mirror of
https://github.com/EsotericSoftware/spine-runtimes.git
synced 2025-12-20 01:06:00 +08:00
88 lines
3.1 KiB
Dart
88 lines
3.1 KiB
Dart
// 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:convert';
|
|
import 'dart:typed_data';
|
|
|
|
import 'ffi_proxy.dart';
|
|
|
|
/// The contents of a native zero-terminated array of UTF-8 code units.
|
|
///
|
|
/// The Utf8 type itself has no functionality, it's only intended to be used
|
|
/// through a `Pointer<Utf8>` representing the entire array. This pointer is
|
|
/// the equivalent of a char pointer (`const char*`) in C code.
|
|
class Utf8 extends Opaque {}
|
|
|
|
/// Extension method for converting a`Pointer<Utf8>` to a [String].
|
|
extension Utf8Pointer on Pointer<Utf8> {
|
|
/// The number of UTF-8 code units in this zero-terminated UTF-8 string.
|
|
///
|
|
/// The UTF-8 code units of the strings are the non-zero code units up to the
|
|
/// first zero code unit.
|
|
int get length {
|
|
_ensureNotNullptr('length');
|
|
final codeUnits = cast<Uint8>();
|
|
return _length(codeUnits);
|
|
}
|
|
|
|
/// Converts this UTF-8 encoded string to a Dart string.
|
|
///
|
|
/// Decodes the UTF-8 code units of this zero-terminated byte array as
|
|
/// Unicode code points and creates a Dart string containing those code
|
|
/// points.
|
|
///
|
|
/// If [length] is provided, zero-termination is ignored and the result can
|
|
/// contain NUL characters.
|
|
///
|
|
/// If [length] is not provided, the returned string is the string up til
|
|
/// but not including the first NUL character.
|
|
String toDartString({int? length}) {
|
|
_ensureNotNullptr('toDartString');
|
|
final codeUnits = cast<Uint8>();
|
|
if (length != null) {
|
|
RangeError.checkNotNegative(length, 'length');
|
|
} else {
|
|
length = _length(codeUnits);
|
|
}
|
|
return utf8.decode(codeUnits.asTypedList(length));
|
|
}
|
|
|
|
static int _length(Pointer<Uint8> codeUnits) {
|
|
var length = 0;
|
|
while (codeUnits[length] != 0) {
|
|
length++;
|
|
}
|
|
return length;
|
|
}
|
|
|
|
void _ensureNotNullptr(String operation) {
|
|
if (this == nullptr) {
|
|
throw UnsupportedError("Operation '$operation' not allowed on a 'nullptr'.");
|
|
}
|
|
}
|
|
}
|
|
|
|
/// Extension method for converting a [String] to a `Pointer<Utf8>`.
|
|
extension StringUtf8Pointer on String {
|
|
/// Creates a zero-terminated [Utf8] code-unit array from this String.
|
|
///
|
|
/// If this [String] contains NUL characters, converting it back to a string
|
|
/// using [Utf8Pointer.toDartString] will truncate the result if a length is
|
|
/// not passed.
|
|
///
|
|
/// Unpaired surrogate code points in this [String] will be encoded as
|
|
/// replacement characters (U+FFFD, encoded as the bytes 0xEF 0xBF 0xBD) in
|
|
/// the UTF-8 encoded result. See [Utf8Encoder] for details on encoding.
|
|
///
|
|
/// Returns an [allocator]-allocated pointer to the result.
|
|
Pointer<Utf8> toNativeUtf8(Allocator allocator) {
|
|
final units = utf8.encode(this);
|
|
final Pointer<Uint8> result = allocator<Uint8>(units.length + 1);
|
|
final Uint8List nativeString = result.asTypedList(units.length + 1);
|
|
nativeString.setAll(0, units);
|
|
nativeString[units.length] = 0;
|
|
return result.cast();
|
|
}
|
|
}
|