E_FAIL);
+    }
+    int dialogOptions = 0;
+    if (options.selectFolders) {
+      dialogOptions |= FILEOPENDIALOGOPTIONS.FOS_PICKFOLDERS;
+    }
+    if (options.allowMultiple) {
+      dialogOptions |= FILEOPENDIALOGOPTIONS.FOS_ALLOWMULTISELECT;
+    }
+    if (dialogOptions != 0) {
+      dialogWrapper.addOptions(dialogOptions);
+    }
+
+    if (initialDirectory != null) {
+      dialogWrapper.setFolder(initialDirectory);
+    }
+    if (suggestedName != null) {
+      dialogWrapper.setFileName(suggestedName);
+    }
+    if (confirmLabel != null) {
+      dialogWrapper.setOkButtonLabel(confirmLabel);
+    }
+
+    if (options.allowedTypes.isNotEmpty) {
+      dialogWrapper.setFileTypeFilters(options.allowedTypes);
+    }
+
+    final List<String?>? files = dialogWrapper.show(parentWindow);
+    if (files != null) {
+      return files;
+    }
+    throw WindowsException(E_FAIL);
+  }
+}

packages/file_selector/file_selector_windows/lib/src/file_selector_dart/dialog_wrapper_factory.dart

@@ -0,0 +1,26 @@
+// 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 'dialog_mode.dart';
+import 'dialog_wrapper.dart';
+import 'ifile_dialog_controller_factory.dart';
+import 'ifile_dialog_factory.dart';
+
+/// Implementation of DialogWrapperFactory that provides [DialogWrapper] instances.
+class DialogWrapperFactory {
+  /// Creates a [DialogWrapperFactory] that makes use of [IFileDialogControllerFactory] and [IFileDialogFactory]
+  /// to create [DialogWrapper] instances.
+  DialogWrapperFactory(
+      this._fileDialogControllerFactory, this._fileDialogFactory);
+
+  final IFileDialogControllerFactory _fileDialogControllerFactory;
+
+  final IFileDialogFactory _fileDialogFactory;
+
+  /// Creates a [DialogWrapper] based on [dialogMode].
+  DialogWrapper createInstance(DialogMode dialogMode) {
+    return DialogWrapper(
+        _fileDialogControllerFactory, _fileDialogFactory, dialogMode);
+  }
+}

packages/file_selector/file_selector_windows/lib/src/file_selector_dart/selection_options.dart

@@ -0,0 +1,25 @@
+// 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 'package:file_selector_platform_interface/file_selector_platform_interface.dart';
+
+/// Options for Dialog window
+class SelectionOptions {
+  /// Creates a new [SelectionOptions] instance with the specified values.
+  /// It defaults [allowMultiple] to false, [selectFolders] to false and no [allowedTypes]
+  SelectionOptions({
+    this.allowMultiple = false,
+    this.selectFolders = false,
+    this.allowedTypes = const <XTypeGroup>[],
+  });
+
+  /// Indicates whether the user is able to select multiple items at the same time or not.
+  bool allowMultiple;
+
+  /// Indicates whether the user is able to select folders or not.
+  bool selectFolders;
+
+  /// A list of file types that can be selected.
+  List<XTypeGroup> allowedTypes;
+}

packages/file_selector/file_selector_windows/test/file_selector_api_test.dart

@@ -0,0 +1,185 @@
+// 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 'package:file_selector_platform_interface/file_selector_platform_interface.dart';
+import 'package:file_selector_windows/src/file_selector_api.dart';
+import 'package:file_selector_windows/src/file_selector_dart/dialog_mode.dart';
+import 'package:file_selector_windows/src/file_selector_dart/dialog_wrapper.dart';
+import 'package:file_selector_windows/src/file_selector_dart/dialog_wrapper_factory.dart';
+import 'package:file_selector_windows/src/file_selector_dart/selection_options.dart';
+import 'package:flutter_test/flutter_test.dart';
+import 'package:mockito/annotations.dart';
+import 'package:mockito/mockito.dart';
+import 'package:win32/win32.dart';
+
+import 'file_selector_api_test.mocks.dart';
+
+@GenerateMocks(<Type>[DialogWrapperFactory, DialogWrapper])
+void main() {
+  const int parentWindow = 1;
+  final MockDialogWrapperFactory mockDialogWrapperFactory =
+      MockDialogWrapperFactory();
+  late MockDialogWrapper mockDialogWrapper;
+  final FileSelectorApi fileSelectorApi =
+      FileSelectorApi.useFakeForegroundWindow(
+          mockDialogWrapperFactory, parentWindow);
+
+  const List<String> expectedFileList = <String>['fileA', 'fileB'];
+  final SelectionOptions emptyOptions = SelectionOptions();
+
+  setUp(() {
+    mockDialogWrapper = MockDialogWrapper();
+    when(mockDialogWrapper.lastResult).thenReturn(S_OK);
+    when(mockDialogWrapperFactory.createInstance(DialogMode.Save))
+        .thenReturn(mockDialogWrapper);
+    when(mockDialogWrapperFactory.createInstance(DialogMode.Open))
+        .thenReturn(mockDialogWrapper);
+    when(mockDialogWrapper.show(parentWindow)).thenReturn(expectedFileList);
+  });
+
+  tearDown(() {
+    reset(mockDialogWrapper);
+    reset(mockDialogWrapperFactory);
+  });
+
+  test('FileSelectorApi should not be null', () {
+    expect(fileSelectorApi, isNotNull);
+  });
+
+  group('showSaveDialog', () {
+    test('should call setFileName if a suggestedName is provided', () {
+      // Arrange
+      const String suggestedName = 'suggestedName';
+
+      // Act
+      fileSelectorApi.showSaveDialog(emptyOptions, null, suggestedName, null);
+
+      // Assert
+      verify(mockDialogWrapper.setFileName(suggestedName)).called(1);
+    });
+
+    test('should create a DialogWrapper with DialogMode Save', () {
+      // Act
+      fileSelectorApi.showSaveDialog(emptyOptions, null, null, null);
+
+      // Assert
+      verify(mockDialogWrapperFactory.createInstance(DialogMode.Save))
+          .called(1);
+    });
+  });
+  group('showOpenDialog', () {
+    test('should create a DialogWrapper with DialogMode Open', () {
+      // Act
+      fileSelectorApi.showOpenDialog(emptyOptions, null, null);
+
+      // Assert
+      verify(mockDialogWrapperFactory.createInstance(DialogMode.Open))
+          .called(1);
+    });
+  });
+  group('Common behavior', () {
+    test('should throw a WindowsException is DialogWrapper can not be created',
+        () {
+      // Arrange
+      when(mockDialogWrapperFactory.createInstance(DialogMode.Open))
+          .thenReturn(mockDialogWrapper);
+      when(mockDialogWrapper.lastResult).thenReturn(E_FAIL);
+
+      // Act - Assert
+      expect(() => fileSelectorApi.showOpenDialog(emptyOptions, null, null),
+          throwsA(const TypeMatcher<WindowsException>()));
+    });
+
+    test('should not call AddOptions if no options are configured', () {
+      // Act
+      fileSelectorApi.showOpenDialog(emptyOptions, null, null);
+
+      // Assert
+      verifyNever(mockDialogWrapper.addOptions(any));
+    });
+    test('should call AddOptions with FOS_PICKFOLDERS configured', () {
+      // Arrange
+      final SelectionOptions options = SelectionOptions(selectFolders: true);
+
+      // Act
+      fileSelectorApi.showOpenDialog(options, null, null);
+
+      // Assert
+      verify(mockDialogWrapper
+              .addOptions(FILEOPENDIALOGOPTIONS.FOS_PICKFOLDERS))
+          .called(1);
+    });
+
+    test('should call AddOptions with FOS_ALLOWMULTISELECT configured', () {
+      // Arrange
+      final SelectionOptions options = SelectionOptions(allowMultiple: true);
+
+      // Act
+      fileSelectorApi.showOpenDialog(options, null, null);
+
+      // Assert
+      verify(mockDialogWrapper
+              .addOptions(FILEOPENDIALOGOPTIONS.FOS_ALLOWMULTISELECT))
+          .called(1);
+    });
+
+    test('should call setFolder if an initialDirectory is provided', () {
+      // Arrange
+      const String initialDirectory = 'path/to/dir';
+
+      // Act
+      fileSelectorApi.showOpenDialog(emptyOptions, initialDirectory, null);
+
+      // Assert
+      verify(mockDialogWrapper.setFolder(initialDirectory)).called(1);
+    });
+
+    test('should call setOkButtonLabel if confirmButtonText is provided', () {
+      // Arrange
+      const String confirmButtonText = 'OK';
+
+      // Act
+      fileSelectorApi.showOpenDialog(emptyOptions, null, confirmButtonText);
+
+      // Assert
+      verify(mockDialogWrapper.setOkButtonLabel(confirmButtonText)).called(1);
+    });
+
+    test('should call setFileTypeFilters with provided allowedTypes',
+        () {
+      // Arrange
+      final SelectionOptions options =
+          SelectionOptions(allowedTypes: <XTypeGroup>[
+        const XTypeGroup(extensions: <String>['jpg', 'png'], label: 'Images'),
+        const XTypeGroup(extensions: <String>['txt', 'json'], label: 'Text'),
+      ]);
+
+      // Act
+      fileSelectorApi.showOpenDialog(options, null, null);
+
+      // Assert
+      verify(mockDialogWrapper.setFileTypeFilters(options.allowedTypes))
+          .called(1);
+    });
+
+    test('should return the file list on success', () {
+      // Act
+      final List<String?> result =
+          fileSelectorApi.showOpenDialog(emptyOptions, null, null);
+
+      // Assert
+      expect(result.length, expectedFileList.length);
+      expect(result, expectedFileList);
+    });
+
+    test('should throw an exception if file list is null', () {
+      // Arrange
+      when(mockDialogWrapper.show(parentWindow)).thenReturn(null);
+
+      // Act - Assert
+      expect(() => fileSelectorApi.showOpenDialog(emptyOptions, null, null),
+          throwsA(const TypeMatcher<WindowsException>()));
+    });
+  });
+}