1/*
2 * Copyright (C) Research In Motion Limited 2010-2011. 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#include "config.h"
21
22#include "core/rendering/svg/SVGTextLayoutAttributesBuilder.h"
23
24#include "core/rendering/svg/RenderSVGInlineText.h"
25#include "core/rendering/svg/RenderSVGText.h"
26#include "core/rendering/svg/SVGTextMetricsBuilder.h"
27#include "core/svg/SVGTextPositioningElement.h"
28
29namespace blink {
30
31SVGTextLayoutAttributesBuilder::SVGTextLayoutAttributesBuilder()
32    : m_textLength(0)
33{
34}
35
36void SVGTextLayoutAttributesBuilder::buildLayoutAttributesForTextRenderer(RenderSVGInlineText* text)
37{
38    ASSERT(text);
39
40    RenderSVGText* textRoot = RenderSVGText::locateRenderSVGTextAncestor(text);
41    if (!textRoot)
42        return;
43
44    if (m_textPositions.isEmpty()) {
45        m_characterDataMap.clear();
46
47        m_textLength = 0;
48        UChar lastCharacter = ' ';
49        collectTextPositioningElements(textRoot, lastCharacter);
50
51        if (!m_textLength)
52            return;
53
54        buildCharacterDataMap(textRoot);
55    }
56
57    SVGTextMetricsBuilder::buildMetricsAndLayoutAttributes(textRoot, text, m_characterDataMap);
58}
59
60bool SVGTextLayoutAttributesBuilder::buildLayoutAttributesForForSubtree(RenderSVGText* textRoot)
61{
62    ASSERT(textRoot);
63
64    m_characterDataMap.clear();
65
66    if (m_textPositions.isEmpty()) {
67        m_textLength = 0;
68        UChar lastCharacter = ' ';
69        collectTextPositioningElements(textRoot, lastCharacter);
70    }
71
72    if (!m_textLength)
73        return false;
74
75    buildCharacterDataMap(textRoot);
76    SVGTextMetricsBuilder::buildMetricsAndLayoutAttributes(textRoot, 0, m_characterDataMap);
77    return true;
78}
79
80void SVGTextLayoutAttributesBuilder::rebuildMetricsForTextRenderer(RenderSVGInlineText* text)
81{
82    ASSERT(text);
83    SVGTextMetricsBuilder::measureTextRenderer(text);
84}
85
86static inline void processRenderSVGInlineText(RenderSVGInlineText* text, unsigned& atCharacter, UChar& lastCharacter)
87{
88    if (text->style()->whiteSpace() == PRE) {
89        atCharacter += text->textLength();
90        return;
91    }
92
93    unsigned textLength = text->textLength();
94    for (unsigned textPosition = 0; textPosition < textLength; ++textPosition) {
95        UChar currentCharacter = text->characterAt(textPosition);
96        if (currentCharacter == ' ' && lastCharacter == ' ')
97            continue;
98
99        lastCharacter = currentCharacter;
100        ++atCharacter;
101    }
102}
103
104void SVGTextLayoutAttributesBuilder::collectTextPositioningElements(RenderObject* start, UChar& lastCharacter)
105{
106    ASSERT(!start->isSVGText() || m_textPositions.isEmpty());
107
108    for (RenderObject* child = start->slowFirstChild(); child; child = child->nextSibling()) {
109        if (child->isSVGInlineText()) {
110            processRenderSVGInlineText(toRenderSVGInlineText(child), m_textLength, lastCharacter);
111            continue;
112        }
113
114        if (!child->isSVGInline())
115            continue;
116
117        SVGTextPositioningElement* element = SVGTextPositioningElement::elementFromRenderer(child);
118        unsigned atPosition = m_textPositions.size();
119        if (element)
120            m_textPositions.append(TextPosition(element, m_textLength));
121
122        collectTextPositioningElements(child, lastCharacter);
123
124        if (!element)
125            continue;
126
127        // Update text position, after we're back from recursion.
128        TextPosition& position = m_textPositions[atPosition];
129        ASSERT(!position.length);
130        position.length = m_textLength - position.start;
131    }
132}
133
134void SVGTextLayoutAttributesBuilder::buildCharacterDataMap(RenderSVGText* textRoot)
135{
136    SVGTextPositioningElement* outermostTextElement = SVGTextPositioningElement::elementFromRenderer(textRoot);
137    ASSERT(outermostTextElement);
138
139    // Grab outermost <text> element value lists and insert them in the character data map.
140    TextPosition wholeTextPosition(outermostTextElement, 0, m_textLength);
141    fillCharacterDataMap(wholeTextPosition);
142
143    // Handle x/y default attributes.
144    SVGCharacterDataMap::iterator it = m_characterDataMap.find(1);
145    if (it == m_characterDataMap.end()) {
146        SVGCharacterData data;
147        data.x = 0;
148        data.y = 0;
149        m_characterDataMap.set(1, data);
150    } else {
151        SVGCharacterData& data = it->value;
152        if (data.x == SVGTextLayoutAttributes::emptyValue())
153            data.x = 0;
154        if (data.y == SVGTextLayoutAttributes::emptyValue())
155            data.y = 0;
156    }
157
158    // Fill character data map using child text positioning elements in top-down order.
159    unsigned size = m_textPositions.size();
160    for (unsigned i = 0; i < size; ++i)
161        fillCharacterDataMap(m_textPositions[i]);
162}
163
164static inline void updateCharacterData(unsigned i, float& lastRotation, SVGCharacterData& data, const SVGLengthContext& lengthContext, const SVGLengthList* xList, const SVGLengthList* yList, const SVGLengthList* dxList, const SVGLengthList* dyList, const SVGNumberList* rotateList)
165{
166    if (xList)
167        data.x = xList->at(i)->value(lengthContext);
168    if (yList)
169        data.y = yList->at(i)->value(lengthContext);
170    if (dxList)
171        data.dx = dxList->at(i)->value(lengthContext);
172    if (dyList)
173        data.dy = dyList->at(i)->value(lengthContext);
174    if (rotateList) {
175        data.rotate = rotateList->at(i)->value();
176        lastRotation = data.rotate;
177    }
178}
179
180void SVGTextLayoutAttributesBuilder::fillCharacterDataMap(const TextPosition& position)
181{
182    RefPtr<SVGLengthList> xList = position.element->x()->currentValue();
183    RefPtr<SVGLengthList> yList = position.element->y()->currentValue();
184    RefPtr<SVGLengthList> dxList = position.element->dx()->currentValue();
185    RefPtr<SVGLengthList> dyList = position.element->dy()->currentValue();
186    RefPtr<SVGNumberList> rotateList = position.element->rotate()->currentValue();
187
188    unsigned xListSize = xList->length();
189    unsigned yListSize = yList->length();
190    unsigned dxListSize = dxList->length();
191    unsigned dyListSize = dyList->length();
192    unsigned rotateListSize = rotateList->length();
193    if (!xListSize && !yListSize && !dxListSize && !dyListSize && !rotateListSize)
194        return;
195
196    float lastRotation = SVGTextLayoutAttributes::emptyValue();
197    SVGLengthContext lengthContext(position.element);
198    for (unsigned i = 0; i < position.length; ++i) {
199        const SVGLengthList* xListPtr = i < xListSize ? xList.get() : 0;
200        const SVGLengthList* yListPtr = i < yListSize ? yList.get() : 0;
201        const SVGLengthList* dxListPtr = i < dxListSize ? dxList.get() : 0;
202        const SVGLengthList* dyListPtr = i < dyListSize ? dyList.get() : 0;
203        const SVGNumberList* rotateListPtr = i < rotateListSize ? rotateList.get() : 0;
204        if (!xListPtr && !yListPtr && !dxListPtr && !dyListPtr && !rotateListPtr)
205            break;
206
207        SVGCharacterDataMap::iterator it = m_characterDataMap.find(position.start + i + 1);
208        if (it == m_characterDataMap.end()) {
209            SVGCharacterData data;
210            updateCharacterData(i, lastRotation, data, lengthContext, xListPtr, yListPtr, dxListPtr, dyListPtr, rotateListPtr);
211            m_characterDataMap.set(position.start + i + 1, data);
212            continue;
213        }
214
215        updateCharacterData(i, lastRotation, it->value, lengthContext, xListPtr, yListPtr, dxListPtr, dyListPtr, rotateListPtr);
216    }
217
218    // The last rotation value always spans the whole scope.
219    if (lastRotation == SVGTextLayoutAttributes::emptyValue())
220        return;
221
222    for (unsigned i = rotateList->length(); i < position.length; ++i) {
223        SVGCharacterDataMap::iterator it = m_characterDataMap.find(position.start + i + 1);
224        if (it == m_characterDataMap.end()) {
225            SVGCharacterData data;
226            data.rotate = lastRotation;
227            m_characterDataMap.set(position.start + i + 1, data);
228            continue;
229        }
230
231        it->value.rotate = lastRotation;
232    }
233}
234
235}
236