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 SVGTextLayoutAttributesBuilder_h
21#define SVGTextLayoutAttributesBuilder_h
22
23#include "SVGTextMetricsBuilder.h"
24
25namespace WebCore {
26
27class RenderObject;
28class RenderSVGInlineText;
29class RenderSVGText;
30class SVGTextPositioningElement;
31
32// SVGTextLayoutAttributesBuilder performs the first layout phase for SVG text.
33//
34// It extracts the x/y/dx/dy/rotate values from the SVGTextPositioningElements in the DOM.
35// These values are propagated to the corresponding RenderSVGInlineText renderers.
36// The first layout phase only extracts the relevant information needed in RenderBlockLineLayout
37// to create the InlineBox tree based on text chunk boundaries & BiDi information.
38// The second layout phase is carried out by SVGTextLayoutEngine.
39
40class SVGTextLayoutAttributesBuilder {
41    WTF_MAKE_NONCOPYABLE(SVGTextLayoutAttributesBuilder);
42public:
43    SVGTextLayoutAttributesBuilder();
44    bool buildLayoutAttributesForForSubtree(RenderSVGText*);
45    void buildLayoutAttributesForTextRenderer(RenderSVGInlineText&);
46
47    void rebuildMetricsForTextRenderer(RenderSVGInlineText*);
48
49    // Invoked whenever the underlying DOM tree changes, so that m_textPositions is rebuild.
50    void clearTextPositioningElements() { m_textPositions.clear(); }
51    unsigned numberOfTextPositioningElements() const { return m_textPositions.size(); }
52
53private:
54    struct TextPosition {
55        TextPosition(SVGTextPositioningElement* newElement = 0, unsigned newStart = 0, unsigned newLength = 0)
56            : element(newElement)
57            , start(newStart)
58            , length(newLength)
59        {
60        }
61
62        SVGTextPositioningElement* element;
63        unsigned start;
64        unsigned length;
65    };
66
67    void buildCharacterDataMap(RenderSVGText*);
68    void collectTextPositioningElements(RenderObject*, bool& lastCharacterWasSpace);
69    void fillCharacterDataMap(const TextPosition&);
70
71private:
72    unsigned m_textLength;
73    Vector<TextPosition> m_textPositions;
74    SVGCharacterDataMap m_characterDataMap;
75    SVGTextMetricsBuilder m_metricsBuilder;
76};
77
78} // namespace WebCore
79
80#endif
81