[file_selector] Migrate to null safety

packages/file_selector/file_selector/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.8.0
+
+Migrate to null safety.
+
 ## 0.7.0+2
 
 * Update the example app: remove the deprecated `RaisedButton` and `FlatButton` widgets.

packages/file_selector/file_selector/example/lib/get_directory_page.dart

@@ -5,9 +5,13 @@ import 'package:flutter/material.dart';
 class GetDirectoryPage extends StatelessWidget {
   void _getDirectoryPath(BuildContext context) async {
     final String confirmButtonText = 'Choose';
-    final String directoryPath = await getDirectoryPath(
+    final String? directoryPath = await getDirectoryPath(
       confirmButtonText: confirmButtonText,
     );
+    if (directoryPath == null) {
+      // Operation was canceled by the user.
+      return;
+    }
     await showDialog(
       context: context,
       builder: (context) => TextDisplay(directoryPath),

packages/file_selector/file_selector/example/lib/open_image_page.dart

@@ -11,6 +11,10 @@ class OpenImagePage extends StatelessWidget {
       extensions: ['jpg', 'png'],
     );
     final List<XFile> files = await openFiles(acceptedTypeGroups: [typeGroup]);
+    if (files.isEmpty) {
+      // Operation was canceled by the user.
+      return;
+    }
     final XFile file = files[0];
     final String fileName = file.name;
     final String filePath = file.path;

packages/file_selector/file_selector/example/lib/open_multiple_images_page.dart

@@ -18,6 +18,10 @@ class OpenMultipleImagesPage extends StatelessWidget {
       jpgsTypeGroup,
       pngTypeGroup,
     ]);
+    if (files.isEmpty) {
+      // Operation was canceled by the user.
+      return;
+    }
     await showDialog(
       context: context,
       builder: (context) => MultipleImagesDisplay(files),

packages/file_selector/file_selector/example/lib/open_text_page.dart

@@ -8,7 +8,11 @@ class OpenTextPage extends StatelessWidget {
       label: 'text',
       extensions: ['txt', 'json'],
     );
-    final XFile file = await openFile(acceptedTypeGroups: [typeGroup]);
+    final XFile? file = await openFile(acceptedTypeGroups: [typeGroup]);
+    if (file == null) {
+      // Operation was canceled by the user.
+      return;
+    }
     final String fileName = file.name;
     final String fileContent = await file.readAsString();
 

packages/file_selector/file_selector/example/lib/save_text_page.dart

@@ -8,7 +8,11 @@ class SaveTextPage extends StatelessWidget {
   final TextEditingController _contentController = TextEditingController();
 
   void _saveFile() async {
-    final String path = await getSavePath();
+    String? path = await getSavePath();
+    if (path == null) {
+      // Operation was canceled by the user.
+      return;
+    }
     final String text = _contentController.text;
     final String fileName = _nameController.text;
     final Uint8List fileData = Uint8List.fromList(text.codeUnits);

packages/file_selector/file_selector/example/pubspec.yaml

@@ -1,24 +1,12 @@
 name: example
 description: A new Flutter project.
 
-# The following line prevents the package from being accidentally published to
-# pub.dev using `pub publish`. This is preferred for private packages.
 publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 
-# The following defines the version and build number for your application.
-# A version number is three numbers separated by dots, like 1.2.43
-# followed by an optional build number separated by a +.
-# Both the version and the builder number may be overridden in flutter
-# build by specifying --build-name and --build-number, respectively.
-# In Android, build-name is used as versionName while build-number used as versionCode.
-# Read more about Android versioning at https://developer.android.com/studio/publish/versioning
-# In iOS, build-name is used as CFBundleShortVersionString while build-number used as CFBundleVersion.
-# Read more about iOS versioning at
-# https://developer.apple.com/library/archive/documentation/General/Reference/InfoPlistKeyReference/Articles/CoreFoundationKeys.html
 version: 1.0.0+1
 
 environment:
-  sdk: ">=2.7.0 <3.0.0"
+  sdk: ">=2.12.0-259.9.beta <3.0.0"
 
 dependencies:
   flutter:
@@ -32,52 +20,9 @@ dependencies:
     # the parent directory to use the current plugin's version.
     path: ../
 
-  # The following adds the Cupertino Icons font to your application.
-  # Use with the CupertinoIcons class for iOS style icons.
-  cupertino_icons: ^0.1.3
-
 dev_dependencies:
   flutter_test:
     sdk: flutter
 
-# For information on the generic Dart part of this file, see the
-# following page: https://dart.dev/tools/pub/pubspec
-
-# The following section is specific to Flutter.
 flutter:
-
-  # The following line ensures that the Material Icons font is
-  # included with your application, so that you can use the icons in
-  # the material Icons class.
   uses-material-design: true
-
-  # To add assets to your application, add an assets section, like this:
-  # assets:
-  #   - images/a_dot_burr.jpeg
-  #   - images/a_dot_ham.jpeg
-
-  # An image asset can refer to one or more resolution-specific "variants", see
-  # https://flutter.dev/assets-and-images/#resolution-aware.
-
-  # For details regarding adding assets from package dependencies, see
-  # https://flutter.dev/assets-and-images/#from-packages
-
-  # To add custom fonts to your application, add a fonts section here,
-  # in this "flutter" section. Each entry in this list should have a
-  # "family" key with the font family name, and a "fonts" key with a
-  # list giving the asset and other descriptors for the font. For
-  # example:
-  # fonts:
-  #   - family: Schyler
-  #     fonts:
-  #       - asset: fonts/Schyler-Regular.ttf
-  #       - asset: fonts/Schyler-Italic.ttf
-  #         style: italic
-  #   - family: Trajan Pro
-  #     fonts:
-  #       - asset: fonts/TrajanPro.ttf
-  #       - asset: fonts/TrajanPro_Bold.ttf
-  #         weight: 700
-  #
-  # For details regarding fonts from package dependencies,
-  # see https://flutter.dev/custom-fonts/#from-packages

packages/file_selector/file_selector/lib/file_selector.dart

@@ -10,10 +10,10 @@ export 'package:file_selector_platform_interface/file_selector_platform_interfac
     show XFile, XTypeGroup;
 
 /// Open file dialog for loading files and return a file path
-Future<XFile> openFile({
-  List<XTypeGroup> acceptedTypeGroups,
-  String initialDirectory,
-  String confirmButtonText,
+Future<XFile?> openFile({
+  List<XTypeGroup> acceptedTypeGroups = const <XTypeGroup>[],
+  String? initialDirectory,
+  String? confirmButtonText,
 }) {
   return FileSelectorPlatform.instance.openFile(
       acceptedTypeGroups: acceptedTypeGroups,
@@ -23,9 +23,9 @@ Future<XFile> openFile({
 
 /// Open file dialog for loading files and return a list of file paths
 Future<List<XFile>> openFiles({
-  List<XTypeGroup> acceptedTypeGroups,
-  String initialDirectory,
-  String confirmButtonText,
+  List<XTypeGroup> acceptedTypeGroups = const <XTypeGroup>[],
+  String? initialDirectory,
+  String? confirmButtonText,
 }) {
   return FileSelectorPlatform.instance.openFiles(
       acceptedTypeGroups: acceptedTypeGroups,
@@ -34,11 +34,11 @@ Future<List<XFile>> openFiles({
 }
 
 /// Saves File to user's file system
-Future<String> getSavePath({
-  List<XTypeGroup> acceptedTypeGroups,
-  String initialDirectory,
-  String suggestedName,
-  String confirmButtonText,
+Future<String?> getSavePath({
+  List<XTypeGroup> acceptedTypeGroups = const <XTypeGroup>[],
+  String? initialDirectory,
+  String? suggestedName,
+  String? confirmButtonText,
 }) async {
   return FileSelectorPlatform.instance.getSavePath(
       acceptedTypeGroups: acceptedTypeGroups,
@@ -48,9 +48,9 @@ Future<String> getSavePath({
 }
 
 /// Gets a directory path from a user's file system
-Future<String> getDirectoryPath({
-  String initialDirectory,
-  String confirmButtonText,
+Future<String?> getDirectoryPath({
+  String? initialDirectory,
+  String? confirmButtonText,
 }) async {
   return FileSelectorPlatform.instance.getDirectoryPath(
       initialDirectory: initialDirectory, confirmButtonText: confirmButtonText);

packages/file_selector/file_selector/pubspec.yaml

@@ -1,21 +1,20 @@
 name: file_selector
 description: Flutter plugin for opening and saving files.
 homepage: https://github.com/flutter/plugins/tree/master/packages/file_selector/file_selector
-version: 0.7.0+2
+version: 0.8.0
 
 dependencies:
   flutter:
     sdk: flutter
-  file_selector_platform_interface: ^1.0.0
+  file_selector_platform_interface: ^2.0.0
 
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  test: ^1.3.0
-  mockito: ^4.1.1
-  plugin_platform_interface: ^1.0.0
-  pedantic: ^1.8.0
+  test: ^1.16.3
+  plugin_platform_interface: ">=1.0.0 <3.0.0"
+  pedantic: ^1.10.0
 
 environment:
-  sdk: ">=2.1.0 <3.0.0"
-  flutter: ">=1.12.13+hotfix.5"
+  sdk: ">=2.12.0-259.9.beta <3.0.0"
+  flutter: ">=1.20.0"