1 /*
2 * Copyright (C) 2006 Oliver Hunt <ojh16@student.canterbury.ac.nz>
3 * Copyright (C) 2006 Apple Computer Inc.
4 * Copyright (C) 2007 Nikolas Zimmermann <zimmermann@kde.org>
5 * Copyright (C) 2008 Rob Buis <buis@kde.org>
6 * Copyright (C) Research In Motion Limited 2010. All rights reserved.
7 *
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Library General Public
10 * License as published by the Free Software Foundation; either
11 * version 2 of the License, or (at your option) any later version.
12 *
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Library General Public License for more details.
17 *
18 * You should have received a copy of the GNU Library General Public License
19 * along with this library; see the file COPYING.LIB. If not, write to
20 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 * Boston, MA 02110-1301, USA.
22 */
23
24 #include "config.h"
25
26 #if ENABLE(SVG)
27 #include "RenderSVGInlineText.h"
28
29 #include "CSSStyleSelector.h"
30 #include "FloatConversion.h"
31 #include "FloatQuad.h"
32 #include "RenderBlock.h"
33 #include "RenderSVGRoot.h"
34 #include "RenderSVGText.h"
35 #include "Settings.h"
36 #include "SVGImageBufferTools.h"
37 #include "SVGInlineTextBox.h"
38 #include "SVGRootInlineBox.h"
39 #include "VisiblePosition.h"
40
41 namespace WebCore {
42
applySVGWhitespaceRules(PassRefPtr<StringImpl> string,bool preserveWhiteSpace)43 static PassRefPtr<StringImpl> applySVGWhitespaceRules(PassRefPtr<StringImpl> string, bool preserveWhiteSpace)
44 {
45 if (preserveWhiteSpace) {
46 // Spec: When xml:space="preserve", the SVG user agent will do the following using a
47 // copy of the original character data content. It will convert all newline and tab
48 // characters into space characters. Then, it will draw all space characters, including
49 // leading, trailing and multiple contiguous space characters.
50 RefPtr<StringImpl> newString = string->replace('\t', ' ');
51 newString = newString->replace('\n', ' ');
52 newString = newString->replace('\r', ' ');
53 return newString.release();
54 }
55
56 // Spec: When xml:space="default", the SVG user agent will do the following using a
57 // copy of the original character data content. First, it will remove all newline
58 // characters. Then it will convert all tab characters into space characters.
59 // Then, it will strip off all leading and trailing space characters.
60 // Then, all contiguous space characters will be consolidated.
61 RefPtr<StringImpl> newString = string->replace('\n', StringImpl::empty());
62 newString = newString->replace('\r', StringImpl::empty());
63 newString = newString->replace('\t', ' ');
64 return newString.release();
65 }
66
RenderSVGInlineText(Node * n,PassRefPtr<StringImpl> string)67 RenderSVGInlineText::RenderSVGInlineText(Node* n, PassRefPtr<StringImpl> string)
68 : RenderText(n, applySVGWhitespaceRules(string, false))
69 , m_scalingFactor(1)
70 {
71 }
72
destroy()73 void RenderSVGInlineText::destroy()
74 {
75 if (RenderSVGText* textRenderer = RenderSVGText::locateRenderSVGTextAncestor(this))
76 textRenderer->setNeedsPositioningValuesUpdate();
77
78 RenderText::destroy();
79 }
80
styleDidChange(StyleDifference diff,const RenderStyle * oldStyle)81 void RenderSVGInlineText::styleDidChange(StyleDifference diff, const RenderStyle* oldStyle)
82 {
83 RenderText::styleDidChange(diff, oldStyle);
84
85 if (diff == StyleDifferenceLayout) {
86 // The text metrics may be influenced by style changes.
87 if (RenderSVGText* textRenderer = RenderSVGText::locateRenderSVGTextAncestor(this))
88 textRenderer->setNeedsPositioningValuesUpdate();
89
90 updateScaledFont();
91 }
92
93 const RenderStyle* newStyle = style();
94 if (!newStyle || newStyle->whiteSpace() != PRE)
95 return;
96
97 if (!oldStyle || oldStyle->whiteSpace() != PRE)
98 setText(applySVGWhitespaceRules(originalText(), true), true);
99 }
100
createTextBox()101 InlineTextBox* RenderSVGInlineText::createTextBox()
102 {
103 InlineTextBox* box = new (renderArena()) SVGInlineTextBox(this);
104 box->setHasVirtualLogicalHeight();
105 return box;
106 }
107
localCaretRect(InlineBox * box,int caretOffset,int *)108 IntRect RenderSVGInlineText::localCaretRect(InlineBox* box, int caretOffset, int*)
109 {
110 if (!box->isInlineTextBox())
111 return IntRect();
112
113 InlineTextBox* textBox = static_cast<InlineTextBox*>(box);
114 if (static_cast<unsigned>(caretOffset) < textBox->start() || static_cast<unsigned>(caretOffset) > textBox->start() + textBox->len())
115 return IntRect();
116
117 // Use the edge of the selection rect to determine the caret rect.
118 if (static_cast<unsigned>(caretOffset) < textBox->start() + textBox->len()) {
119 IntRect rect = textBox->selectionRect(0, 0, caretOffset, caretOffset + 1);
120 int x = box->isLeftToRightDirection() ? rect.x() : rect.maxX();
121 return IntRect(x, rect.y(), caretWidth, rect.height());
122 }
123
124 IntRect rect = textBox->selectionRect(0, 0, caretOffset - 1, caretOffset);
125 int x = box->isLeftToRightDirection() ? rect.maxX() : rect.x();
126 return IntRect(x, rect.y(), caretWidth, rect.height());
127 }
128
linesBoundingBox() const129 IntRect RenderSVGInlineText::linesBoundingBox() const
130 {
131 IntRect boundingBox;
132 for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox())
133 boundingBox.unite(box->calculateBoundaries());
134 return boundingBox;
135 }
136
characterStartsNewTextChunk(int position) const137 bool RenderSVGInlineText::characterStartsNewTextChunk(int position) const
138 {
139 ASSERT(m_attributes.xValues().size() == textLength());
140 ASSERT(m_attributes.yValues().size() == textLength());
141 ASSERT(position >= 0);
142 ASSERT(position < static_cast<int>(textLength()));
143
144 // Each <textPath> element starts a new text chunk, regardless of any x/y values.
145 if (!position && parent()->isSVGTextPath() && !previousSibling())
146 return true;
147
148 int currentPosition = 0;
149 unsigned size = m_attributes.textMetricsValues().size();
150 for (unsigned i = 0; i < size; ++i) {
151 const SVGTextMetrics& metrics = m_attributes.textMetricsValues().at(i);
152
153 // We found the desired character.
154 if (currentPosition == position) {
155 return m_attributes.xValues().at(position) != SVGTextLayoutAttributes::emptyValue()
156 || m_attributes.yValues().at(position) != SVGTextLayoutAttributes::emptyValue();
157 }
158
159 currentPosition += metrics.length();
160 if (currentPosition > position)
161 break;
162 }
163
164 // The desired position is available in the x/y list, but not in the character data values list.
165 // That means the previous character data described a single glyph, consisting of multiple unicode characters.
166 // The consequence is that the desired character does not define a new absolute x/y position, even if present in the x/y test.
167 // This code is tested by svg/W3C-SVG-1.1/text-text-06-t.svg (and described in detail, why this influences chunk detection).
168 return false;
169 }
170
positionForPoint(const IntPoint & point)171 VisiblePosition RenderSVGInlineText::positionForPoint(const IntPoint& point)
172 {
173 if (!firstTextBox() || !textLength())
174 return createVisiblePosition(0, DOWNSTREAM);
175
176 float baseline = m_scaledFont.fontMetrics().floatAscent();
177
178 RenderBlock* containingBlock = this->containingBlock();
179 ASSERT(containingBlock);
180
181 // Map local point to absolute point, as the character origins stored in the text fragments use absolute coordinates.
182 FloatPoint absolutePoint(point);
183 absolutePoint.move(containingBlock->x(), containingBlock->y());
184
185 float closestDistance = std::numeric_limits<float>::max();
186 float closestDistancePosition = 0;
187 const SVGTextFragment* closestDistanceFragment = 0;
188 SVGInlineTextBox* closestDistanceBox = 0;
189
190 AffineTransform fragmentTransform;
191 for (InlineTextBox* box = firstTextBox(); box; box = box->nextTextBox()) {
192 if (!box->isSVGInlineTextBox())
193 continue;
194
195 SVGInlineTextBox* textBox = static_cast<SVGInlineTextBox*>(box);
196 Vector<SVGTextFragment>& fragments = textBox->textFragments();
197
198 unsigned textFragmentsSize = fragments.size();
199 for (unsigned i = 0; i < textFragmentsSize; ++i) {
200 const SVGTextFragment& fragment = fragments.at(i);
201 FloatRect fragmentRect(fragment.x, fragment.y - baseline, fragment.width, fragment.height);
202 fragment.buildFragmentTransform(fragmentTransform);
203 if (!fragmentTransform.isIdentity())
204 fragmentRect = fragmentTransform.mapRect(fragmentRect);
205
206 float distance = powf(fragmentRect.x() - absolutePoint.x(), 2) +
207 powf(fragmentRect.y() + fragmentRect.height() / 2 - absolutePoint.y(), 2);
208
209 if (distance < closestDistance) {
210 closestDistance = distance;
211 closestDistanceBox = textBox;
212 closestDistanceFragment = &fragment;
213 closestDistancePosition = fragmentRect.x();
214 }
215 }
216 }
217
218 if (!closestDistanceFragment)
219 return createVisiblePosition(0, DOWNSTREAM);
220
221 int offset = closestDistanceBox->offsetForPositionInFragment(*closestDistanceFragment, absolutePoint.x() - closestDistancePosition, true);
222 return createVisiblePosition(offset + closestDistanceBox->start(), offset > 0 ? VP_UPSTREAM_IF_POSSIBLE : DOWNSTREAM);
223 }
224
updateScaledFont()225 void RenderSVGInlineText::updateScaledFont()
226 {
227 computeNewScaledFontForStyle(this, style(), m_scalingFactor, m_scaledFont);
228 }
229
computeNewScaledFontForStyle(RenderObject * renderer,const RenderStyle * style,float & scalingFactor,Font & scaledFont)230 void RenderSVGInlineText::computeNewScaledFontForStyle(RenderObject* renderer, const RenderStyle* style, float& scalingFactor, Font& scaledFont)
231 {
232 ASSERT(style);
233 ASSERT(renderer);
234
235 Document* document = renderer->document();
236 ASSERT(document);
237
238 CSSStyleSelector* styleSelector = document->styleSelector();
239 ASSERT(styleSelector);
240
241 // Alter font-size to the right on-screen value, to avoid scaling the glyphs themselves.
242 AffineTransform ctm;
243 SVGImageBufferTools::calculateTransformationToOutermostSVGCoordinateSystem(renderer, ctm);
244 scalingFactor = narrowPrecisionToFloat(sqrt((pow(ctm.xScale(), 2) + pow(ctm.yScale(), 2)) / 2));
245 if (scalingFactor == 1 || !scalingFactor) {
246 scalingFactor = 1;
247 scaledFont = style->font();
248 return;
249 }
250
251 FontDescription fontDescription(style->fontDescription());
252 fontDescription.setComputedSize(fontDescription.computedSize() * scalingFactor);
253
254 scaledFont = Font(fontDescription, 0, 0);
255 scaledFont.update(styleSelector->fontSelector());
256 }
257
258 }
259
260 #endif // ENABLE(SVG)
261
