Source/WebCore/platform/graphics/mac/FontComplexTextMac.cpp

   1 /*
   2  * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
   3  *
   4  * Redistribution and use in source and binary forms, with or without
   5  * modification, are permitted provided that the following conditions
   6  * are met:
   7  * 1. Redistributions of source code must retain the above copyright
   8  *    notice, this list of conditions and the following disclaimer.
   9  * 2. Redistributions in binary form must reproduce the above copyright
  10  *    notice, this list of conditions and the following disclaimer in the
  11  *    documentation and/or other materials provided with the distribution.
  12  *
  13  * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY
  14  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  16  * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY
  17  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  18  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  19  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
  20  * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  21  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  22  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  23  */
  24
  25 #include "config.h"
  26 #include "Font.h"
  27
  28 #include "ComplexTextController.h"
  29 #include "FontGlyphs.h"
  30 #include "GlyphBuffer.h"
  31 #include "GraphicsContext.h"
  32 #include "IntRect.h"
  33 #include "LayoutRect.h"
  34 #include "SimpleFontData.h"
  35 #include "TextRun.h"
  36 #include <wtf/MathExtras.h>
  37
  38 namespace WebCore {
  39
  40 void Font::adjustSelectionRectForComplexText(const TextRun& run, LayoutRect& selectionRect, unsigned from, unsigned to) const
  41 {
  42     ComplexTextController controller(this, run);
  43     controller.advance(from);
  44     float beforeWidth = controller.runWidthSoFar();
  45     controller.advance(to);
  46     float afterWidth = controller.runWidthSoFar();
  47
  48     if (run.rtl())
  49         selectionRect.move(controller.totalWidth() - afterWidth, 0);
  50     else
  51         selectionRect.move(beforeWidth, 0);
  52     selectionRect.setWidth(afterWidth - beforeWidth);
  53 }
  54
  55 float Font::getGlyphsAndAdvancesForComplexText(const TextRun& run, unsigned from, unsigned to, GlyphBuffer& glyphBuffer, ForTextEmphasisOrNot forTextEmphasis) const
  56 {
  57     float initialAdvance;
  58
  59     ComplexTextController controller(this, run, false, 0, forTextEmphasis);
  60     controller.advance(from);
  61     float beforeWidth = controller.runWidthSoFar();
  62     controller.advance(to, &glyphBuffer);
  63
  64     if (glyphBuffer.isEmpty())
  65         return 0;
  66
  67     float afterWidth = controller.runWidthSoFar();
  68
  69     if (run.rtl()) {
  70         initialAdvance = controller.totalWidth() + controller.finalRoundingWidth() - afterWidth;
  71         glyphBuffer.reverse(0, glyphBuffer.size());
  72     } else
  73         initialAdvance = beforeWidth;
  74
  75     return initialAdvance;
  76 }
  77
  78 float Font::drawComplexText(GraphicsContext* context, const TextRun& run, const FloatPoint& point, unsigned from, unsigned to) const
  79 {
  80     // This glyph buffer holds our glyphs + advances + font data for each glyph.
  81     GlyphBuffer glyphBuffer;
  82
  83     float startX = point.x() + getGlyphsAndAdvancesForComplexText(run, from, to, glyphBuffer);
  84
  85     // We couldn't generate any glyphs for the run.  Give up.
  86     if (glyphBuffer.isEmpty())
  87         return 0;
  88
  89     // Draw the glyph buffer now at the starting point returned in startX.
  90     FloatPoint startPoint(startX, point.y());
  91     drawGlyphBuffer(context, run, glyphBuffer, startPoint);
  92
  93     return startPoint.x() - startX;
  94 }
  95
  96 void Font::drawEmphasisMarksForComplexText(GraphicsContext* context, const TextRun& run, const AtomicString& mark, const FloatPoint& point, unsigned from, unsigned to) const
  97 {
  98     GlyphBuffer glyphBuffer;
  99     float initialAdvance = getGlyphsAndAdvancesForComplexText(run, from, to, glyphBuffer, ForTextEmphasis);
 100
 101     if (glyphBuffer.isEmpty())
 102         return;
 103
 104     drawEmphasisMarks(context, run, glyphBuffer, mark, FloatPoint(point.x() + initialAdvance, point.y()));
 105 }
 106
 107 float Font::floatWidthForComplexText(const TextRun& run, HashSet<const SimpleFontData*>* fallbackFonts, GlyphOverflow* glyphOverflow) const
 108 {
 109     ComplexTextController controller(this, run, true, fallbackFonts);
 110     if (glyphOverflow) {
 111         glyphOverflow->top = std::max<int>(glyphOverflow->top, ceilf(-controller.minGlyphBoundingBoxY()) - (glyphOverflow->computeBounds ? 0 : fontMetrics().ascent()));
 112         glyphOverflow->bottom = std::max<int>(glyphOverflow->bottom, ceilf(controller.maxGlyphBoundingBoxY()) - (glyphOverflow->computeBounds ? 0 : fontMetrics().descent()));
 113         glyphOverflow->left = std::max<int>(0, ceilf(-controller.minGlyphBoundingBoxX()));
 114         glyphOverflow->right = std::max<int>(0, ceilf(controller.maxGlyphBoundingBoxX() - controller.totalWidth()));
 115     }
 116     return controller.totalWidth();
 117 }
 118
 119 int Font::offsetForPositionForComplexText(const TextRun& run, float x, bool includePartialGlyphs) const
 120 {
 121     ComplexTextController controller(this, run);
 122     return controller.offsetForPosition(x, includePartialGlyphs);
 123 }
 124
 125 const SimpleFontData* Font::fontDataForCombiningCharacterSequence(const UChar* characters, size_t length, FontDataVariant variant) const
 126 {
 127     UChar32 baseCharacter;
 128     size_t baseCharacterLength = 0;
 129     U16_NEXT(characters, baseCharacterLength, length, baseCharacter);
 130
 131     GlyphData baseCharacterGlyphData = glyphDataForCharacter(baseCharacter, false, variant);
 132
 133     if (!baseCharacterGlyphData.glyph)
 134         return 0;
 135
 136     if (length == baseCharacterLength)
 137         return baseCharacterGlyphData.fontData;
 138
 139     bool triedBaseCharacterFontData = false;
 140
 141     unsigned i = 0;
 142     for (const FontData* fontData = fontDataAt(0); fontData; fontData = fontDataAt(++i)) {
 143         const SimpleFontData* simpleFontData = fontData->fontDataForCharacter(baseCharacter);
 144 #if PLATFORM(IOS)
 145         if (baseCharacter >= 0x0600 && baseCharacter <= 0x06ff && simpleFontData->shouldNotBeUsedForArabic())
 146             continue;
 147 #endif
 148         if (variant == NormalVariant) {
 149             if (simpleFontData->platformData().orientation() == Vertical) {
 150                 if (isCJKIdeographOrSymbol(baseCharacter) && !simpleFontData->hasVerticalGlyphs()) {
 151                     variant = BrokenIdeographVariant;
 152                     simpleFontData = simpleFontData->brokenIdeographFontData().get();
 153                 } else if (m_fontDescription.nonCJKGlyphOrientation() == NonCJKGlyphOrientationVerticalRight) {
 154                     SimpleFontData* verticalRightFontData = simpleFontData->verticalRightOrientationFontData().get();
 155                     Glyph verticalRightGlyph = verticalRightFontData->glyphForCharacter(baseCharacter);
 156                     if (verticalRightGlyph == baseCharacterGlyphData.glyph)
 157                         simpleFontData = verticalRightFontData;
 158                 } else {
 159                     SimpleFontData* uprightFontData = simpleFontData->uprightOrientationFontData().get();
 160                     Glyph uprightGlyph = uprightFontData->glyphForCharacter(baseCharacter);
 161                     if (uprightGlyph != baseCharacterGlyphData.glyph)
 162                         simpleFontData = uprightFontData;
 163                 }
 164             }
 165         } else {
 166             if (const SimpleFontData* variantFontData = simpleFontData->variantFontData(m_fontDescription, variant).get())
 167                 simpleFontData = variantFontData;
 168         }
 169
 170         if (simpleFontData == baseCharacterGlyphData.fontData)
 171             triedBaseCharacterFontData = true;
 172
 173         if (simpleFontData->canRenderCombiningCharacterSequence(characters, length))
 174             return simpleFontData;
 175     }
 176
 177     if (!triedBaseCharacterFontData && baseCharacterGlyphData.fontData && baseCharacterGlyphData.fontData->canRenderCombiningCharacterSequence(characters, length))
 178         return baseCharacterGlyphData.fontData;
 179
 180     return SimpleFontData::systemFallback();
 181 }
 182
 183 } // namespace WebCore