| // Copyright (c) 2019, the Dart project authors. Please see the AUTHORS file |
| // for details. 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:ffi'; |
| import 'dart:typed_data'; |
| |
| import 'package:ffi/ffi.dart'; |
| |
| /// [Utf16] implements conversion between Dart strings and zero-terminated |
| /// UTF-16 encoded "char*" strings in C. |
| /// |
| /// [Utf16] is represented as a struct so that `Pointer<Utf16>` can be used in |
| /// native function signatures. |
| class Utf16 extends Opaque { |
| /// Convert a [String] to a UTF-16 encoded zero-terminated C string. |
| /// |
| /// If [string] contains NULL characters, the converted string will be truncated |
| /// prematurely. Unpaired surrogate code points in [string] will be preserved |
| /// in the UTF-16 encoded result. See [Utf16Encoder] for details on encoding. |
| /// |
| /// Returns a malloc-allocated pointer to the result. |
| static Pointer<Utf16> toUtf16(String string) { |
| final units = string.codeUnits; |
| final Pointer<Uint16> result = allocate<Uint16>(count: units.length + 1); |
| final Uint16List nativeString = result.asTypedList(units.length + 1); |
| nativeString.setAll(0, units); |
| nativeString[units.length] = 0; |
| return result.cast(); |
| } |
| } |