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Sourcecode: xulrunner-1.9 version File versions

nsAccessibilityUtils.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
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 *
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 * 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) 2007
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Alexander Surkov <surkov.alexander@gmail.com> (original author)
 *
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 * 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"),
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#include "nsAccessibilityUtils.h"

#include "nsIAccessibleTypes.h"
#include "nsPIAccessible.h"
#include "nsAccessibleEventData.h"

#include "nsIDocument.h"
#include "nsIDOMAbstractView.h"
#include "nsIDOMDocument.h"
#include "nsIDOMDocumentView.h"
#include "nsIDOMRange.h"
#include "nsIDOMXULSelectCntrlEl.h"
#include "nsIDOMXULSelectCntrlItemEl.h"
#include "nsIDOMWindowInternal.h"
#include "nsIEventListenerManager.h"
#include "nsIPresShell.h"
#include "nsPresContext.h"
#include "nsIEventStateManager.h"
#include "nsISelection2.h"
#include "nsISelectionController.h"

#include "nsContentCID.h"
#include "nsComponentManagerUtils.h"
#include "nsIInterfaceRequestorUtils.h"

static NS_DEFINE_IID(kRangeCID, NS_RANGE_CID);

void
nsAccUtils::GetAccAttr(nsIPersistentProperties *aAttributes, nsIAtom *aAttrName,
                       nsAString& aAttrValue)
{
  nsCAutoString attrName;
  aAttrName->ToUTF8String(attrName);
  aAttributes->GetStringProperty(attrName, aAttrValue);
}

void
nsAccUtils::SetAccAttr(nsIPersistentProperties *aAttributes, nsIAtom *aAttrName,
                       const nsAString& aAttrValue)
{
  nsAutoString oldValue;
  nsCAutoString attrName;

  aAttrName->ToUTF8String(attrName);
  aAttributes->SetStringProperty(attrName, aAttrValue, oldValue);
}

void
nsAccUtils::GetAccGroupAttrs(nsIPersistentProperties *aAttributes,
                             PRInt32 *aLevel, PRInt32 *aPosInSet,
                             PRInt32 *aSetSize)
{
  *aLevel = 0;
  *aPosInSet = 0;
  *aSetSize = 0;

  nsAutoString value;
  PRInt32 error = NS_OK;

  GetAccAttr(aAttributes, nsAccessibilityAtoms::level, value);
  if (!value.IsEmpty()) {
    PRInt32 level = value.ToInteger(&error);
    if (NS_SUCCEEDED(error))
      *aLevel = level;
  }

  GetAccAttr(aAttributes, nsAccessibilityAtoms::posinset, value);
  if (!value.IsEmpty()) {
    PRInt32 posInSet = value.ToInteger(&error);
    if (NS_SUCCEEDED(error))
      *aPosInSet = posInSet;
  }

  GetAccAttr(aAttributes, nsAccessibilityAtoms::setsize, value);
  if (!value.IsEmpty()) {
    PRInt32 sizeSet = value.ToInteger(&error);
    if (NS_SUCCEEDED(error))
      *aSetSize = sizeSet;
  }
}

PRBool
nsAccUtils::HasAccGroupAttrs(nsIPersistentProperties *aAttributes)
{
  nsAutoString value;

  GetAccAttr(aAttributes, nsAccessibilityAtoms::setsize, value);
  if (!value.IsEmpty()) {
    GetAccAttr(aAttributes, nsAccessibilityAtoms::posinset, value);
    return !value.IsEmpty();
  }

  return PR_FALSE;
}

void
nsAccUtils::SetAccGroupAttrs(nsIPersistentProperties *aAttributes,
                             PRInt32 aLevel, PRInt32 aPosInSet,
                             PRInt32 aSetSize)
{
  nsAutoString value;

  if (aLevel) {
    value.AppendInt(aLevel);
    SetAccAttr(aAttributes, nsAccessibilityAtoms::level, value);
  }

  if (aSetSize && aPosInSet) {
    value.Truncate();
    value.AppendInt(aPosInSet);
    SetAccAttr(aAttributes, nsAccessibilityAtoms::posinset, value);

    value.Truncate();
    value.AppendInt(aSetSize);
    SetAccAttr(aAttributes, nsAccessibilityAtoms::setsize, value);
  }
}

void
nsAccUtils::SetAccAttrsForXULSelectControlItem(nsIDOMNode *aNode,
                                               nsIPersistentProperties *aAttributes)
{
  nsCOMPtr<nsIDOMXULSelectControlItemElement> item(do_QueryInterface(aNode));
  if (!item)
    return;

  nsCOMPtr<nsIDOMXULSelectControlElement> control;
  item->GetControl(getter_AddRefs(control));
  if (!control)
    return;

  PRUint32 itemsCount;
  control->GetItemCount(&itemsCount);
  PRInt32 indexOf;
  control->GetIndexOfItem(item, &indexOf);

  SetAccGroupAttrs(aAttributes, 0, indexOf + 1, itemsCount);
}

PRBool
nsAccUtils::HasListener(nsIContent *aContent, const nsAString& aEventType)
{
  NS_ENSURE_ARG_POINTER(aContent);
  nsCOMPtr<nsIEventListenerManager> listenerManager;
  aContent->GetListenerManager(PR_FALSE, getter_AddRefs(listenerManager));

  return listenerManager && listenerManager->HasListenersFor(aEventType);  
}

PRUint32
nsAccUtils::GetAccessKeyFor(nsIContent *aContent)
{
  if (!aContent)
    return 0;

  // Accesskeys are registered by @accesskey attribute only. At first check
  // whether it is presented on the given element to avoid the slow
  // nsIEventStateManager::GetRegisteredAccessKey() method.
  if (!aContent->HasAttr(kNameSpaceID_None, nsAccessibilityAtoms::accesskey))
    return 0;

  nsCOMPtr<nsIDocument> doc = aContent->GetOwnerDoc();
  if (!doc)
    return 0;

  nsCOMPtr<nsIPresShell> presShell = doc->GetPrimaryShell();
  if (!presShell)
    return 0;

  nsPresContext *presContext = presShell->GetPresContext();
  if (!presContext)
    return 0;

  nsIEventStateManager *esm = presContext->EventStateManager();
  if (!esm)
    return 0;

  PRUint32 key = 0;
  esm->GetRegisteredAccessKey(aContent, &key);
  return key;
}

nsresult
nsAccUtils::FireAccEvent(PRUint32 aEventType, nsIAccessible *aAccessible,
                         PRBool aIsAsynch)
{
  NS_ENSURE_ARG(aAccessible);

  nsCOMPtr<nsPIAccessible> pAccessible(do_QueryInterface(aAccessible));
  NS_ASSERTION(pAccessible, "Accessible doesn't implement nsPIAccessible");

  nsCOMPtr<nsIAccessibleEvent> event =
    new nsAccEvent(aEventType, aAccessible, nsnull, aIsAsynch);
  NS_ENSURE_TRUE(event, NS_ERROR_OUT_OF_MEMORY);

  return pAccessible->FireAccessibleEvent(event);
}

PRBool
nsAccUtils::IsAncestorOf(nsIDOMNode *aPossibleAncestorNode,
                         nsIDOMNode *aPossibleDescendantNode)
{
  NS_ENSURE_ARG_POINTER(aPossibleAncestorNode);
  NS_ENSURE_ARG_POINTER(aPossibleDescendantNode);

  nsCOMPtr<nsIDOMNode> loopNode = aPossibleDescendantNode;
  nsCOMPtr<nsIDOMNode> parentNode;
  while (NS_SUCCEEDED(loopNode->GetParentNode(getter_AddRefs(parentNode))) &&
         parentNode) {
    if (parentNode == aPossibleAncestorNode) {
      return PR_TRUE;
    }
    loopNode.swap(parentNode);
  }
  return PR_FALSE;
}

already_AddRefed<nsIAccessible>
nsAccUtils::GetAncestorWithRole(nsIAccessible *aDescendant, PRUint32 aRole)
{
  nsCOMPtr<nsIAccessible> parentAccessible = aDescendant, testRoleAccessible;
  while (NS_SUCCEEDED(parentAccessible->GetParent(getter_AddRefs(testRoleAccessible))) &&
         testRoleAccessible) {
    PRUint32 testRole;
    testRoleAccessible->GetFinalRole(&testRole);
    if (testRole == aRole) {
      nsIAccessible *returnAccessible = testRoleAccessible;
      NS_ADDREF(returnAccessible);
      return returnAccessible;
    }
    nsCOMPtr<nsIAccessibleDocument> docAccessible = do_QueryInterface(testRoleAccessible);
    if (docAccessible) {
      break;
    }
    parentAccessible.swap(testRoleAccessible);
  }
  return nsnull;
}

nsresult
nsAccUtils::ScrollSubstringTo(nsIFrame *aFrame,
                              nsIDOMNode *aStartNode, PRInt32 aStartIndex,
                              nsIDOMNode *aEndNode, PRInt32 aEndIndex,
                              PRUint32 aScrollType)
{
  if (!aFrame || !aStartNode || !aEndNode)
    return NS_ERROR_FAILURE;

  nsPresContext *presContext = aFrame->PresContext();

  nsCOMPtr<nsIDOMRange> scrollToRange = do_CreateInstance(kRangeCID);
  NS_ENSURE_TRUE(scrollToRange, NS_ERROR_FAILURE);

  nsCOMPtr<nsISelectionController> selCon;
  aFrame->GetSelectionController(presContext, getter_AddRefs(selCon));
  NS_ENSURE_TRUE(selCon, NS_ERROR_FAILURE);

  scrollToRange->SetStart(aStartNode, aStartIndex);
  scrollToRange->SetEnd(aEndNode, aEndIndex);

  nsCOMPtr<nsISelection> selection1;
  selCon->GetSelection(nsISelectionController::SELECTION_ACCESSIBILITY,
                       getter_AddRefs(selection1));

  nsCOMPtr<nsISelection2> selection(do_QueryInterface(selection1));
  if (selection) {
    selection->RemoveAllRanges();
    selection->AddRange(scrollToRange);

    PRInt16 vPercent, hPercent;
    ConvertScrollTypeToPercents(aScrollType, &vPercent, &hPercent);
    selection->ScrollIntoView(nsISelectionController::SELECTION_ANCHOR_REGION,
                              PR_TRUE, vPercent, hPercent);

    selection->CollapseToStart();
  }

  return NS_OK;
}

void
nsAccUtils::ConvertScrollTypeToPercents(PRUint32 aScrollType,
                                        PRInt16 *aVPercent,
                                        PRInt16 *aHPercent)
{
  switch (aScrollType)
  {
    case nsIAccessibleScrollType::SCROLL_TYPE_TOP_LEFT:
      *aVPercent = NS_PRESSHELL_SCROLL_TOP;
      *aHPercent = NS_PRESSHELL_SCROLL_LEFT;
      break;
    case nsIAccessibleScrollType::SCROLL_TYPE_BOTTOM_RIGHT:
      *aVPercent = NS_PRESSHELL_SCROLL_BOTTOM;
      *aHPercent = NS_PRESSHELL_SCROLL_RIGHT;
      break;
    case nsIAccessibleScrollType::SCROLL_TYPE_TOP_EDGE:
      *aVPercent = NS_PRESSHELL_SCROLL_TOP;
      *aHPercent = NS_PRESSHELL_SCROLL_ANYWHERE;
      break;
    case nsIAccessibleScrollType::SCROLL_TYPE_BOTTOM_EDGE:
      *aVPercent = NS_PRESSHELL_SCROLL_BOTTOM;
      *aHPercent = NS_PRESSHELL_SCROLL_ANYWHERE;
      break;
    case nsIAccessibleScrollType::SCROLL_TYPE_LEFT_EDGE:
      *aVPercent = NS_PRESSHELL_SCROLL_ANYWHERE;
      *aHPercent = NS_PRESSHELL_SCROLL_LEFT;
      break;
    case nsIAccessibleScrollType::SCROLL_TYPE_RIGHT_EDGE:
      *aVPercent = NS_PRESSHELL_SCROLL_ANYWHERE;
      *aHPercent = NS_PRESSHELL_SCROLL_RIGHT;
      break;
    default:
      *aVPercent = NS_PRESSHELL_SCROLL_ANYWHERE;
      *aHPercent = NS_PRESSHELL_SCROLL_ANYWHERE;
  }
}

nsIntPoint
nsAccUtils::GetScreenCoordsForWindow(nsIDOMNode *aNode)
{
  nsIntPoint coords(0, 0);
  nsCOMPtr<nsIDocShellTreeItem> treeItem(GetDocShellTreeItemFor(aNode));
  if (!treeItem)
    return coords;

  nsCOMPtr<nsIDocShellTreeItem> rootTreeItem;
  treeItem->GetRootTreeItem(getter_AddRefs(rootTreeItem));
  nsCOMPtr<nsIDOMDocument> domDoc = do_GetInterface(rootTreeItem);
  nsCOMPtr<nsIDOMDocumentView> docView(do_QueryInterface(domDoc));
  if (!docView)
    return coords;

  nsCOMPtr<nsIDOMAbstractView> abstractView;
  docView->GetDefaultView(getter_AddRefs(abstractView));
  nsCOMPtr<nsIDOMWindowInternal> windowInter(do_QueryInterface(abstractView));
  if (!windowInter)
    return coords;

  windowInter->GetScreenX(&coords.x);
  windowInter->GetScreenY(&coords.y);
  return coords;
}

already_AddRefed<nsIDocShellTreeItem>
nsAccUtils::GetDocShellTreeItemFor(nsIDOMNode *aNode)
{
  if (!aNode)
    return nsnull;

  nsCOMPtr<nsIDOMDocument> domDoc;
  aNode->GetOwnerDocument(getter_AddRefs(domDoc));
  nsCOMPtr<nsIDocument> doc(do_QueryInterface(domDoc));
  if (!doc)
    doc = do_QueryInterface(aNode);

  NS_ASSERTION(doc, "No document for node passed in");
  NS_ENSURE_TRUE(doc, nsnull);

  nsCOMPtr<nsISupports> container = doc->GetContainer();
  nsIDocShellTreeItem *docShellTreeItem = nsnull;
  if (container)
    CallQueryInterface(container, &docShellTreeItem);

  return docShellTreeItem;
}


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