InlineTextItem.cpp [plain text]
#include "config.h"
#include "InlineTextItem.h"
#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
#include "FontCascade.h"
#include "InlineSoftLineBreakItem.h"
#include "TextUtil.h"
#include <wtf/unicode/CharacterNames.h>
namespace WebCore {
namespace Layout {
static_assert(sizeof(InlineItem) == sizeof(InlineTextItem), "");
static inline bool isWhitespaceCharacter(UChar character, bool preserveNewline)
{
return character == ' ' || character == '\t' || (character == '\n' && !preserveNewline);
}
static unsigned moveToNextNonWhitespacePosition(const StringView& textContent, unsigned startPosition, bool preserveNewline)
{
auto nextNonWhiteSpacePosition = startPosition;
while (nextNonWhiteSpacePosition < textContent.length() && isWhitespaceCharacter(textContent[nextNonWhiteSpacePosition], preserveNewline))
++nextNonWhiteSpacePosition;
return nextNonWhiteSpacePosition - startPosition;
}
static unsigned moveToNextBreakablePosition(unsigned startPosition, LazyLineBreakIterator& lineBreakIterator, const RenderStyle& style)
{
auto textLength = lineBreakIterator.stringView().length();
auto startPositionForNextBreakablePosition = startPosition;
while (startPositionForNextBreakablePosition < textLength) {
auto nextBreakablePosition = TextUtil::findNextBreakablePosition(lineBreakIterator, startPositionForNextBreakablePosition, style);
if (nextBreakablePosition != startPosition)
return nextBreakablePosition - startPosition;
++startPositionForNextBreakablePosition;
}
return textLength - startPosition;
}
void InlineTextItem::createAndAppendTextItems(InlineItems& inlineContent, const InlineTextBox& inlineTextBox)
{
auto text = inlineTextBox.content();
if (!text.length())
return inlineContent.append(InlineTextItem::createEmptyItem(inlineTextBox));
auto& style = inlineTextBox.style();
auto& font = style.fontCascade();
LazyLineBreakIterator lineBreakIterator(text);
unsigned currentPosition = 0;
auto inlineItemWidth = [&](auto startPosition, auto length) -> Optional<InlineLayoutUnit> {
if (!inlineTextBox.canUseSimplifiedContentMeasuring())
return { };
return TextUtil::width(inlineTextBox, startPosition, startPosition + length);
};
while (currentPosition < text.length()) {
auto isSegmentBreakCandidate = [](auto character) {
return character == '\n';
};
if (isSegmentBreakCandidate(text[currentPosition]) && style.preserveNewline()) {
inlineContent.append(InlineSoftLineBreakItem::createSoftLineBreakItem(inlineTextBox, currentPosition));
++currentPosition;
continue;
}
if (isWhitespaceCharacter(text[currentPosition], style.preserveNewline())) {
auto appendWhitespaceItem = [&] (auto startPosition, auto itemLength) {
auto simpleSingleWhitespaceContent = inlineTextBox.canUseSimplifiedContentMeasuring() && (itemLength == 1 || style.collapseWhiteSpace());
auto width = simpleSingleWhitespaceContent ? makeOptional(InlineLayoutUnit { font.spaceWidth() }) : inlineItemWidth(startPosition, itemLength);
inlineContent.append(InlineTextItem::createWhitespaceItem(inlineTextBox, startPosition, itemLength, width));
};
auto length = moveToNextNonWhitespacePosition(text, currentPosition, style.preserveNewline());
if (style.whiteSpace() == WhiteSpace::BreakSpaces) {
for (unsigned i = 0; i < length; ++i)
appendWhitespaceItem(currentPosition + i, 1);
} else
appendWhitespaceItem(currentPosition, length);
currentPosition += length;
continue;
}
auto length = moveToNextBreakablePosition(currentPosition, lineBreakIterator, style);
inlineContent.append(InlineTextItem::createNonWhitespaceItem(inlineTextBox, currentPosition, length, inlineItemWidth(currentPosition, length)));
currentPosition += length;
}
}
bool InlineTextItem::isEmptyContent() const
{
return !m_length || (m_length == 1 && inlineTextBox().content()[start()] == zeroWidthSpace);
}
}
}
#endif