/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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 * 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.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):
 *
 * 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
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 * ***** END LICENSE BLOCK ***** */
#ifndef nsIFormControl_h___
#define nsIFormControl_h___

#include "nsISupports.h"
class nsIDOMHTMLFormElement;
class nsPresContext;
class nsPresState;
class nsIContent;
class nsString;
class nsIFormProcessor;
class nsIFormSubmission;

#define NS_FORM_BUTTON_BUTTON   1
#define NS_FORM_BUTTON_RESET    2
#define NS_FORM_BUTTON_SUBMIT   3
#define NS_FORM_FIELDSET        4
#define NS_FORM_INPUT_BUTTON    5
#define NS_FORM_INPUT_CHECKBOX  6
#define NS_FORM_INPUT_FILE      7
#define NS_FORM_INPUT_HIDDEN    8
#define NS_FORM_INPUT_RESET     9
#define NS_FORM_INPUT_IMAGE    10
#define NS_FORM_INPUT_PASSWORD 11
#define NS_FORM_INPUT_RADIO    12
#define NS_FORM_INPUT_SUBMIT   13
#define NS_FORM_INPUT_TEXT     14
#define NS_FORM_LABEL          15
#define NS_FORM_OPTION         16
#define NS_FORM_OPTGROUP       17
#define NS_FORM_LEGEND         18
#define NS_FORM_SELECT         19
#define NS_FORM_TEXTAREA       20
#define NS_FORM_OBJECT         21

#define NS_IFORMCONTROL_IID   \
{ 0x119c5ce8, 0xf4b0, 0x456c, \
  {0x83, 0x4d, 0xb1, 0x90, 0x3d, 0x99, 0x9f, 0xb3} }


/**
 * Interface which all form controls (e.g. buttons, checkboxes, text,
 * radio buttons, select, etc) implement in addition to their dom specific
 * interface.
 */
class nsIFormControl : public nsISupports
{
public:

  NS_DECLARE_STATIC_IID_ACCESSOR(NS_IFORMCONTROL_IID)

  /**
   * Get the form for this form control.
   * @param aForm the form [OUT]
   */
  NS_IMETHOD GetForm(nsIDOMHTMLFormElement** aForm) = 0;

  /**
   * Set the form for this form control.
   * @param aForm the form.  Either this, or the control's current
   *        form must be null.
   *
   * XXXbz We should really have a SetForm method (which takes aForm
   * and nothing else) and a ClearForm() method (which takes
   * aRemoveFromForm fand aNotify).
   * 
   * @param aRemoveFromForm set false if you do not want this element removed
   *        from the form.  (Used by nsFormControlList::Clear())
   * @param aNotify If true, send nsIDocumentObserver notifications as needed.
   *
   * @note that when setting a new form aNotify is ignored and the
   * control is not added to the form itself.  It adds itself when it
   * gets bound to the tree thereafter, so that it can be properly
   * sorted with the other controls in the form.
   */
  NS_IMETHOD SetForm(nsIDOMHTMLFormElement* aForm,
                     PRBool aRemoveFromForm,
                     PRBool aNotify) = 0;

  /**
   * Get the type of this control as an int (see NS_FORM_* above)
   * @return the type of this control
   */
  NS_IMETHOD_(PRInt32) GetType() const = 0 ;

  /**
   * Reset this form control (as it should be when the user clicks the Reset
   * button)
   */
  NS_IMETHOD Reset() = 0;

  /**
   * Tells the form control to submit its names and values to the form
   * submission object
   * @param aFormSubmission the form submission to notify of names/values/files
   *                       to submit
   * @param aSubmitElement the element that was pressed to submit (possibly
   *                       null)
   */
  NS_IMETHOD SubmitNamesValues(nsIFormSubmission* aFormSubmission,
                               nsIContent* aSubmitElement) = 0;

  /**
   * Save to presentation state.  The form control will determine whether it
   * has anything to save and if so, create an entry in the layout history for
   * its pres context.
   */
  NS_IMETHOD SaveState() = 0;

  /**
   * Restore from presentation state.  You pass in the presentation state for
   * this form control (generated with GenerateStateKey() + "-C") and the form
   * control will grab its state from there.
   *
   * @param aState the pres state to use to restore the control
   * @return PR_TRUE if the form control was a checkbox and its
   *         checked state was restored, PR_FALSE otherwise.
   */
  virtual PRBool RestoreState(nsPresState* aState) = 0;

  virtual PRBool AllowDrop() = 0;

  /**
   * Returns true if this is a control which submits the form when
   * activated by the user.
   * @return Whether this is a submit control.
   */
  virtual PRBool IsSubmitControl() const = 0;
};

NS_DEFINE_STATIC_IID_ACCESSOR(nsIFormControl, NS_IFORMCONTROL_IID)

#endif /* nsIFormControl_h___ */
