gecko/accessible/src/base/AccCollector.cpp

/* ***** 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
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 *
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 * 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
 * Mozilla Foundation.
 * Portions created by the Initial Developer are Copyright (C) 2010
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *  Alexander Surkov <surkov.alexander@gmail.com> (original author)
 *
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 * either 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"),
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#include "AccCollector.h"

#include "nsAccessible.h"

////////////////////////////////////////////////////////////////////////////////
// nsAccCollector
////////////////////////////////////////////////////////////////////////////////

AccCollector::
  AccCollector(nsAccessible* aRoot, filters::FilterFuncPtr aFilterFunc) :
  mFilterFunc(aFilterFunc), mRoot(aRoot), mRootChildIdx(0)
{
}

AccCollector::~AccCollector()
{
}

PRUint32
AccCollector::Count()
{
  EnsureNGetIndex(nsnull);
  return mObjects.Length();
}

nsAccessible*
AccCollector::GetAccessibleAt(PRUint32 aIndex)
{
  nsAccessible *accessible = mObjects.SafeElementAt(aIndex, nsnull);
  if (accessible)
    return accessible;

  return EnsureNGetObject(aIndex);
}

PRInt32
AccCollector::GetIndexAt(nsAccessible *aAccessible)
{
  PRInt32 index = mObjects.IndexOf(aAccessible);
  if (index != -1)
    return index;

  return EnsureNGetIndex(aAccessible);
}

////////////////////////////////////////////////////////////////////////////////
// nsAccCollector protected

nsAccessible*
AccCollector::EnsureNGetObject(PRUint32 aIndex)
{
  PRInt32 childCount = mRoot->GetChildCount();
  while (mRootChildIdx < childCount) {
    nsAccessible* child = mRoot->GetChildAt(mRootChildIdx++);
    if (!mFilterFunc(child))
      continue;

    mObjects.AppendElement(child);
    if (mObjects.Length() - 1 == aIndex)
      return mObjects[aIndex];
  }

  return nsnull;
}

PRInt32
AccCollector::EnsureNGetIndex(nsAccessible* aAccessible)
{
  PRInt32 childCount = mRoot->GetChildCount();
  while (mRootChildIdx < childCount) {
    nsAccessible* child = mRoot->GetChildAt(mRootChildIdx++);
    if (!mFilterFunc(child))
      continue;

    mObjects.AppendElement(child);
    if (child == aAccessible)
      return mObjects.Length() - 1;
  }

  return -1;
}