nsAccessible.cpp

/* -*- 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):
 *   John Gaunt (jgaunt@netscape.com)
 *   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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 * decision by deleting the provisions above and replace them with the notice
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 * the provisions above, a recipient may use your version of this file under
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 * ***** END LICENSE BLOCK ***** */

#include "nsAccessible.h"
#include "nsIAccessibleDocument.h"
#include "nsIDocument.h"
#include "nsIDOMNSDocument.h"
#include "nsIImageDocument.h"
#include "nsIPresShell.h"
#include "nsPresContext.h"
#include "nsIContent.h"
#include "nsIFrame.h"
#include "nsIScrollableView.h"
#include "nsIViewManager.h"
#include "nsIWidget.h"
#include "nsIDOMDocumentView.h"
#include "nsIDOMAbstractView.h"
#include "nsIDOM3Node.h"
#include "nsIDOMWindowInternal.h"
#include "nsPIDOMWindow.h"
#include "nsIDOMElement.h"
#include "nsHTMLLinkAccessible.h"
#include "nsISelection.h"
#include "nsISelectionController.h"
#include "nsIServiceManager.h"
#include "nsXPIDLString.h"

#include "nsIDOMComment.h"
#include "nsITextContent.h"
#include "nsIDOMHTMLImageElement.h"
#include "nsIDOMHTMLInputElement.h"
#include "nsIDOMHTMLBRElement.h"
#include "nsIAtom.h"
#include "nsGUIEvent.h"
#include "nsIDocShellTreeItem.h"

#include "nsIDOMHTMLInputElement.h"
#include "nsIDOMXULSelectCntrlEl.h"
#include "nsIDOMXULSelectCntrlItemEl.h"
#include "nsIDOMHTMLObjectElement.h"
#include "nsIDOMXULButtonElement.h"
#include "nsIDOMXULCheckboxElement.h"
#include "nsIDOMDocument.h"
#include "nsIDOMDocumentXBL.h"
#include "nsIDOMHTMLDocument.h"
#include "nsIDOMXULDocument.h"
#include "nsIDOMXULElement.h"
#include "nsIDOMXULLabelElement.h"
#include "nsIForm.h"
#include "nsIFormControl.h"
#include "nsIPrefService.h"
#include "nsIPrefBranch.h"
#include "nsIScriptGlobalObject.h"
#include "nsIFocusController.h"
#include "nsAccessibleTreeWalker.h"
#include "nsIURI.h"
#include "nsIImageLoadingContent.h"
#include "nsITimer.h"
#include "nsIDOMHTMLDocument.h"
#include "nsArray.h"

#ifdef NS_DEBUG
#include "nsIFrameDebug.h"
#include "nsIDOMCharacterData.h"
#endif

/*
 * Class nsAccessible
 */

//-----------------------------------------------------
// construction 
//-----------------------------------------------------
NS_IMPL_ADDREF_INHERITED(nsAccessible, nsAccessNode)
NS_IMPL_RELEASE_INHERITED(nsAccessible, nsAccessNode)

nsresult nsAccessible::QueryInterface(REFNSIID aIID, void** aInstancePtr)
{
  // Custom-built QueryInterface() knows when we support nsIAccessibleSelectable
  // based on role attribute and waistate:multiselect
  *aInstancePtr = nsnull;
  
  if (aIID.Equals(NS_GET_IID(nsIAccessible))) {
    *aInstancePtr = NS_STATIC_CAST(nsIAccessible*, this);
    NS_ADDREF_THIS();
    return NS_OK;
  }

  if(aIID.Equals(NS_GET_IID(nsPIAccessible))) {
    *aInstancePtr = NS_STATIC_CAST(nsPIAccessible*, this);
    NS_ADDREF_THIS();
    return NS_OK;
  }

  if (aIID.Equals(NS_GET_IID(nsIAccessibleSelectable))) {
    nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
    if (!content) {
      return NS_ERROR_FAILURE; // This accessible has been shut down
    }
    if (HasRoleAttribute(content)) {
      // If we have an XHTML role attribute present and the
      // waistate multiselect attribute not empty or false, then we need
      // to support nsIAccessibleSelectable
      // If either attribute (role or multiselect) change, then we'll
      // destroy this accessible so that we can follow COM identity rules.
      nsAutoString multiSelect;
      content->GetAttr(kNameSpaceID_WAIProperties,
                       nsAccessibilityAtoms::multiselect,
                       multiSelect);
      if (!multiSelect.IsEmpty() && !multiSelect.EqualsLiteral("false")) {
        *aInstancePtr = NS_STATIC_CAST(nsIAccessibleSelectable*, this);
        NS_ADDREF_THIS();
      }
    }
  }

  return nsAccessNode::QueryInterface(aIID, aInstancePtr);
}

nsAccessible::nsAccessible(nsIDOMNode* aNode, nsIWeakReference* aShell): nsAccessNodeWrap(aNode, aShell), 
  mParent(nsnull), mFirstChild(nsnull), mNextSibling(nsnull), mRoleMapEntry(nsnull),
  mAccChildCount(eChildCountUninitialized)
{
#ifdef NS_DEBUG_X
   {
     nsCOMPtr<nsIPresShell> shell(do_QueryReferent(aShell));
     printf(">>> %p Created Acc - Con: %p  Acc: %p  PS: %p", 
             (nsIAccessible*)this, aContent, aAccessible, shell.get());
     if (shell && aContent != nsnull) {
       nsIFrame* frame;
       shell->GetPrimaryFrameFor(aContent, &frame);
       char * name;
       if (GetNameForFrame(frame, &name)) {
         printf(" Name:[%s]", name);
         nsMemory::Free(name);
       }
     }
     printf("\n");
   }
#endif
}

//-----------------------------------------------------
// destruction
//-----------------------------------------------------
nsAccessible::~nsAccessible()
{
}

NS_IMETHODIMP nsAccessible::GetName(nsAString& aName)
{
  aName.Truncate();
  nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
  if (!content) {
    return NS_ERROR_FAILURE;  // Node shut down
  }

  PRBool canAggregateName = mRoleMapEntry &&
                            mRoleMapEntry->nameRule == eNameOkFromChildren;

  if (content->IsContentOfType(nsIContent::eHTML)) {
    return GetHTMLName(aName, canAggregateName);
  }

  if (content->IsContentOfType(nsIContent::eXUL)) {
    return GetXULName(aName, canAggregateName);
  }

  return NS_OK;
}

NS_IMETHODIMP nsAccessible::GetDescription(nsAString& aDescription)
{
  // There are 4 conditions that make an accessible have no accDescription:
  // 1. it's a text node; or
  // 2. It has no DHTML describedby property
  // 3. it doesn't have an accName; or
  // 4. its title attribute already equals to its accName nsAutoString name; 
  nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
  if (!content) {
    return NS_ERROR_FAILURE;  // Node shut down
  }
  if (!content->IsContentOfType(nsIContent::eTEXT)) {
    nsAutoString description;
    nsresult rv = GetTextFromRelationID(nsAccessibilityAtoms::describedby, description);
    if (NS_FAILED(rv)) {
      PRBool isXUL = content->IsContentOfType(nsIContent::eXUL);
      if (isXUL) {
        // Try XUL <description control="[id]">description text</description>
        nsIContent *descriptionContent =
          GetXULLabelContent(content, nsAccessibilityAtoms::description);
        if (descriptionContent) {
          // We have a description content node
          AppendFlatStringFromSubtree(descriptionContent, &description);
        }
      }
      if (description.IsEmpty()) {
        nsIAtom *descAtom = isXUL ? nsAccessibilityAtoms::tooltiptext :
                                    nsAccessibilityAtoms::title;
        if (NS_CONTENT_ATTR_HAS_VALUE ==
            content->GetAttr(kNameSpaceID_None, descAtom, description)) {
          nsAutoString name;
          GetName(name);
          if (name.IsEmpty() || description == name) {
            // Don't use tooltip for a description if this object
            // has no name or the tooltip is the same as the name
            description.Truncate();
          }
        }
      }
    }
    description.CompressWhitespace();
    aDescription = description;
  }

  return NS_OK;
}

// mask values for ui.key.chromeAccess and ui.key.contentAccess
#define NS_MODIFIER_SHIFT    1
#define NS_MODIFIER_CONTROL  2
#define NS_MODIFIER_ALT      4
#define NS_MODIFIER_META     8

// returns the accesskey modifier mask used in the given node's context
// (i.e. chrome or content), or 0 if an error occurs
static PRInt32
GetAccessModifierMask(nsIDOMElement* aDOMNode)
{
  nsCOMPtr<nsIPrefBranch> prefBranch =
    do_GetService(NS_PREFSERVICE_CONTRACTID);
  if (!prefBranch)
    return 0;

  // use ui.key.generalAccessKey (unless it is -1)
  PRInt32 accessKey;
  nsresult rv = prefBranch->GetIntPref("ui.key.generalAccessKey", &accessKey);
  if (NS_SUCCEEDED(rv) && accessKey != -1) {
    switch (accessKey) {
      case nsIDOMKeyEvent::DOM_VK_SHIFT:   return NS_MODIFIER_SHIFT;
      case nsIDOMKeyEvent::DOM_VK_CONTROL: return NS_MODIFIER_CONTROL;
      case nsIDOMKeyEvent::DOM_VK_ALT:     return NS_MODIFIER_ALT;
      case nsIDOMKeyEvent::DOM_VK_META:    return NS_MODIFIER_META;
      default:                             return 0;
    }
  }

  // get the docShell to this DOMNode, return 0 on failure
  nsCOMPtr<nsIContent> content(do_QueryInterface(aDOMNode));
  nsCOMPtr<nsIDocument> document = content->GetCurrentDoc();
  if (!document)
    return 0;
  nsCOMPtr<nsISupports> container = document->GetContainer();
  if (!container)
    return 0;
  nsCOMPtr<nsIDocShellTreeItem> treeItem(do_QueryInterface(container));
  if (!treeItem)
    return 0;

  // determine the access modifier used in this context
  PRInt32 itemType, accessModifierMask = 0;
  treeItem->GetItemType(&itemType);
  switch (itemType) {

  case nsIDocShellTreeItem::typeChrome:
    rv = prefBranch->GetIntPref("ui.key.chromeAccess", &accessModifierMask);
    break;

  case nsIDocShellTreeItem::typeContent:
    rv = prefBranch->GetIntPref("ui.key.contentAccess", &accessModifierMask);
    break;
  }

  return NS_SUCCEEDED(rv) ? accessModifierMask : 0;
}

NS_IMETHODIMP nsAccessible::GetKeyboardShortcut(nsAString& _retval)
{
  nsCOMPtr<nsIDOMElement> elt(do_QueryInterface(mDOMNode));
  if (elt) {
    nsAutoString accesskey;
    elt->GetAttribute(NS_LITERAL_STRING("accesskey"), accesskey);
    if (accesskey.IsEmpty()) {
      nsCOMPtr<nsIContent> content = do_QueryInterface(elt);
      nsIContent *labelContent = GetLabelContent(content);
      if (labelContent) {
        labelContent->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::accesskey, accesskey);
      }
      if (accesskey.IsEmpty()) {
        return NS_ERROR_FAILURE;
      }
    }

    // append the modifiers in reverse order
    // (result: Control+Alt+Shift+Meta+<key>)
    nsAutoString propertyKey;
    PRInt32 modifierMask = GetAccessModifierMask(elt);
    if (modifierMask & NS_MODIFIER_META) {
      propertyKey.AssignLiteral("VK_META");
      nsAccessible::GetFullKeyName(propertyKey, accesskey, accesskey);
    }
    if (modifierMask & NS_MODIFIER_SHIFT) {
      propertyKey.AssignLiteral("VK_SHIFT");
      nsAccessible::GetFullKeyName(propertyKey, accesskey, accesskey);
    }
    if (modifierMask & NS_MODIFIER_ALT) {
      propertyKey.AssignLiteral("VK_ALT");
      nsAccessible::GetFullKeyName(propertyKey, accesskey, accesskey);
    }
    if (modifierMask & NS_MODIFIER_CONTROL) {
      propertyKey.AssignLiteral("VK_CONTROL");
      nsAccessible::GetFullKeyName(propertyKey, accesskey, accesskey);
    }
    _retval= accesskey;
    return NS_OK;
  }
  return NS_ERROR_FAILURE;
}

NS_IMETHODIMP nsAccessible::SetParent(nsIAccessible *aParent)
{
  mParent = aParent;
  return NS_OK;
}

NS_IMETHODIMP nsAccessible::SetFirstChild(nsIAccessible *aFirstChild)
{
  mFirstChild = aFirstChild;
  return NS_OK;
}

NS_IMETHODIMP nsAccessible::SetNextSibling(nsIAccessible *aNextSibling)
{
  mNextSibling = aNextSibling? aNextSibling: DEAD_END_ACCESSIBLE;
  return NS_OK;
}

NS_IMETHODIMP nsAccessible::Init()
{
  nsIContent *content = GetRoleContent(mDOMNode);
  nsAutoString roleString;
  if (content && GetRoleAttribute(content, roleString)) {
    // QI to nsIDOM3Node causes some overhead. Unfortunately we need to do this each
    // time there is a role attribute, because the prefixe to namespace mappings
    // can change within any subtree via the xmlns attribute
    nsCOMPtr<nsIDOM3Node> dom3Node(do_QueryInterface(content));
    if (dom3Node) {
      nsAutoString prefix;
      NS_NAMED_LITERAL_STRING(kWAIRoles_Namespace, "http://www.w3.org/2005/01/wai-rdf/GUIRoleTaxonomy#");
      dom3Node->LookupPrefix(kWAIRoles_Namespace, prefix);
      if (prefix.IsEmpty()) {
        // In HTML we are hardcoded to allow the exact prefix "wairole:" to 
        // always indicate that we are using the WAI roles. This allows DHTML accessibility
        // to be used within HTML
        nsCOMPtr<nsIDOMNSDocument> doc(do_QueryInterface(content->GetDocument()));
        if (doc) {
          nsAutoString mimeType;
          doc->GetContentType(mimeType);
          if (mimeType.EqualsLiteral("text/html")) {
            prefix = NS_LITERAL_STRING("wairole");
          }
        }
      }
      prefix += ':';
      PRUint32 length = prefix.Length();
      if (length > 1 && StringBeginsWith(roleString, prefix)) {
        roleString.Cut(0, length);
        nsCString utf8Role = NS_ConvertUCS2toUTF8(roleString); // For easy comparison
        ToLowerCase(utf8Role);
        PRUint32 index;
        for (index = 0; gWAIRoleMap[index].roleString; index ++) {
          if (utf8Role.Equals(gWAIRoleMap[index].roleString)) {
            break; // The dynamic role attribute maps to an entry in our table
          }
        }
        // Always use some entry if there is a role string
        // If no match, we use the last entry which maps to ROLE_NOTHING
        mRoleMapEntry = &gWAIRoleMap[index];
      }
    }
  }

  return nsAccessNodeWrap::Init();
}

nsIContent *nsAccessible::GetRoleContent(nsIDOMNode *aDOMNode)
{
  // Given the DOM node for an acessible, return content node that
  // we should look at role string from
  // For non-document accessibles, this is the associated content node.
  // For doc accessibles, first try the <body> if it's HTML and there is
  // a role attribute used there.
  // For any other doc accessible , this is the document element.
  nsCOMPtr<nsIContent> content(do_QueryInterface(aDOMNode));
  if (!content) {
    nsCOMPtr<nsIDOMDocument> domDoc(do_QueryInterface(aDOMNode));
    if (domDoc) {
      nsCOMPtr<nsIDOMHTMLDocument> htmlDoc(do_QueryInterface(aDOMNode));
      if (htmlDoc) {
        nsCOMPtr<nsIDOMHTMLElement> bodyElement;
        htmlDoc->GetBody(getter_AddRefs(bodyElement));
        content = do_QueryInterface(bodyElement);
      }
      if (!content || !HasRoleAttribute(content)) {
        nsCOMPtr<nsIDOMElement> docElement;
        domDoc->GetDocumentElement(getter_AddRefs(docElement));
        content = do_QueryInterface(docElement);
      }
    }
  }
  return content;
}

NS_IMETHODIMP nsAccessible::Shutdown()
{
  mNextSibling = nsnull;
  // Make sure none of it's children point to this parent
  if (mFirstChild) {
    nsCOMPtr<nsIAccessible> current(mFirstChild), next;
    while (current) {
      nsCOMPtr<nsPIAccessible> privateAcc(do_QueryInterface(current));
      current->GetNextSibling(getter_AddRefs(next));
      privateAcc->SetParent(nsnull);
      current = next;
    }
  }
  // Now invalidate the child count and pointers to other accessibles
  InvalidateChildren();
  if (mParent) {
    nsCOMPtr<nsPIAccessible> privateParent(do_QueryInterface(mParent));
    privateParent->InvalidateChildren();
    mParent = nsnull;
  }

  return nsAccessNodeWrap::Shutdown();
}

NS_IMETHODIMP nsAccessible::InvalidateChildren()
{
  // Document has transformed, reset our invalid children and child count
  mAccChildCount = -1;
  mFirstChild = nsnull;
  return NS_OK;
}

NS_IMETHODIMP nsAccessible::GetParent(nsIAccessible **  aParent)
{
  if (!mWeakShell) {
    // This node has been shut down
    *aParent = nsnull;
    return NS_ERROR_FAILURE;
  }
  if (mParent) {
    *aParent = mParent;
    NS_ADDREF(*aParent);
    return NS_OK;
  }

  *aParent = nsnull;
  // Last argument of PR_TRUE indicates to walk anonymous content
  nsAccessibleTreeWalker walker(mWeakShell, mDOMNode, PR_TRUE); 
  if (NS_SUCCEEDED(walker.GetParent())) {
    *aParent = walker.mState.accessible;
    SetParent(*aParent); // Cache it, unless perhaps accessible class overrides SetParent
    NS_ADDREF(*aParent);
  }

  return NS_OK;
}

  /* readonly attribute nsIAccessible nextSibling; */
NS_IMETHODIMP nsAccessible::GetNextSibling(nsIAccessible * *aNextSibling) 
{ 
  *aNextSibling = nsnull; 
  if (!mWeakShell) {
    // This node has been shut down
    return NS_ERROR_FAILURE;
  }
  if (!mParent) {
    nsCOMPtr<nsIAccessible> parent;
    GetParent(getter_AddRefs(parent));
    if (parent) {
      PRInt32 numChildren;
      parent->GetChildCount(&numChildren);  // Make sure we cache all of the children
    }
  }

  if (mNextSibling || !mParent) {
    // If no parent, don't try to calculate a new sibling
    // It either means we're at the root or shutting down the parent
    if (mNextSibling != DEAD_END_ACCESSIBLE) {
      NS_IF_ADDREF(*aNextSibling = mNextSibling);
    }
    return NS_OK;
  }

  return NS_ERROR_FAILURE;
}

  /* readonly attribute nsIAccessible previousSibling; */
NS_IMETHODIMP nsAccessible::GetPreviousSibling(nsIAccessible * *aPreviousSibling) 
{
  *aPreviousSibling = nsnull;

  if (!mWeakShell) {
    // This node has been shut down
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIAccessible> parent;
  if (NS_FAILED(GetParent(getter_AddRefs(parent)))) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIAccessible> testAccessible, prevSibling;
  parent->GetFirstChild(getter_AddRefs(testAccessible));
  while (testAccessible && this != testAccessible) {
    prevSibling = testAccessible;
    prevSibling->GetNextSibling(getter_AddRefs(testAccessible));
  }

  if (!prevSibling) {
    return NS_ERROR_FAILURE;
  }

  NS_ADDREF(*aPreviousSibling = prevSibling);
  return NS_OK;
}

  /* readonly attribute nsIAccessible firstChild; */
NS_IMETHODIMP nsAccessible::GetFirstChild(nsIAccessible * *aFirstChild) 
{  
  if (gIsCacheDisabled) {
    InvalidateChildren();
  }
  PRInt32 numChildren;
  GetChildCount(&numChildren);  // Make sure we cache all of the children

  NS_IF_ADDREF(*aFirstChild = mFirstChild);

  return NS_OK;  
}

  /* readonly attribute nsIAccessible lastChild; */
NS_IMETHODIMP nsAccessible::GetLastChild(nsIAccessible * *aLastChild)
{  
  GetChildAt(-1, aLastChild);
  return NS_OK;
}

NS_IMETHODIMP nsAccessible::GetChildAt(PRInt32 aChildNum, nsIAccessible **aChild)
{
  // aChildNum is a zero-based index

  PRInt32 numChildren;
  GetChildCount(&numChildren);

  // If no children or aChildNum is larger than numChildren, return null
  if (aChildNum >= numChildren || numChildren == 0 || !mWeakShell) {
    *aChild = nsnull;
    return NS_ERROR_FAILURE;
  // If aChildNum is less than zero, set aChild to last index
  } else if (aChildNum < 0) {
    aChildNum = numChildren - 1;
  }

  nsCOMPtr<nsIAccessible> current(mFirstChild), nextSibling;
  PRInt32 index = 0;

  while (current) {
    nextSibling = current;
    if (++index > aChildNum) {
      break;
    }
    nextSibling->GetNextSibling(getter_AddRefs(current));
  }

  NS_IF_ADDREF(*aChild = nextSibling);

  return NS_OK;
}

void nsAccessible::CacheChildren(PRBool aWalkAnonContent)
{
  if (!mWeakShell) {
    // This node has been shut down
    mAccChildCount = -1;
    return;
  }

  if (mAccChildCount == eChildCountUninitialized) {
    nsAccessibleTreeWalker walker(mWeakShell, mDOMNode, aWalkAnonContent);
    // Seed the frame hint early while we're still on a container node.
    // This is better than doing the GetPrimaryFrameFor() later on
    // a text node, because text nodes aren't in the frame map.
    walker.mState.frame = GetFrame();

    nsCOMPtr<nsPIAccessible> privatePrevAccessible;
    mAccChildCount = 0;
    walker.GetFirstChild();
    SetFirstChild(walker.mState.accessible);

    while (walker.mState.accessible) {
      ++mAccChildCount;
      privatePrevAccessible = do_QueryInterface(walker.mState.accessible);
      privatePrevAccessible->SetParent(this);
      walker.GetNextSibling();
      privatePrevAccessible->SetNextSibling(walker.mState.accessible);
    }
  }
}

/* readonly attribute long childCount; */
NS_IMETHODIMP nsAccessible::GetChildCount(PRInt32 *aAccChildCount) 
{
  CacheChildren(PR_TRUE);
  *aAccChildCount = mAccChildCount;
  return NS_OK;  
}

/* readonly attribute long indexInParent; */
NS_IMETHODIMP nsAccessible::GetIndexInParent(PRInt32 *aIndexInParent)
{
  *aIndexInParent = -1;
  if (!mWeakShell) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIAccessible> parent;
  GetParent(getter_AddRefs(parent));
  if (!parent) {
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsIAccessible> sibling;
  parent->GetFirstChild(getter_AddRefs(sibling));
  if (!sibling) {
    return NS_ERROR_FAILURE;
  }

  *aIndexInParent = 0;
  while (sibling != this) {
    NS_ASSERTION(sibling, "Never ran into the same child that we started from");

    if (!sibling)
      return NS_ERROR_FAILURE;

    ++*aIndexInParent;
    nsCOMPtr<nsIAccessible> tempAccessible;
    sibling->GetNextSibling(getter_AddRefs(tempAccessible));
    sibling = tempAccessible;
  }

  return NS_OK;
}

nsresult nsAccessible::GetTranslatedString(const nsAString& aKey, nsAString& aStringOut)
{
  nsXPIDLString xsValue;

  if (!gStringBundle || 
    NS_FAILED(gStringBundle->GetStringFromName(PromiseFlatString(aKey).get(), getter_Copies(xsValue)))) 
    return NS_ERROR_FAILURE;

  aStringOut.Assign(xsValue);
  return NS_OK;
}

nsresult nsAccessible::GetFullKeyName(const nsAString& aModifierName, const nsAString& aKeyName, nsAString& aStringOut)
{
  nsXPIDLString modifierName, separator;

  if (!gKeyStringBundle ||
      NS_FAILED(gKeyStringBundle->GetStringFromName(PromiseFlatString(aModifierName).get(), 
                                                    getter_Copies(modifierName))) ||
      NS_FAILED(gKeyStringBundle->GetStringFromName(PromiseFlatString(NS_LITERAL_STRING("MODIFIER_SEPARATOR")).get(), 
                                                    getter_Copies(separator)))) {
    return NS_ERROR_FAILURE;
  }

  aStringOut = modifierName + separator + aKeyName; 
  return NS_OK;
}

PRBool nsAccessible::IsPartiallyVisible(PRBool *aIsOffscreen) 
{
  // We need to know if at least a kMinPixels around the object is visible
  // Otherwise it will be marked STATE_OFFSCREEN and STATE_INVISIBLE
  
  *aIsOffscreen = PR_FALSE;

  const PRUint16 kMinPixels  = 12;
   // Set up the variables we need, return false if we can't get at them all
  nsCOMPtr<nsIPresShell> shell(GetPresShell());
  if (!shell) 
    return PR_FALSE;

  nsIViewManager* viewManager = shell->GetViewManager();
  if (!viewManager)
    return PR_FALSE;

  nsIFrame *frame = GetFrame();
  if (!frame) {
    return PR_FALSE;
  }

  // If visibility:hidden or visibility:collapsed then mark with STATE_INVISIBLE
  if (!frame->GetStyleVisibility()->IsVisible())
  {
      return PR_FALSE;
  }

  nsPresContext *presContext = shell->GetPresContext();
  if (!presContext)
    return PR_FALSE;

  // Get the bounds of the current frame, relative to the current view.
  // We don't use the more accurate GetBoundsRect, because that is more expensive 
  // and the STATE_OFFSCREEN flag that this is used for only needs to be a rough indicator

  nsRect relFrameRect = frame->GetRect();
  nsPoint frameOffset;
  nsIView *containingView = frame->GetViewExternal();
  if (!containingView) {
    frame->GetOffsetFromView(frameOffset, &containingView);
    if (!containingView)
      return PR_FALSE;  // no view -- not visible
    relFrameRect.x = frameOffset.x;
    relFrameRect.y = frameOffset.y;
  }

  float p2t;
  p2t = presContext->PixelsToTwips();
  nsRectVisibility rectVisibility;
  viewManager->GetRectVisibility(containingView, relFrameRect, 
                                 NS_STATIC_CAST(PRUint16, (kMinPixels * p2t)), 
                                 &rectVisibility);

  if (rectVisibility == nsRectVisibility_kVisible ||
      (rectVisibility == nsRectVisibility_kZeroAreaRect && frame->GetNextInFlow())) {
    // This view says it is visible, but we need to check the parent view chain :(
    // Note: zero area rects can occur in the first frame of a multi-frame text flow,
    //       in which case the next frame exists because the text flow is visible
    while ((containingView = containingView->GetParent()) != nsnull) {
      if (containingView->GetVisibility() == nsViewVisibility_kHide) {
        return PR_FALSE;
      }
    }
    return PR_TRUE;
  }

  *aIsOffscreen = rectVisibility != nsRectVisibility_kZeroAreaRect;
  return PR_FALSE;
}

/* readonly attribute wstring state; */
NS_IMETHODIMP nsAccessible::GetState(PRUint32 *aState) 
{ 
  *aState = 0;

  nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
  if (!content) {
    return NS_ERROR_FAILURE;  // Node shut down
  }

  // Set STATE_UNAVAILABLE state based on disabled attribute
  // The disabled attribute is mostly used in XUL elements and HTML forms, but
  // if someone sets it on another attribute, 
  // it seems reasonable to consider it unavailable
  PRBool isDisabled;
  if (content->IsContentOfType(nsIContent::eHTML)) {
    // In HTML, just the presence of the disabled attribute means it is disabled,
    // therefore disabled="false" indicates disabled!
    isDisabled = content->HasAttr(kNameSpaceID_None, nsAccessibilityAtoms::disabled);
  }
  else {
    nsAutoString disabled;
    content->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::disabled, disabled);
    isDisabled = disabled.EqualsLiteral("true");
  }
  if (isDisabled) {
    *aState |= STATE_UNAVAILABLE;
  }
  else if (content->IsContentOfType(nsIContent::eELEMENT)) {
    if (!mRoleMapEntry) {
      // Default state for element accessible is focusable unless role is manually set
      // Subclasses of nsAccessible will clear focusable state if necessary
      *aState |= STATE_FOCUSABLE;
    }
    else {
      nsIFrame *frame = GetFrame();
      if (frame && frame->IsFocusable()) {
        *aState |= STATE_FOCUSABLE;
      }
    }

    if (gLastFocusedNode == mDOMNode) {
      *aState |= STATE_FOCUSED;
    }
  }

  // Check if STATE_OFFSCREEN bitflag should be turned on for this object
  PRBool isOffscreen;
  if (!IsPartiallyVisible(&isOffscreen)) {
    *aState |= STATE_INVISIBLE;
    if (isOffscreen)
      *aState |= STATE_OFFSCREEN;
  }

  return NS_OK;
}

  /* readonly attribute boolean focusedChild; */
NS_IMETHODIMP nsAccessible::GetFocusedChild(nsIAccessible **aFocusedChild) 
{ 
  nsCOMPtr<nsIAccessible> focusedChild;
  if (gLastFocusedNode == mDOMNode) {
    focusedChild = this;
  }
  else if (gLastFocusedNode) {
    nsCOMPtr<nsIAccessibilityService> accService =
      do_GetService("@mozilla.org/accessibilityService;1");
    NS_ENSURE_TRUE(accService, NS_ERROR_FAILURE);
    accService->GetAccessibleInWeakShell(gLastFocusedNode, mWeakShell, 
                                         getter_AddRefs(focusedChild));
    if (focusedChild) {
      nsCOMPtr<nsIAccessible> focusedParentAccessible;
      focusedChild->GetParent(getter_AddRefs(focusedParentAccessible));
      if (focusedParentAccessible != this) {
        focusedChild = nsnull;
      }
    }
  }

  NS_IF_ADDREF(*aFocusedChild = focusedChild);
  return NS_OK;
}

  /* nsIAccessible getChildAtPoint (in long x, in long y); */
NS_IMETHODIMP nsAccessible::GetChildAtPoint(PRInt32 tx, PRInt32 ty, nsIAccessible **aAccessible)
{
  *aAccessible = nsnull;
  PRInt32 numChildren; // Make sure all children cached first
  GetChildCount(&numChildren);

  nsCOMPtr<nsIAccessible> child;
  GetFirstChild(getter_AddRefs(child));

  PRInt32 x, y, w, h;
  PRUint32 state;

  while (child) {
    child->GetBounds(&x, &y, &w, &h);
    if (tx >= x && tx < x + w && ty >= y && ty < y + h) {
      child->GetFinalState(&state);
      if ((state & (STATE_OFFSCREEN|STATE_INVISIBLE)) == 0) {   // Don't walk into offscreen items
        NS_ADDREF(*aAccessible = child);
        return NS_OK;
      }
    }
    nsCOMPtr<nsIAccessible> next;
    child->GetNextSibling(getter_AddRefs(next));
    child = next;
  }

  GetState(&state);
  GetBounds(&x, &y, &w, &h);
  if ((state & (STATE_OFFSCREEN|STATE_INVISIBLE)) == 0 &&
      tx >= x && tx < x + w && ty >= y && ty < y + h) {
    *aAccessible = this;
    NS_ADDREF_THIS();
    return NS_OK;
  }
  return NS_ERROR_FAILURE;
}

void nsAccessible::GetScreenOrigin(nsPresContext *aPresContext, nsIFrame *aFrame, nsRect *aRect)
{
  aRect->x = aRect->y = 0;

  if (!aPresContext) {
    return;
  }

  nsPoint origin(0,0);
  nsIView *view = aFrame->GetViewExternal();
  if (!view) {
    aFrame->GetOffsetFromView(origin, &view);
    NS_ASSERTION(view, "Frame has no view");
  }

  nsPoint viewOrigin(0,0);
  nsIWidget *widget = view->GetNearestWidget(&viewOrigin);
  origin += viewOrigin;

  // Get the scale from that Presentation Context
  float t2p = aPresContext->TwipsToPixels();

  // Convert to pixels using that scale
  origin.x = NSTwipsToIntPixels(origin.x, t2p);
  origin.y = NSTwipsToIntPixels(origin.y, t2p);
  
  // Add the widget's screen coordinates to the offset we've counted
  NS_ASSERTION(widget, "No widget for top view");
  widget->WidgetToScreen(nsRect(origin.x, origin.y, 1, 1), *aRect);
}

void nsAccessible::GetBoundsRect(nsRect& aTotalBounds, nsIFrame** aBoundingFrame)
{
/*
 * This method is used to determine the bounds of a content node.
 * Because HTML wraps and links are not always rectangular, this
 * method uses the following algorithm:
 *
 * 1) Start with an empty rectangle
 * 2) Add the rect for the primary frame from for the DOM node.
 * 3) For each next frame at the same depth with the same DOM node, add that rect to total
 * 4) If that frame is an inline frame, search deeper at that point in the tree, adding all rects
 */

  // Initialization area
  *aBoundingFrame = nsnull;
  nsIFrame *firstFrame = GetBoundsFrame();
  if (!firstFrame)
    return;

  // Find common relative parent
  // This is an ancestor frame that will incompass all frames for this content node.
  // We need the relative parent so we can get absolute screen coordinates
  nsIFrame *ancestorFrame = firstFrame;

  while (ancestorFrame) {  
    *aBoundingFrame = ancestorFrame;
    // If any other frame type, we only need to deal with the primary frame
    // Otherwise, there may be more frames attached to the same content node
    if (!IsCorrectFrameType(ancestorFrame, nsAccessibilityAtoms::inlineFrame) &&
        !IsCorrectFrameType(ancestorFrame, nsAccessibilityAtoms::textFrame))
      break;
    ancestorFrame = ancestorFrame->GetParent();
  }

  nsIFrame *iterFrame = firstFrame;
  nsCOMPtr<nsIContent> firstContent(do_QueryInterface(mDOMNode));
  nsIContent* iterContent = firstContent;
  PRInt32 depth = 0;

  // Look only at frames below this depth, or at this depth (if we're still on the content node we started with)
  while (iterContent == firstContent || depth > 0) {
    // Coordinates will come back relative to parent frame
    nsRect currFrameBounds = iterFrame->GetRect();
    
    // Make this frame's bounds relative to common parent frame
    currFrameBounds +=
      iterFrame->GetParent()->GetOffsetToExternal(*aBoundingFrame);

    // Add this frame's bounds to total
    aTotalBounds.UnionRect(aTotalBounds, currFrameBounds);

    nsIFrame *iterNextFrame = nsnull;

    if (IsCorrectFrameType(iterFrame, nsAccessibilityAtoms::inlineFrame)) {
      // Only do deeper bounds search if we're on an inline frame
      // Inline frames can contain larger frames inside of them
      iterNextFrame = iterFrame->GetFirstChild(nsnull);
    }

    if (iterNextFrame) 
      ++depth;  // Child was found in code above this: We are going deeper in this iteration of the loop
    else {  
      // Use next sibling if it exists, or go back up the tree to get the first next-in-flow or next-sibling 
      // within our search
      while (iterFrame) {
        iterNextFrame = iterFrame->GetNextInFlow();
        if (!iterNextFrame)
          iterNextFrame = iterFrame->GetNextSibling();
        if (iterNextFrame || --depth < 0) 
          break;
        iterFrame = iterFrame->GetParent();
      }
    }

    // Get ready for the next round of our loop
    iterFrame = iterNextFrame;
    if (iterFrame == nsnull)
      break;
    iterContent = nsnull;
    if (depth == 0)
      iterContent = iterFrame->GetContent();
  }
}


/* void getBounds (out long x, out long y, out long width, out long height); */
NS_IMETHODIMP nsAccessible::GetBounds(PRInt32 *x, PRInt32 *y, PRInt32 *width, PRInt32 *height)
{
  // This routine will get the entire rectange for all the frames in this node
  // -------------------------------------------------------------------------
  //      Primary Frame for node
  //  Another frame, same node                <- Example
  //  Another frame, same node

  nsPresContext *presContext = GetPresContext();
  if (!presContext)
  {
    *x = *y = *width = *height = 0;
    return NS_ERROR_FAILURE;
  }

  float t2p;
  t2p = presContext->TwipsToPixels();   // Get pixels to twips conversion factor

  nsRect unionRectTwips;
  nsIFrame* aBoundingFrame = nsnull;
  GetBoundsRect(unionRectTwips, &aBoundingFrame);   // Unions up all primary frames for this node and all siblings after it
  if (!aBoundingFrame) {
    *x = *y = *width = *height = 0;
    return NS_ERROR_FAILURE;
  }

  *x      = NSTwipsToIntPixels(unionRectTwips.x, t2p); 
  *y      = NSTwipsToIntPixels(unionRectTwips.y, t2p);
  *width  = NSTwipsToIntPixels(unionRectTwips.width, t2p);
  *height = NSTwipsToIntPixels(unionRectTwips.height, t2p);

  // We have the union of the rectangle, now we need to put it in absolute screen coords

  nsRect orgRectPixels, pageRectPixels;
  GetScreenOrigin(presContext, aBoundingFrame, &orgRectPixels);
  *x += orgRectPixels.x;
  *y += orgRectPixels.y;

  return NS_OK;
}

// helpers

/**
  * Static
  * Helper method to help sub classes make sure they have the proper
  *     frame when walking the frame tree to get at children and such
  */
PRBool nsAccessible::IsCorrectFrameType( nsIFrame* aFrame, nsIAtom* aAtom ) 
{
  NS_ASSERTION(aFrame != nsnull, "aFrame is null in call to IsCorrectFrameType!");
  NS_ASSERTION(aAtom != nsnull, "aAtom is null in call to IsCorrectFrameType!");

  return aFrame->GetType() == aAtom;
}


nsIFrame* nsAccessible::GetBoundsFrame()
{
  return GetFrame();
}

already_AddRefed<nsIAccessible>
nsAccessible::GetMultiSelectFor(nsIDOMNode *aNode)
{
  NS_ENSURE_TRUE(aNode, nsnull);
  nsCOMPtr<nsIAccessibilityService> accService =
    do_GetService("@mozilla.org/accessibilityService;1");
  NS_ENSURE_TRUE(accService, nsnull);
  nsCOMPtr<nsIAccessible> accessible;
  accService->GetAccessibleFor(aNode, getter_AddRefs(accessible));
  if (!accessible) {
    return nsnull;
  }

  PRUint32 state;
  accessible->GetFinalState(&state);
  if (0 == (state & STATE_SELECTABLE)) {
    return nsnull;
  }

  PRUint32 containerRole;
  while (0 == (state & STATE_MULTISELECTABLE)) {
    nsIAccessible *current = accessible;
    current->GetParent(getter_AddRefs(accessible));
    if (!accessible || (NS_SUCCEEDED(accessible->GetFinalRole(&containerRole)) &&
                        containerRole == ROLE_PANE)) {
      return nsnull;
    }
    accessible->GetFinalState(&state);
  }
  nsIAccessible *returnAccessible = nsnull;
  accessible.swap(returnAccessible);
  return returnAccessible;
}

nsresult nsAccessible::SetNonTextSelection(PRBool aSelect)
{
  nsCOMPtr<nsIAccessible> multiSelect = GetMultiSelectFor(mDOMNode);
  if (!multiSelect) {
    return aSelect ? TakeFocus() : NS_ERROR_FAILURE;
  }
  nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
  NS_ASSERTION(content, "Called for dead accessible");

  // For DHTML widgets use WAI namespace
  PRUint32 nameSpaceID = mRoleMapEntry ? kNameSpaceID_WAIProperties : kNameSpaceID_None;
  if (aSelect) {
    return content->SetAttr(nameSpaceID, nsAccessibilityAtoms::selected, NS_LITERAL_STRING("true"), PR_TRUE);
  }
  return content->UnsetAttr(nameSpaceID, nsAccessibilityAtoms::selected, PR_TRUE);
}

/* void removeSelection (); */
NS_IMETHODIMP nsAccessible::RemoveSelection()
{
  if (!mDOMNode) {
    return NS_ERROR_FAILURE;
  }

  PRUint32 state;
  GetFinalState(&state);
  if (state & STATE_SELECTABLE) {
    return SetNonTextSelection(PR_TRUE);
  }

  nsCOMPtr<nsISelectionController> control(do_QueryReferent(mWeakShell));
  if (!control) {
    return NS_ERROR_FAILURE;  
  }

  nsCOMPtr<nsISelection> selection;
  nsresult rv = control->GetSelection(nsISelectionController::SELECTION_NORMAL, getter_AddRefs(selection));
  if (NS_FAILED(rv))
    return rv;

  nsCOMPtr<nsIDOMNode> parent;
  rv = mDOMNode->GetParentNode(getter_AddRefs(parent));
  if (NS_FAILED(rv))
    return rv;

  rv = selection->Collapse(parent, 0);
  if (NS_FAILED(rv))
    return rv;

  return NS_OK;
}

/* void takeSelection (); */
NS_IMETHODIMP nsAccessible::TakeSelection()
{
  if (!mDOMNode) {
    return NS_ERROR_FAILURE;
  }

  PRUint32 state;
  GetFinalState(&state);
  if (state & STATE_SELECTABLE) {
    return SetNonTextSelection(PR_TRUE);
  }

  nsCOMPtr<nsISelectionController> control(do_QueryReferent(mWeakShell));
  if (!control) {
    return NS_ERROR_FAILURE;  
  }
 
  nsCOMPtr<nsISelection> selection;
  nsresult rv = control->GetSelection(nsISelectionController::SELECTION_NORMAL, getter_AddRefs(selection));
  if (NS_FAILED(rv))
    return rv;

  nsCOMPtr<nsIDOMNode> parent;
  rv = mDOMNode->GetParentNode(getter_AddRefs(parent));
  if (NS_FAILED(rv))
    return rv;

  PRInt32 offsetInParent = 0;
  nsCOMPtr<nsIDOMNode> child;
  rv = parent->GetFirstChild(getter_AddRefs(child));
  if (NS_FAILED(rv))
    return rv;

  nsCOMPtr<nsIDOMNode> next; 

  while(child)
  {
    if (child == mDOMNode) {
      // Collapse selection to just before desired element,
      rv = selection->Collapse(parent, offsetInParent);
      if (NS_FAILED(rv))
        return rv;

      // then extend it to just after
      rv = selection->Extend(parent, offsetInParent+1);
      return rv;
    }

     child->GetNextSibling(getter_AddRefs(next));
     child = next;
     offsetInParent++;
  }

  // didn't find a child
  return NS_ERROR_FAILURE;
}

/* void takeFocus (); */
NS_IMETHODIMP nsAccessible::TakeFocus()
{ 
  nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
  if (!content) {
    return NS_ERROR_FAILURE;
  }
  content->SetFocus(GetPresContext());

  return NS_OK;
}

nsresult nsAccessible::AppendStringWithSpaces(nsAString *aFlatString, const nsAString& textEquivalent)
{
  // Insert spaces to insure that words from controls aren't jammed together
  if (!textEquivalent.IsEmpty()) {
    if (!aFlatString->IsEmpty())
      aFlatString->Append(PRUnichar(' '));
    aFlatString->Append(textEquivalent);
    aFlatString->Append(PRUnichar(' '));
  }
  return NS_OK;
}

nsresult nsAccessible::AppendNameFromAccessibleFor(nsIContent *aContent,
                                                   nsAString *aFlatString,
                                                   PRBool aFromValue)
{
  nsAutoString textEquivalent, value;

  nsCOMPtr<nsIDOMNode> domNode(do_QueryInterface(aContent));
  nsCOMPtr<nsIAccessible> accessible;
  if (domNode == mDOMNode) {
    accessible = this;
  }
  else {
    nsCOMPtr<nsIAccessibilityService> accService =
      do_GetService("@mozilla.org/accessibilityService;1");
    NS_ENSURE_TRUE(accService, NS_ERROR_FAILURE);
    accService->GetAccessibleInWeakShell(domNode, mWeakShell, getter_AddRefs(accessible));
  }
  if (accessible) {
    if (aFromValue) {
      accessible->GetFinalValue(textEquivalent);
    }
    else {
      accessible->GetName(textEquivalent);
    }
  }

  textEquivalent.CompressWhitespace();
  return AppendStringWithSpaces(aFlatString, textEquivalent);
}

/*
 * AppendFlatStringFromContentNode and AppendFlatStringFromSubtree
 *
 * This method will glean useful text, in whatever form it exists, from any content node given to it.
 * It is used by any decendant of nsAccessible that needs to get text from a single node, as
 * well as by nsAccessible::AppendFlatStringFromSubtree, which gleans and concatenates text from any node and
 * that node's decendants.
 */

nsresult nsAccessible::AppendFlatStringFromContentNode(nsIContent *aContent, nsAString *aFlatString)
{
  if (aContent->IsContentOfType(nsIContent::eTEXT)) {
    nsCOMPtr<nsITextContent> textContent(do_QueryInterface(aContent));
    NS_ASSERTION(textContent, "No text content for text content type");
    // If it's a text node, append the text
    PRBool isHTMLBlock = PR_FALSE;
    nsCOMPtr<nsIPresShell> shell = GetPresShell();
    if (!shell) {
      return NS_ERROR_FAILURE;  
    }

    nsIContent *parentContent = aContent->GetParent();
    nsCOMPtr<nsIContent> appendedSubtreeStart(do_QueryInterface(mDOMNode));
    if (parentContent && parentContent != appendedSubtreeStart) {
      nsIFrame *frame;
      shell->GetPrimaryFrameFor(parentContent, &frame);
      if (frame) {
        // If this text is inside a block level frame (as opposed to span level), we need to add spaces around that 
        // block's text, so we don't get words jammed together in final name
        // Extra spaces will be trimmed out later
        const nsStyleDisplay* display = frame->GetStyleDisplay();
        if (display->IsBlockLevel() ||
          display->mDisplay == NS_STYLE_DISPLAY_TABLE_CELL) {
          isHTMLBlock = PR_TRUE;
          if (!aFlatString->IsEmpty()) {
            aFlatString->Append(PRUnichar(' '));
          }
        }
      }
    }
    if (textContent->TextLength() > 0) {
      nsAutoString text;
      textContent->AppendTextTo(text);
      if (!text.IsEmpty())
        aFlatString->Append(text);
      if (isHTMLBlock && !aFlatString->IsEmpty())
        aFlatString->Append(PRUnichar(' '));
    }
    return NS_OK;
  }

  nsAutoString textEquivalent;
  if (!aContent->IsContentOfType(nsIContent::eHTML)) {
    if (aContent->IsContentOfType(nsIContent::eXUL)) {
      nsCOMPtr<nsIPresShell> shell = GetPresShell();
      if (!shell) {
        return NS_ERROR_FAILURE;  
      }
      nsIFrame *frame;
      shell->GetPrimaryFrameFor(aContent, &frame);
      if (!frame || !frame->GetStyleVisibility()->IsVisible()) {
        return NS_OK;
      }
 
      nsCOMPtr<nsIDOMXULLabeledControlElement> labeledEl(do_QueryInterface(aContent));
      if (labeledEl) {
        labeledEl->GetLabel(textEquivalent);
      }
      else {
        aContent->GetAttr(kNameSpaceID_None,
                          nsAccessibilityAtoms::tooltiptext, textEquivalent);
      }
      AppendNameFromAccessibleFor(aContent, &textEquivalent, PR_TRUE /* use value */);

      return AppendStringWithSpaces(aFlatString, textEquivalent);
    }
    return NS_OK; // Not HTML and not XUL -- we don't handle it yet
  }

  nsCOMPtr<nsIAtom> tag = aContent->Tag();
  if (tag == nsAccessibilityAtoms::img) {
    return AppendNameFromAccessibleFor(aContent, aFlatString);
  }

  if (tag == nsAccessibilityAtoms::input) {
    nsAutoString inputType;
    aContent->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::type, inputType);
    if (inputType.LowerCaseEqualsLiteral("button") ||
        inputType.LowerCaseEqualsLiteral("submit") ||
        inputType.LowerCaseEqualsLiteral("reset") ||
        inputType.LowerCaseEqualsLiteral("image")) {
      return AppendNameFromAccessibleFor(aContent, aFlatString);
    }
  }

  if (tag == nsAccessibilityAtoms::object && !aContent->GetChildCount()) {
    // If object has no alternative content children, try title
    aContent->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::title, textEquivalent);
  }
  else if (tag == nsAccessibilityAtoms::br) {
    // If it's a line break, insert a space so that words aren't jammed together
    aFlatString->AppendLiteral("\r\n");
    return NS_OK;
  }
  else if (tag != nsAccessibilityAtoms::a && tag != nsAccessibilityAtoms::area) { 
    AppendNameFromAccessibleFor(aContent, aFlatString, PR_TRUE /* use value */);
  }

  textEquivalent.CompressWhitespace();
  return AppendStringWithSpaces(aFlatString, textEquivalent);
}


nsresult nsAccessible::AppendFlatStringFromSubtree(nsIContent *aContent, nsAString *aFlatString)
{
  nsresult rv = AppendFlatStringFromSubtreeRecurse(aContent, aFlatString);
  if (NS_SUCCEEDED(rv) && !aFlatString->IsEmpty()) {
    nsAString::const_iterator start, end;
    aFlatString->BeginReading(start);
    aFlatString->EndReading(end);

    PRInt32 spacesToTruncate = 0;
    while (-- end != start && *end == ' ')
      ++ spacesToTruncate;

    if (spacesToTruncate > 0)
      aFlatString->Truncate(aFlatString->Length() - spacesToTruncate);
  }

  return rv;
}

nsresult nsAccessible::AppendFlatStringFromSubtreeRecurse(nsIContent *aContent, nsAString *aFlatString)
{
  // Depth first search for all text nodes that are decendants of content node.
  // Append all the text into one flat string
  PRUint32 numChildren = 0;
  nsCOMPtr<nsIDOMXULSelectControlElement> selectControlEl(do_QueryInterface(aContent));
  if (!selectControlEl) {  // Don't walk children of elements with options, just get label directly
    numChildren = aContent->GetChildCount();
  }

  if (numChildren == 0) {
    // There are no children or they are irrelvant: get the text from the current node
    AppendFlatStringFromContentNode(aContent, aFlatString);
    return NS_OK;
  }

  // There are relevant children: use them to get the text.
  PRUint32 index;
  for (index = 0; index < numChildren; index++) {
    AppendFlatStringFromSubtreeRecurse(aContent->GetChildAt(index), aFlatString);
  }
  return NS_OK;
}

nsIContent *nsAccessible::GetLabelContent(nsIContent *aForNode)
{
  return aForNode->IsContentOfType(nsIContent::eXUL) ? GetXULLabelContent(aForNode) :
                                                       GetHTMLLabelContent(aForNode);
}
 
nsIContent* nsAccessible::GetXULLabelContent(nsIContent *aForNode, nsIAtom *aLabelType)
{
  nsAutoString controlID;
  nsIContent *labelContent = GetContentPointingTo(&controlID, aForNode, nsnull,
                                                  kNameSpaceID_None, aLabelType);
  if (labelContent) {
    return labelContent;
  }

  // If we're in anonymous content, determine whether we should use
  // the binding parent based on where the id for this control is
  aForNode->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::id, controlID);
  if (controlID.IsEmpty()) {
    // If no control ID and we're anonymous content
    // get ID from parent that inserted us.
    aForNode = aForNode->GetBindingParent();
    if (aForNode) {
      aForNode->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::id, controlID);
    }
    if (controlID.IsEmpty()) {
      return nsnull;
    }
  }
  
  // Look for label in subtrees of nearby ancestors
  static const PRUint32 kAncestorLevelsToSearch = 5;
  PRUint32 count = 0;
  while (!labelContent && ++count <= kAncestorLevelsToSearch && 
         (aForNode = aForNode->GetParent()) != nsnull) {
    labelContent = GetContentPointingTo(&controlID, aForNode,
                                        nsAccessibilityAtoms::control,
                                        kNameSpaceID_None, aLabelType);
  }

  return labelContent;
}

nsIContent* nsAccessible::GetHTMLLabelContent(nsIContent *aForNode)
{
  nsIContent *walkUpContent = aForNode;

  // go up tree get name of ancestor label if there is one. Don't go up farther than form element
  while ((walkUpContent = walkUpContent->GetParent()) != nsnull) {
    nsIAtom *tag = walkUpContent->Tag();
    if (tag == nsAccessibilityAtoms::label) {
      return walkUpContent;
    }
    if (tag == nsAccessibilityAtoms::form ||
        tag == nsAccessibilityAtoms::body) {
      // Reached top ancestor in form
      // There can be a label targeted at this control using the 
      // for="control_id" attribute. To save computing time, only 
      // look for those inside of a form element
      nsAutoString forId;
      aForNode->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::id, forId);
      // Actually we'll be walking down the content this time, with a depth first search
      if (forId.IsEmpty()) {
        break;
      }
      return GetContentPointingTo(&forId, walkUpContent, nsAccessibilityAtoms::_for); 
    }
  }

  return nsnull;
}

nsresult nsAccessible::GetTextFromRelationID(nsIAtom *aIDAttrib, nsString &aName)
{
  // Get DHTML name from content subtree pointed to by ID attribute
  aName.Truncate();
  nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
  NS_ASSERTION(content, "Called from shutdown accessible");

  nsAutoString ids;
  if (NS_CONTENT_ATTR_NOT_THERE ==
      content->GetAttr(kNameSpaceID_WAIProperties, aIDAttrib, ids)) {
    return NS_ERROR_FAILURE;
  }
  ids.CompressWhitespace(PR_TRUE, PR_TRUE);

  nsCOMPtr<nsIDOMDocument> domDoc;
  mDOMNode->GetOwnerDocument(getter_AddRefs(domDoc));
  NS_ENSURE_TRUE(domDoc, NS_ERROR_FAILURE);
  
  nsresult rv = NS_ERROR_FAILURE;

  // Support idlist as in aaa::labelledby="id1 id2 id3"
  while (PR_TRUE) {
    nsAutoString id;
    PRInt32 idLength = ids.FindChar(' ');  // -1 means end of string, not space found
    NS_ASSERTION(idLength != 0, "Should not be 0 because of CompressWhitespace() call above");
    id = Substring(ids, 0, idLength);
    if (idLength == -1) {
      ids.Truncate();
    }
    else {
      ids.Cut(0, idLength + 1);
    }
    if (!id.IsEmpty() && id.Last() == ' ') {
      id.Truncate(idLength - 1);  // Eliminate trailing space if it's there
    }

    if (id.IsEmpty()) {
      break;
    }
    if (!aName.IsEmpty()) {
      aName += ' '; // Need whitespace between multiple labels or descriptions
    }
    nsCOMPtr<nsIDOMElement> labelElement;
    domDoc->GetElementById(id, getter_AddRefs(labelElement));
    content = do_QueryInterface(labelElement);
    if (!content) {
      return NS_OK;
    }
    // We have a label content
    rv = AppendFlatStringFromSubtree(content, &aName);
    if (NS_SUCCEEDED(rv)) {
      aName.CompressWhitespace();
    }
  }
  
  return rv;
}

// Pass in aForAttrib == nsnull if any <label> will do
nsIContent *nsAccessible::GetContentPointingTo(const nsAString *aId,
                                               nsIContent *aLookContent,
                                               nsIAtom *aForAttrib,
                                               PRUint32 aForAttribNameSpace,
                                               nsIAtom *aTagType)
{
  if (!aTagType || aLookContent->Tag() == aTagType) {
    if (aForAttrib) {
      nsAutoString labelIsFor;
      aLookContent->GetAttr(aForAttribNameSpace, aForAttrib, labelIsFor);
      if (labelIsFor.Equals(*aId)) {
        return aLookContent;
      }
    }
    if (aTagType) {
      return nsnull;
    }
  }

  // Recursively search descendents for labels
  PRUint32 count  = 0;
  nsIContent *child;

  while ((child = aLookContent->GetChildAt(count++)) != nsnull) {
    nsIContent *labelContent = GetContentPointingTo(aId, child, aForAttrib,
                                                    aForAttribNameSpace, aTagType);
    if (labelContent) {
      return labelContent;
    }
  }
  return nsnull;
}

/**
  * Only called if the element is not a nsIDOMXULControlElement. Initially walks up
  *   the DOM tree to the form, concatonating label elements as it goes. Then checks for
  *   labels with the for="controlID" property.
  */
nsresult nsAccessible::GetHTMLName(nsAString& aLabel, PRBool aCanAggregateSubtree)
{
  nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
  if (!content) {
    return NS_ERROR_FAILURE;   // Node shut down
  }

  // Check for DHTML accessibility labelledby relationship property
  nsAutoString label;
  nsresult rv = GetTextFromRelationID(nsAccessibilityAtoms::labelledby, label);
  if (NS_SUCCEEDED(rv)) {
    aLabel = label;
    return rv;
  }

  nsIContent *labelContent = GetHTMLLabelContent(content);
  if (labelContent) {
    AppendFlatStringFromSubtree(labelContent, &label);
    label.CompressWhitespace();
    if (!label.IsEmpty()) {
      aLabel = label;
      return NS_OK;
    }
  }

  if (aCanAggregateSubtree) {
    // Don't use AppendFlatStringFromSubtree for container widgets like menulist
    nsresult rv = AppendFlatStringFromSubtree(content, &aLabel);
    if (NS_SUCCEEDED(rv)) {
      return NS_OK;
    }
  }

  // Still try the title as as fallback method in that case.
  if (NS_CONTENT_ATTR_NOT_THERE ==
      content->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::title, aLabel)) {
    aLabel.SetIsVoid(PR_TRUE);
  }
  return NS_OK;
}

/**
  * 3 main cases for XUL Controls to be labeled
  *   1 - control contains label="foo"
  *   2 - control has, as a child, a label element
  *        - label has either value="foo" or children
  *   3 - non-child label contains control="controlID"
  *        - label has either value="foo" or children
  * Once a label is found, the search is discontinued, so a control
  *  that has a label child as well as having a label external to
  *  the control that uses the control="controlID" syntax will use
  *  the child label for its Name.
  */
nsresult nsAccessible::GetXULName(nsAString& aLabel, PRBool aCanAggregateSubtree)
{
  nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
  NS_ASSERTION(content, "No nsIContent for DOM node");

  // First check for label override via accessibility labelledby relationship
  nsAutoString label;
  nsresult rv = GetTextFromRelationID(nsAccessibilityAtoms::labelledby, label);
  if (NS_SUCCEEDED(rv)) {
    aLabel = label;
    return rv;
  }

  // CASE #1 (via label attribute) -- great majority of the cases
  nsCOMPtr<nsIDOMXULLabeledControlElement> labeledEl(do_QueryInterface(mDOMNode));
  if (labeledEl) {
    rv = labeledEl->GetLabel(label);
  }
  else {
    nsCOMPtr<nsIDOMXULSelectControlItemElement> itemEl(do_QueryInterface(mDOMNode));
    if (itemEl) {
      rv = itemEl->GetLabel(label);
    }
    else {
      nsCOMPtr<nsIDOMXULSelectControlElement> select(do_QueryInterface(mDOMNode));
      // Use label if this is not a select control element which 
      // uses label attribute to indicate which option is selected
      if (!select) {
        nsCOMPtr<nsIDOMXULElement> xulEl(do_QueryInterface(mDOMNode));
        if (xulEl) {
          rv = xulEl->GetAttribute(NS_LITERAL_STRING("label"), label);
        }
      }
    }
  }

  // CASES #2 and #3 ------ label as a child or <label control="id" ... > </label>
  if (NS_FAILED(rv) || label.IsEmpty()) {
    label.Truncate();
    nsIContent *labelContent = GetXULLabelContent(content);
    nsCOMPtr<nsIDOMXULLabelElement> xulLabel(do_QueryInterface(labelContent));
    // Check if label's value attribute is used
    if (xulLabel && NS_SUCCEEDED(xulLabel->GetValue(label)) && label.IsEmpty()) {
      // If no value attribute, a non-empty label must contain
      // children that define it's text -- possibly using HTML
      AppendFlatStringFromSubtree(labelContent, &label);
    }
  }

  // XXX If CompressWhiteSpace worked on nsAString we could avoid a copy
  label.CompressWhitespace();
  if (!label.IsEmpty()) {
    aLabel = label;
    return NS_OK;
  }

  content->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::tooltiptext, label);
  label.CompressWhitespace();
  if (!label.IsEmpty()) {
    aLabel = label;
    return NS_OK;
  }

  // Can get text from title of <toolbaritem> if we're a child of a <toolbaritem>
  nsIContent *bindingParent = content->GetBindingParent();
  nsIContent *parent = bindingParent? bindingParent->GetParent() :
                                      content->GetParent();
  while (parent) {
    if (parent->Tag() == nsAccessibilityAtoms::toolbaritem &&
        parent->HasAttr(kNameSpaceID_None, nsAccessibilityAtoms::title)) {
      parent->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::title, label);
      label.CompressWhitespace();
      aLabel = label;
      return NS_OK;
    }
    parent = parent->GetParent();
  }

  // Don't use AppendFlatStringFromSubtree for container widgets like menulist
  return aCanAggregateSubtree? AppendFlatStringFromSubtree(content, &aLabel) : NS_OK;
}

NS_IMETHODIMP nsAccessible::FireToolkitEvent(PRUint32 aEvent, nsIAccessible *aTarget, void * aData)
{
  if (!mWeakShell)
    return NS_ERROR_FAILURE; // Don't fire event for accessible that has been shut down
  nsCOMPtr<nsIAccessibleDocument> docAccessible(GetDocAccessible());
  nsCOMPtr<nsPIAccessible> eventHandlingAccessible(do_QueryInterface(docAccessible));
  if (eventHandlingAccessible) {
    return eventHandlingAccessible->FireToolkitEvent(aEvent, aTarget, aData);
  }

  return NS_ERROR_FAILURE;
}

nsRoleMapEntry nsAccessible::gWAIRoleMap[] = 
{
  // This list of WAI-defined roles are currently hardcoded.
  // Eventually we will most likely be loading an RDF resource that contains this information
  // Using RDF will also allow for role extensibility. See bug 280138.
  // XXX Should we store attribute names in this table as atoms instead of strings?
  // Definition of nsRoleMapEntry and nsStateMapEntry contains comments explaining this table.
  {"alert", ROLE_ALERT, eNameOkFromChildren, eNoValue, eNoReqStates, END_ENTRY},
  {"alertdialog", ROLE_ALERT, eNameOkFromChildren, eNoValue, eNoReqStates, END_ENTRY},
  {"application", ROLE_APPLICATION, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"button", ROLE_PUSHBUTTON, eNameOkFromChildren, eNoValue, eNoReqStates,
            {"pressed", BOOL_STATE, STATE_PRESSED},
            {"haspopup", BOOL_STATE, STATE_HASPOPUP}, END_ENTRY},
  {"buttonsubmit", ROLE_PUSHBUTTON, eNameOkFromChildren, eNoValue, STATE_DEFAULT, END_ENTRY},
  {"buttoncancel", ROLE_PUSHBUTTON, eNameOkFromChildren, eNoValue, eNoReqStates, END_ENTRY},
  {"checkbox", ROLE_CHECKBUTTON, eNameOkFromChildren, eNoValue, STATE_CHECKABLE,
            {"checked", BOOL_STATE, STATE_CHECKED},
            {"readonly", BOOL_STATE, STATE_READONLY}, END_ENTRY},
  {"checkboxtristate", ROLE_CHECKBUTTON, eNameOkFromChildren, eNoValue, STATE_CHECKABLE,
            {"checked", BOOL_STATE, STATE_CHECKED},
            {"checked", "mixed", STATE_MIXED},
            {"readonly", BOOL_STATE, STATE_READONLY}, END_ENTRY},
  {"columnheader", ROLE_COLUMNHEADER, eNameOkFromChildren, eNoValue, eNoReqStates,
            {"selected", BOOL_STATE, STATE_SELECTED | STATE_SELECTABLE},
            {"selected", "false", STATE_SELECTABLE},
            {"readonly", BOOL_STATE, STATE_READONLY}, END_ENTRY},
  {"combobox", ROLE_COMBOBOX, eNameLabelOrTitle, eHasValueMinMax, eNoReqStates,
            {"readonly", BOOL_STATE, STATE_READONLY},
            {"multiselect", BOOL_STATE, STATE_MULTISELECTABLE | STATE_EXTSELECTABLE}, END_ENTRY},
  {"description", ROLE_STATICTEXT, eNameOkFromChildren, eNoValue, eNoReqStates, END_ENTRY},
  {"dialog", ROLE_DIALOG, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"document", ROLE_DOCUMENT, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"label", ROLE_STATICTEXT, eNameOkFromChildren, eNoValue, eNoReqStates, END_ENTRY},
  {"list", ROLE_LIST, eNameLabelOrTitle, eNoValue, eNoReqStates,
            {"readonly", BOOL_STATE, STATE_READONLY},
            {"multiselect", BOOL_STATE, STATE_MULTISELECTABLE | STATE_EXTSELECTABLE}, END_ENTRY},
  {"listbox", ROLE_LIST, eNameLabelOrTitle, eNoValue, eNoReqStates,
            {"readonly", BOOL_STATE, STATE_READONLY},
            {"multiselect", BOOL_STATE, STATE_MULTISELECTABLE | STATE_EXTSELECTABLE}, END_ENTRY},
  {"listitem", ROLE_LISTITEM, eNameOkFromChildren, eNoValue, eNoReqStates,
            {"selected", BOOL_STATE, STATE_SELECTED | STATE_SELECTABLE},
            {"selected", "false", STATE_SELECTABLE},
            {"checked", BOOL_STATE, STATE_CHECKED | STATE_CHECKABLE},
            {"checked", "false", STATE_CHECKABLE}, END_ENTRY},
  {"menu", ROLE_MENUPOPUP, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"menubar", ROLE_MENUBAR, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"menuitem", ROLE_MENUITEM, eNameOkFromChildren, eNoValue, eNoReqStates,
            {"haspopup", BOOL_STATE, STATE_HASPOPUP},
            {"checked", BOOL_STATE, STATE_CHECKED | STATE_CHECKABLE},
            {"checked", "mixed", STATE_MIXED},
            {"checked", "false", STATE_CHECKABLE}, END_ENTRY},
  {"menuitemcheckbox", ROLE_MENUITEM, eNameOkFromChildren, eNoValue, STATE_CHECKABLE,
            {"checked", BOOL_STATE, STATE_CHECKED }, END_ENTRY},
  {"menuitemradio", ROLE_MENUITEM, eNameOkFromChildren, eNoValue, STATE_CHECKABLE,
            {"checked", BOOL_STATE, STATE_CHECKED }, END_ENTRY},
  {"grid", ROLE_TABLE, eNameLabelOrTitle, eNoValue, STATE_FOCUSABLE,
            {"multiselectable", BOOL_STATE, STATE_MULTISELECTABLE | STATE_EXTSELECTABLE},
            {"readonly", BOOL_STATE, STATE_READONLY}, END_ENTRY},
  {"gridcell", ROLE_CELL, eNameOkFromChildren, eNoValue, eNoReqStates,
            {"selected", BOOL_STATE, STATE_SELECTED | STATE_SELECTABLE},
            {"selected", "false", STATE_SELECTABLE},
            {"readonly", BOOL_STATE, STATE_READONLY}, END_ENTRY},
  {"group", ROLE_GROUPING, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"link", ROLE_LINK, eNameLabelOrTitle, eNoValue, STATE_LINKED, END_ENTRY},
  {"option", ROLE_LISTITEM, eNameOkFromChildren, eNoValue, eNoReqStates,
            {"selected", BOOL_STATE, STATE_SELECTED | STATE_SELECTABLE},
            {"selected", "false", STATE_SELECTABLE},
            {"checked", BOOL_STATE, STATE_CHECKED | STATE_CHECKABLE},
            {"checked", "false", STATE_CHECKABLE}, END_ENTRY},
  {"progressbar", ROLE_PROGRESSBAR, eNameLabelOrTitle, eHasValueMinMax, STATE_READONLY,
            {"valuenow", "unknown", STATE_MIXED}, END_ENTRY},
  {"radio", ROLE_RADIOBUTTON, eNameOkFromChildren, eNoValue, eNoReqStates,
            {"checked", BOOL_STATE, STATE_CHECKED}, END_ENTRY},
  {"radiogroup", ROLE_GROUPING, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"rowheader", ROLE_ROWHEADER, eNameOkFromChildren, eNoValue, eNoReqStates,
            {"selected", BOOL_STATE, STATE_SELECTED | STATE_SELECTABLE},
            {"selected", "false", STATE_SELECTABLE},
            {"readonly", BOOL_STATE, STATE_READONLY}, END_ENTRY},
  {"secret", ROLE_PASSWORD_TEXT, eNameLabelOrTitle, eNoValue, STATE_PROTECTED,
             END_ENTRY},  // EXT_STATE_SINGLE_LINE manually supported in code
  {"separator", ROLE_SEPARATOR, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"slider", ROLE_SLIDER, eNameLabelOrTitle, eHasValueMinMax, eNoReqStates,
            {"readonly", BOOL_STATE, STATE_READONLY}, END_ENTRY},
  {"spinbutton", ROLE_SPINBUTTON, eNameLabelOrTitle, eHasValueMinMax, eNoReqStates,
            {"readonly", BOOL_STATE, STATE_READONLY}, END_ENTRY},
  {"spreadsheet", ROLE_TABLE, eNameLabelOrTitle, eNoValue, STATE_MULTISELECTABLE | STATE_EXTSELECTABLE | STATE_FOCUSABLE,
            {"readonly", BOOL_STATE, STATE_READONLY}, END_ENTRY},  // Still supported, but deprecated in favor of grid
  {"table", ROLE_TABLE, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"td", ROLE_CELL, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"th", ROLE_CELL, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"tab", ROLE_PAGETAB, eNameOkFromChildren, eNoValue, eNoReqStates, END_ENTRY},
  {"tablist", ROLE_PAGETABLIST, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"tabpanel", ROLE_PROPERTYPAGE, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"textarea", ROLE_TEXT, eNameLabelOrTitle, eHasValueMinMax, eNoReqStates,
            {"readonly", BOOL_STATE, STATE_READONLY}, END_ENTRY}, // XXX EXT_STATE_MULTI_LINE supported in code
  {"textfield", ROLE_TEXT, eNameLabelOrTitle, eHasValueMinMax, eNoReqStates,
            {"readonly", BOOL_STATE, STATE_READONLY}, 
            {"haspopup", BOOL_STATE, STATE_HASPOPUP}, END_ENTRY}, // XXX EXT_STATE_SINGLE_LINE supported in code
  {"toolbar", ROLE_TOOLBAR, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY},
  {"tree", ROLE_OUTLINE, eNameLabelOrTitle, eNoValue, eNoReqStates,
            {"readonly", BOOL_STATE, STATE_READONLY},
            {"multiselectable", BOOL_STATE, STATE_MULTISELECTABLE | STATE_EXTSELECTABLE}, END_ENTRY},
  {"treeitem", ROLE_OUTLINEITEM, eNameOkFromChildren, eNoValue, eNoReqStates,
            {"selected", BOOL_STATE, STATE_SELECTED | STATE_SELECTABLE},
            {"selected", "false", STATE_SELECTABLE},
            {"expanded", BOOL_STATE, STATE_EXPANDED},
            {"expanded", "false", STATE_COLLAPSED},
            {"checked", BOOL_STATE, STATE_CHECKED | STATE_CHECKABLE},
            {"checked", "mixed", STATE_MIXED},
            {"checked", "false", STATE_CHECKABLE},},
  {nsnull, ROLE_NOTHING, eNameLabelOrTitle, eNoValue, eNoReqStates, END_ENTRY} // Last item
};

// XHTML 2 roles
// These don't need a mapping - they are exposed either through DOM or via MSAA role string
// banner, contentinfo, main, navigation, note, search, secondary, seealso

nsStateMapEntry nsAccessible::gUnivStateMap[] = {
  {"disabled", BOOL_STATE, STATE_UNAVAILABLE},
  {"required", BOOL_STATE, STATE_REQUIRED},
  {"invalid", BOOL_STATE, STATE_INVALID}
};

NS_IMETHODIMP nsAccessible::GetFinalRole(PRUint32 *aRole)
{
  if (mRoleMapEntry) {
    *aRole = mRoleMapEntry->role;
    if (*aRole != ROLE_NOTHING) {
      return NS_OK;
    }
  }
  return mDOMNode ? GetRole(aRole) : NS_ERROR_FAILURE;  // Node already shut down
}

PRBool nsAccessible::MappedAttrState(nsIContent *aContent, PRUint32 *aStateInOut,
                                     nsStateMapEntry *aStateMapEntry)
{
  // Return true if we should continue
  if (!aStateMapEntry->attributeName) {
    return PR_FALSE;  // Stop looking -- no more states
  }

  nsAutoString attribValue;
  nsCOMPtr<nsIAtom> attribAtom = do_GetAtom(aStateMapEntry->attributeName); // XXX put atoms directly in entry
  if (NS_CONTENT_ATTR_HAS_VALUE == aContent->GetAttr(kNameSpaceID_WAIProperties,
                                                     attribAtom,
                                                     attribValue)) {
    if (aStateMapEntry->attributeValue == BOOL_STATE) {
      // No attribute value map specified in state map entry indicates state cleared
      if (attribValue.EqualsLiteral("false")) {
        return *aStateInOut &= ~aStateMapEntry->state;
      }
      return *aStateInOut |= aStateMapEntry->state;
    }
    if (NS_ConvertUTF16toUTF8(attribValue).Equals(aStateMapEntry->attributeValue)) {
      return *aStateInOut |= aStateMapEntry->state;
    }
  }

  return PR_TRUE;
}

NS_IMETHODIMP nsAccessible::GetFinalState(PRUint32 *aState)
{
  *aState = 0;
  if (!mDOMNode) {
    return NS_ERROR_FAILURE;  // Node already shut down
  }
  nsresult rv = GetState(aState);
  if (NS_FAILED(rv)) {
    return rv;
  }

  // Test for universal states first
  nsIContent *content = GetRoleContent(mDOMNode);
  if (!content) {
    return NS_ERROR_FAILURE;  // Node already shut down
  }
  for (PRInt32 index = 0; index < NS_ARRAY_LENGTH(gUnivStateMap); index ++) {
    MappedAttrState(content, aState, &gUnivStateMap[index]);
  }
  if (!mRoleMapEntry) {
    return rv;
  }

  PRUint32 finalState = *aState;
  finalState &= ~STATE_READONLY;  // Once DHTML role is used, we're only readonly if DHTML readonly used

  if (finalState & STATE_UNAVAILABLE) {
    // Disabled elements are not selectable or focusable, even if disabled
    // via DHTML accessibility disabled property
    finalState &= ~(STATE_SELECTABLE | STATE_FOCUSABLE);
  }

  finalState |= mRoleMapEntry->state;
  if (MappedAttrState(content, &finalState, &mRoleMapEntry->attributeMap1) &&
      MappedAttrState(content, &finalState, &mRoleMapEntry->attributeMap2) &&
      MappedAttrState(content, &finalState, &mRoleMapEntry->attributeMap3) &&
      MappedAttrState(content, &finalState, &mRoleMapEntry->attributeMap4) &&
      MappedAttrState(content, &finalState, &mRoleMapEntry->attributeMap5) &&
      MappedAttrState(content, &finalState, &mRoleMapEntry->attributeMap6)) {
    MappedAttrState(content, &finalState, &mRoleMapEntry->attributeMap7);
  }

  *aState = finalState;
  return rv;
}

NS_IMETHODIMP nsAccessible::GetFinalValue(nsAString& aValue)
{
  if (!mDOMNode) {
    return NS_ERROR_FAILURE;  // Node already shut down
  }
  if (mRoleMapEntry) {
    if (mRoleMapEntry->valueRule == eNoValue) {
      return NS_OK;
    }
    nsCOMPtr<nsIContent> content(do_QueryInterface(mDOMNode));
    if (content &&
        NS_CONTENT_ATTR_HAS_VALUE == content->GetAttr(kNameSpaceID_WAIProperties,
                                                      nsAccessibilityAtoms::valuenow,
                                                      aValue)) {
      return NS_OK;
    }
  }
  return GetValue(aValue);
}

// Not implemented by this class

/* DOMString getValue (); */
NS_IMETHODIMP nsAccessible::GetValue(nsAString& _retval)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

/* void setName (in DOMString name); */
NS_IMETHODIMP nsAccessible::SetName(const nsAString& name)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

/* DOMString getKeyBinding (); */
NS_IMETHODIMP nsAccessible::GetKeyBinding(nsAString& _retval)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

/* unsigned long getRole (); */
NS_IMETHODIMP nsAccessible::GetRole(PRUint32 *aRole)
{
  *aRole = ROLE_NOTHING;
  return NS_OK;
}

/* PRUint8 getAccNumActions (); */
NS_IMETHODIMP nsAccessible::GetNumActions(PRUint8 *aNumActions)
{
  *aNumActions = 0;
  return NS_OK;
}

/* DOMString getAccActionName (in PRUint8 index); */
NS_IMETHODIMP nsAccessible::GetActionName(PRUint8 index, nsAString& aName)
{
  return NS_ERROR_FAILURE;
}

/* void doAction (in PRUint8 index); */
NS_IMETHODIMP nsAccessible::DoAction(PRUint8 index)
{
  return NS_ERROR_FAILURE;
}

/* DOMString getHelp (); */
NS_IMETHODIMP nsAccessible::GetHelp(nsAString& _retval)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

/* nsIAccessible getAccessibleToRight(); */
NS_IMETHODIMP nsAccessible::GetAccessibleToRight(nsIAccessible **_retval)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

/* nsIAccessible getAccessibleToLeft(); */
NS_IMETHODIMP nsAccessible::GetAccessibleToLeft(nsIAccessible **_retval)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

/* nsIAccessible getAccessibleAbove(); */
NS_IMETHODIMP nsAccessible::GetAccessibleAbove(nsIAccessible **_retval)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

/* nsIAccessible getAccessibleBelow(); */
NS_IMETHODIMP nsAccessible::GetAccessibleBelow(nsIAccessible **_retval)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

already_AddRefed<nsIDOMNode> nsAccessible::GetInverseRelatedNode(nsIAtom *aRelationAttr,
                                                                 PRUint32 aAncestorLevelsToSearch)
{
  // aAncestorLevelsToSearch is an optimization used for label and description searches.
  // We expect the control to be relatively near the label/description in the DOM tree,
  // so to optimize we don't search the entire DOM tree.
  nsIContent *content = GetRoleContent(mDOMNode);
  if (!content) {
    return nsnull; // Node shut down
  }
  nsAutoString controlID;
  content->GetAttr(kNameSpaceID_None, nsAccessibilityAtoms::id, controlID);
  if (controlID.IsEmpty()) {
    return nsnull;
  }
  nsIDOMNode *relatedNode = nsnull;
  // Something might be pointing to us
  PRUint32 count = 0;
  nsIContent *start = content;
  while ((!aAncestorLevelsToSearch || ++count <= aAncestorLevelsToSearch) && 
        (start = start->GetParent()) != nsnull) {
    nsIContent *description = GetContentPointingTo(&controlID, start,
                                                   aRelationAttr,
                                                   kNameSpaceID_WAIProperties,
                                                   nsnull);
    if (description) {
      nsIDOMNode *relatedNode;
      CallQueryInterface(description, &relatedNode);
      return relatedNode;
    }
  }
  return nsnull;
}


/* nsIAccessible getAccessibleRelated(); */
NS_IMETHODIMP nsAccessible::GetAccessibleRelated(PRUint32 aRelationType, nsIAccessible **aRelated)
{
  *aRelated = nsnull;

  // Relationships are defined on the same content node
  // that the role would be defined on
  nsIContent *content = GetRoleContent(mDOMNode);
  if (!content) {
    return NS_ERROR_FAILURE;  // Node already shut down
  }

  nsCOMPtr<nsIDOMNode> relatedNode;
  nsAutoString relatedID;

  // Search for the related DOM node according to the specified "relation type"
  switch (aRelationType)
  {
  case RELATION_LABEL_FOR:
    {
      if (content->Tag() == nsAccessibilityAtoms::label) {
        nsIAtom *relatedIDAttr = content->IsContentOfType(nsIContent::eHTML) ?
          nsAccessibilityAtoms::_for : nsAccessibilityAtoms::control;
        content->GetAttr(kNameSpaceID_None, relatedIDAttr, relatedID);
      }
      if (relatedID.IsEmpty()) {
        const PRUint32 kAncestorLevelsToSearch = 3;
        relatedNode = GetInverseRelatedNode(nsAccessibilityAtoms::labelledby, kAncestorLevelsToSearch);
      }
      break;
    }
  case RELATION_LABELLED_BY:
    {
      content->GetAttr(kNameSpaceID_WAIProperties,
                       nsAccessibilityAtoms::labelledby, relatedID);
      if (relatedID.IsEmpty()) {
        relatedNode = do_QueryInterface(GetLabelContent(content));
      }
      break;
    }
  case RELATION_DESCRIBED_BY:
    {
      content->GetAttr(kNameSpaceID_WAIProperties,
                       nsAccessibilityAtoms::describedby, relatedID);
      if (relatedID.IsEmpty()) {
        nsIContent *description =
          GetXULLabelContent(content, nsAccessibilityAtoms::description);
        relatedNode = do_QueryInterface(description);
      }
      break;
    }
  case RELATION_DESCRIPTION_FOR:
    {
      const PRUint32 kAncestorLevelsToSearch = 3;
      relatedNode = GetInverseRelatedNode(nsAccessibilityAtoms::describedby, kAncestorLevelsToSearch);
      if (!relatedNode && content->Tag() == nsAccessibilityAtoms::description &&
          content->IsContentOfType(nsIContent::eXUL)) {
        // This affectively adds an optional control attribute to xul:description,
        // which only affects accessibility, by allowing the description to be
        // tied to a control.
        content->GetAttr(kNameSpaceID_None,
                         nsAccessibilityAtoms::control, relatedID);
      }
      break;
    }
  case RELATION_CONTROLLED_BY: 
    {
      relatedNode = GetInverseRelatedNode(nsAccessibilityAtoms::controls);
      break;
    }
  case RELATION_CONTROLLER_FOR:
    {
      content->GetAttr(kNameSpaceID_WAIProperties,
                       nsAccessibilityAtoms::controls, relatedID);
      break;
    }
  case RELATION_FLOWS_TO:
    {
      content->GetAttr(kNameSpaceID_WAIProperties,
                       nsAccessibilityAtoms::flowto, relatedID);
      break;
    }
  case RELATION_FLOWS_FROM:
    {
      relatedNode = GetInverseRelatedNode(nsAccessibilityAtoms::flowto);
      break;
    }
    
  case RELATION_DEFAULT_BUTTON:
    {
      if (content->IsContentOfType(nsIContent::eHTML)) {
        nsCOMPtr<nsIForm> form;
        while ((form = do_QueryInterface(content)) == nsnull &&
               (content = content->GetParent()) != nsnull) /* nothing */ ;

        if (form) {
          // We have a <form> element, so iterate through and try to find a submit button
          nsCOMPtr<nsISimpleEnumerator> formControls;
          form->GetControlEnumerator(getter_AddRefs(formControls));
          nsCOMPtr<nsISupports> controlSupports;
          PRBool hasMoreElements;
          while (NS_SUCCEEDED(formControls->HasMoreElements(&hasMoreElements)) &&
                hasMoreElements) {
            nsresult rv = formControls->GetNext(getter_AddRefs(controlSupports));
            nsCOMPtr<nsIFormControl> control = do_QueryInterface(controlSupports);    
            if (control) {
              PRInt32 type = control->GetType();
              if (type == NS_FORM_INPUT_SUBMIT || type == NS_FORM_BUTTON_SUBMIT ||
                  type == NS_FORM_INPUT_IMAGE) {
                relatedNode = do_QueryInterface(control);
                break;
              }
            }
          }
        }
      }
      else {
        // In XUL, use first <button default="true" .../> in the document
        nsCOMPtr<nsIDOMXULDocument> xulDoc = do_QueryInterface(content->GetDocument());
        nsCOMPtr<nsIDOMXULButtonElement> buttonEl;
        if (xulDoc) {
          nsCOMPtr<nsIDOMNodeList> possibleDefaultButtons;
          xulDoc->GetElementsByAttribute(NS_LITERAL_STRING("default"),
                                         NS_LITERAL_STRING("true"),
                                         getter_AddRefs(possibleDefaultButtons));
          if (possibleDefaultButtons) {
            PRUint32 length;
            possibleDefaultButtons->GetLength(&length);
            nsCOMPtr<nsIDOMNode> possibleButton;
            // Check for button in list of default="true" elements
            for (PRUint32 count = 0; count < length && !buttonEl; count ++) {
              possibleDefaultButtons->Item(count, getter_AddRefs(possibleButton));
              buttonEl = do_QueryInterface(possibleButton);
            }
          }
          if (!buttonEl) { // Check for anonymous accept button in <dialog>
            nsCOMPtr<nsIDOMDocumentXBL> xblDoc(do_QueryInterface(xulDoc));
            if (xblDoc) {
              nsCOMPtr<nsIDOMDocument> domDoc = do_QueryInterface(xulDoc);
              NS_ASSERTION(domDoc, "No DOM document");
              nsCOMPtr<nsIDOMElement> rootEl;
              domDoc->GetDocumentElement(getter_AddRefs(rootEl));
              if (rootEl) {
                nsCOMPtr<nsIDOMElement> possibleButtonEl;
                xblDoc->GetAnonymousElementByAttribute(rootEl,
                                                      NS_LITERAL_STRING("default"),
                                                      NS_LITERAL_STRING("true"),
                                                      getter_AddRefs(possibleButtonEl));
                buttonEl = do_QueryInterface(possibleButtonEl);
              }
            }
          }
          relatedNode = do_QueryInterface(buttonEl);
        }
      }
      break;
    }
  default:
    return NS_ERROR_NOT_IMPLEMENTED;
  }

  if (!relatedID.IsEmpty()) {
    // In some cases we need to get the relatedNode from an ID-style attribute
    nsCOMPtr<nsIDOMDocument> domDoc;
    mDOMNode->GetOwnerDocument(getter_AddRefs(domDoc));
    NS_ENSURE_TRUE(domDoc, NS_ERROR_FAILURE);
    nsCOMPtr<nsIDOMElement> relatedEl;
    domDoc->GetElementById(relatedID, getter_AddRefs(relatedEl));
    relatedNode = do_QueryInterface(relatedEl);
  }

  // Return the corresponding accessible if the related DOM node is found
  if (relatedNode) {
    nsCOMPtr<nsIAccessibilityService> accService =
      do_GetService("@mozilla.org/accessibilityService;1");
    NS_ENSURE_TRUE(accService, NS_ERROR_FAILURE);
    return accService->GetAccessibleInWeakShell(relatedNode, mWeakShell, aRelated);
  }
  return NS_ERROR_FAILURE;
}

/* void addSelection (); */
NS_IMETHODIMP nsAccessible::AddSelection()
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

/* void extendSelection (); */
NS_IMETHODIMP nsAccessible::ExtendSelection()
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

/* unsigned long getExtState (); */
NS_IMETHODIMP nsAccessible::GetExtState(PRUint32 *aExtState)
{
  if (!mDOMNode) {
    return NS_ERROR_FAILURE; // Node shut down
  }
  *aExtState = 0;
  // XXX We can remove this hack once we support RDF-based role & state maps
  if (mRoleMapEntry && mRoleMapEntry->role == ROLE_TEXT) {
    *aExtState = NS_LITERAL_CSTRING("textarea").Equals(mRoleMapEntry->roleString) ? 
       EXT_STATE_MULTI_LINE : EXT_STATE_SINGLE_LINE;
  }
  return NS_OK;
}

/* [noscript] void getNativeInterface(out voidPtr aOutAccessible); */
NS_IMETHODIMP nsAccessible::GetNativeInterface(void **aOutAccessible)
{
  return NS_ERROR_NOT_IMPLEMENTED;
}

void nsAccessible::DoCommandCallback(nsITimer *aTimer, void *aClosure)
{
  NS_ASSERTION(gDoCommandTimer, "How did we get here if there was no gDoCommandTimer?");
  NS_RELEASE(gDoCommandTimer);

  nsIContent *content = NS_REINTERPRET_CAST(nsIContent*, aClosure);
  nsCOMPtr<nsIDOMXULElement> xulElement(do_QueryInterface(content));
  if (xulElement) {
    xulElement->Click();
  }
  else {
    nsIDocument *doc = content->GetDocument();
    if (!doc) {
      return;
    }
    nsCOMPtr<nsIPresShell> presShell = doc->GetShellAt(0);
    nsPIDOMWindow *outerWindow = doc->GetWindow();
    if (presShell && outerWindow) {
      nsAutoPopupStatePusher popupStatePusher(outerWindow, openAllowed);

      nsMouseEvent downEvent(PR_TRUE, NS_MOUSE_LEFT_BUTTON_DOWN, nsnull,
                              nsMouseEvent::eSynthesized);
      nsMouseEvent upEvent(PR_TRUE, NS_MOUSE_LEFT_BUTTON_UP, nsnull,
                              nsMouseEvent::eSynthesized);
      nsMouseEvent clickEvent(PR_TRUE, NS_MOUSE_LEFT_CLICK, nsnull,
                              nsMouseEvent::eSynthesized);

      nsEventStatus eventStatus = nsEventStatus_eIgnore;
      presShell->HandleDOMEventWithTarget(content, &downEvent, &eventStatus);
      presShell->HandleDOMEventWithTarget(content, &upEvent, &eventStatus);
      presShell->HandleDOMEventWithTarget(content, &clickEvent, &eventStatus);
    }
  }
}

/*
 * Use Timer to execute "Click" command of XUL/HTML element (e.g. menuitem, button...).
 *
 * When "Click" is to open a "modal" dialog/window, it won't return untill the
 * dialog/window is closed. If executing "Click" command directly in
 * nsXXXAccessible::DoAction, it will block AT-Tools(e.g. GOK) that invoke
 * "action" of mozilla accessibles direclty.
 */
nsresult nsAccessible::DoCommand(nsIContent *aContent)
{
  nsCOMPtr<nsIContent> content = aContent;
  if (!content) {
    content = do_QueryInterface(mDOMNode);
  }
  if (gDoCommandTimer) {
    // Already have timer going for another command
    NS_WARNING("Doubling up on do command timers doesn't work. This wasn't expected.");
    return NS_ERROR_FAILURE;
  }

  nsCOMPtr<nsITimer> timer = do_CreateInstance("@mozilla.org/timer;1");
  if (!timer) {
    return NS_ERROR_OUT_OF_MEMORY;
  } 

  NS_ADDREF(gDoCommandTimer = timer);
  return gDoCommandTimer->InitWithFuncCallback(DoCommandCallback,
                                               (void*)content, 0,
                                               nsITimer::TYPE_ONE_SHOT);
}

already_AddRefed<nsIAccessible>
nsAccessible::GetNextWithState(nsIAccessible *aStart, PRUint32 matchState)
{
  // Return the next descendant that matches one of the states in matchState
  // Uses depth first search
  NS_ASSERTION(matchState, "GetNextWithState() not called with a state to match");
  NS_ASSERTION(aStart, "GetNextWithState() not called with an accessible to start with");
  nsCOMPtr<nsIAccessible> look, current = aStart;
  PRUint32 state = 0;
  while (0 == (state & matchState)) {
    current->GetFirstChild(getter_AddRefs(look));
    while (!look) {
      if (current == this) {
        return nsnull; // At top of subtree
      }
      current->GetNextSibling(getter_AddRefs(look));
      if (!look) {
        current->GetParent(getter_AddRefs(look));
        current.swap(look);
        continue;
      }
    }
    current.swap(look);
    current->GetFinalState(&state);
  }

  nsIAccessible *returnAccessible = nsnull;
  current.swap(returnAccessible);

  return returnAccessible;
}

// nsIAccessibleSelectable
NS_IMETHODIMP nsAccessible::GetSelectedChildren(nsIArray **aSelectedAccessibles)
{
  *aSelectedAccessibles = nsnull;

  nsCOMPtr<nsIMutableArray> selectedAccessibles;
  NS_NewArray(getter_AddRefs(selectedAccessibles));
  if (!selectedAccessibles)
    return NS_ERROR_OUT_OF_MEMORY;

  nsCOMPtr<nsIAccessible> selected = this;
  while ((selected = GetNextWithState(selected, STATE_SELECTED)) != nsnull) {
    selectedAccessibles->AppendElement(selected, PR_FALSE);
  }

  PRUint32 length = 0;
  selectedAccessibles->GetLength(&length); 
  if (length) { // length of nsIArray containing selected options
    *aSelectedAccessibles = selectedAccessibles;
    NS_ADDREF(*aSelectedAccessibles);
  }

  return NS_OK;
}

// return the nth selected descendant nsIAccessible object
NS_IMETHODIMP nsAccessible::RefSelection(PRInt32 aIndex, nsIAccessible **aSelected)
{
  *aSelected = nsnull;
  if (aIndex < 0) {
    return NS_ERROR_FAILURE;
  }
  nsCOMPtr<nsIAccessible> selected = this;
  PRInt32 count = 0;
  while (count ++ <= aIndex) {
    selected = GetNextWithState(selected, STATE_SELECTED);
    if (!selected) {
      return NS_ERROR_FAILURE; // aIndex out of range
    }
  }
  NS_IF_ADDREF(*aSelected = selected);
  return NS_OK;
}

NS_IMETHODIMP nsAccessible::GetSelectionCount(PRInt32 *aSelectionCount)
{
  *aSelectionCount = 0;
  nsCOMPtr<nsIAccessible> selected = this;
  while ((selected = GetNextWithState(selected, STATE_SELECTED)) != nsnull) {
    ++ *aSelectionCount;
  }

  return NS_OK;
}

NS_IMETHODIMP nsAccessible::AddChildToSelection(PRInt32 aIndex)
{
  // Tree views and other container widgets which may have grandchildren should
  // implement a selection methods for their specific interfaces, because being
  // able to deal with selection on a per-child basis would not be enough.

  NS_ENSURE_TRUE(aIndex >= 0, NS_ERROR_FAILURE);

  nsCOMPtr<nsIAccessible> child;
  GetChildAt(aIndex, getter_AddRefs(child));

  PRUint32 state;
  nsresult rv = child->GetFinalState(&state);
  NS_ENSURE_SUCCESS(rv, rv);

  if (!(state & STATE_SELECTABLE)) {
    return NS_OK;
  }

  return child->TakeSelection();
}

NS_IMETHODIMP nsAccessible::RemoveChildFromSelection(PRInt32 aIndex)
{
  // Tree views and other container widgets which may have grandchildren should
  // implement a selection methods for their specific interfaces, because being
  // able to deal with selection on a per-child basis would not be enough.

  NS_ENSURE_TRUE(aIndex >= 0, NS_ERROR_FAILURE);

  nsCOMPtr<nsIAccessible> child;
  GetChildAt(aIndex, getter_AddRefs(child));

  PRUint32 state;
  nsresult rv = child->GetFinalState(&state);
  NS_ENSURE_SUCCESS(rv, rv);

  if (!(state & STATE_SELECTED)) {
    return NS_OK;
  }

  return child->RemoveSelection();
}

NS_IMETHODIMP nsAccessible::IsChildSelected(PRInt32 aIndex, PRBool *aIsSelected)
{
  // Tree views and other container widgets which may have grandchildren should
  // implement a selection methods for their specific interfaces, because being
  // able to deal with selection on a per-child basis would not be enough.

  *aIsSelected = PR_FALSE;
  NS_ENSURE_TRUE(aIndex >= 0, NS_ERROR_FAILURE);

  nsCOMPtr<nsIAccessible> child;
  GetChildAt(aIndex, getter_AddRefs(child));

  PRUint32 state;
  nsresult rv = child->GetFinalState(&state);
  NS_ENSURE_SUCCESS(rv, rv);

  if (state & STATE_SELECTED) {
    *aIsSelected = PR_TRUE;
  }
  return NS_OK;
}

NS_IMETHODIMP nsAccessible::ClearSelection()
{
  nsCOMPtr<nsIAccessible> selected = this;
  while ((selected = GetNextWithState(selected, STATE_SELECTED)) != nsnull) {
    selected->RemoveSelection();
  }
  return NS_OK;
}

NS_IMETHODIMP nsAccessible::SelectAllSelection(PRBool *_retval)
{
  nsCOMPtr<nsIAccessible> selectable = this;
  while ((selectable = GetNextWithState(selectable, STATE_SELECTED)) != nsnull) {
    selectable->TakeSelection();
  }
  return NS_OK;
}

#ifdef MOZ_ACCESSIBILITY_ATK
// static helper functions
nsresult nsAccessible::GetParentBlockNode(nsIPresShell *aPresShell, nsIDOMNode *aCurrentNode, nsIDOMNode **aBlockNode)
{
  *aBlockNode = nsnull;

  nsCOMPtr<nsIContent> content(do_QueryInterface(aCurrentNode));
  if (! content)
    return NS_ERROR_FAILURE;

  nsIFrame *frame = nsnull;
  aPresShell->GetPrimaryFrameFor(content, &frame);
  if (! frame)
    return NS_ERROR_FAILURE;

  nsIFrame *parentFrame = GetParentBlockFrame(frame);
  if (! parentFrame)
    return NS_ERROR_FAILURE;

  nsPresContext *presContext = aPresShell->GetPresContext();
  nsIAtom* frameType = nsnull;
  while (frame && (frameType = frame->GetType()) != nsAccessibilityAtoms::textFrame) {
    frame = frame->GetFirstChild(nsnull);
  }
  if (! frame || frameType != nsAccessibilityAtoms::textFrame)
    return NS_ERROR_FAILURE;

  PRInt32 index = 0;
  nsIFrame *firstTextFrame = nsnull;
  FindTextFrame(index, presContext, parentFrame->GetFirstChild(nsnull),
                &firstTextFrame, frame);
  if (firstTextFrame) {
    nsIContent *content = firstTextFrame->GetContent();

    if (content) {
      CallQueryInterface(content, aBlockNode);
    }

    return NS_OK;
  }
  else {
    //XXX, why?
  }
  return NS_ERROR_FAILURE;
}

nsIFrame* nsAccessible::GetParentBlockFrame(nsIFrame *aFrame)
{
  if (! aFrame)
    return nsnull;

  nsIFrame* frame = aFrame;
  while (frame && frame->GetType() != nsAccessibilityAtoms::blockFrame) {
    nsIFrame* parentFrame = frame->GetParent();
    frame = parentFrame;
  }
  return frame;
}

PRBool nsAccessible::FindTextFrame(PRInt32 &index, nsPresContext *aPresContext, nsIFrame *aCurFrame, 
                                   nsIFrame **aFirstTextFrame, const nsIFrame *aTextFrame)
// Do a depth-first traversal to find the given text frame(aTextFrame)'s index of the block frame(aCurFrame)
//   it belongs to, also return the first text frame within the same block.
// Parameters:
//   index        [in/out] - the current index - finally, it will be the aTextFrame's index in its block;
//   aCurFrame        [in] - the current frame - its initial value is the first child frame of the block frame;
//   aFirstTextFrame [out] - the first text frame which is within the same block with aTextFrame;
//   aTextFrame       [in] - the text frame we are looking for;
// Return:
//   PR_TRUE  - the aTextFrame was found in its block frame;
//   PR_FALSE - the aTextFrame was NOT found in its block frame;
{
  while (aCurFrame) {

    if (aCurFrame == aTextFrame) {
      if (index == 0)
        *aFirstTextFrame = aCurFrame;
      // we got it, stop traversing
      return PR_TRUE;
    }

    nsIAtom* frameType = aCurFrame->GetType();
    if (frameType == nsAccessibilityAtoms::blockFrame) {
      // every block frame will reset the index
      index = 0;
    }
    else {
      if (frameType == nsAccessibilityAtoms::textFrame) {
        nsRect frameRect = aCurFrame->GetRect();
       // skip the empty frame
        if (! frameRect.IsEmpty()) {
          if (index == 0)
            *aFirstTextFrame = aCurFrame;
          index++;
        }
      }

      // we won't expand the tree under a block frame.
      if (FindTextFrame(index, aPresContext, aCurFrame->GetFirstChild(nsnull),
                        aFirstTextFrame, aTextFrame))
        return PR_TRUE;
    }

    nsIFrame* siblingFrame = aCurFrame->GetNextSibling();
    aCurFrame = siblingFrame;
  }
  return PR_FALSE;
}
#endif //MOZ_ACCESSIBILITY_ATK