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/*
* Copyright (C) 2018 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. AND ITS CONTRIBUTORS ``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 ITS 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 "TextUtil.h"
#if ENABLE(LAYOUT_FORMATTING_CONTEXT)
#include "FontCascade.h"
#include "RenderStyle.h"
namespace WebCore {
namespace Layout {
Optional<unsigned> TextUtil::hyphenPositionBefore(const InlineItem&, unsigned, unsigned)
{
return WTF::nullopt;
}
LayoutUnit TextUtil::width(const Box& inlineBox, unsigned from, unsigned to, LayoutUnit contentLogicalLeft)
{
auto& style = inlineBox.style();
auto& font = style.fontCascade();
if (!font.size() || from == to)
return 0;
auto text = inlineBox.textContent();
ASSERT(to <= text.length());
if (font.isFixedPitch())
return fixedPitchWidth(text, style, from, to, contentLogicalLeft);
auto hasKerningOrLigatures = font.enableKerning() || font.requiresShaping();
auto measureWithEndSpace = hasKerningOrLigatures && to < text.length() && text[to] == ' ';
if (measureWithEndSpace)
++to;
LayoutUnit width;
auto tabWidth = style.collapseWhiteSpace() ? TabSize(0) : style.tabSize();
WebCore::TextRun run(StringView(text).substring(from, to - from), contentLogicalLeft);
if (tabWidth)
run.setTabSize(true, tabWidth);
width = font.width(run);
if (measureWithEndSpace)
width -= (font.spaceWidth() + font.wordSpacing());
return std::max<LayoutUnit>(0, width);
}
LayoutUnit TextUtil::fixedPitchWidth(String text, const RenderStyle& style, unsigned from, unsigned to, LayoutUnit contentLogicalLeft)
{
auto& font = style.fontCascade();
auto monospaceCharacterWidth = font.spaceWidth();
LayoutUnit width;
for (auto i = from; i < to; ++i) {
auto character = text[i];
if (character >= ' ' || character == '\n')
width += monospaceCharacterWidth;
else if (character == '\t')
width += style.collapseWhiteSpace() ? monospaceCharacterWidth : font.tabWidth(style.tabSize(), contentLogicalLeft + width);
if (i > from && (character == ' ' || character == '\t' || character == '\n'))
width += font.wordSpacing();
}
return width;
}
bool TextUtil::isTrimmableContent(const InlineItem& inlineItem)
{
if (!is<InlineTextItem>(inlineItem))
return false;
auto& inlineTextItem = downcast<InlineTextItem>(inlineItem);
return inlineTextItem.isWhitespace() && inlineTextItem.style().collapseWhiteSpace();
}
TextUtil::SplitData TextUtil::split(const Box& inlineBox, unsigned startPosition, unsigned length, LayoutUnit textWidth, LayoutUnit availableWidth, LayoutUnit contentLogicalLeft)
{
// FIXME This should take hypens into account.
ASSERT(availableWidth >= 0);
auto left = startPosition;
// Pathological case of (extremely)long string and narrow lines.
// Adjust the range so that we can pick a reasonable midpoint.
LayoutUnit averageCharacterWidth = textWidth / length;
auto right = std::min<unsigned>(left + (2 * availableWidth / averageCharacterWidth).toUnsigned(), (startPosition + length - 1));
// Preserve the left width for the final split position so that we don't need to remeasure the left side again.
LayoutUnit leftSideWidth = 0;
while (left < right) {
auto middle = (left + right) / 2;
auto width = TextUtil::width(inlineBox, startPosition, middle + 1, contentLogicalLeft);
if (width < availableWidth) {
left = middle + 1;
leftSideWidth = width;
} else if (width > availableWidth)
right = middle;
else {
right = middle + 1;
leftSideWidth = width;
break;
}
}
return { startPosition, right - startPosition, leftSideWidth };
}
}
}
#endif