gecko/accessible/src/base/nsDocAccessible.h

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * 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) 2003
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Original Author: Aaron Leventhal (aaronl@netscape.com)
 *
 * 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
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 * ***** END LICENSE BLOCK ***** */

#ifndef _nsDocAccessible_H_
#define _nsDocAccessible_H_

#include "nsHyperTextAccessibleWrap.h"
#include "nsIAccessibleDocument.h"
#include "nsIDocument.h"
#include "nsIDocumentObserver.h"
#include "nsIEditor.h"
#include "nsIObserver.h"
#include "nsIScrollPositionListener.h"
#include "nsITimer.h"
#include "nsIWeakReference.h"
#include "nsCOMArray.h"
#include "nsIDocShellTreeNode.h"

class nsIScrollableView;

const PRUint32 kDefaultCacheSize = 256;

#define NS_DOCACCESSIBLE_IMPL_CID                       \
{  /* 5641921c-a093-4292-9dca-0b51813db57d */           \
  0x5641921c,                                           \
  0xa093,                                               \
  0x4292,                                               \
  { 0x9d, 0xca, 0x0b, 0x51, 0x81, 0x3d, 0xb5, 0x7d }    \
}

class nsDocAccessible : public nsHyperTextAccessibleWrap,
                        public nsIAccessibleDocument,
                        public nsIDocumentObserver,
                        public nsIObserver,
                        public nsIScrollPositionListener,
                        public nsSupportsWeakReference
{  
  NS_DECL_ISUPPORTS_INHERITED
  NS_DECL_CYCLE_COLLECTION_CLASS_INHERITED(nsDocAccessible, nsAccessible)

  NS_DECL_NSIACCESSIBLEDOCUMENT
  NS_DECLARE_STATIC_IID_ACCESSOR(NS_DOCACCESSIBLE_IMPL_CID)

  NS_DECL_NSIOBSERVER

public:
  nsDocAccessible(nsIDOMNode *aNode, nsIWeakReference* aShell);
  virtual ~nsDocAccessible();

  // nsIAccessible
  NS_IMETHOD GetName(nsAString& aName);
  NS_IMETHOD GetDescription(nsAString& aDescription);
  NS_IMETHOD GetAttributes(nsIPersistentProperties **aAttributes);
  NS_IMETHOD GetFocusedChild(nsIAccessible **aFocusedChild);
  NS_IMETHOD TakeFocus(void);

  // nsIScrollPositionListener
  NS_IMETHOD ScrollPositionWillChange(nscoord aX, nscoord aY);
  virtual void ViewPositionDidChange(nsTArray<nsIWidget::Configuration>* aConfigurations) {}
  NS_IMETHOD ScrollPositionDidChange(nscoord aX, nscoord aY);

  // nsIDocumentObserver
  NS_DECL_NSIDOCUMENTOBSERVER

  // nsAccessNode
  virtual nsresult Init();
  virtual nsresult Shutdown();
  virtual nsIFrame* GetFrame();
  virtual PRBool IsDefunct();

  // nsAccessible
  virtual nsresult GetRoleInternal(PRUint32 *aRole);
  virtual nsresult GetStateInternal(PRUint32 *aState, PRUint32 *aExtraState);
  virtual nsresult GetARIAState(PRUint32 *aState, PRUint32 *aExtraState);

  virtual void SetRoleMapEntry(nsRoleMapEntry* aRoleMapEntry);
  virtual nsAccessible* GetParent();

  // nsIAccessibleText
  NS_IMETHOD GetAssociatedEditor(nsIEditor **aEditor);

  // nsDocAccessible

  /**
   * Non-virtual method to fire a delayed event after a 0 length timeout.
   *
   * @param aEventType   [in] the nsIAccessibleEvent event type
   * @param aDOMNode     [in] DOM node the accesible event should be fired for
   * @param aAllowDupes  [in] rule to process an event (see EEventRule constants)
   * @param aIsAsynch    [in] set to PR_TRUE if this is not being called from
   *                      code synchronous with a DOM event
   */
  nsresult FireDelayedAccessibleEvent(PRUint32 aEventType, nsIDOMNode *aDOMNode,
                                      nsAccEvent::EEventRule aAllowDupes = nsAccEvent::eRemoveDupes,
                                      PRBool aIsAsynch = PR_FALSE,
                                      EIsFromUserInput aIsFromUserInput = eAutoDetect);

  /**
   * Fire accessible event after timeout.
   *
   * @param aEvent  [in] the event to fire
   */
  nsresult FireDelayedAccessibleEvent(nsAccEvent *aEvent);

  /**
   * Find the accessible object in the accessibility cache that corresponds to
   * the given node or the first ancestor of it that has an accessible object
   * associated with it. Clear that accessible object's parent's cache of
   * accessible children and remove the accessible object and any descendants
   * from the accessible cache. Fires proper events. New accessible objects will
   * be created and cached again on demand.
   *
   * @param aContent  [in] the child that is changing
   * @param aEvent    [in] the event from nsIAccessibleEvent that caused
   *                   the change.
   */
  void InvalidateCacheSubtree(nsIContent *aContent, PRUint32 aEvent);

  /**
   * Cache access node.
   *
   * @param  aUniquID     [in] the unique identifier of accessible
   * @param  aAccessNode  [in] accessible to cache
   */
  void CacheAccessNode(void *aUniqueID, nsIAccessNode *aAccessNode);

  /**
   * Remove the given access node from document cache.
   */
  void RemoveAccessNodeFromCache(nsIAccessNode *aAccessNode);

  /**
   * Fire document load events.
   *
   * @param  aEventType  [in] nsIAccessibleEvent constant
   */
  virtual void FireDocLoadEvents(PRUint32 aEventType);

  /**
   * Process the event when the queue of pending events is untwisted. Fire
   * accessible events as result of the processing.
   */
  void ProcessPendingEvent(nsAccEvent* aEvent);

protected:
  /**
   * Iterates through sub documents and shut them down.
   */
  void ShutdownChildDocuments(nsIDocShellTreeItem *aStart);

    virtual void GetBoundsRect(nsRect& aRect, nsIFrame** aRelativeFrame);
    virtual nsresult AddEventListeners();
    virtual nsresult RemoveEventListeners();
    void AddScrollListener();
    void RemoveScrollListener();

    /**
     * For any accessibles in this subtree, invalidate their knowledge of
     * their children. Only weak refrences are destroyed, not accessibles.
     * @param aStartNode  The root of the subrtee to invalidate accessible child refs in
     */
    void InvalidateChildrenInSubtree(nsIDOMNode *aStartNode);
    void RefreshNodes(nsIDOMNode *aStartNode);
    static void ScrollTimerCallback(nsITimer *aTimer, void *aClosure);

    /**
     * Fires accessible events when attribute is changed.
     *
     * @param aContent - node that attribute is changed for
     * @param aNameSpaceID - namespace of changed attribute
     * @param aAttribute - changed attribute
     */
    void AttributeChangedImpl(nsIContent* aContent, PRInt32 aNameSpaceID, nsIAtom* aAttribute);

    /**
     * Fires accessible events when ARIA attribute is changed.
     *
     * @param aContent - node that attribute is changed for
     * @param aAttribute - changed attribute
     */
    void ARIAAttributeChanged(nsIContent* aContent, nsIAtom* aAttribute);

    /**
     * Fire text changed event for character data changed. The method is used
     * from nsIMutationObserver methods.
     *
     * @param aContent     the text node holding changed data
     * @param aInfo        info structure describing how the data was changed
     * @param aIsInserted  the flag pointed whether removed or inserted
     *                     characters should be cause of event
     */
    void FireTextChangeEventForText(nsIContent *aContent,
                                    CharacterDataChangeInfo* aInfo,
                                    PRBool aIsInserted);

  /**
   * Create a text change event for a changed node.
   *
   * @param  aContainerAccessible  [in] the parent accessible for the node
   * @param  aNode                 [in] the node that is being inserted or
   *                                 removed, or shown/hidden
   * @param  aAccessible           [in] the accessible for that node, or nsnull
   *                                 if none exists
   * @param  aIsInserting          [in] is aChangeNode being created or shown
   *                                 (vs. removed or hidden)
   * @param  aIsAsync              [in] whether casual change is async
   * @param  aIsFromUserInput      [in] the event is known to be from user input
   */
  already_AddRefed<nsAccEvent>
    CreateTextChangeEventForNode(nsIAccessible *aContainerAccessible,
                                 nsIDOMNode *aNode,
                                 nsIAccessible *aAccessible,
                                 PRBool aIsInserting,
                                 PRBool aIsAsynch,
                                 EIsFromUserInput aIsFromUserInput = eAutoDetect);

  /**
   * Used to define should the event be fired on a delay.
   */
  enum EEventFiringType {
    eNormalEvent,
    eDelayedEvent
  };

  /**
   * Fire show/hide events for either the current node if it has an accessible,
   * or the first-line accessible descendants of the given node.
   *
   * @param  aDOMNode          [in] the given node
   * @param  aAvoidOnThisNode  [in] call with PR_TRUE the first time to
   *                             prevent event firing on root node for change
   * @param  aEventType        [in] event type to fire an event
   * @param  aDelayedOrNormal  [in] whether to fire the event on a delay
   * @param  aIsAsyncChange    [in] whether casual change is async
   * @param  aIsFromUserInput  [in] the event is known to be from user input
   */
  nsresult FireShowHideEvents(nsIDOMNode *aDOMNode, PRBool aAvoidOnThisNode,
                              PRUint32 aEventType,
                              EEventFiringType aDelayedOrNormal,
                              PRBool aIsAsyncChange,
                              EIsFromUserInput aIsFromUserInput = eAutoDetect);

    /**
     * If the given accessible object is a ROLE_ENTRY, fire a value change event for it
     */
    void FireValueChangeForTextFields(nsIAccessible *aPossibleTextFieldAccessible);

    nsAccessNodeHashtable mAccessNodeCache;
    void *mWnd;
    nsCOMPtr<nsIDocument> mDocument;
    nsCOMPtr<nsITimer> mScrollWatchTimer;
    PRUint16 mScrollPositionChangedTicks; // Used for tracking scroll events
    PRPackedBool mIsContentLoaded;
    PRPackedBool mIsLoadCompleteFired;

protected:

  nsRefPtr<nsAccEventQueue> mEventQueue;

    static PRUint32 gLastFocusedAccessiblesState;
    static nsIAtom *gLastFocusedFrameType;
};

NS_DEFINE_STATIC_IID_ACCESSOR(nsDocAccessible,
                              NS_DOCACCESSIBLE_IMPL_CID)

#endif