gecko/accessible/src/xul/nsXULComboboxAccessible.cpp

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 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
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 * The Original Code is mozilla.org code.
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 * The Initial Developer of the Original Code is
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 * Portions created by the Initial Developer are Copyright (C) 2009
 * the Initial Developer. All Rights Reserved.
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 * Contributor(s):
 *   Aaron Leventhal <aaronl@netscape.com> (original author)
 *   Kyle Yuan <kyle.yuan@sun.com>
 *   Alexander Surkov <surkov.alexander@gmail.com>
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#include "nsXULComboboxAccessible.h"

#include "nsAccessibilityService.h"

#include "nsIDOMXULMenuListElement.h"
#include "nsIDOMXULSelectCntrlItemEl.h"

////////////////////////////////////////////////////////////////////////////////
// nsXULComboboxAccessible
////////////////////////////////////////////////////////////////////////////////

nsXULComboboxAccessible::
  nsXULComboboxAccessible(nsIDOMNode* aDOMNode, nsIWeakReference* aShell) :
  nsAccessibleWrap(aDOMNode, aShell)
{
}

nsresult
nsXULComboboxAccessible::Init()
{
  nsresult rv = nsAccessibleWrap::Init();
  nsCoreUtils::GeneratePopupTree(mDOMNode);
  return rv;
}

nsresult
nsXULComboboxAccessible::GetRoleInternal(PRUint32 *aRole)
{
  nsCOMPtr<nsIContent> content = do_QueryInterface(mDOMNode);
  if (!content) {
    return NS_ERROR_FAILURE;
  }
  if (content->AttrValueIs(kNameSpaceID_None, nsAccessibilityAtoms::type,
                           NS_LITERAL_STRING("autocomplete"), eIgnoreCase)) {
    *aRole = nsIAccessibleRole::ROLE_AUTOCOMPLETE;
  } else {
    *aRole = nsIAccessibleRole::ROLE_COMBOBOX;
  }
  return NS_OK;
}

nsresult
nsXULComboboxAccessible::GetStateInternal(PRUint32 *aState,
                                          PRUint32 *aExtraState)
{
  // As a nsComboboxAccessible we can have the following states:
  //     STATE_FOCUSED
  //     STATE_FOCUSABLE
  //     STATE_HASPOPUP
  //     STATE_EXPANDED
  //     STATE_COLLAPSED

  // Get focus status from base class
  nsresult rv = nsAccessible::GetStateInternal(aState, aExtraState);
  NS_ENSURE_A11Y_SUCCESS(rv, rv);

  nsCOMPtr<nsIDOMXULMenuListElement> menuList(do_QueryInterface(mDOMNode));
  if (menuList) {
    PRBool isOpen;
    menuList->GetOpen(&isOpen);
    if (isOpen) {
      *aState |= nsIAccessibleStates::STATE_EXPANDED;
    }
    else {
      *aState |= nsIAccessibleStates::STATE_COLLAPSED;
    }
  }

  *aState |= nsIAccessibleStates::STATE_HASPOPUP |
             nsIAccessibleStates::STATE_FOCUSABLE;

  return NS_OK;
}

NS_IMETHODIMP
nsXULComboboxAccessible::GetValue(nsAString& aValue)
{
  aValue.Truncate();

  if (IsDefunct())
    return NS_ERROR_FAILURE;

  // The value is the option or text shown entered in the combobox.
  nsCOMPtr<nsIDOMXULMenuListElement> menuList(do_QueryInterface(mDOMNode));
  if (menuList)
    return menuList->GetLabel(aValue);

  return NS_ERROR_FAILURE;
}

NS_IMETHODIMP
nsXULComboboxAccessible::GetDescription(nsAString& aDescription)
{
  aDescription.Truncate();

  if (IsDefunct())
    return NS_ERROR_FAILURE;

  // Use description of currently focused option
  nsCOMPtr<nsIDOMXULMenuListElement> menuListElm(do_QueryInterface(mDOMNode));
  if (!menuListElm)
    return NS_ERROR_FAILURE;

  nsCOMPtr<nsIDOMXULSelectControlItemElement> focusedOptionItem;
  menuListElm->GetSelectedItem(getter_AddRefs(focusedOptionItem));
  nsCOMPtr<nsIDOMNode> focusedOptionNode(do_QueryInterface(focusedOptionItem));
  if (focusedOptionNode) {
    nsAccessible *focusedOption =
      GetAccService()->GetAccessibleInWeakShell(focusedOptionNode, mWeakShell);
    NS_ENSURE_TRUE(focusedOption, NS_ERROR_FAILURE);

    return focusedOption->GetDescription(aDescription);
  }

  return NS_OK;
}

PRBool
nsXULComboboxAccessible::GetAllowsAnonChildAccessibles()
{
  nsCOMPtr<nsIContent> content = do_QueryInterface(mDOMNode);
  NS_ASSERTION(content, "No content during accessible tree building!");
  if (!content)
    return PR_FALSE;

  if (content->NodeInfo()->Equals(nsAccessibilityAtoms::textbox, kNameSpaceID_XUL) ||
      content->AttrValueIs(kNameSpaceID_None, nsAccessibilityAtoms::editable,
                           nsAccessibilityAtoms::_true, eIgnoreCase)) {
    // Both the XUL <textbox type="autocomplete"> and <menulist editable="true"> widgets
    // use nsXULComboboxAccessible. We need to walk the anonymous children for these
    // so that the entry field is a child
    return PR_TRUE;
  }

  // Argument of PR_FALSE indicates we don't walk anonymous children for
  // menuitems
  return PR_FALSE;
}

NS_IMETHODIMP
nsXULComboboxAccessible::GetNumActions(PRUint8 *aNumActions)
{
  NS_ENSURE_ARG_POINTER(aNumActions);

  // Just one action (click).
  *aNumActions = 1;
  return NS_OK;
}

NS_IMETHODIMP
nsXULComboboxAccessible::DoAction(PRUint8 aIndex)
{
  if (aIndex != nsXULComboboxAccessible::eAction_Click) {
    return NS_ERROR_INVALID_ARG;
  }

  if (IsDefunct())
    return NS_ERROR_FAILURE;

  // Programmaticaly toggle the combo box.
  nsCOMPtr<nsIDOMXULMenuListElement> menuList(do_QueryInterface(mDOMNode));
  if (!menuList) {
    return NS_ERROR_FAILURE;
  }
  PRBool isDroppedDown;
  menuList->GetOpen(&isDroppedDown);
  return menuList->SetOpen(!isDroppedDown);
}

NS_IMETHODIMP
nsXULComboboxAccessible::GetActionName(PRUint8 aIndex, nsAString& aName)
{
  if (aIndex != nsXULComboboxAccessible::eAction_Click) {
    return NS_ERROR_INVALID_ARG;
  }

  if (IsDefunct())
    return NS_ERROR_FAILURE;

  // Our action name is the reverse of our state:
  //     if we are close -> open is our name.
  //     if we are open -> close is our name.
  // Uses the frame to get the state, updated on every click.

  nsCOMPtr<nsIDOMXULMenuListElement> menuList(do_QueryInterface(mDOMNode));
  if (!menuList) {
    return NS_ERROR_FAILURE;
  }
  PRBool isDroppedDown;
  menuList->GetOpen(&isDroppedDown);
  if (isDroppedDown)
    aName.AssignLiteral("close"); 
  else
    aName.AssignLiteral("open"); 

  return NS_OK;
}