gecko/content/base/src/nsDocument.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is mozilla.org code.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

/*
 * Base class for all our document implementations.
 */

#ifndef nsDocument_h___
#define nsDocument_h___

#include "nsCOMPtr.h"
#include "nsAutoPtr.h"
#include "nsCRT.h"
#include "nsIDocument.h"
#include "nsWeakReference.h"
#include "nsWeakPtr.h"
#include "nsVoidArray.h"
#include "nsTArray.h"
#include "nsHashSets.h"
#include "nsIDOMXMLDocument.h"
#include "nsIDOM3Document.h"
#include "nsIDOMDocumentView.h"
#include "nsIDOMDocumentXBL.h"
#include "nsIDOMNSDocument.h"
#include "nsIDOMNSDocumentStyle.h"
#include "nsIDOMDocumentRange.h"
#include "nsIDOMDocumentTraversal.h"
#include "nsStubDocumentObserver.h"
#include "nsIDOM3EventTarget.h"
#include "nsIDOMNSEventTarget.h"
#include "nsIDOMStyleSheetList.h"
#include "nsIScriptGlobalObject.h"
#include "nsIDOMEventTarget.h"
#include "nsIContent.h"
#include "nsIEventListenerManager.h"
#include "nsIDOM3Node.h"
#include "nsIDOMNodeSelector.h"
#include "nsIPrincipal.h"
#include "nsIParser.h"
#include "nsBindingManager.h"
#include "nsINodeInfo.h"
#include "nsIDOMDocumentEvent.h"
#include "nsIDOM3DocumentEvent.h"
#include "nsHashtable.h"
#include "nsInterfaceHashtable.h"
#include "nsIBoxObject.h"
#include "nsPIBoxObject.h"
#include "nsIScriptObjectPrincipal.h"
#include "nsIURI.h"
#include "nsScriptLoader.h"
#include "nsIRadioGroupContainer.h"
#include "nsIScriptEventManager.h"
#include "nsILayoutHistoryState.h"
#include "nsIRequest.h"
#include "nsILoadGroup.h"
#include "nsTObserverArray.h"
#include "nsStubMutationObserver.h"
#include "nsIChannel.h"
#include "nsCycleCollectionParticipant.h"
#include "nsContentList.h"
#include "nsGkAtoms.h"
#include "nsIApplicationCache.h"
#include "nsIApplicationCacheContainer.h"
#include "nsStyleSet.h"
#include "pldhash.h"
#include "nsAttrAndChildArray.h"
#include "nsDOMAttributeMap.h"
#include "nsContentUtils.h"
#include "nsThreadUtils.h"
#include "nsIDocumentViewer.h"
#include "nsIDOMXPathNSResolver.h"
#include "nsIInterfaceRequestor.h"
#include "nsILoadContext.h"
#include "nsIProgressEventSink.h"
#include "nsISecurityEventSink.h"
#include "nsIChannelEventSink.h"
#include "imgIRequest.h"
#include "nsIDOMDOMImplementation.h"

#define XML_DECLARATION_BITS_DECLARATION_EXISTS   (1 << 0)
#define XML_DECLARATION_BITS_ENCODING_EXISTS      (1 << 1)
#define XML_DECLARATION_BITS_STANDALONE_EXISTS    (1 << 2)
#define XML_DECLARATION_BITS_STANDALONE_YES       (1 << 3)


class nsIEventListenerManager;
class nsDOMStyleSheetList;
class nsDOMStyleSheetSetList;
class nsIOutputStream;
class nsDocument;
class nsIDTD;
class nsIRadioVisitor;
class nsIFormControl;
struct nsRadioGroupStruct;
class nsOnloadBlocker;
class nsUnblockOnloadEvent;
class nsChildContentList;
class nsXMLEventsManager;
class nsHTMLStyleSheet;
class nsHTMLCSSStyleSheet;

/**
 * Right now our identifier map entries contain information for 'name'
 * and 'id' mappings of a given string. This is so that
 * nsHTMLDocument::ResolveName only has to do one hash lookup instead
 * of two. It's not clear whether this still matters for performance.
 * 
 * We also store the document.all result list here. This is mainly so that
 * when all elements with the given ID are removed and we remove
 * the ID's nsIdentifierMapEntry, the document.all result is released too.
 * Perhaps the document.all results should have their own hashtable
 * in nsHTMLDocument.
 */
class nsIdentifierMapEntry : public nsStringHashKey
{
public:
  typedef mozilla::dom::Element Element;
  
  nsIdentifierMapEntry(const nsAString& aKey) :
    nsStringHashKey(&aKey), mNameContentList(nsnull)
  {
  }
  nsIdentifierMapEntry(const nsAString *aKey) :
    nsStringHashKey(aKey), mNameContentList(nsnull)
  {
  }
  nsIdentifierMapEntry(const nsIdentifierMapEntry& aOther) :
    nsStringHashKey(&aOther.GetKey())
  {
    NS_ERROR("Should never be called");
  }
  ~nsIdentifierMapEntry();

  void SetInvalidName();
  PRBool IsInvalidName();
  void AddNameElement(Element* aElement);
  void RemoveNameElement(Element* aElement);
  PRBool HasNameContentList() {
    return mNameContentList != nsnull;
  }
  nsBaseContentList* GetNameContentList() {
    return mNameContentList;
  }
  nsresult CreateNameContentList();

  /**
   * Returns the element if we know the element associated with this
   * id. Otherwise returns null.
   */
  Element* GetIdElement();
  /**
   * Append all the elements with this id to aElements
   */
  void AppendAllIdContent(nsCOMArray<nsIContent>* aElements);
  /**
   * This can fire ID change callbacks.
   * @return true if the content could be added, false if we failed due
   * to OOM.
   */
  PRBool AddIdElement(Element* aElement);
  /**
   * This can fire ID change callbacks.
   * @return true if this map entry should be removed
   */
  PRBool RemoveIdElement(Element* aElement);

  PRBool HasContentChangeCallback() { return mChangeCallbacks != nsnull; }
  void AddContentChangeCallback(nsIDocument::IDTargetObserver aCallback, void* aData);
  void RemoveContentChangeCallback(nsIDocument::IDTargetObserver aCallback, void* aData);

  void Traverse(nsCycleCollectionTraversalCallback* aCallback);

  void SetDocAllList(nsContentList* aContentList) { mDocAllList = aContentList; }
  nsContentList* GetDocAllList() { return mDocAllList; }

  struct ChangeCallback {
    nsIDocument::IDTargetObserver mCallback;
    void* mData;
  };

  struct ChangeCallbackEntry : public PLDHashEntryHdr {
    typedef const ChangeCallback KeyType;
    typedef const ChangeCallback* KeyTypePointer;

    ChangeCallbackEntry(const ChangeCallback* key) :
      mKey(*key) { }
    ChangeCallbackEntry(const ChangeCallbackEntry& toCopy) :
      mKey(toCopy.mKey) { }

    KeyType GetKey() const { return mKey; }
    PRBool KeyEquals(KeyTypePointer aKey) const {
      return aKey->mCallback == mKey.mCallback &&
             aKey->mData == mKey.mData;
    }

    static KeyTypePointer KeyToPointer(KeyType& aKey) { return &aKey; }
    static PLDHashNumber HashKey(KeyTypePointer aKey)
    {
      return (NS_PTR_TO_INT32(aKey->mCallback) >> 2) ^
             (NS_PTR_TO_INT32(aKey->mData));
    }
    enum { ALLOW_MEMMOVE = PR_TRUE };
    
    ChangeCallback mKey;
  };

private:
  void FireChangeCallbacks(Element* aOldElement, Element* aNewElement);

  // empty if there are no elementswith this ID.
  // The elementsnodes are stored addrefed.
  nsSmallVoidArray mIdContentList;
  // NAME_NOT_VALID if this id cannot be used as a 'name'.  Otherwise
  // stores Elements.
  nsBaseContentList *mNameContentList;
  nsRefPtr<nsContentList> mDocAllList;
  nsAutoPtr<nsTHashtable<ChangeCallbackEntry> > mChangeCallbacks;
};

class nsDocHeaderData
{
public:
  nsDocHeaderData(nsIAtom* aField, const nsAString& aData)
    : mField(aField), mData(aData), mNext(nsnull)
  {
  }

  ~nsDocHeaderData(void)
  {
    delete mNext;
  }

  nsCOMPtr<nsIAtom> mField;
  nsString          mData;
  nsDocHeaderData*  mNext;
};

class nsDOMStyleSheetList : public nsIDOMStyleSheetList,
                            public nsStubDocumentObserver
{
public:
  nsDOMStyleSheetList(nsIDocument *aDocument);
  virtual ~nsDOMStyleSheetList();

  NS_DECL_ISUPPORTS

  NS_DECL_NSIDOMSTYLESHEETLIST

  // nsIDocumentObserver
  virtual void NodeWillBeDestroyed(const nsINode *aNode);
  virtual void StyleSheetAdded(nsIDocument *aDocument,
                               nsIStyleSheet* aStyleSheet,
                               PRBool aDocumentSheet);
  virtual void StyleSheetRemoved(nsIDocument *aDocument,
                                 nsIStyleSheet* aStyleSheet,
                                 PRBool aDocumentSheet);

  nsIStyleSheet* GetItemAt(PRUint32 aIndex);

  static nsDOMStyleSheetList* FromSupports(nsISupports* aSupports)
  {
    nsIDOMStyleSheetList* list = static_cast<nsIDOMStyleSheetList*>(aSupports);
#ifdef DEBUG
    {
      nsCOMPtr<nsIDOMStyleSheetList> list_qi = do_QueryInterface(aSupports);

      // If this assertion fires the QI implementation for the object in
      // question doesn't use the nsIDOMStyleSheetList pointer as the
      // nsISupports pointer. That must be fixed, or we'll crash...
      NS_ASSERTION(list_qi == list, "Uh, fix QI!");
    }
#endif
    return static_cast<nsDOMStyleSheetList*>(list);
  }

protected:
  PRInt32       mLength;
  nsIDocument*  mDocument;
};

class nsOnloadBlocker : public nsIRequest
{
public:
  nsOnloadBlocker() {}

  NS_DECL_ISUPPORTS
  NS_DECL_NSIREQUEST

private:
  ~nsOnloadBlocker() {}
};

class nsExternalResourceMap
{
public:
  typedef nsIDocument::ExternalResourceLoad ExternalResourceLoad;
  nsExternalResourceMap();

  /**
   * Request an external resource document.  This does exactly what
   * nsIDocument::RequestExternalResource is documented to do.
   */
  nsIDocument* RequestResource(nsIURI* aURI,
                               nsINode* aRequestingNode,
                               nsDocument* aDisplayDocument,
                               ExternalResourceLoad** aPendingLoad);

  /**
   * Enumerate the resource documents.  See
   * nsIDocument::EnumerateExternalResources.
   */
  void EnumerateResources(nsIDocument::nsSubDocEnumFunc aCallback, void* aData);

  /**
   * Traverse ourselves for cycle-collection
   */
  void Traverse(nsCycleCollectionTraversalCallback* aCallback) const;

  /**
   * Shut ourselves down (used for cycle-collection unlink), as well
   * as for document destruction.
   */
  void Shutdown()
  {
    mPendingLoads.Clear();
    mMap.Clear();
    mHaveShutDown = PR_TRUE;
  }

  PRBool HaveShutDown() const
  {
    return mHaveShutDown;
  }

  // Needs to be public so we can traverse them sanely
  struct ExternalResource
  {
    ~ExternalResource();
    nsCOMPtr<nsIDocument> mDocument;
    nsCOMPtr<nsIContentViewer> mViewer;
    nsCOMPtr<nsILoadGroup> mLoadGroup;
  };

protected:
  class PendingLoad : public ExternalResourceLoad,
                      public nsIStreamListener
  {
  public:
    PendingLoad(nsDocument* aDisplayDocument) :
      mDisplayDocument(aDisplayDocument)
    {}

    NS_DECL_ISUPPORTS
    NS_DECL_NSISTREAMLISTENER
    NS_DECL_NSIREQUESTOBSERVER

    /**
     * Start aURI loading.  This will perform the necessary security checks and
     * so forth.
     */
    nsresult StartLoad(nsIURI* aURI, nsINode* aRequestingNode);

    /**
     * Set up an nsIDocumentViewer based on aRequest.  This is guaranteed to
     * put null in *aViewer and *aLoadGroup on all failures.
     */
    nsresult SetupViewer(nsIRequest* aRequest, nsIDocumentViewer** aViewer,
                         nsILoadGroup** aLoadGroup);

  private:
    nsRefPtr<nsDocument> mDisplayDocument;
    nsCOMPtr<nsIStreamListener> mTargetListener;
    nsCOMPtr<nsIURI> mURI;
  };
  friend class PendingLoad;

  class LoadgroupCallbacks : public nsIInterfaceRequestor
  {
  public:
    LoadgroupCallbacks(nsIInterfaceRequestor* aOtherCallbacks)
      : mCallbacks(aOtherCallbacks)
    {}
    NS_DECL_ISUPPORTS
    NS_DECL_NSIINTERFACEREQUESTOR
  private:
    // The only reason it's safe to hold a strong ref here without leaking is
    // that the notificationCallbacks on a loadgroup aren't the docshell itself
    // but a shim that holds a weak reference to the docshell.
    nsCOMPtr<nsIInterfaceRequestor> mCallbacks;

    // Use shims for interfaces that docshell implements directly so that we
    // don't hand out references to the docshell.  The shims should all allow
    // getInterface back on us, but other than that each one should only
    // implement one interface.
    
    // XXXbz I wish we could just derive the _allcaps thing from _i
#define DECL_SHIM(_i, _allcaps)                                              \
    class _i##Shim : public nsIInterfaceRequestor,                           \
                     public _i                                               \
    {                                                                        \
    public:                                                                  \
      _i##Shim(nsIInterfaceRequestor* aIfreq, _i* aRealPtr)                  \
        : mIfReq(aIfreq), mRealPtr(aRealPtr)                                 \
      {                                                                      \
        NS_ASSERTION(mIfReq, "Expected non-null here");                      \
        NS_ASSERTION(mRealPtr, "Expected non-null here");                    \
      }                                                                      \
      NS_DECL_ISUPPORTS                                                      \
      NS_FORWARD_NSIINTERFACEREQUESTOR(mIfReq->);                            \
      NS_FORWARD_##_allcaps(mRealPtr->);                                     \
    private:                                                                 \
      nsCOMPtr<nsIInterfaceRequestor> mIfReq;                                \
      nsCOMPtr<_i> mRealPtr;                                                 \
    };

    DECL_SHIM(nsILoadContext, NSILOADCONTEXT)
    DECL_SHIM(nsIProgressEventSink, NSIPROGRESSEVENTSINK)
    DECL_SHIM(nsIChannelEventSink, NSICHANNELEVENTSINK)
    DECL_SHIM(nsISecurityEventSink, NSISECURITYEVENTSINK)
    DECL_SHIM(nsIApplicationCacheContainer, NSIAPPLICATIONCACHECONTAINER)
#undef DECL_SHIM
  };
  
  /**
   * Add an ExternalResource for aURI.  aViewer and aLoadGroup might be null
   * when this is called if the URI didn't result in an XML document.  This
   * function makes sure to remove the pending load for aURI, if any, from our
   * hashtable, and to notify its observers, if any.
   */
  nsresult AddExternalResource(nsIURI* aURI, nsIDocumentViewer* aViewer,
                               nsILoadGroup* aLoadGroup,
                               nsIDocument* aDisplayDocument);
  
  nsClassHashtable<nsURIHashKey, ExternalResource> mMap;
  nsRefPtrHashtable<nsURIHashKey, PendingLoad> mPendingLoads;
  PRPackedBool mHaveShutDown;
};

// Base class for our document implementations.
//
// Note that this class *implements* nsIDOMXMLDocument, but it's not
// really an nsIDOMXMLDocument. The reason for implementing
// nsIDOMXMLDocument on this class is to avoid having to duplicate all
// its inherited methods on document classes that *are*
// nsIDOMXMLDocument's. nsDocument's QI should *not* claim to support
// nsIDOMXMLDocument unless someone writes a real implementation of
// the interface.
class nsDocument : public nsIDocument,
                   public nsIDOMXMLDocument, // inherits nsIDOMDocument
                   public nsIDOMNSDocument,
                   public nsIDOMDocumentEvent,
                   public nsIDOM3DocumentEvent,
                   public nsIDOMNSDocumentStyle,
                   public nsIDOMDocumentView,
                   public nsIDOMDocumentRange,
                   public nsIDOMDocumentTraversal,
                   public nsIDOMDocumentXBL,
                   public nsIDOM3Document,
                   public nsSupportsWeakReference,
                   public nsIDOMEventTarget,
                   public nsIDOM3EventTarget,
                   public nsIDOMNSEventTarget,
                   public nsIScriptObjectPrincipal,
                   public nsIRadioGroupContainer,
                   public nsIApplicationCacheContainer,
                   public nsStubMutationObserver
{
public:
  typedef mozilla::dom::Element Element;

  NS_DECL_CYCLE_COLLECTING_ISUPPORTS

  using nsINode::GetScriptTypeID;

  virtual void Reset(nsIChannel *aChannel, nsILoadGroup *aLoadGroup);
  virtual void ResetToURI(nsIURI *aURI, nsILoadGroup *aLoadGroup,
                          nsIPrincipal* aPrincipal);

  // StartDocumentLoad is pure virtual so that subclasses must override it.
  // The nsDocument StartDocumentLoad does some setup, but does NOT set
  // *aDocListener; this is the job of subclasses.
  virtual nsresult StartDocumentLoad(const char* aCommand,
                                     nsIChannel* aChannel,
                                     nsILoadGroup* aLoadGroup,
                                     nsISupports* aContainer,
                                     nsIStreamListener **aDocListener,
                                     PRBool aReset = PR_TRUE,
                                     nsIContentSink* aContentSink = nsnull) = 0;

  virtual void StopDocumentLoad();

  virtual void NotifyPossibleTitleChange(PRBool aBoundTitleElement);

  virtual void SetDocumentURI(nsIURI* aURI);
  
  /**
   * Set the principal responsible for this document.
   */
  virtual void SetPrincipal(nsIPrincipal *aPrincipal);

  /**
   * Get the Content-Type of this document.
   */
  // NS_IMETHOD GetContentType(nsAString& aContentType);
  // Already declared in nsIDOMNSDocument

  /**
   * Set the Content-Type of this document.
   */
  virtual void SetContentType(const nsAString& aContentType);

  virtual nsresult SetBaseURI(nsIURI* aURI);

  /**
   * Get/Set the base target of a link in a document.
   */
  virtual void GetBaseTarget(nsAString &aBaseTarget);

  /**
   * Return a standard name for the document's character set. This will
   * trigger a startDocumentLoad if necessary to answer the question.
   */
  virtual void SetDocumentCharacterSet(const nsACString& aCharSetID);

  /**
   * Add an observer that gets notified whenever the charset changes.
   */
  virtual nsresult AddCharSetObserver(nsIObserver* aObserver);

  /**
   * Remove a charset observer.
   */
  virtual void RemoveCharSetObserver(nsIObserver* aObserver);

  virtual Element* AddIDTargetObserver(nsIAtom* aID, IDTargetObserver aObserver,
                                       void* aData);
  virtual void RemoveIDTargetObserver(nsIAtom* aID,
                                      IDTargetObserver aObserver, void* aData);

  /**
   * Access HTTP header data (this may also get set from other sources, like
   * HTML META tags).
   */
  virtual void GetHeaderData(nsIAtom* aHeaderField, nsAString& aData) const;
  virtual void SetHeaderData(nsIAtom* aheaderField,
                             const nsAString& aData);

  /**
   * Create a new presentation shell that will use aContext for
   * its presentation context (presentation context's <b>must not</b> be
   * shared among multiple presentation shell's).
   */
  virtual nsresult CreateShell(nsPresContext* aContext,
                               nsIViewManager* aViewManager,
                               nsStyleSet* aStyleSet,
                               nsIPresShell** aInstancePtrResult);

  virtual nsresult SetSubDocumentFor(nsIContent *aContent,
                                     nsIDocument* aSubDoc);
  virtual nsIDocument* GetSubDocumentFor(nsIContent *aContent) const;
  virtual nsIContent* FindContentForSubDocument(nsIDocument *aDocument) const;
  virtual Element* GetRootElementInternal() const;

  /**
   * Get the style sheets owned by this document.
   * These are ordered, highest priority last
   */
  virtual PRInt32 GetNumberOfStyleSheets() const;
  virtual nsIStyleSheet* GetStyleSheetAt(PRInt32 aIndex) const;
  virtual PRInt32 GetIndexOfStyleSheet(nsIStyleSheet* aSheet) const;
  virtual void AddStyleSheet(nsIStyleSheet* aSheet);
  virtual void RemoveStyleSheet(nsIStyleSheet* aSheet);

  virtual void UpdateStyleSheets(nsCOMArray<nsIStyleSheet>& aOldSheets,
                                 nsCOMArray<nsIStyleSheet>& aNewSheets);
  virtual void AddStyleSheetToStyleSets(nsIStyleSheet* aSheet);
  virtual void RemoveStyleSheetFromStyleSets(nsIStyleSheet* aSheet);

  virtual void InsertStyleSheetAt(nsIStyleSheet* aSheet, PRInt32 aIndex);
  virtual void SetStyleSheetApplicableState(nsIStyleSheet* aSheet,
                                            PRBool aApplicable);

  virtual PRInt32 GetNumberOfCatalogStyleSheets() const;
  virtual nsIStyleSheet* GetCatalogStyleSheetAt(PRInt32 aIndex) const;
  virtual void AddCatalogStyleSheet(nsIStyleSheet* aSheet);
  virtual void EnsureCatalogStyleSheet(const char *aStyleSheetURI);

  virtual nsIChannel* GetChannel() const {
    return mChannel;
  }

  /**
   * Get this document's attribute stylesheet.  May return null if
   * there isn't one.
   */
  virtual nsHTMLStyleSheet* GetAttributeStyleSheet() const {
    return mAttrStyleSheet;
  }

  /**
   * Get this document's inline style sheet.  May return null if there
   * isn't one
   */
  virtual nsHTMLCSSStyleSheet* GetInlineStyleSheet() const {
    return mStyleAttrStyleSheet;
  }
  
  /**
   * Set the object from which a document can get a script context.
   * This is the context within which all scripts (during document
   * creation and during event handling) will run.
   */
  virtual nsIScriptGlobalObject* GetScriptGlobalObject() const;
  virtual void SetScriptGlobalObject(nsIScriptGlobalObject* aGlobalObject);

  virtual void SetScriptHandlingObject(nsIScriptGlobalObject* aScriptObject);

  virtual nsIScriptGlobalObject* GetScopeObject();

  /**
   * Get the script loader for this document
   */
  virtual nsScriptLoader* ScriptLoader();

  /**
   * Add/Remove an element to the document's id and name hashes
   */
  virtual void AddToIdTable(mozilla::dom::Element* aElement, nsIAtom* aId);
  virtual void RemoveFromIdTable(mozilla::dom::Element* aElement,
                                 nsIAtom* aId);
  virtual void AddToNameTable(mozilla::dom::Element* aElement,
                              nsIAtom* aName);
  virtual void RemoveFromNameTable(mozilla::dom::Element* aElement,
                                   nsIAtom* aName);

  /**
   * Add a new observer of document change notifications. Whenever
   * content is changed, appended, inserted or removed the observers are
   * informed.
   */
  virtual void AddObserver(nsIDocumentObserver* aObserver);

  /**
   * Remove an observer of document change notifications. This will
   * return false if the observer cannot be found.
   */
  virtual PRBool RemoveObserver(nsIDocumentObserver* aObserver);

  // Observation hooks used to propagate notifications to document
  // observers.
  virtual void BeginUpdate(nsUpdateType aUpdateType);
  virtual void EndUpdate(nsUpdateType aUpdateType);
  virtual void BeginLoad();
  virtual void EndLoad();

  virtual void SetReadyStateInternal(ReadyState rs);
  virtual ReadyState GetReadyStateEnum();

  virtual void ContentStatesChanged(nsIContent* aContent1,
                                    nsIContent* aContent2,
                                    PRInt32 aStateMask);
  virtual void DocumentStatesChanged(PRInt32 aStateMask);

  virtual void StyleRuleChanged(nsIStyleSheet* aStyleSheet,
                                nsIStyleRule* aOldStyleRule,
                                nsIStyleRule* aNewStyleRule);
  virtual void StyleRuleAdded(nsIStyleSheet* aStyleSheet,
                              nsIStyleRule* aStyleRule);
  virtual void StyleRuleRemoved(nsIStyleSheet* aStyleSheet,
                                nsIStyleRule* aStyleRule);

  virtual void FlushPendingNotifications(mozFlushType aType);
  virtual void FlushExternalResources(mozFlushType aType);
  virtual nsIScriptEventManager* GetScriptEventManager();
  virtual void SetXMLDeclaration(const PRUnichar *aVersion,
                                 const PRUnichar *aEncoding,
                                 const PRInt32 aStandalone);
  virtual void GetXMLDeclaration(nsAString& aVersion,
                                 nsAString& aEncoding,
                                 nsAString& Standalone);
  virtual PRBool IsScriptEnabled();

  virtual void OnPageShow(PRBool aPersisted, nsIDOMEventTarget* aDispatchStartTarget);
  virtual void OnPageHide(PRBool aPersisted, nsIDOMEventTarget* aDispatchStartTarget);
  
  virtual void WillDispatchMutationEvent(nsINode* aTarget);
  virtual void MutationEventDispatched(nsINode* aTarget);

  // nsINode
  virtual PRBool IsNodeOfType(PRUint32 aFlags) const;
  virtual nsIContent *GetChildAt(PRUint32 aIndex) const;
  virtual nsIContent * const * GetChildArray(PRUint32* aChildCount) const;
  virtual PRInt32 IndexOf(nsINode* aPossibleChild) const;
  virtual PRUint32 GetChildCount() const;
  virtual nsresult InsertChildAt(nsIContent* aKid, PRUint32 aIndex,
                                 PRBool aNotify);
  virtual nsresult AppendChildTo(nsIContent* aKid, PRBool aNotify);
  virtual nsresult RemoveChildAt(PRUint32 aIndex, PRBool aNotify, PRBool aMutationEvent = PR_TRUE);
  virtual nsresult PreHandleEvent(nsEventChainPreVisitor& aVisitor);
  virtual nsresult PostHandleEvent(nsEventChainPostVisitor& aVisitor);
  virtual nsresult DispatchDOMEvent(nsEvent* aEvent, nsIDOMEvent* aDOMEvent,
                                    nsPresContext* aPresContext,
                                    nsEventStatus* aEventStatus);
  virtual nsIEventListenerManager* GetListenerManager(PRBool aCreateIfNotFound);
  virtual nsresult AddEventListenerByIID(nsIDOMEventListener *aListener,
                                         const nsIID& aIID);
  virtual nsresult RemoveEventListenerByIID(nsIDOMEventListener *aListener,
                                            const nsIID& aIID);
  virtual nsresult GetSystemEventGroup(nsIDOMEventGroup** aGroup);
  virtual nsIScriptContext* GetContextForEventHandlers(nsresult* aRv)
  {
    return nsContentUtils::GetContextForEventHandlers(this, aRv);
  }
  virtual nsresult Clone(nsINodeInfo *aNodeInfo, nsINode **aResult) const
  {
    return NS_ERROR_NOT_IMPLEMENTED;
  }
  virtual PRBool IsEqualNode(nsINode* aOther);
  virtual void GetTextContent(nsAString &aTextContent);

  // nsIRadioGroupContainer
  NS_IMETHOD WalkRadioGroup(const nsAString& aName,
                            nsIRadioVisitor* aVisitor,
                            PRBool aFlushContent);
  NS_IMETHOD SetCurrentRadioButton(const nsAString& aName,
                                   nsIDOMHTMLInputElement* aRadio);
  NS_IMETHOD GetCurrentRadioButton(const nsAString& aName,
                                   nsIDOMHTMLInputElement** aRadio);
  NS_IMETHOD GetPositionInGroup(nsIDOMHTMLInputElement *aRadio,
                                PRInt32 *aPositionIndex,
                                PRInt32 *aItemsInGroup);
  NS_IMETHOD GetNextRadioButton(const nsAString& aName,
                                const PRBool aPrevious,
                                nsIDOMHTMLInputElement*  aFocusedRadio,
                                nsIDOMHTMLInputElement** aRadioOut);
  NS_IMETHOD AddToRadioGroup(const nsAString& aName,
                             nsIFormControl* aRadio);
  NS_IMETHOD RemoveFromRadioGroup(const nsAString& aName,
                                  nsIFormControl* aRadio);

  // for radio group
  nsresult GetRadioGroup(const nsAString& aName,
                         nsRadioGroupStruct **aRadioGroup);

  // nsIDOMNode
  NS_DECL_NSIDOMNODE

  // nsIDOMDocument
  NS_DECL_NSIDOMDOCUMENT

  // nsIDOM3Document
  NS_DECL_NSIDOM3DOCUMENT

  // nsIDOMXMLDocument
  NS_DECL_NSIDOMXMLDOCUMENT

  // nsIDOMNSDocument
  NS_DECL_NSIDOMNSDOCUMENT

  // nsIDOMDocumentEvent
  NS_DECL_NSIDOMDOCUMENTEVENT

  // nsIDOM3DocumentEvent
  NS_DECL_NSIDOM3DOCUMENTEVENT

  // nsIDOMDocumentStyle
  NS_DECL_NSIDOMDOCUMENTSTYLE

  // nsIDOMNSDocumentStyle
  NS_DECL_NSIDOMNSDOCUMENTSTYLE

  // nsIDOMDocumentView
  NS_DECL_NSIDOMDOCUMENTVIEW

  // nsIDOMDocumentRange
  NS_DECL_NSIDOMDOCUMENTRANGE

  // nsIDOMDocumentTraversal
  NS_DECL_NSIDOMDOCUMENTTRAVERSAL

  // nsIDOMDocumentXBL
  NS_DECL_NSIDOMDOCUMENTXBL

  // nsIDOMEventTarget
  NS_DECL_NSIDOMEVENTTARGET

  // nsIDOM3EventTarget
  NS_DECL_NSIDOM3EVENTTARGET

  // nsIDOMNSEventTarget
  NS_DECL_NSIDOMNSEVENTTARGET

  // nsIScriptObjectPrincipal
  virtual nsIPrincipal* GetPrincipal();

  // nsIApplicationCacheContainer
  NS_DECL_NSIAPPLICATIONCACHECONTAINER

  virtual nsresult Init();
  
  virtual nsresult AddXMLEventsContent(nsIContent * aXMLEventsElement);

  virtual nsresult CreateElem(const nsAString& aName, nsIAtom *aPrefix,
                              PRInt32 aNamespaceID,
                              PRBool aDocumentDefaultType,
                              nsIContent **aResult);

  nsresult CreateElement(const nsAString& aTagName,
                         nsIContent** aReturn);

  nsresult CreateTextNode(const nsAString& aData, nsIContent** aReturn);

  virtual NS_HIDDEN_(nsresult) Sanitize();

  virtual NS_HIDDEN_(void) EnumerateSubDocuments(nsSubDocEnumFunc aCallback,
                                                 void *aData);

  virtual NS_HIDDEN_(PRBool) CanSavePresentation(nsIRequest *aNewRequest);
  virtual NS_HIDDEN_(void) Destroy();
  virtual NS_HIDDEN_(void) RemovedFromDocShell();
  virtual NS_HIDDEN_(already_AddRefed<nsILayoutHistoryState>) GetLayoutHistoryState() const;

  virtual NS_HIDDEN_(void) BlockOnload();
  virtual NS_HIDDEN_(void) UnblockOnload(PRBool aFireSync);

  virtual NS_HIDDEN_(void) AddStyleRelevantLink(mozilla::dom::Link* aLink);
  virtual NS_HIDDEN_(void) ForgetLink(mozilla::dom::Link* aLink);

  NS_HIDDEN_(void) ClearBoxObjectFor(nsIContent* aContent);
  NS_IMETHOD GetBoxObjectFor(nsIDOMElement* aElement, nsIBoxObject** aResult);

  virtual NS_HIDDEN_(nsresult) GetXBLChildNodesFor(nsIContent* aContent,
                                                   nsIDOMNodeList** aResult);
  virtual NS_HIDDEN_(nsresult) GetContentListFor(nsIContent* aContent,
                                                 nsIDOMNodeList** aResult);

  virtual NS_HIDDEN_(nsresult) ElementFromPointHelper(float aX, float aY,
                                                      PRBool aIgnoreRootScrollFrame,
                                                      PRBool aFlushLayout,
                                                      nsIDOMElement** aReturn);

  virtual NS_HIDDEN_(nsresult) NodesFromRectHelper(float aX, float aY,
                                                   float aTopSize, float aRightSize,
                                                   float aBottomSize, float aLeftSize,
                                                   PRBool aIgnoreRootScrollFrame,
                                                   PRBool aFlushLayout,
                                                   nsIDOMNodeList** aReturn);

  virtual NS_HIDDEN_(void) FlushSkinBindings();

  virtual NS_HIDDEN_(nsresult) InitializeFrameLoader(nsFrameLoader* aLoader);
  virtual NS_HIDDEN_(nsresult) FinalizeFrameLoader(nsFrameLoader* aLoader);
  virtual NS_HIDDEN_(void) TryCancelFrameLoaderInitialization(nsIDocShell* aShell);
  virtual NS_HIDDEN_(PRBool) FrameLoaderScheduledToBeFinalized(nsIDocShell* aShell);
  virtual NS_HIDDEN_(nsIDocument*)
    RequestExternalResource(nsIURI* aURI,
                            nsINode* aRequestingNode,
                            ExternalResourceLoad** aPendingLoad);
  virtual NS_HIDDEN_(void)
    EnumerateExternalResources(nsSubDocEnumFunc aCallback, void* aData);

  nsTArray<nsCString> mFileDataUris;

#ifdef MOZ_SMIL
  // Returns our (lazily-initialized) animation controller.
  // If HasAnimationController is true, this is guaranteed to return non-null.
  nsSMILAnimationController* GetAnimationController();
#endif // MOZ_SMIL

  virtual void SuppressEventHandling(PRUint32 aIncrease);

  virtual void UnsuppressEventHandlingAndFireEvents(PRBool aFireEvents);
  
  void DecreaseEventSuppression() { --mEventsSuppressed; }

  NS_DECL_CYCLE_COLLECTION_SCRIPT_HOLDER_CLASS_AMBIGUOUS(nsDocument,
                                                         nsIDocument)

  void DoNotifyPossibleTitleChange();

  nsExternalResourceMap& ExternalResourceMap()
  {
    return mExternalResourceMap;
  }

  void SetLoadedAsData(PRBool aLoadedAsData) { mLoadedAsData = aLoadedAsData; }

  nsresult CloneDocHelper(nsDocument* clone) const;

  void MaybeInitializeFinalizeFrameLoaders();

  void MaybeEndOutermostXBLUpdate();

  virtual void MaybePreLoadImage(nsIURI* uri);

  virtual void PreloadStyle(nsIURI* uri, const nsAString& charset);

  virtual nsresult LoadChromeSheetSync(nsIURI* uri, PRBool isAgentSheet,
                                       nsCSSStyleSheet** sheet);

  virtual nsISupports* GetCurrentContentSink();

  virtual PRInt32 GetDocumentState();

  virtual void RegisterFileDataUri(nsACString& aUri);

  // Only BlockOnload should call this!
  void AsyncBlockOnload();

  virtual void SetScrollToRef(nsIURI *aDocumentURI);
  virtual void ScrollToRef();
  virtual void ResetScrolledToRefAlready();
  virtual void SetChangeScrollPosWhenScrollingToRef(PRBool aValue);

  already_AddRefed<nsContentList>
    GetElementsByTagName(const nsAString& aTagName);
  already_AddRefed<nsContentList>
    GetElementsByTagNameNS(const nsAString& aNamespaceURI,
                           const nsAString& aLocalName);

  virtual mozilla::dom::Element *GetElementById(const nsAString& aElementId);

protected:
  friend class nsNodeUtils;

  /**
   * Check that aId is not empty and log a message to the console
   * service if it is.
   * @returns PR_TRUE if aId looks correct, PR_FALSE otherwise.
   */
  static inline PRBool CheckGetElementByIdArg(const nsAString& aId)
  {
    if (aId.IsEmpty()) {
      ReportEmptyGetElementByIdArg();
      return PR_FALSE;
    }
    return PR_TRUE;
  }

  static void ReportEmptyGetElementByIdArg();

  void DispatchContentLoadedEvents();

  void RetrieveRelevantHeaders(nsIChannel *aChannel);

  static PRBool TryChannelCharset(nsIChannel *aChannel,
                                  PRInt32& aCharsetSource,
                                  nsACString& aCharset);

  // Call this before the document does something that will unbind all content.
  // That will stop us from doing a lot of work as each element is removed.
  void DestroyElementMaps();

  // Refreshes the hrefs of all the links in the document.
  void RefreshLinkHrefs();

  nsIContent* GetFirstBaseNodeWithHref();
  nsresult SetFirstBaseNodeWithHref(nsIContent *node);

  // Get the first <title> element with the given IsNodeOfType type, or
  // return null if there isn't one
  nsIContent* GetTitleContent(PRUint32 aNodeType);
  // Find the first "title" element in the given IsNodeOfType type and
  // append the concatenation of its text node children to aTitle. Do
  // nothing if there is no such element.
  void GetTitleFromElement(PRUint32 aNodeType, nsAString& aTitle);

  nsresult doCreateShell(nsPresContext* aContext,
                         nsIViewManager* aViewManager, nsStyleSet* aStyleSet,
                         nsCompatibility aCompatMode,
                         nsIPresShell** aInstancePtrResult);

  nsresult ResetStylesheetsToURI(nsIURI* aURI);
  virtual nsStyleSet::sheetType GetAttrSheetType();
  void FillStyleSet(nsStyleSet* aStyleSet);

  // Return whether all the presshells for this document are safe to flush
  PRBool IsSafeToFlush() const;
  
  virtual PRInt32 GetDefaultNamespaceID() const
  {
    return kNameSpaceID_None;
  }

  void DispatchPageTransition(nsPIDOMEventTarget* aDispatchTarget,
                              const nsAString& aType,
                              PRBool aPersisted);

  virtual nsPIDOMWindow *GetWindowInternal();
  virtual nsPIDOMWindow *GetInnerWindowInternal();
  virtual nsIScriptGlobalObject* GetScriptHandlingObjectInternal() const;

#define NS_DOCUMENT_NOTIFY_OBSERVERS(func_, params_)                        \
  NS_OBSERVER_ARRAY_NOTIFY_XPCOM_OBSERVERS(mObservers, nsIDocumentObserver, \
                                           func_, params_);
  
#ifdef DEBUG
  void VerifyRootContentState();
#endif

  nsDocument(const char* aContentType);
  virtual ~nsDocument();

  void EnsureOnloadBlocker();

  nsCString mReferrer;
  nsString mLastModified;

  nsTArray<nsIObserver*> mCharSetObservers;

  PLDHashTable *mSubDocuments;

  // Array of owning references to all children
  nsAttrAndChildArray mChildren;

  // Pointer to our parser if we're currently in the process of being
  // parsed into.
  nsCOMPtr<nsIParser> mParser;

  // Weak reference to our sink for in case we no longer have a parser.  This
  // will allow us to flush out any pending stuff from the sink even if
  // EndLoad() has already happened.
  nsWeakPtr mWeakSink;

  nsCOMArray<nsIStyleSheet> mStyleSheets;
  nsCOMArray<nsIStyleSheet> mCatalogSheets;

  // Array of observers
  nsTObserverArray<nsIDocumentObserver*> mObservers;

  // If document is created for example using
  // document.implementation.createDocument(...), mScriptObject points to
  // the script global object of the original document.
  nsWeakPtr mScriptObject;

  // Weak reference to the scope object (aka the script global object)
  // that, unlike mScriptGlobalObject, is never unset once set. This
  // is a weak reference to avoid leaks due to circular references.
  nsWeakPtr mScopeObject;

  nsCOMPtr<nsIEventListenerManager> mListenerManager;
  nsCOMPtr<nsIDOMStyleSheetList> mDOMStyleSheets;
  nsRefPtr<nsDOMStyleSheetSetList> mStyleSheetSetList;
  nsRefPtr<nsScriptLoader> mScriptLoader;
  nsDocHeaderData* mHeaderData;
  /* mIdentifierMap works as follows for IDs:
   * 1) Attribute changes affect the table immediately (removing and adding
   *    entries as needed).
   * 2) Removals from the DOM affect the table immediately
   * 3) Additions to the DOM always update existing entries for names, and add
   *    new ones for IDs.
   */
  nsTHashtable<nsIdentifierMapEntry> mIdentifierMap;

  nsClassHashtable<nsStringHashKey, nsRadioGroupStruct> mRadioGroups;

  // True if the document has been detached from its content viewer.
  PRPackedBool mIsGoingAway:1;
  // True if the document is being destroyed.
  PRPackedBool mInDestructor:1;

  // True if this document has ever had an HTML or SVG <title> element
  // bound to it
  PRPackedBool mMayHaveTitleElement:1;

  PRPackedBool mHasWarnedAboutBoxObjects:1;

  PRPackedBool mDelayFrameLoaderInitialization:1;

  PRPackedBool mSynchronousDOMContentLoaded:1;

  // If true, we have an input encoding.  If this is false, then the
  // document was created entirely in memory
  PRPackedBool mHaveInputEncoding:1;

  PRPackedBool mInXBLUpdate:1;

  // This flag is only set in nsXMLDocument, for e.g. documents used in XBL. We
  // don't want animations to play in such documents, so we need to store the
  // flag here so that we can check it in nsDocument::GetAnimationController.
  PRPackedBool mLoadedAsInteractiveData:1;

  PRUint8 mXMLDeclarationBits;

  PRUint8 mDefaultElementType;

  nsInterfaceHashtable<nsVoidPtrHashKey, nsPIBoxObject> *mBoxObjectTable;

  // The channel that got passed to StartDocumentLoad(), if any
  nsCOMPtr<nsIChannel> mChannel;
  nsRefPtr<nsHTMLStyleSheet> mAttrStyleSheet;
  nsRefPtr<nsHTMLCSSStyleSheet> mStyleAttrStyleSheet;
  nsRefPtr<nsXMLEventsManager> mXMLEventsManager;

  nsCOMPtr<nsIScriptEventManager> mScriptEventManager;

  nsString mBaseTarget;

  // Our update nesting level
  PRUint32 mUpdateNestLevel;

  // The application cache that this document is associated with, if
  // any.  This can change during the lifetime of the document.
  nsCOMPtr<nsIApplicationCache> mApplicationCache;

  nsCOMPtr<nsIContent> mFirstBaseNodeWithHref;

  PRInt32 mDocumentState;
  PRInt32 mGotDocumentState;

private:
  friend class nsUnblockOnloadEvent;

  void PostUnblockOnloadEvent();
  void DoUnblockOnload();

  nsresult CheckFrameOptions();
  nsresult InitCSP();

  /**
   * See if aDocument is a child of this.  If so, return the frame element in
   * this document that holds currentDoc (or an ancestor).
   */
  already_AddRefed<nsIDOMElement>
    CheckAncestryAndGetFrame(nsIDocument* aDocument) const;

  // Just like EnableStyleSheetsForSet, but doesn't check whether
  // aSheetSet is null and allows the caller to control whether to set
  // aSheetSet as the preferred set in the CSSLoader.
  void EnableStyleSheetsForSetInternal(const nsAString& aSheetSet,
                                       PRBool aUpdateCSSLoader);

  // These are not implemented and not supported.
  nsDocument(const nsDocument& aOther);
  nsDocument& operator=(const nsDocument& aOther);

  nsCOMPtr<nsISupports> mXPathEvaluatorTearoff;

  // The layout history state that should be used by nodes in this
  // document.  We only actually store a pointer to it when:
  // 1)  We have no script global object.
  // 2)  We haven't had Destroy() called on us yet.
  nsCOMPtr<nsILayoutHistoryState> mLayoutHistoryState;

  // Currently active onload blockers
  PRUint32 mOnloadBlockCount;
  // Onload blockers which haven't been activated yet
  PRUint32 mAsyncOnloadBlockCount;
  nsCOMPtr<nsIRequest> mOnloadBlocker;
  ReadyState mReadyState;

  // A hashtable of styled links keyed by address pointer.
  nsTHashtable<nsPtrHashKey<mozilla::dom::Link> > mStyledLinks;
#ifdef DEBUG
  // Indicates whether mStyledLinks was cleared or not.  This is used to track
  // state so we can provide useful assertions to consumers of ForgetLink and
  // AddStyleRelevantLink.
  bool mStyledLinksCleared;
#endif

  // Member to store out last-selected stylesheet set.
  nsString mLastStyleSheetSet;

  nsTArray<nsRefPtr<nsFrameLoader> > mInitializableFrameLoaders;
  nsTArray<nsRefPtr<nsFrameLoader> > mFinalizableFrameLoaders;
  nsRefPtr<nsRunnableMethod<nsDocument> > mFrameLoaderRunner;

  nsRevocableEventPtr<nsRunnableMethod<nsDocument, void, false> >
    mPendingTitleChangeEvent;

  nsExternalResourceMap mExternalResourceMap;

  // All images in process of being preloaded
  nsCOMArray<imgIRequest> mPreloadingImages;

  nsCOMPtr<nsIDOMDOMImplementation> mDOMImplementation;

  nsCString mScrollToRef;
  PRUint8 mScrolledToRefAlready : 1;
  PRUint8 mChangeScrollPosWhenScrollingToRef : 1;

#ifdef DEBUG
protected:
  PRBool mWillReparent;
#endif
};

#define NS_DOCUMENT_INTERFACE_TABLE_BEGIN(_class)                             \
  NS_NODE_OFFSET_AND_INTERFACE_TABLE_BEGIN(_class)                            \
  NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(_class, nsIDOMDocument, nsDocument)      \
  NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(_class, nsIDOMNSDocument, nsDocument)    \
  NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(_class, nsIDOMDocumentEvent, nsDocument) \
  NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(_class, nsIDOMDocumentView, nsDocument)  \
  NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(_class, nsIDOMDocumentTraversal,         \
                                     nsDocument)                              \
  NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(_class, nsIDOMEventTarget, nsDocument)   \
  NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(_class, nsIDOMNode, nsDocument)          \
  NS_INTERFACE_TABLE_ENTRY_AMBIGUOUS(_class, nsIDOM3Document, nsDocument)

#endif /* nsDocument_h___ */