1/*
2 * Copyright (C) 2010 Google, Inc. All Rights Reserved.
3 * Copyright (C) 2011 Apple Inc. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY GOOGLE INC. ``AS IS'' AND ANY
15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL GOOGLE INC. OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#ifndef HTMLConstructionSite_h
28#define HTMLConstructionSite_h
29
30#include "core/dom/Document.h"
31#include "core/dom/ParserContentPolicy.h"
32#include "core/html/parser/HTMLElementStack.h"
33#include "core/html/parser/HTMLFormattingElementList.h"
34#include "wtf/Noncopyable.h"
35#include "wtf/PassRefPtr.h"
36#include "wtf/RefPtr.h"
37#include "wtf/Vector.h"
38#include "wtf/text/StringBuilder.h"
39
40namespace blink {
41
42struct HTMLConstructionSiteTask {
43    ALLOW_ONLY_INLINE_ALLOCATION();
44public:
45    enum Operation {
46        Insert,
47        InsertText, // Handles possible merging of text nodes.
48        InsertAlreadyParsedChild, // Insert w/o calling begin/end parsing.
49        Reparent,
50        TakeAllChildren,
51    };
52
53    explicit HTMLConstructionSiteTask(Operation op)
54        : operation(op)
55        , selfClosing(false)
56    {
57    }
58
59    void trace(Visitor* visitor)
60    {
61        visitor->trace(parent);
62        visitor->trace(nextChild);
63        visitor->trace(child);
64    }
65
66    ContainerNode* oldParent()
67    {
68        // It's sort of ugly, but we store the |oldParent| in the |child| field
69        // of the task so that we don't bloat the HTMLConstructionSiteTask
70        // object in the common case of the Insert operation.
71        return toContainerNode(child.get());
72    }
73
74    Operation operation;
75    RefPtrWillBeMember<ContainerNode> parent;
76    RefPtrWillBeMember<Node> nextChild;
77    RefPtrWillBeMember<Node> child;
78    bool selfClosing;
79};
80
81} // namespace blink
82
83WTF_ALLOW_MOVE_INIT_AND_COMPARE_WITH_MEM_FUNCTIONS(blink::HTMLConstructionSiteTask);
84
85namespace blink {
86
87// Note: These are intentionally ordered so that when we concatonate
88// strings and whitespaces the resulting whitespace is ws = min(ws1, ws2).
89enum WhitespaceMode {
90    WhitespaceUnknown,
91    NotAllWhitespace,
92    AllWhitespace,
93};
94
95enum FlushMode {
96    // Flush pending text. Flush queued tasks.
97    FlushAlways,
98
99    // Flush pending text if node has length limit. Flush queued tasks.
100    FlushIfAtTextLimit,
101};
102
103class AtomicHTMLToken;
104class Document;
105class Element;
106class HTMLFormElement;
107
108class HTMLConstructionSite FINAL {
109    WTF_MAKE_NONCOPYABLE(HTMLConstructionSite);
110    DISALLOW_ALLOCATION();
111public:
112    HTMLConstructionSite(Document*, ParserContentPolicy);
113    HTMLConstructionSite(DocumentFragment*, ParserContentPolicy);
114    ~HTMLConstructionSite();
115    void trace(Visitor*);
116
117    void detach();
118
119    // executeQueuedTasks empties the queue but does not flush pending text.
120    // NOTE: Possible reentrancy via JavaScript execution.
121    void executeQueuedTasks();
122
123    // flushPendingText turns pending text into queued Text insertions, but does not execute them.
124    void flushPendingText(FlushMode);
125
126    // Called before every token in HTMLTreeBuilder::processToken, thus inlined:
127    void flush(FlushMode mode)
128    {
129        if (!hasPendingTasks())
130            return;
131        flushPendingText(mode);
132        executeQueuedTasks(); // NOTE: Possible reentrancy via JavaScript execution.
133        ASSERT(mode == FlushIfAtTextLimit || !hasPendingTasks());
134    }
135
136    bool hasPendingTasks()
137    {
138        return !m_pendingText.isEmpty() || !m_taskQueue.isEmpty();
139    }
140
141    void setDefaultCompatibilityMode();
142    void processEndOfFile();
143    void finishedParsing();
144
145    void insertDoctype(AtomicHTMLToken*);
146    void insertComment(AtomicHTMLToken*);
147    void insertCommentOnDocument(AtomicHTMLToken*);
148    void insertCommentOnHTMLHtmlElement(AtomicHTMLToken*);
149    void insertHTMLElement(AtomicHTMLToken*);
150    void insertSelfClosingHTMLElement(AtomicHTMLToken*);
151    void insertFormattingElement(AtomicHTMLToken*);
152    void insertHTMLHeadElement(AtomicHTMLToken*);
153    void insertHTMLBodyElement(AtomicHTMLToken*);
154    void insertHTMLFormElement(AtomicHTMLToken*, bool isDemoted = false);
155    void insertScriptElement(AtomicHTMLToken*);
156    void insertTextNode(const String&, WhitespaceMode = WhitespaceUnknown);
157    void insertForeignElement(AtomicHTMLToken*, const AtomicString& namespaceURI);
158
159    void insertHTMLHtmlStartTagBeforeHTML(AtomicHTMLToken*);
160    void insertHTMLHtmlStartTagInBody(AtomicHTMLToken*);
161    void insertHTMLBodyStartTagInBody(AtomicHTMLToken*);
162
163    void reparent(HTMLElementStack::ElementRecord* newParent, HTMLElementStack::ElementRecord* child);
164    void reparent(HTMLElementStack::ElementRecord* newParent, HTMLStackItem* child);
165    // insertAlreadyParsedChild assumes that |child| has already been parsed (i.e., we're just
166    // moving it around in the tree rather than parsing it for the first time). That means
167    // this function doesn't call beginParsingChildren / finishParsingChildren.
168    void insertAlreadyParsedChild(HTMLStackItem* newParent, HTMLElementStack::ElementRecord* child);
169    void takeAllChildren(HTMLStackItem* newParent, HTMLElementStack::ElementRecord* oldParent);
170
171    PassRefPtrWillBeRawPtr<HTMLStackItem> createElementFromSavedToken(HTMLStackItem*);
172
173    bool shouldFosterParent() const;
174    void fosterParent(PassRefPtrWillBeRawPtr<Node>);
175
176    bool indexOfFirstUnopenFormattingElement(unsigned& firstUnopenElementIndex) const;
177    void reconstructTheActiveFormattingElements();
178
179    void generateImpliedEndTags();
180    void generateImpliedEndTagsWithExclusion(const AtomicString& tagName);
181
182    bool inQuirksMode();
183
184    bool isEmpty() const { return !m_openElements.stackDepth(); }
185    HTMLElementStack::ElementRecord* currentElementRecord() const { return m_openElements.topRecord(); }
186    Element* currentElement() const { return m_openElements.top(); }
187    ContainerNode* currentNode() const { return m_openElements.topNode(); }
188    HTMLStackItem* currentStackItem() const { return m_openElements.topStackItem(); }
189    HTMLStackItem* oneBelowTop() const { return m_openElements.oneBelowTop(); }
190    Document& ownerDocumentForCurrentNode();
191    HTMLElementStack* openElements() const { return &m_openElements; }
192    HTMLFormattingElementList* activeFormattingElements() const { return &m_activeFormattingElements; }
193    bool currentIsRootNode() { return m_openElements.topNode() == m_openElements.rootNode(); }
194
195    Element* head() const { return m_head->element(); }
196    HTMLStackItem* headStackItem() const { return m_head.get(); }
197
198    void setForm(HTMLFormElement*);
199    HTMLFormElement* form() const { return m_form.get(); }
200    PassRefPtrWillBeRawPtr<HTMLFormElement> takeForm();
201
202    ParserContentPolicy parserContentPolicy() { return m_parserContentPolicy; }
203
204    class RedirectToFosterParentGuard {
205        WTF_MAKE_NONCOPYABLE(RedirectToFosterParentGuard);
206    public:
207        RedirectToFosterParentGuard(HTMLConstructionSite& tree)
208            : m_tree(tree)
209            , m_wasRedirectingBefore(tree.m_redirectAttachToFosterParent)
210        {
211            m_tree.m_redirectAttachToFosterParent = true;
212        }
213
214        ~RedirectToFosterParentGuard()
215        {
216            m_tree.m_redirectAttachToFosterParent = m_wasRedirectingBefore;
217        }
218
219    private:
220        HTMLConstructionSite& m_tree;
221        bool m_wasRedirectingBefore;
222    };
223
224private:
225    // In the common case, this queue will have only one task because most
226    // tokens produce only one DOM mutation.
227    typedef WillBeHeapVector<HTMLConstructionSiteTask, 1> TaskQueue;
228
229    void setCompatibilityMode(Document::CompatibilityMode);
230    void setCompatibilityModeFromDoctype(const String& name, const String& publicId, const String& systemId);
231
232    void attachLater(ContainerNode* parent, PassRefPtrWillBeRawPtr<Node> child, bool selfClosing = false);
233
234    void findFosterSite(HTMLConstructionSiteTask&);
235
236    PassRefPtrWillBeRawPtr<HTMLElement> createHTMLElement(AtomicHTMLToken*);
237    PassRefPtrWillBeRawPtr<Element> createElement(AtomicHTMLToken*, const AtomicString& namespaceURI);
238
239    void mergeAttributesFromTokenIntoElement(AtomicHTMLToken*, Element*);
240    void dispatchDocumentElementAvailableIfNeeded();
241
242    void executeTask(HTMLConstructionSiteTask&);
243    void queueTask(const HTMLConstructionSiteTask&);
244
245    RawPtrWillBeMember<Document> m_document;
246
247    // This is the root ContainerNode to which the parser attaches all newly
248    // constructed nodes. It points to a DocumentFragment when parsing fragments
249    // and a Document in all other cases.
250    RawPtrWillBeMember<ContainerNode> m_attachmentRoot;
251
252    RefPtrWillBeMember<HTMLStackItem> m_head;
253    RefPtrWillBeMember<HTMLFormElement> m_form;
254    mutable HTMLElementStack m_openElements;
255    mutable HTMLFormattingElementList m_activeFormattingElements;
256
257    TaskQueue m_taskQueue;
258
259    class PendingText FINAL {
260        DISALLOW_ALLOCATION();
261    public:
262        PendingText()
263            : whitespaceMode(WhitespaceUnknown)
264        {
265        }
266
267        void append(PassRefPtrWillBeRawPtr<ContainerNode> newParent, PassRefPtrWillBeRawPtr<Node> newNextChild, const String& newString, WhitespaceMode newWhitespaceMode)
268        {
269            ASSERT(!parent || parent == newParent);
270            parent = newParent;
271            ASSERT(!nextChild || nextChild == newNextChild);
272            nextChild = newNextChild;
273            stringBuilder.append(newString);
274            whitespaceMode = std::min(whitespaceMode, newWhitespaceMode);
275        }
276
277        void swap(PendingText& other)
278        {
279            std::swap(whitespaceMode, other.whitespaceMode);
280            parent.swap(other.parent);
281            nextChild.swap(other.nextChild);
282            stringBuilder.swap(other.stringBuilder);
283        }
284
285        void discard()
286        {
287            PendingText discardedText;
288            swap(discardedText);
289        }
290
291        bool isEmpty()
292        {
293            // When the stringbuilder is empty, the parent and whitespace should also be "empty".
294            ASSERT(stringBuilder.isEmpty() == !parent);
295            ASSERT(!stringBuilder.isEmpty() || !nextChild);
296            ASSERT(!stringBuilder.isEmpty() || (whitespaceMode == WhitespaceUnknown));
297            return stringBuilder.isEmpty();
298        }
299
300        void trace(Visitor*);
301
302        RefPtrWillBeMember<ContainerNode> parent;
303        RefPtrWillBeMember<Node> nextChild;
304        StringBuilder stringBuilder;
305        WhitespaceMode whitespaceMode;
306    };
307
308    PendingText m_pendingText;
309
310    ParserContentPolicy m_parserContentPolicy;
311    bool m_isParsingFragment;
312
313    // http://www.whatwg.org/specs/web-apps/current-work/multipage/tokenization.html#parsing-main-intable
314    // In the "in table" insertion mode, we sometimes get into a state where
315    // "whenever a node would be inserted into the current node, it must instead
316    // be foster parented."  This flag tracks whether we're in that state.
317    bool m_redirectAttachToFosterParent;
318
319    bool m_inQuirksMode;
320};
321
322} // namespace blink
323
324#endif
325