1 /* 2 * Copyright (C) Research In Motion Limited 2010-2012. All rights reserved. 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Library General Public 6 * License as published by the Free Software Foundation; either 7 * version 2 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Library General Public License for more details. 13 * 14 * You should have received a copy of the GNU Library General Public License 15 * along with this library; see the file COPYING.LIB. If not, write to 16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 17 * Boston, MA 02110-1301, USA. 18 */ 19 20 #ifndef SVGTextLayoutEngine_h 21 #define SVGTextLayoutEngine_h 22 23 #include "core/rendering/svg/SVGTextChunkBuilder.h" 24 #include "core/rendering/svg/SVGTextFragment.h" 25 #include "core/rendering/svg/SVGTextLayoutAttributes.h" 26 #include "core/rendering/svg/SVGTextMetrics.h" 27 #include "platform/graphics/Path.h" 28 #include "wtf/Vector.h" 29 30 namespace blink { 31 32 class RenderObject; 33 class RenderStyle; 34 class RenderSVGInlineText; 35 class SVGInlineTextBox; 36 37 // SVGTextLayoutEngine performs the second layout phase for SVG text. 38 // 39 // The InlineBox tree was created, containing the text chunk information, necessary to apply 40 // certain SVG specific text layout properties (text-length adjustments and text-anchor). 41 // The second layout phase uses the SVGTextLayoutAttributes stored in the individual 42 // RenderSVGInlineText renderers to compute the final positions for each character 43 // which are stored in the SVGInlineTextBox objects. 44 45 class SVGTextLayoutEngine { 46 WTF_MAKE_NONCOPYABLE(SVGTextLayoutEngine); 47 public: 48 SVGTextLayoutEngine(Vector<SVGTextLayoutAttributes*>&); 49 50 Vector<SVGTextLayoutAttributes*>& layoutAttributes() { return m_layoutAttributes; } 51 52 void beginTextPathLayout(RenderObject*, SVGTextLayoutEngine& lineLayout); 53 void endTextPathLayout(); 54 55 void layoutInlineTextBox(SVGInlineTextBox*); 56 void finishLayout(); 57 58 private: 59 void updateCharacterPositionIfNeeded(float& x, float& y); 60 void updateCurrentTextPosition(float x, float y, float glyphAdvance); 61 void updateRelativePositionAdjustmentsIfNeeded(float dx, float dy); 62 63 void recordTextFragment(SVGInlineTextBox*, const Vector<SVGTextMetrics>&); 64 bool parentDefinesTextLength(RenderObject*) const; 65 66 void layoutTextOnLineOrPath(SVGInlineTextBox*, const RenderSVGInlineText&, const RenderStyle&); 67 void finalizeTransformMatrices(Vector<SVGInlineTextBox*>&); 68 69 bool currentLogicalCharacterAttributes(SVGTextLayoutAttributes*&); 70 bool currentLogicalCharacterMetrics(SVGTextLayoutAttributes*&, SVGTextMetrics&); 71 bool currentVisualCharacterMetrics(SVGInlineTextBox*, const Vector<SVGTextMetrics>&, SVGTextMetrics&); 72 73 void advanceToNextLogicalCharacter(const SVGTextMetrics&); 74 void advanceToNextVisualCharacter(const SVGTextMetrics&); 75 76 private: 77 Vector<SVGTextLayoutAttributes*>& m_layoutAttributes; 78 79 Vector<SVGInlineTextBox*> m_lineLayoutBoxes; 80 Vector<SVGInlineTextBox*> m_pathLayoutBoxes; 81 SVGTextChunkBuilder m_chunkLayoutBuilder; 82 83 SVGTextFragment m_currentTextFragment; 84 unsigned m_layoutAttributesPosition; 85 unsigned m_logicalCharacterOffset; 86 unsigned m_logicalMetricsListOffset; 87 unsigned m_visualCharacterOffset; 88 unsigned m_visualMetricsListOffset; 89 float m_x; 90 float m_y; 91 float m_dx; 92 float m_dy; 93 bool m_isVerticalText; 94 bool m_inPathLayout; 95 96 // Text on path layout 97 Path::PositionCalculator* m_textPathCalculator; 98 float m_textPathLength; 99 float m_textPathStartOffset; 100 float m_textPathCurrentOffset; 101 float m_textPathSpacing; 102 float m_textPathScaling; 103 }; 104 105 } // namespace blink 106 107 #endif 108
