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1 /*
2  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
3  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
4  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Library General Public
8  * License as published by the Free Software Foundation; either
9  * version 2 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Library General Public License for more details.
15  *
16  * You should have received a copy of the GNU Library General Public License
17  * along with this library; see the file COPYING.LIB.  If not, write to
18  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
19  * Boston, MA 02110-1301, USA.
20  */
21 
22 #include "config.h"
23 #include "Text.h"
24 
25 #include "CString.h"
26 #include "ExceptionCode.h"
27 #include "RenderText.h"
28 #include "TextBreakIterator.h"
29 
30 #if ENABLE(SVG)
31 #include "RenderSVGInlineText.h"
32 #include "SVGNames.h"
33 #endif
34 
35 #if ENABLE(WML)
36 #include "WMLDocument.h"
37 #include "WMLVariables.h"
38 #endif
39 
40 using namespace std;
41 
42 namespace WebCore {
43 
Text(Document * document,const String & data)44 Text::Text(Document* document, const String& data)
45     : CharacterData(document, data, CreateText)
46 {
47 }
48 
create(Document * document,const String & data)49 PassRefPtr<Text> Text::create(Document* document, const String& data)
50 {
51     return adoptRef(new Text(document, data));
52 }
53 
splitText(unsigned offset,ExceptionCode & ec)54 PassRefPtr<Text> Text::splitText(unsigned offset, ExceptionCode& ec)
55 {
56     ec = 0;
57 
58     // INDEX_SIZE_ERR: Raised if the specified offset is negative or greater than
59     // the number of 16-bit units in data.
60     if (offset > length()) {
61         ec = INDEX_SIZE_ERR;
62         return 0;
63     }
64 
65     RefPtr<StringImpl> oldStr = dataImpl();
66     RefPtr<Text> newText = virtualCreate(oldStr->substring(offset));
67     setDataImpl(oldStr->substring(0, offset));
68 
69     dispatchModifiedEvent(oldStr.get());
70 
71     if (parentNode())
72         parentNode()->insertBefore(newText.get(), nextSibling(), ec);
73     if (ec)
74         return 0;
75 
76     if (parentNode())
77         document()->textNodeSplit(this);
78 
79     if (renderer())
80         toRenderText(renderer())->setTextWithOffset(dataImpl(), 0, oldStr->length());
81 
82     return newText.release();
83 }
84 
earliestLogicallyAdjacentTextNode(const Text * t)85 static const Text* earliestLogicallyAdjacentTextNode(const Text* t)
86 {
87     const Node* n = t;
88     while ((n = n->previousSibling())) {
89         Node::NodeType type = n->nodeType();
90         if (type == Node::TEXT_NODE || type == Node::CDATA_SECTION_NODE) {
91             t = static_cast<const Text*>(n);
92             continue;
93         }
94 
95         // We would need to visit EntityReference child text nodes if they existed
96         ASSERT(type != Node::ENTITY_REFERENCE_NODE || !n->hasChildNodes());
97         break;
98     }
99     return t;
100 }
101 
latestLogicallyAdjacentTextNode(const Text * t)102 static const Text* latestLogicallyAdjacentTextNode(const Text* t)
103 {
104     const Node* n = t;
105     while ((n = n->nextSibling())) {
106         Node::NodeType type = n->nodeType();
107         if (type == Node::TEXT_NODE || type == Node::CDATA_SECTION_NODE) {
108             t = static_cast<const Text*>(n);
109             continue;
110         }
111 
112         // We would need to visit EntityReference child text nodes if they existed
113         ASSERT(type != Node::ENTITY_REFERENCE_NODE || !n->hasChildNodes());
114         break;
115     }
116     return t;
117 }
118 
wholeText() const119 String Text::wholeText() const
120 {
121     const Text* startText = earliestLogicallyAdjacentTextNode(this);
122     const Text* endText = latestLogicallyAdjacentTextNode(this);
123 
124     Node* onePastEndText = endText->nextSibling();
125     unsigned resultLength = 0;
126     for (const Node* n = startText; n != onePastEndText; n = n->nextSibling()) {
127         if (!n->isTextNode())
128             continue;
129         const Text* t = static_cast<const Text*>(n);
130         const String& data = t->data();
131         if (std::numeric_limits<unsigned>::max() - data.length() < resultLength)
132             CRASH();
133         resultLength += data.length();
134     }
135     UChar* resultData;
136     String result = String::createUninitialized(resultLength, resultData);
137     UChar* p = resultData;
138     for (const Node* n = startText; n != onePastEndText; n = n->nextSibling()) {
139         if (!n->isTextNode())
140             continue;
141         const Text* t = static_cast<const Text*>(n);
142         const String& data = t->data();
143         unsigned dataLength = data.length();
144         memcpy(p, data.characters(), dataLength * sizeof(UChar));
145         p += dataLength;
146     }
147     ASSERT(p == resultData + resultLength);
148 
149     return result;
150 }
151 
replaceWholeText(const String & newText,ExceptionCode &)152 PassRefPtr<Text> Text::replaceWholeText(const String& newText, ExceptionCode&)
153 {
154     // Remove all adjacent text nodes, and replace the contents of this one.
155 
156     // Protect startText and endText against mutation event handlers removing the last ref
157     RefPtr<Text> startText = const_cast<Text*>(earliestLogicallyAdjacentTextNode(this));
158     RefPtr<Text> endText = const_cast<Text*>(latestLogicallyAdjacentTextNode(this));
159 
160     RefPtr<Text> protectedThis(this); // Mutation event handlers could cause our last ref to go away
161     Node* parent = parentNode(); // Protect against mutation handlers moving this node during traversal
162     ExceptionCode ignored = 0;
163     for (RefPtr<Node> n = startText; n && n != this && n->isTextNode() && n->parentNode() == parent;) {
164         RefPtr<Node> nodeToRemove(n.release());
165         n = nodeToRemove->nextSibling();
166         parent->removeChild(nodeToRemove.get(), ignored);
167     }
168 
169     if (this != endText) {
170         Node* onePastEndText = endText->nextSibling();
171         for (RefPtr<Node> n = nextSibling(); n && n != onePastEndText && n->isTextNode() && n->parentNode() == parent;) {
172             RefPtr<Node> nodeToRemove(n.release());
173             n = nodeToRemove->nextSibling();
174             parent->removeChild(nodeToRemove.get(), ignored);
175         }
176     }
177 
178     if (newText.isEmpty()) {
179         if (parent && parentNode() == parent)
180             parent->removeChild(this, ignored);
181         return 0;
182     }
183 
184     setData(newText, ignored);
185     return protectedThis.release();
186 }
187 
nodeName() const188 String Text::nodeName() const
189 {
190     return textAtom.string();
191 }
192 
nodeType() const193 Node::NodeType Text::nodeType() const
194 {
195     return TEXT_NODE;
196 }
197 
cloneNode(bool)198 PassRefPtr<Node> Text::cloneNode(bool /*deep*/)
199 {
200     return create(document(), data());
201 }
202 
rendererIsNeeded(RenderStyle * style)203 bool Text::rendererIsNeeded(RenderStyle *style)
204 {
205     if (!CharacterData::rendererIsNeeded(style))
206         return false;
207 
208     bool onlyWS = containsOnlyWhitespace();
209     if (!onlyWS)
210         return true;
211 
212     RenderObject *par = parentNode()->renderer();
213 
214     if (par->isTable() || par->isTableRow() || par->isTableSection() || par->isTableCol() || par->isFrameSet())
215         return false;
216 
217     if (style->preserveNewline()) // pre/pre-wrap/pre-line always make renderers.
218         return true;
219 
220     RenderObject *prev = previousRenderer();
221     if (prev && prev->isBR()) // <span><br/> <br/></span>
222         return false;
223 
224     if (par->isRenderInline()) {
225         // <span><div/> <div/></span>
226         if (prev && !prev->isInline())
227             return false;
228     } else {
229         if (par->isRenderBlock() && !par->childrenInline() && (!prev || !prev->isInline()))
230             return false;
231 
232         RenderObject *first = par->firstChild();
233         while (first && first->isFloatingOrPositioned())
234             first = first->nextSibling();
235         RenderObject *next = nextRenderer();
236         if (!first || next == first)
237             // Whitespace at the start of a block just goes away.  Don't even
238             // make a render object for this text.
239             return false;
240     }
241 
242     return true;
243 }
244 
createRenderer(RenderArena * arena,RenderStyle *)245 RenderObject* Text::createRenderer(RenderArena* arena, RenderStyle*)
246 {
247 #if ENABLE(SVG)
248     if (parentNode()->isSVGElement()
249 #if ENABLE(SVG_FOREIGN_OBJECT)
250         && !parentNode()->hasTagName(SVGNames::foreignObjectTag)
251 #endif
252     )
253         return new (arena) RenderSVGInlineText(this, dataImpl());
254 #endif
255 
256     return new (arena) RenderText(this, dataImpl());
257 }
258 
attach()259 void Text::attach()
260 {
261 #if ENABLE(WML)
262     if (document()->isWMLDocument() && !containsOnlyWhitespace()) {
263         String text = data();
264         ASSERT(!text.isEmpty());
265 
266         text = substituteVariableReferences(text, document());
267 
268         ExceptionCode code = 0;
269         setData(text, code);
270         ASSERT(!code);
271     }
272 #endif
273 
274     createRendererIfNeeded();
275     CharacterData::attach();
276 }
277 
recalcStyle(StyleChange change)278 void Text::recalcStyle(StyleChange change)
279 {
280     if (change != NoChange && parentNode()) {
281         if (renderer())
282             renderer()->setStyle(parentNode()->renderer()->style());
283     }
284     if (needsStyleRecalc()) {
285         if (renderer()) {
286             if (renderer()->isText())
287                 toRenderText(renderer())->setText(dataImpl());
288         } else {
289             if (attached())
290                 detach();
291             attach();
292         }
293     }
294     setNeedsStyleRecalc(NoStyleChange);
295 }
296 
childTypeAllowed(NodeType)297 bool Text::childTypeAllowed(NodeType)
298 {
299     return false;
300 }
301 
virtualCreate(const String & data)302 PassRefPtr<Text> Text::virtualCreate(const String& data)
303 {
304     return create(document(), data);
305 }
306 
createWithLengthLimit(Document * document,const String & data,unsigned & charsLeft,unsigned maxChars)307 PassRefPtr<Text> Text::createWithLengthLimit(Document* document, const String& data, unsigned& charsLeft, unsigned maxChars)
308 {
309     unsigned dataLength = data.length();
310 
311     if (charsLeft == dataLength && charsLeft <= maxChars) {
312         charsLeft = 0;
313         return create(document, data);
314     }
315 
316     unsigned start = dataLength - charsLeft;
317     unsigned end = start + min(charsLeft, maxChars);
318 
319     // Check we are not on an unbreakable boundary.
320     // Some text break iterator implementations work best if the passed buffer is as small as possible,
321     // see <https://bugs.webkit.org/show_bug.cgi?id=29092>.
322     // We need at least two characters look-ahead to account for UTF-16 surrogates.
323     if (end < dataLength) {
324         TextBreakIterator* it = characterBreakIterator(data.characters() + start, (end + 2 > dataLength) ? dataLength - start : end - start + 2);
325         if (!isTextBreak(it, end - start))
326             end = textBreakPreceding(it, end - start) + start;
327     }
328 
329     // If we have maxChars of unbreakable characters the above could lead to
330     // an infinite loop.
331     // FIXME: It would be better to just have the old value of end before calling
332     // textBreakPreceding rather than this, because this exceeds the length limit.
333     if (end <= start)
334         end = dataLength;
335 
336     charsLeft = dataLength - end;
337     return create(document, data.substring(start, end - start));
338 }
339 
340 #ifndef NDEBUG
formatForDebugger(char * buffer,unsigned length) const341 void Text::formatForDebugger(char *buffer, unsigned length) const
342 {
343     String result;
344     String s;
345 
346     s = nodeName();
347     if (s.length() > 0) {
348         result += s;
349     }
350 
351     s = data();
352     if (s.length() > 0) {
353         if (result.length() > 0)
354             result += "; ";
355         result += "value=";
356         result += s;
357     }
358 
359     strncpy(buffer, result.utf8().data(), length - 1);
360 }
361 #endif
362 
363 } // namespace WebCore
364