/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * The contents of this file are subject to the Netscape Public License
 * Version 1.0 (the "NPL"); you may not use this file except in
 * compliance with the NPL.  You may obtain a copy of the NPL at
 * http://www.mozilla.org/NPL/
 *
 * Software distributed under the NPL is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the NPL
 * for the specific language governing rights and limitations under the
 * NPL.
 *
 * The Initial Developer of this code under the NPL is Netscape
 * Communications Corporation.  Portions created by Netscape are
 * Copyright (C) 1998 Netscape Communications Corporation.  All Rights
 * Reserved.
 */

#ifndef nsTextEditRules_h__
#define nsTextEditRules_h__

#include "nsIEditor.h"
#include "nsEditRules.h"
#include "nsCOMPtr.h"
#include "nsIDOMNode.h"
#include "TypeInState.h"

class PlaceholderTxn;
class nsTextEditor;

/** Object that encapsulates HTML text-specific editing rules.
  *  
  * To be a good citizen, edit rules must live by these restrictions:
  * 1. All data manipulation is through the editor.  
  *    Content nodes in the document tree must <B>not</B> be manipulated directly.
  *    Content nodes in document fragments that are not part of the document itself
  *    may be manipulated at will.  Operations on document fragments must <B>not</B>
  *    go through the editor.
  * 2. Selection must not be explicitly set by the rule method.  
  *    Any manipulation of Selection must be done by the editor.
  */
class nsTextEditRules : public nsEditRules
{
public:

  nsTextEditRules();
  virtual ~nsTextEditRules();

  // nsEditRules methods
  NS_IMETHOD Init(nsIEditor *aEditor);
  NS_IMETHOD WillDoAction(nsIDOMSelection *aSelection, nsRulesInfo *aInfo, PRBool *aCancel);
  NS_IMETHOD DidDoAction(nsIDOMSelection *aSelection, nsRulesInfo *aInfo, nsresult aResult);

  // nsTextEditRules action id's
  enum 
  {
    kUndo            = 1000,
    kRedo            = 1001,
    kInsertText      = 2000,
    kDeleteSelection = 2001
  };
  
protected:

  // nsTextEditRules implementation methods
  nsresult WillInsertText(nsIDOMSelection  *aSelection, 
                            PRBool          *aCancel,
                            PlaceholderTxn **aTxn,
                            const nsString *inString,
                            nsString       *outString,
                            TypeInState    typeInState);
  nsresult DidInsertText(nsIDOMSelection *aSelection, nsresult aResult);
  nsresult CreateStyleForInsertText(nsIDOMSelection *aSelection, TypeInState &aTypeInState);

  nsresult WillInsert(nsIDOMSelection *aSelection, PRBool *aCancel);
  nsresult DidInsert(nsIDOMSelection *aSelection, nsresult aResult);

  nsresult WillDeleteSelection(nsIDOMSelection *aSelection, PRBool *aCancel);
  nsresult DidDeleteSelection(nsIDOMSelection *aSelection, nsresult aResult);

  nsresult WillUndo(nsIDOMSelection *aSelection, PRBool *aCancel);
  nsresult DidUndo(nsIDOMSelection *aSelection, nsresult aResult);

  nsresult WillRedo(nsIDOMSelection *aSelection, PRBool *aCancel);
  nsresult DidRedo(nsIDOMSelection *aSelection, nsresult aResult);

  // helper functions
  static PRBool NodeIsType(nsIDOMNode *aNode, nsIAtom *aTag);
  static PRBool IsEditable(nsIDOMNode *aNode);
  
  /** insert aNode into a new style node of type aTag.
    * aSelection is optional.  If provided, aSelection is set to (aNode, 0)
    * if aNode was successfully placed in a new style node
    */
  nsresult InsertStyleNode(nsIDOMNode *aNode, 
                             nsIAtom    *aTag, 
                             nsIDOMSelection *aSelection);

  /** create a new style node of type aTag in aParentNode, and put a new text node 
    * in the new style node.  
    * If aSelection is provided and points to a text node, just call InsertStyleNode instead.
    * aSelection is optional.  If provided, aSelection is set to (newTextNode, 0)
    * if newTextNode was successfully created.
    */
  nsresult InsertStyleAndNewTextNode(nsIDOMNode *aParentNode, 
                                       nsIAtom    *aTag, 
                                       nsIDOMSelection *aSelection);
  
  // data
  nsTextEditor *mEditor;  // note that we do not refcount the editor
  nsCOMPtr<nsIDOMNode> mBogusNode;  // magic node acts as placeholder in empty doc
};



class nsTextRulesInfo : public nsRulesInfo
{
 public:
 
  nsTextRulesInfo(int aAction) : nsRulesInfo(aAction),placeTxn(0),inString(0),outString(0),typeInState() {}
  virtual ~nsTextRulesInfo() {}
  
  // used by kInsertText
  PlaceholderTxn **placeTxn;
  const nsString *inString;
  nsString *outString;
  TypeInState typeInState;
};

#endif //nsTextEditRules_h__