/* -*- 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 Communicator client 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):
 *
 * 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
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

#include "nsHTMLFieldSetElement.h"
#include "nsIDOMHTMLFormElement.h"
#include "nsIDOMEventTarget.h"
#include "nsStyleConsts.h"
#include "nsIForm.h"
#include "nsIFormControl.h"
#include "nsGUIEvent.h"
#include "nsEventDispatcher.h"


NS_IMPL_NS_NEW_HTML_ELEMENT(FieldSet)


nsHTMLFieldSetElement::nsHTMLFieldSetElement(already_AddRefed<nsINodeInfo> aNodeInfo)
  : nsGenericHTMLFormElement(aNodeInfo)
  , mElements(nsnull)
  , mFirstLegend(nsnull)
{
  // <fieldset> is always barred from constraint validation.
  SetBarredFromConstraintValidation(PR_TRUE);

  // We start out enabled
  AddStatesSilently(NS_EVENT_STATE_ENABLED);
}

nsHTMLFieldSetElement::~nsHTMLFieldSetElement()
{
  PRUint32 length = mDependentElements.Length();
  for (PRUint32 i=0; i<length; ++i) {
    mDependentElements[i]->ForgetFieldSet(this);
  }
}

// nsISupports

NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN_INHERITED(nsHTMLFieldSetElement,
                                                nsGenericHTMLFormElement)
  NS_IMPL_CYCLE_COLLECTION_UNLINK_NSCOMPTR(mElements)
NS_IMPL_CYCLE_COLLECTION_UNLINK_END

NS_IMPL_CYCLE_COLLECTION_CLASS(nsHTMLFieldSetElement)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN_INHERITED(nsHTMLFieldSetElement,
                                                  nsGenericHTMLFormElement)
  NS_IMPL_CYCLE_COLLECTION_TRAVERSE_NSCOMPTR_AMBIGUOUS(mElements, nsIDOMNodeList)
NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END

NS_IMPL_ADDREF_INHERITED(nsHTMLFieldSetElement, nsGenericElement)
NS_IMPL_RELEASE_INHERITED(nsHTMLFieldSetElement, nsGenericElement)

DOMCI_NODE_DATA(HTMLFieldSetElement, nsHTMLFieldSetElement)

// QueryInterface implementation for nsHTMLFieldSetElement
NS_INTERFACE_TABLE_HEAD_CYCLE_COLLECTION_INHERITED(nsHTMLFieldSetElement)
  NS_HTML_CONTENT_INTERFACE_TABLE2(nsHTMLFieldSetElement,
                                   nsIDOMHTMLFieldSetElement,
                                   nsIConstraintValidation)
  NS_HTML_CONTENT_INTERFACE_TABLE_TO_MAP_SEGUE(nsHTMLFieldSetElement,
                                               nsGenericHTMLFormElement)
NS_HTML_CONTENT_INTERFACE_TABLE_TAIL_CLASSINFO(HTMLFieldSetElement)

NS_IMPL_ELEMENT_CLONE(nsHTMLFieldSetElement)


NS_IMPL_BOOL_ATTR(nsHTMLFieldSetElement, Disabled, disabled)
NS_IMPL_STRING_ATTR(nsHTMLFieldSetElement, Name, name)

// nsIConstraintValidation
NS_IMPL_NSICONSTRAINTVALIDATION(nsHTMLFieldSetElement)

// nsIContent
nsresult
nsHTMLFieldSetElement::PreHandleEvent(nsEventChainPreVisitor& aVisitor)
{
  // Do not process any DOM events if the element is disabled.
  aVisitor.mCanHandle = PR_FALSE;
  if (IsElementDisabledForEvents(aVisitor.mEvent->message, NULL)) {
    return NS_OK;
  }

  return nsGenericHTMLFormElement::PreHandleEvent(aVisitor);
}

nsresult
nsHTMLFieldSetElement::AfterSetAttr(PRInt32 aNameSpaceID, nsIAtom* aName,
                                    const nsAString* aValue, PRBool aNotify)
{
  if (aNameSpaceID == kNameSpaceID_None && aName == nsGkAtoms::disabled &&
      nsINode::GetFirstChild()) {
    if (!mElements) {
      mElements = new nsContentList(this, MatchListedElements, nsnull, nsnull,
                                    PR_TRUE);
    }

    PRUint32 length = mElements->Length(PR_TRUE);
    for (PRUint32 i=0; i<length; ++i) {
      static_cast<nsGenericHTMLFormElement*>(mElements->GetNodeAt(i))
        ->FieldSetDisabledChanged(aNotify);
    }
  }

  return nsGenericHTMLFormElement::AfterSetAttr(aNameSpaceID, aName,
                                                aValue, aNotify);
}

// nsIDOMHTMLFieldSetElement

NS_IMETHODIMP
nsHTMLFieldSetElement::GetForm(nsIDOMHTMLFormElement** aForm)
{
  return nsGenericHTMLFormElement::GetForm(aForm);
}

NS_IMETHODIMP
nsHTMLFieldSetElement::GetType(nsAString& aType)
{
  aType.AssignLiteral("fieldset");
  return NS_OK;
}

/* static */
PRBool
nsHTMLFieldSetElement::MatchListedElements(nsIContent* aContent, PRInt32 aNamespaceID,
                                           nsIAtom* aAtom, void* aData)
{
  nsCOMPtr<nsIFormControl> formControl = do_QueryInterface(aContent);
  return formControl && formControl->GetType() != NS_FORM_LABEL &&
                        formControl->GetType() != NS_FORM_PROGRESS;
}

NS_IMETHODIMP
nsHTMLFieldSetElement::GetElements(nsIDOMHTMLCollection** aElements)
{
  if (!mElements) {
    mElements = new nsContentList(this, MatchListedElements, nsnull, nsnull,
                                  PR_TRUE);
  }

  NS_ADDREF(*aElements = mElements);
  return NS_OK;
}

// nsIFormControl

nsresult
nsHTMLFieldSetElement::Reset()
{
  return NS_OK;
}

NS_IMETHODIMP
nsHTMLFieldSetElement::SubmitNamesValues(nsFormSubmission* aFormSubmission)
{
  return NS_OK;
}

nsresult
nsHTMLFieldSetElement::InsertChildAt(nsIContent* aChild, PRUint32 aIndex,
                                     PRBool aNotify)
{
  bool firstLegendHasChanged = false;

  if (aChild->IsHTML(nsGkAtoms::legend)) {
    if (!mFirstLegend) {
      mFirstLegend = aChild;
      // We do not want to notify the first time mFirstElement is set.
    } else {
      // If mFirstLegend is before aIndex, we do not change it.
      // Otherwise, mFirstLegend is now aChild.
      if (PRInt32(aIndex) <= IndexOf(mFirstLegend)) {
        mFirstLegend = aChild;
        firstLegendHasChanged = true;
      }
    }
  }

  nsresult rv = nsGenericHTMLFormElement::InsertChildAt(aChild, aIndex, aNotify);
  NS_ENSURE_SUCCESS(rv, rv);

  if (firstLegendHasChanged) {
    NotifyElementsForFirstLegendChange(aNotify);
  }

  return rv;
}

nsresult
nsHTMLFieldSetElement::RemoveChildAt(PRUint32 aIndex, PRBool aNotify)
{
  bool firstLegendHasChanged = false;

  if (mFirstLegend && (GetChildAt(aIndex) == mFirstLegend)) {
    // If we are removing the first legend we have to found another one.
    nsIContent* child = mFirstLegend->GetNextSibling();
    mFirstLegend = nsnull;
    firstLegendHasChanged = true;

    for (; child; child = child->GetNextSibling()) {
      if (child->IsHTML(nsGkAtoms::legend)) {
        mFirstLegend = child;
        break;
      }
    }
  }

  nsresult rv = nsGenericHTMLFormElement::RemoveChildAt(aIndex, aNotify);
  NS_ENSURE_SUCCESS(rv, rv);

  if (firstLegendHasChanged) {
    NotifyElementsForFirstLegendChange(aNotify);
  }

  return rv;
}

void
nsHTMLFieldSetElement::NotifyElementsForFirstLegendChange(PRBool aNotify)
{
  /**
   * NOTE: this could be optimized if only call when the fieldset is currently
   * disabled.
   * This should also make sure that mElements is set when we happen to be here.
   * However, this method shouldn't be called very often in normal use cases.
   */
  if (!mElements) {
    mElements = new nsContentList(this, MatchListedElements, nsnull, nsnull,
                                  PR_TRUE);
  }

  PRUint32 length = mElements->Length(PR_TRUE);
  for (PRUint32 i=0; i<length; ++i) {
    static_cast<nsGenericHTMLFormElement*>(mElements->GetNodeAt(i))
      ->FieldSetFirstLegendChanged(aNotify);
  }
}

