Mozilla/mozilla/accessible/src/html/nsHTMLSelectAccessible.cpp

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * Version: NPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.1 (the "License"); you may not use this file except in
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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 
 * Netscape Communications Corporation.
 * Portions created by the Initial Developer are Copyright (C) 1998
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 * Original Author: Eric Vaughan (evaughan@netscape.com)
 *
 *
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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 "nsCOMPtr.h"
#include "nsHTMLSelectAccessible.h"
#include "nsIAccessibilityService.h"
#include "nsIFrame.h"
#include "nsIComboboxControlFrame.h"
#include "nsIDOMEventReceiver.h"
#include "nsIDOMHTMLCollection.h"
#include "nsIDOMHTMLInputElement.h"
#include "nsIDOMHTMLOptionElement.h"
#include "nsIDOMHTMLSelectElement.h"
#include "nsIListControlFrame.h"
#include "nsIServiceManager.h"
#include "nsLayoutAtoms.h"

/**
  * Selects, Listboxes and Comboboxes, are made up of a number of different
  *  widgets, some of which are shared between the two. This file contains 
  *  all of the widgets for both of the Selects, for HTML only. Some of them
  *  extend classes from nsSelectAccessible.cpp, which contains base classes 
  *  that are also extended by the XUL Select Accessibility support.
  *
  *  Listbox:
  *     - nsHTMLListboxAccessible
  *        - nsHTMLSelctListAccessible
  *           - nsHTMLSelectOptionAccessible
  *
  *  Comboboxes:
  *     - nsHTMLComboboxAccessilbe
  *        - nsHTMLComboboxTextFieldAccessible
  *        - nsHTMLComboboxButtonAccessible
  *        - nsHTMLComboboxWindowAccessilbe
  *           - nsHTMLSelctListAccessible
  *              - nsHTMLSelectOptionAccessible
  */

/** ------------------------------------------------------ */
/**  First, the common widgets                             */
/** ------------------------------------------------------ */

/** ----- nsHTMLSelectListAccessible ----- */

/** Default Constructor */
nsHTMLSelectListAccessible::nsHTMLSelectListAccessible(nsIAccessible* aParent, 
                                                       nsIDOMNode* aDOMNode, 
                                                       nsIWeakReference* aShell)
:nsSelectListAccessible(aParent, aDOMNode, aShell)
{
}

/**
  * As a nsHTMLSelectListAccessible we can have the following states:
  *     STATE_MULTISELECTABLE
  *     STATE_EXTSELECTABLE
  */
NS_IMETHODIMP nsHTMLSelectListAccessible::GetAccState(PRUint32 *_retval)
{
  nsCOMPtr<nsIDOMHTMLSelectElement> select (do_QueryInterface(mDOMNode));
  if ( select ) {
    PRBool multiple;
    select->GetMultiple(&multiple);
    if ( multiple )
      *_retval |= STATE_MULTISELECTABLE | STATE_EXTSELECTABLE;
  }

  return NS_OK;
}

/**
  * Gets the last child of the DOM node and creates and returns
  *  a nsHTMLSelectOptionAccessible.
  */
NS_IMETHODIMP nsHTMLSelectListAccessible::GetAccLastChild(nsIAccessible **_retval)
{
  nsCOMPtr<nsIDOMNode> last;
  mDOMNode->GetLastChild(getter_AddRefs(last));

  *_retval = new nsHTMLSelectOptionAccessible(this, last, mPresShell);
  if ( ! *_retval )
    return NS_ERROR_FAILURE;
  NS_ADDREF(*_retval);
  return NS_OK;
}

/**
  * Gets the First child of the DOM node and creates and returns
  *  a nsHTMLSelectOptionAccessible.
  */
NS_IMETHODIMP nsHTMLSelectListAccessible::GetAccFirstChild(nsIAccessible **_retval)
{
  nsCOMPtr<nsIDOMNode> first;
  mDOMNode->GetFirstChild(getter_AddRefs(first));

  *_retval = new nsHTMLSelectOptionAccessible(this, first, mPresShell);
  if ( ! *_retval )
    return NS_ERROR_FAILURE;
  NS_ADDREF(*_retval);
  return NS_OK;
}

/** ----- nsHTMLSelectOptionAccessible ----- */

/** Default Constructor */
nsHTMLSelectOptionAccessible::nsHTMLSelectOptionAccessible(nsIAccessible* aParent, nsIDOMNode* aDOMNode, nsIWeakReference* aShell):
nsSelectOptionAccessible(aParent, aDOMNode, aShell)
{
}

/**
  * Gets the next sibling of the DOM node and creates and returns
  *  a nsHTMLSelectOptionAccessible.
  */
NS_IMETHODIMP nsHTMLSelectOptionAccessible::GetAccNextSibling(nsIAccessible **_retval)
{ 
  *_retval = nsnull;

  nsCOMPtr<nsIDOMNode> next;
  mDOMNode->GetNextSibling(getter_AddRefs(next));

  if (next) {
    *_retval = new nsHTMLSelectOptionAccessible(mParent, next, mPresShell);
    if ( ! *_retval )
      return NS_ERROR_FAILURE;
    NS_ADDREF(*_retval);
  }

  return NS_OK;
} 

/**
  * Gets the previous sibling of the DOM node and creates and returns
  *  a nsHTMLSelectOptionAccessible.
  */
NS_IMETHODIMP nsHTMLSelectOptionAccessible::GetAccPreviousSibling(nsIAccessible **_retval)
{ 
  *_retval = nsnull;

  nsCOMPtr<nsIDOMNode> prev;
  mDOMNode->GetPreviousSibling(getter_AddRefs(prev));

  if (prev) {
    *_retval = new nsHTMLSelectOptionAccessible(mParent, prev, mPresShell);
    if ( ! *_retval )
      return NS_ERROR_FAILURE;
    NS_ADDREF(*_retval);
  }

  return NS_OK;
} 

/**
  * As a nsHTMLSelectOptionAccessible we can have the following states:
  *     STATE_SELECTABLE
  *     STATE_SELECTED
  *     STATE_FOCUSED
  *     STATE_FOCUSABLE
  *     STATE_INVISIBLE -- not implemented yet
  */
NS_IMETHODIMP nsHTMLSelectOptionAccessible::GetAccState(PRUint32 *_retval)
{
  *_retval = 0;
  nsCOMPtr<nsIDOMNode> focusedOptionNode, parentNode;
  mParent->AccGetDOMNode(getter_AddRefs(parentNode));
  // find out if we are the focused node
  GetFocusedOptionNode(mPresShell, parentNode, focusedOptionNode);
  if (focusedOptionNode == mDOMNode)
    *_retval |= STATE_FOCUSED;

  // Are we selected?
  nsCOMPtr<nsIDOMHTMLOptionElement> option (do_QueryInterface(mDOMNode));
  if ( option ) {
    PRBool isSelected = PR_FALSE;
    option->GetSelected(&isSelected);
    if ( isSelected ) 
      *_retval |= STATE_SELECTED;
  }

  *_retval |= STATE_SELECTABLE | STATE_FOCUSABLE;
  
  return NS_OK;
}

/**
  * Helper method for getting the focused DOM Node from our parent(list) node. We
  *  need to use the frame to get the focused option because for some reason we
  *  weren't getting the proper notification when the focus changed using the DOM
  */
nsresult nsHTMLSelectOptionAccessible::GetFocusedOptionNode(nsIWeakReference *aPresShell, 
                                                            nsIDOMNode *aListNode, 
                                                            nsCOMPtr<nsIDOMNode>& aFocusedOptionNode)
{
  NS_ASSERTION(aListNode, "Called GetFocusedOptionNode without a valid list node");
  nsCOMPtr<nsIPresShell> shell(do_QueryReferent(aPresShell));
  if (!shell)
    return NS_ERROR_FAILURE;

  nsIFrame *frame = nsnull;
  nsCOMPtr<nsIContent> content(do_QueryInterface(aListNode));
  shell->GetPrimaryFrameFor(content, &frame);

  nsresult rv;
  nsCOMPtr<nsIListControlFrame> listFrame(do_QueryInterface(frame, &rv));
  if (NS_FAILED(rv))
    return rv;  // How can list content not have a list frame?
  NS_ASSERTION(listFrame, "We don't have a list frame, but rv returned a success code.");

  // Get what's focused by asking frame for "selected item". 
  PRInt32 focusedOptionIndex = 0;
  rv = listFrame->GetSelectedIndex(&focusedOptionIndex);  

  nsCOMPtr<nsIDOMHTMLCollection> options;

  // Get options
  if (NS_SUCCEEDED(rv)) {
    nsCOMPtr<nsIDOMHTMLSelectElement> selectElement(do_QueryInterface(aListNode));
    NS_ASSERTION(selectElement, "No select element where it should be");
    rv = selectElement->GetOptions(getter_AddRefs(options));
  }

  // Either use options and focused index, or default to list node itself
  if (NS_SUCCEEDED(rv) && options && focusedOptionIndex >= 0)   // Something is focused
    rv = options->Item(focusedOptionIndex, getter_AddRefs(aFocusedOptionNode));
  else {  // If no options in list or focusedOptionIndex <0, then we are not focused on an item
    aFocusedOptionNode = aListNode;  // return normal target content
    rv = NS_OK;
  }

  return rv;
}

/** ------------------------------------------------------ */
/**  Secondly, the Listbox widget                          */
/** ------------------------------------------------------ */

/** ----- nsHTMLListboxAccessible ----- */

/** Constructor */
nsHTMLListboxAccessible::nsHTMLListboxAccessible(nsIDOMNode* aDOMNode, nsIWeakReference* aShell):
nsListboxAccessible(aDOMNode, aShell)
{
}

/** Inherit the ISupports impl from nsAccessible, we handle nsIAccessibleSelectable */
NS_IMPL_ISUPPORTS_INHERITED1(nsHTMLListboxAccessible, nsListboxAccessible, nsIAccessibleSelectable)

/** 
  * Our last (and only) child is an nsHTMLSelectListAccessible object 
  */
NS_IMETHODIMP nsHTMLListboxAccessible::GetAccLastChild(nsIAccessible **_retval)
{
  *_retval = new nsHTMLSelectListAccessible(this, mDOMNode, mPresShell);
  if ( ! *_retval )
    return NS_ERROR_FAILURE;
  NS_ADDREF(*_retval);
  return NS_OK;
}

/** 
  * Our first (and only) child is an nsHTMLSelectListAccessible object
  */
NS_IMETHODIMP nsHTMLListboxAccessible::GetAccFirstChild(nsIAccessible **_retval)
{
  *_retval = new nsHTMLSelectListAccessible(this, mDOMNode, mPresShell);
  if ( ! *_retval )
    return NS_ERROR_FAILURE;
  NS_ADDREF(*_retval);
  return NS_OK;
}

/**
  * Our value is the value of our ( first ) selected child. nsIDOMHTMLSelectElement
  *     returns this by default with GetValue().
  */
NS_IMETHODIMP nsHTMLListboxAccessible::GetAccValue(nsAWritableString& _retval)
{
  nsCOMPtr<nsIDOMHTMLSelectElement> select (do_QueryInterface(mDOMNode));
  if ( select ) {
    select->GetValue(_retval);  
    return NS_OK;
  }
  return NS_ERROR_FAILURE;
}

/**
  * nsIAccessibleSelectable method. 
  *   - gets from the Select DOMNode the list of all Select Options
  *   - iterates through all of the options looking for selected Options
  *   - creates IAccessible objects for selected Options
  *   - Returns the IAccessibles for selectd Options in the nsISupportsArray
  *
  * retval will be nsnull if:
  *   - there are no Options in the Select Element
  *   - there are Options but none are selected
  *   - the DOMNode is not a nsIDOMHTMLSelectElement ( shouldn't happen )
  */
NS_IMETHODIMP nsHTMLListboxAccessible::GetSelectedChildren(nsISupportsArray **_retval)
{
  nsCOMPtr<nsIDOMHTMLSelectElement> select(do_QueryInterface(mDOMNode));
  if(select) {
    nsCOMPtr<nsIDOMHTMLCollection> options;
    // get all the options in the select
    select->GetOptions(getter_AddRefs(options));
    if (options) {
      // set up variables we need to get the selected options and to get their nsIAccessile objects
      PRUint32 length;
      options->GetLength(&length);
      nsCOMPtr<nsIAccessibilityService> accService(do_GetService("@mozilla.org/accessibilityService;1"));
      nsCOMPtr<nsISupportsArray> selectedAccessibles;
      NS_NewISupportsArray(getter_AddRefs(selectedAccessibles));
      if (!selectedAccessibles || !accService)
        return NS_ERROR_FAILURE;
      // find the selected options and get the accessible objects;
      PRBool isSelected = PR_FALSE;
      nsCOMPtr<nsIPresContext> context;
      GetPresContext(context);
      for (PRUint32 i = 0 ; i < length ; i++) {
        nsCOMPtr<nsIDOMNode> tempNode;
        options->Item(i,getter_AddRefs(tempNode));
        if (tempNode) {
          nsCOMPtr<nsIDOMHTMLOptionElement> tempOption(do_QueryInterface(tempNode));
          if (tempOption)
            tempOption->GetSelected(&isSelected);
          if (isSelected) {
            nsCOMPtr<nsIAccessible> tempAccess;
            accService->CreateHTMLSelectOptionAccessible(tempOption, this, context, getter_AddRefs(tempAccess));
            if ( tempAccess )
              selectedAccessibles->AppendElement(tempAccess);
            isSelected = PR_FALSE;
          }
        }
      }
      selectedAccessibles->Count(&length); // reusing length
      if ( length != 0 ) { // length of nsISupportsArray containing selected options
        *_retval = selectedAccessibles;
        NS_IF_ADDREF(*_retval);
        return NS_OK;
      }
    }
  }
  // no options, not a select or none of the options are selected
  *_retval = nsnull;
  return NS_OK;
}

/** ------------------------------------------------------ */
/**  Finally, the Combobox widgets                         */
/** ------------------------------------------------------ */

/** ----- nsHTMLComboboxAccessible ----- */

/** Constructor */
nsHTMLComboboxAccessible::nsHTMLComboboxAccessible(nsIDOMNode* aDOMNode, nsIWeakReference* aShell):
nsComboboxAccessible(aDOMNode, aShell)
{
}

/** 
  * Our last child is an nsHTMLComboboxWindowAccessible object 
  */
NS_IMETHODIMP nsHTMLComboboxAccessible::GetAccLastChild(nsIAccessible **_retval)
{
  *_retval = new nsHTMLComboboxWindowAccessible(this, mDOMNode, mPresShell);
  if (! *_retval)
    return NS_ERROR_FAILURE;
  NS_ADDREF(*_retval);
  return NS_OK;
}

/** 
  * Our last child is an nsHTMLComboboxTextFieldAccessible object 
  */
NS_IMETHODIMP nsHTMLComboboxAccessible::GetAccFirstChild(nsIAccessible **_retval)
{
  *_retval = new nsHTMLComboboxTextFieldAccessible(this, mDOMNode, mPresShell);
  if (! *_retval)
    return NS_ERROR_FAILURE;
  NS_ADDREF(*_retval);
  return NS_OK;
}

/**
  * Our value is the value of our ( first ) selected child. nsIDOMHTMLSelectElement
  *     returns this by default with GetValue().
  */
NS_IMETHODIMP nsHTMLComboboxAccessible::GetAccValue(nsAWritableString& _retval)
{
  nsCOMPtr<nsIDOMHTMLSelectElement> select (do_QueryInterface(mDOMNode));
  if (select) {
    select->GetValue(_retval);  
    return NS_OK;
  }
  return NS_ERROR_FAILURE;
}

/** ----- nsHTMLComboboxTextFieldAccessible ----- */

/** Constructor */
nsHTMLComboboxTextFieldAccessible::nsHTMLComboboxTextFieldAccessible(nsIAccessible* aParent, 
                                                                 nsIDOMNode* aDOMNode, 
                                                                 nsIWeakReference* aShell):
nsComboboxTextFieldAccessible(aParent, aDOMNode, aShell)
{
}

/**
  * Our next sibling is an nsHTMLComboboxButtonAccessible object
  */
NS_IMETHODIMP nsHTMLComboboxTextFieldAccessible::GetAccNextSibling(nsIAccessible **_retval)
{ 
  nsCOMPtr<nsIAccessible> parent;
  GetAccParent(getter_AddRefs(parent));

  *_retval = new nsHTMLComboboxButtonAccessible(parent, mDOMNode, mPresShell);
  if (! *_retval)
    return NS_ERROR_FAILURE;
  NS_ADDREF(*_retval);
  return NS_OK;
} 

/** -----ComboboxButtonAccessible ----- */

/** Constructor -- cache our parent */
nsHTMLComboboxButtonAccessible::nsHTMLComboboxButtonAccessible(nsIAccessible* aParent, 
                                                           nsIDOMNode* aDOMNode, 
                                                           nsIWeakReference* aShell):
nsComboboxButtonAccessible(aParent, aDOMNode, aShell)
{
}

/**
  * Programmaticaly click on the button, causing either the display or
  *     the hiding of the drop down box ( window ).
  *     Walks the Frame tree and checks for proper frames.
  */
NS_IMETHODIMP nsHTMLComboboxButtonAccessible::AccDoAction(PRUint8 index)
{
  nsIFrame* frame = nsAccessible::GetBoundsFrame();
  nsCOMPtr<nsIPresContext> context;
  GetPresContext(context);
  if (!context)
    return NS_ERROR_FAILURE;

  frame->FirstChild(context, nsnull, &frame);
#ifdef DEBUG
  if (! nsAccessible::IsCorrectFrameType(frame, nsLayoutAtoms::blockFrame))
    return NS_ERROR_FAILURE;
#endif

  frame->GetNextSibling(&frame);
#ifdef DEBUG
  if (! nsAccessible::IsCorrectFrameType(frame, nsLayoutAtoms::gfxButtonControlFrame))
    return NS_ERROR_FAILURE;
#endif

  nsCOMPtr<nsIContent> content;
  frame->GetContent(getter_AddRefs(content));

  // We only have one action, click. Any other index is meaningless(wrong)
  if (index == eAction_Click) {
    nsCOMPtr<nsIDOMHTMLInputElement> element(do_QueryInterface(content));
    if (element)
    {
       element->Click();
       return NS_OK;
    }
    return NS_ERROR_FAILURE;
  }
  return NS_ERROR_INVALID_ARG;
}

/**
  * Our next sibling is an nsHTMLComboboxWindowAccessible object
  */
NS_IMETHODIMP nsHTMLComboboxButtonAccessible::GetAccNextSibling(nsIAccessible **_retval)
{ 
  nsCOMPtr<nsIAccessible> parent;
  GetAccParent(getter_AddRefs(parent));

  *_retval = new nsHTMLComboboxWindowAccessible(parent, mDOMNode, mPresShell);
  if (! *_retval)
    return NS_ERROR_OUT_OF_MEMORY;
  NS_ADDREF(*_retval);
  return NS_OK;
} 

/**
  * Our next sibling is an nsHTMLComboboxTextFieldAccessible object
  */
NS_IMETHODIMP nsHTMLComboboxButtonAccessible::GetAccPreviousSibling(nsIAccessible **_retval)
{ 
  nsCOMPtr<nsIAccessible> parent;
  GetAccParent(getter_AddRefs(parent));

  *_retval = new nsHTMLComboboxTextFieldAccessible(parent, mDOMNode, mPresShell);
  if (! *_retval)
    return NS_ERROR_FAILURE;
  NS_ADDREF(*_retval);
  return NS_OK;
} 

/** ----- nsHTMLComboboxWindowAccessible ----- */

/**
  * Constructor -- cache our parent
  */
nsHTMLComboboxWindowAccessible::nsHTMLComboboxWindowAccessible(nsIAccessible* aParent, 
                                                           nsIDOMNode* aDOMNode, 
                                                           nsIWeakReference* aShell):
nsComboboxWindowAccessible(aParent, aDOMNode, aShell)
{
}
 
/**
  * Our previous sibling is a nsHTMLComboboxButtonAccessible object
  */
NS_IMETHODIMP nsHTMLComboboxWindowAccessible::GetAccPreviousSibling(nsIAccessible **_retval)
{ 
  nsCOMPtr<nsIAccessible> parent;
  GetAccParent(getter_AddRefs(parent));

  *_retval = new nsHTMLComboboxButtonAccessible(parent, mDOMNode, mPresShell);
  if (! *_retval)
    return NS_ERROR_FAILURE;
  NS_ADDREF(*_retval);
  return NS_OK;
} 

/**
  * We only have one child, a list
  */
NS_IMETHODIMP nsHTMLComboboxWindowAccessible::GetAccLastChild(nsIAccessible **_retval)
{
  *_retval = new nsHTMLSelectListAccessible(this, mDOMNode, mPresShell);
  if (! *_retval)
    return NS_ERROR_FAILURE;
  NS_ADDREF(*_retval);
  return NS_OK;
}

/**
  * We only have one child, a list
  */
NS_IMETHODIMP nsHTMLComboboxWindowAccessible::GetAccFirstChild(nsIAccessible **_retval)
{
  *_retval = new nsHTMLSelectListAccessible(this, mDOMNode, mPresShell);
  if (! *_retval)
    return NS_ERROR_FAILURE;
  NS_ADDREF(*_retval);
  return NS_OK;
}