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/*
* Copyright (C) 2024 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
* CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "config.h"
#include "TextSpacing.h"
#include "Font.h"
namespace WebCore {
using namespace TextSpacing;
bool TextSpacingTrim::shouldTrimSpacing(const CharactersData& charactersData) const
{
switch (m_trim) {
case TrimType::SpaceAll:
return false;
case TrimType::Auto:
return false;
case TrimType::TrimAll:
return charactersData.currentCharacterClass == CharacterClass::FullWidthOpeningPunctuation || charactersData.currentCharacterClass == CharacterClass::FullWidthClosingPunctuation || charactersData.currentCharacterClass == CharacterClass::FullWidthMiddleDotPunctuation;
default:
return false;
}
}
bool TextAutospace::shouldApplySpacing(CharacterClass firstCharacterClass, CharacterClass secondCharacterClass) const
{
constexpr uint8_t ideographAlphaMask = static_cast<uint8_t>(CharacterClass::Ideograph) | static_cast<uint8_t>(CharacterClass::NonIdeographLetter);
constexpr uint8_t ideographNumericMask = static_cast<uint8_t>(CharacterClass::Ideograph) | static_cast<uint8_t>(CharacterClass::NonIdeographNumeral);
uint8_t characterClassesMask = (static_cast<uint8_t>(firstCharacterClass) | static_cast<uint8_t>(secondCharacterClass));
if (hasIdeographAlpha() && characterClassesMask == ideographAlphaMask)
return true;
if (hasIdeographNumeric() && characterClassesMask == ideographNumericMask)
return true;
return false;
}
bool TextAutospace::shouldApplySpacing(char32_t firstCharacter, char32_t secondCharacter) const
{
return shouldApplySpacing(TextSpacing::characterClass(firstCharacter), TextSpacing::characterClass(secondCharacter));
}
float TextAutospace::textAutospaceSize(const Font& font)
{
// https://www.w3.org/TR/css-text-4/#text-autospace-property
// The amount of space introduced by these keywords is 1/8 of the CJK advance measure, i.e 0.125ic.
return 0.125 * font.fontMetrics().ideogramWidth().value_or(0);
}
namespace TextSpacing {
bool isIdeograph(char32_t character)
{
// Lowest possible ideographic codepoint
if (character < 0x2E80)
return false;
// All characters in the range of U+3041 to U+30FF, except those that belong to Unicode Punctuation [P*]
if ((character >= 0x3041 && character <= 0x30FF) && !isPunctuation(character))
return true;
// CJK Strokes (U+31C0 to U+31EF).
if (character >= 0x31C0 && character <= 0x31EF)
return true;
// Katakana Phonetic Extensions (U+31F0 to U+31FF)
if (character >= 0x31F0 && character <= 0x31FF)
return true;
if (isOfScriptType(character, UScriptCode::USCRIPT_HAN))
return true;
return false;
}
static bool isNonIdeographicNumeral(char32_t character, uint32_t generalCategoryMask)
{
// FIXME: Should also check that it is not: upright in vertical text flow using the text-orientation property or the text-combine-upright property.
return (generalCategoryMask & U_GC_ND_MASK) && !isEastAsianFullWidth(character);
}
// Classes are defined at https://www.w3.org/TR/css-text-4/#text-spacing-classes
CharacterClass characterClass(char32_t character)
{
auto generalCategoryMask = U_GET_GC_MASK(character);
if (isIdeograph(character))
return CharacterClass::Ideograph;
// We already know it is not an Ideograph from here
// FIXME: Should also check that it is not: upright in vertical text flow using the text-orientation property or the text-combine-upright property.
if (generalCategoryMask & (U_GC_M_MASK | U_GC_L_MASK)) {
if (!isEastAsianFullWidth(character))
return CharacterClass::NonIdeographLetter;
// General Category M/L won't apply to anything else
return CharacterClass::Undefined;
}
if (isNonIdeographicNumeral(character, generalCategoryMask))
return CharacterClass::NonIdeographNumeral;
if (generalCategoryMask & U_GC_P_MASK) {
if (isCJKSymbolOrPunctuation(character) || isEastAsianFullWidth(character)) {
if (isOpeningPunctuation(generalCategoryMask))
return CharacterClass::FullWidthOpeningPunctuation;
if (isClosingPunctuation(generalCategoryMask))
return CharacterClass::FullWidthClosingPunctuation;
}
if (character == leftSingleQuotationMark || character == leftDoubleQuotationMark)
return CharacterClass::FullWidthOpeningPunctuation;
if (character == rightSingleQuotationMark || character == rightDoubleQuotationMark)
return CharacterClass::FullWidthClosingPunctuation;
}
if (isFullwidthMiddleDotPunctuation(character))
return CharacterClass::FullWidthMiddleDotPunctuation;
// FIXME: implement remaining classes for text-autospace: punctuation
return CharacterClass::Undefined;
}
RefPtr<Font> getHalfWidthFontIfNeeded(const Font& font, const TextSpacingTrim& textSpacingTrim, CharactersData& charactersData)
{
return textSpacingTrim.shouldTrimSpacing(charactersData) ? font.halfWidthFont() : nullptr;
}
} // namespace TextSpacing
} // namespace WebCore
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