Merge pull request #942 from w1th0utnam3/master

Fix KDialog file open dialog and file filters

CHANGELOG.md

@@ -1,3 +1,8 @@
+## 4.3.3
+
+#### Desktop (Linux)
+Introduces two fixes for the KDE Plasma Linux implementation which uses `kdialog` to open the file picker dialogs. Firstly, the selection of multiple files is fixed so that file paths with blanks/spaces are handled correctly. Secondly, file type filters are implemented. Thank you @w1th0utnam3.
+
 ## 4.3.2
 
 #### Desktop (Windows)

CONTRIBUTING.md

@@ -0,0 +1,13 @@
+# Contributing to File Picker
+
+:+1: :tada: First off, thanks for taking the time to contribute to _File Picker_! :tada: :+1:
+
+The following is a first version of guidelines for contributing to _File Picker_. Feel free to propose changes to this document in a pull request.
+
+## Issue a Pull Request
+
+* **Dart code only:** before creating a pull request, please **write unit tests** if you added changes to Dart code under `lib/` (Java/Objective-C code is currently not tested). Please ensure that the **code analysis** via `dart analyze` throws no errors. Please also make sure that your **code is formatted correctly** via `dart format`. You can take a look into our CI pipeline at `.github/workflows/main.yml` for further details. The CI pipeline is triggered automatically when you create a pull request on GitHub. All steps in our pipeline must run without errors.
+
+* Please **update the package version** in `pubspec.yaml` and `CHANGELOG.md`. We use [semantic versionining (SemVer)](https://semver.org/). TL;DR: increase the patch version when your pull request contains a bug fix. Increase the minor version when a new feature is added. Breaking changes to _File Picker_'s public API should result in an increase in the major version.
+
+* Please **update the changelog** in `CHANGELOG.md`. Add a new level two heading with the updated package version to the top of the document, e.g. `## major.minor.patch`. Below that, add another level four heading that notes the affected platform(s), e.g. `#### Desktop (Linux)` or `Android`, and describe your changes. If your pull request is associated to an issue, then please reference the issue. The changelog will be shown on https://pub.dev/packages/file_picker/changelog.

lib/src/file_picker.dart

@@ -2,9 +2,9 @@ import 'dart:async';
 import 'dart:io';
 
 import 'package:file_picker/src/file_picker_io.dart';
-import 'package:file_picker/src/file_picker_linux.dart';
 import 'package:file_picker/src/file_picker_macos.dart';
 import 'package:file_picker/src/file_picker_result.dart';
+import 'package:file_picker/src/linux/file_picker_linux.dart';
 import 'package:file_picker/src/windows/stub.dart'
     if (dart.library.io) 'package:file_picker/src/windows/file_picker_windows.dart';
 import 'package:plugin_platform_interface/plugin_platform_interface.dart';

lib/src/linux/dialog_handler.dart

@@ -0,0 +1,42 @@
+import 'package:file_picker/file_picker.dart';
+import 'package:file_picker/src/linux/kdialog_handler.dart';
+import 'package:file_picker/src/linux/qarma_and_zenity_handler.dart';
+
+abstract class DialogHandler {
+  factory DialogHandler(String pathToExecutable) {
+    pathToExecutable = pathToExecutable.toLowerCase();
+
+    if (pathToExecutable.endsWith('kdialog')) {
+      return KDialogHandler();
+    } else if (pathToExecutable.endsWith('qarma') ||
+        pathToExecutable.endsWith('zenity')) {
+      return QarmaAndZenityHandler();
+    }
+    throw UnimplementedError(
+      'DialogHandler for executable $pathToExecutable has not been implemented',
+    );
+  }
+
+  /// Generates the command line arguments to open a dialog with the respective
+  /// dialog tool (`kdialog`, `qarma`, or `zenity`).
+  List<String> generateCommandLineArguments(
+    String dialogTitle, {
+    String fileFilter = '',
+    String fileName = '',
+    bool multipleFiles = false,
+    bool pickDirectory = false,
+    bool saveFile = false,
+  });
+
+  /// Converts the specified combination of [type] and [allowedExtensions] into
+  /// the format required by the respective dialog tool (`kdialog`, `qarma`,
+  /// or `zenity`) to filter for specific file types.
+  ///
+  /// [allowedExtensions] must only be used in combination with [type] equal to
+  /// [FileType.custom].
+  String fileTypeToFileFilter(FileType type, List<String>? allowedExtensions);
+
+  /// Converts the result string (stdout) of `qarma`, `zenity` or `kdialog`
+  /// into a [List<String>] of file paths.
+  List<String> resultStringToFilePaths(String fileSelectionResult);
+}