1 files changed, 135 insertions, 0 deletions
diff --git a/Source/WebCore/rendering/RenderCombineText.cpp b/Source/WebCore/rendering/RenderCombineText.cpp
new file mode 100644
index 0000000..1b20bd8
--- /dev/null
+++ b/Source/WebCore/rendering/RenderCombineText.cpp
@@ -0,0 +1,135 @@
+/*
+ * 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;
+}
+
+unsigned RenderCombineText::width(unsigned from, unsigned length, const Font& font, int 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(IntPoint& textOrigin, const IntRect& 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().floatWidth(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.floatWidth(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