gecko-dev/intl/lwbrk/nsPangoBreaker.cpp

62 строки
2.2 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsComplexBreaker.h"
#include <pango/pango-break.h>
#include "nsUTF8Utils.h"
#include "nsString.h"
#include "nsTArray.h"
void NS_GetComplexLineBreaks(const char16_t* aText, uint32_t aLength,
uint8_t* aBreakBefore) {
NS_ASSERTION(aText, "aText shouldn't be null");
memset(aBreakBefore, uint8_t(false), aLength * sizeof(uint8_t));
AutoTArray<PangoLogAttr, 2000> attrBuffer;
// XXX(Bug 1631371) Check if this should use a fallible operation as it
// pretended earlier.
attrBuffer.AppendElements(aLength + 1);
// `PangoLogAttr` doesn't have a default constructor (it is a C struct), so
// we need to manually initialize the new elements. See bug 1808182.
memset(attrBuffer.Elements(), 0, attrBuffer.Length() * sizeof(PangoLogAttr));
NS_ConvertUTF16toUTF8 aUTF8(aText, aLength);
const gchar* p = aUTF8.Data();
const gchar* end = p + aUTF8.Length();
uint32_t u16Offset = 0;
static PangoLanguage* language = pango_language_from_string("en");
while (p < end) {
PangoLogAttr* attr = attrBuffer.Elements();
pango_get_log_attrs(p, end - p, -1, language, attr, attrBuffer.Length());
while (p < end) {
aBreakBefore[u16Offset] = attr->is_line_break;
if (NS_IS_LOW_SURROGATE(aText[u16Offset]))
aBreakBefore[++u16Offset] = false; // Skip high surrogate
++u16Offset;
// We're iterating over text obtained from NS_ConvertUTF16toUTF8,
// so we know we have valid UTF-8 and don't need to check for
// errors.
uint32_t ch = UTF8CharEnumerator::NextChar(&p, end);
++attr;
if (!ch) {
// pango_break (pango 1.16.2) only analyses text before the
// first NUL (but sets one extra attr). Workaround loop to call
// pango_break again to analyse after the NUL is done somewhere else
// (gfx/thebes/gfxFontconfigFonts.cpp: SetupClusterBoundaries()).
// So, we do the same here for pango_get_log_attrs.
break;
}
}
}
}