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#pragma once
21
22#include "Path.h"
23#include "SVGTextChunkBuilder.h"
24#include "SVGTextFragment.h"
25#include "SVGTextLayoutAttributes.h"
26
27namespace WebCore {
28
29class RenderObject;
30class RenderStyle;
31class RenderSVGInlineText;
32class RenderSVGTextPath;
33class SVGElement;
34class SVGInlineTextBox;
35class SVGRenderStyle;
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
45class SVGTextLayoutEngine {
46 WTF_MAKE_NONCOPYABLE(SVGTextLayoutEngine);
47public:
48 SVGTextLayoutEngine(Vector<SVGTextLayoutAttributes*>&);
49
50 Vector<SVGTextLayoutAttributes*>& layoutAttributes() { return m_layoutAttributes; }
51 SVGTextChunkBuilder& chunkLayoutBuilder() { return m_chunkLayoutBuilder; }
52
53 void beginTextPathLayout(RenderSVGTextPath&, SVGTextLayoutEngine& lineLayout);
54 void endTextPathLayout();
55
56 void layoutInlineTextBox(SVGInlineTextBox&);
57 void finishLayout();
58
59private:
60 void updateCharacerPositionIfNeeded(float& x, float& y);
61 void updateCurrentTextPosition(float x, float y, float glyphAdvance);
62 void updateRelativePositionAdjustmentsIfNeeded(float dx, float dy);
63
64 void recordTextFragment(SVGInlineTextBox&, Vector<SVGTextMetrics>&);
65 bool parentDefinesTextLength(RenderObject*) const;
66
67 void layoutTextOnLineOrPath(SVGInlineTextBox&, RenderSVGInlineText&, const RenderStyle&);
68 void finalizeTransformMatrices(Vector<SVGInlineTextBox*>&);
69
70 bool currentLogicalCharacterAttributes(SVGTextLayoutAttributes*&);
71 bool currentLogicalCharacterMetrics(SVGTextLayoutAttributes*&, SVGTextMetrics&);
72 bool currentVisualCharacterMetrics(const SVGInlineTextBox&, Vector<SVGTextMetrics>&, SVGTextMetrics&);
73
74 void advanceToNextLogicalCharacter(const SVGTextMetrics&);
75 void advanceToNextVisualCharacter(const SVGTextMetrics&);
76
77private:
78 Vector<SVGTextLayoutAttributes*>& m_layoutAttributes;
79
80 Vector<SVGInlineTextBox*> m_lineLayoutBoxes;
81 Vector<SVGInlineTextBox*> m_pathLayoutBoxes;
82 SVGTextChunkBuilder m_chunkLayoutBuilder;
83
84 SVGTextFragment m_currentTextFragment;
85 unsigned m_layoutAttributesPosition;
86 unsigned m_logicalCharacterOffset;
87 unsigned m_logicalMetricsListOffset;
88 unsigned m_visualCharacterOffset;
89 unsigned m_visualMetricsListOffset;
90 float m_x;
91 float m_y;
92 float m_dx;
93 float m_dy;
94 bool m_isVerticalText;
95 bool m_inPathLayout;
96
97 // Text on path layout
98 Path m_textPath;
99 float m_textPathLength;
100 float m_textPathStartOffset;
101 float m_textPathCurrentOffset;
102 float m_textPathSpacing;
103 float m_textPathScaling;
104};
105
106} // namespace WebCore
107