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/*
* Copyright (C) 2011 Apple Inc. All rights reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public License
* along with this library; see the file COPYING.LIB. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
* Boston, MA 02110-1301, USA.
*
*/
#include "config.h"
#include "RenderCombineText.h"
#include "TextRun.h"
namespace WebCore {
const float textCombineMargin = 1.1f; // Allow em + 10% margin
RenderCombineText::RenderCombineText(Node* node, PassRefPtr<StringImpl> string)
: RenderText(node, string)
, m_combinedTextWidth(0)
, m_isCombined(false)
, m_needsFontUpdate(false)
{
}
void RenderCombineText::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
{
RenderText::styleDidChange(diff, oldStyle);
if (m_isCombined)
RenderText::setTextInternal(originalText()); // This RenderCombineText has been combined once. Restore the original text for the next combineText().
m_needsFontUpdate = true;
}
void RenderCombineText::setTextInternal(PassRefPtr<StringImpl> text)
{
RenderText::setTextInternal(text);
m_needsFontUpdate = true;
}
float RenderCombineText::width(unsigned from, unsigned length, const Font& font, float xPosition, HashSet<const SimpleFontData*>* fallbackFonts, GlyphOverflow* glyphOverflow) const
{
if (!characters())
return 0;
if (m_isCombined)
return font.size();
return RenderText::width(from, length, font, xPosition, fallbackFonts, glyphOverflow);
}
void RenderCombineText::adjustTextOrigin(FloatPoint& textOrigin, const FloatRect& boxRect) const
{
if (m_isCombined)
textOrigin.move(boxRect.height() / 2 - ceilf(m_combinedTextWidth) / 2, style()->font().pixelSize());
}
void RenderCombineText::charactersToRender(int start, const UChar*& characters, int& length) const
{
if (m_isCombined) {
length = originalText()->length();
characters = originalText()->characters();
return;
}
characters = text()->characters() + start;
}
void RenderCombineText::combineText()
{
if (!m_needsFontUpdate)
return;
m_isCombined = false;
m_needsFontUpdate = false;
// CSS3 spec says text-combine works only in vertical writing mode.
if (style()->isHorizontalWritingMode())
return;
TextRun run = TextRun(String(text()));
FontDescription description = style()->font().fontDescription();
float emWidth = description.computedSize() * textCombineMargin;
bool shouldUpdateFont = false;
description.setOrientation(Horizontal); // We are going to draw combined text horizontally.
m_combinedTextWidth = style()->font().width(run);
m_isCombined = m_combinedTextWidth <= emWidth;
if (m_isCombined)
shouldUpdateFont = style()->setFontDescription(description); // Need to change font orientation to horizontal.
else {
// Need to try compressed glyphs.
static const FontWidthVariant widthVariants[] = { HalfWidth, ThirdWidth, QuarterWidth };
for (size_t i = 0 ; i < WTF_ARRAY_LENGTH(widthVariants) ; ++i) {
description.setWidthVariant(widthVariants[i]);
Font compressedFont = Font(description, style()->font().letterSpacing(), style()->font().wordSpacing());
compressedFont.update(style()->font().fontSelector());
float runWidth = compressedFont.width(run);
if (runWidth <= emWidth) {
m_combinedTextWidth = runWidth;
m_isCombined = true;
// Replace my font with the new one.
shouldUpdateFont = style()->setFontDescription(description);
break;
}
}
}
if (shouldUpdateFont)
style()->font().update(style()->font().fontSelector());
if (m_isCombined) {
static const UChar newCharacter = objectReplacementCharacter;
DEFINE_STATIC_LOCAL(String, objectReplacementCharacterString, (&newCharacter, 1));
RenderText::setTextInternal(objectReplacementCharacterString.impl());
}
}
} // namespace WebCore
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