/* -*- Mode: IDL; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * 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 the Mozilla browser.
 * 
 * The Initial Developer of the Original Code is Netscape
 * Communications, Inc.  Portions created by Netscape are
 * Copyright (C) 1999, Mozilla.  All Rights Reserved.
 * 
 * Contributor(s):
 *   Daniel Glazman <glazman@netscape.com>
 */

#include "nsISupports.idl"
#include "domstubs.idl"

interface nsIURI;
interface nsIAtom;
interface nsISelection;
interface nsISelectionController;
interface nsIDocumentStateListener;
interface nsIOutputStream;
interface nsITransactionManager;
interface nsITransaction;
interface nsIEditorObserver;
interface nsIEditActionListener;

%{C++

#include "nsAWritableString.h"

//class nsIDOMDocument;
//class nsIDOMElement;
//class nsIDOMNode;
class nsIPresShell;
class nsIContent;
typedef short EDirection;
%}


[ptr] native nsIPresShellPtr(nsIPresShell);
[ptr] native nsIContentPtr(nsIContent);


[scriptable, uuid(06b979ce-1dd2-11b2-b6c7-a8bc47aa06b6)]

interface nsIEditor  : nsISupports
{
%{C++
  typedef short EDirection;
%}
  const short eNone = 0;
  const short eNext = 1;
  const short ePrevious = 2;
  const short eNextWord = 3;
  const short ePreviousWord = 4;
  const short eToBeginningOfLine = 5;
  const short eToEndOfLine = 6;

  /**
   * Init is to tell the implementation of nsIEditor to begin its services
   * @param aDoc            The dom document interface being observed
   * @param aPresShell      TEMP: The presentation shell displaying the document
   *                        once events can tell us from what pres shell they originated, 
   *                        this will no longer be necessary and the editor will no longer be
   *                        linked to a single pres shell.
   * @param aRoot           This is the root of the editable section of this document. if it is null then we get root from document body.
   * @param aSelCon         this should be used to get the selection location
   * @param aFlags          A bitmask of flags for specifying the behavior of the editor.
   */
  [noscript] void Init(in nsIDOMDocument doc, in nsIPresShellPtr shell, in nsIContentPtr aRoot, in nsISelectionController aSelCon, in unsigned long aFlags);

  void SetAttributeOrEquivalent(in nsIDOMElement element, in DOMString sourceAttrName, in DOMString sourceAttrValue);
  /**
   * PostCreate should be called after Init, and is the time that the editor tells
   * its documentStateObservers that the document has been created.
   */
  void PostCreate();

  /**
   * PreDestroy is called before the editor goes away, and gives the editor a chance
   * to tell its documentStateObservers that the document is going away.
   */
  void PreDestroy();

  /** return the edit flags for this editor */
  void GetFlags(out unsigned long flags);

  /** set the edit flags for this editor.  May be called at any time. */
  void SetFlags(in unsigned long aFlags);

  /**
   * return the DOM Document this editor is associated with
   *
   * @param aDoc [OUT] the dom interface being observed, refcounted
   */
  void GetDocument(out nsIDOMDocument doc);

  /** return the body element 
   *  @param aElement return value for the root of the editable document
  */
  void GetRootElement(out nsIDOMElement element);

  /**
   * return the presentation shell this editor is associated with
   *
   * @param aPS [OUT] the pres shell, refcounted
   */
  //NS_IMETHOD GetPresShell(nsIPresShell **aPS);

  /**
   * return the selection controller for the current presentation
   *
   * @param aSelCon [OUT] the selection controller, refcounted
   */
  void GetSelectionController(out nsISelectionController selectioncontroller);


  /** 
   * return the DOM Selection for the presentation shell that has focus
   * (or most recently had focus.)
   * @param aSelection [OUT] the dom interface for the selection
   */
  void GetSelection(out nsISelection selection);


  /* ------------ Selected content removal -------------- */

  /** 
   * DeleteSelection removes all nodes in the current selection.
   * @param aDir  if eLTR, delete to the right (for example, the DEL key)
   *              if eRTL, delete to the left (for example, the BACKSPACE key)
   */
  void DeleteSelection(in short action);


  /* ------------ Document info and file methods -------------- */
  
  /** Returns true if the document has no *meaningful* content */
  void GetDocumentIsEmpty(out boolean documentIsEmpty);
  
  /** Returns true if the document is modifed and needs saving */
  void GetDocumentModified(out boolean outDocModified);

  /** Returns the current 'Save' document character set */
  void GetDocumentCharacterSet(out DOMString characterSet);

  /** Sets the current 'Save' document character set */
  void SetDocumentCharacterSet(in DOMString characterSet);

  /** to be used ONLY when we need to override the doc's modification state (such as when it's saved)
    */
  void ResetModificationCount();

  /** Gets the modification count of the document we are editing. Zero means unchanged.
    * @return the modification count of the document being edited. Zero means unchanged.
    */
  long GetModificationCount();

  /** called each time we modify the document. Increments the modification count of the document.
    * @param  aModCount  the number of modifications to increase or decrease count by
    */
  void IncrementModificationCount(in long aModCount);
  
  /* ------------ Transaction methods -------------- */

  /** GetTransactionManagerDo() Get the transaction manager
    *
    * @return aTxnManager the transaction manager that the editor is using
    */
  void GetTransactionManager(out nsITransactionManager txnManager);

  /** Do() fires a transaction.  It is provided here so clients can create their own transactions.
    * If a transaction manager is present, it is used.  
    * Otherwise, the transaction is just executed directly.
    *
    * @param aTxn the transaction to execute
    */
  void Do(in nsITransaction txn);


  /** turn the undo system on or off
    * @param aEnable  if PR_TRUE, the undo system is turned on if it is available
    *                 if PR_FALSE the undo system is turned off if it was previously on
    * @return         if aEnable is PR_TRUE, returns NS_OK if the undo system could be initialized properly
    *                 if aEnable is PR_FALSE, returns NS_OK.
    */
  void EnableUndo(in boolean enable);

  /** Undo reverses the effects of the last Do operation, if Undo is enabled in the editor.
    * It is provided here so clients need no knowledge of whether the editor has a transaction manager or not.
    * If a transaction manager is present, it is told to undo and the result of
    * that undo is returned.  
    * Otherwise, the Undo request is ignored and an error NS_ERROR_NOT_AVAILABLE is returned.
    *
    */
  void Undo(in unsigned long count);

  /** returns state information about the undo system.
    * @param aIsEnabled [OUT] PR_TRUE if undo is enabled
    * @param aCanUndo   [OUT] PR_TRUE if at least one transaction is currently ready to be undone.
    */
  void CanUndo(out boolean isEnabled, out boolean canUndo);

  /** Redo reverses the effects of the last Undo operation
    * It is provided here so clients need no knowledge of whether the editor has a transaction manager or not.
    * If a transaction manager is present, it is told to redo and the result of the previously undone
    * transaction is reapplied to the document.
    * If no transaction is available for Redo, or if the document has no transaction manager,
    * the Redo request is ignored and an error NS_ERROR_NOT_AVAILABLE is returned.
    *
    */
  void Redo(in unsigned long count);

  /** returns state information about the redo system.
    * @param aIsEnabled [OUT] PR_TRUE if redo is enabled
    * @param aCanRedo   [OUT] PR_TRUE if at least one transaction is currently ready to be redone.
    */
  void CanRedo(out boolean isEnabled, out boolean canRedo);

  /** BeginTransaction is a signal from the caller to the editor that the caller will execute multiple updates
    * to the content tree that should be treated as a single logical operation,
    * in the most efficient way possible.<br>
    * All transactions executed between a call to BeginTransaction and EndTransaction will be undoable as
    * an atomic action.<br>
    * EndTransaction must be called after BeginTransaction.<br>
    * Calls to BeginTransaction can be nested, as long as EndTransaction is called once per BeginUpdate.
    */
  void BeginTransaction();

  /** EndTransaction is a signal to the editor that the caller is finished updating the content model.<br>
    * BeginUpdate must be called before EndTransaction is called.<br>
    * Calls to BeginTransaction can be nested, as long as EndTransaction is called once per BeginTransaction.
    */
  void EndTransaction();

  void BeginPlaceHolderTransaction(in nsIAtom name);
  void EndPlaceHolderTransaction();
  void ShouldTxnSetSelection(out boolean result);

  /** Set the flag that prevents InsertElementTxn from changing the selection
    * @param   should  Set false to suppress changing the selection;
    *                  i.e., before using InsertElement() to insert under <head> element
    * WARNING: You must be very careful to reset back to PR_TRUE after
    *          setting PR_FALSE, else selection/caret is trashed
    *          for further editing
    */
  void SetShouldTxnSetSelection(in boolean should);

  /* ------------ Clipboard methods -------------- */

  /** cut the currently selected text, putting it into the OS clipboard
    * What if no text is selected?
    * What about mixed selections?
    * What are the clipboard formats?
    */
  void Cut();

  /** Can we cut? True if the doc is modifiable, and we have a non-
    * collapsed selection.
    */
  void CanCut(out boolean canCut);
  
  /** copy the currently selected text, putting it into the OS clipboard
    * What if no text is selected?
    * What about mixed selections?
    * What are the clipboard formats?
    */
  void Copy();
  
  /** Can we copy? True if we have a non-collapsed selection.
    */
  void CanCopy(out boolean aCanCopy);
  
  /** paste the text in the OS clipboard at the cursor position, replacing
    * the selected text (if any)
    */
  void Paste(in long aSelectionType);

  /** Can we paste? True if the doc is modifiable, and we have
    * pasteable data in the clipboard.
    */
  void CanPaste(in long aSelectionType, out boolean aCanPaste);

  /* ------------ Selection methods -------------- */

  /** sets the document selection to the entire contents of the document */
  void SelectAll();

  /** sets the document selection to the beginning of the document */
  void BeginningOfDocument();

  /** sets the document selection to the end of the document */
  void EndOfDocument();

  /** Can we paste? True if the doc is modifiable, and we have
     * pasteable data in the clipboard.
     */
   /* ------------ Drag/Drop methods -------------- */
  
   /** 
    * CanDrag decides if a drag should be started
    * (for example, based on the current selection and mousepoint).
    */
  void CanDrag(in nsIDOMEvent aEvent, out boolean aCanDrag);
 
   /** 
    * DoDrag transfers the relevant data (as appropriate)
    * to a transferable so it can later be dropped.
    */
  void DoDrag(in nsIDOMEvent aEvent);
 
   /** 
    * InsertFromDrop looks for a dragsession and inserts the
    * relevant data in response to a drop.
    */
  void InsertFromDrop(in nsIDOMEvent aEvent);

  /* ------------ Node manipulation methods -------------- */

  /**
   * SetAttribute() sets the attribute of aElement.
   * No checking is done to see if aAttribute is a legal attribute of the node,
   * or if aValue is a legal value of aAttribute.
   *
   * @param aElement    the content element to operate on
   * @param aAttribute  the string representation of the attribute to set
   * @param aValue      the value to set aAttribute to
   */
  void SetAttribute(in nsIDOMElement aElement, in DOMString attributestr, in DOMString attvalue);

  /**
   * GetAttributeValue() retrieves the attribute's value for aElement.
   *
   * @param aElement      the content element to operate on
   * @param aAttribute    the string representation of the attribute to get
   * @param aResultValue  the value of aAttribute.  only valid if aResultIsSet is PR_TRUE
   * @param aResultIsSet  PR_TRUE if aAttribute is set on the current node, PR_FALSE if it is not.
   */
  void GetAttributeValue(in nsIDOMElement aElement, 
                               in DOMString attributestr, 
                               out DOMString resultValue, 
                               out boolean resultIsSet);

  /**
   * RemoveAttribute() deletes aAttribute from the attribute list of aElement.
   * If aAttribute is not an attribute of aElement, nothing is done.
   *
   * @param aElement      the content element to operate on
   * @param aAttribute    the string representation of the attribute to get
   */
  void RemoveAttribute(in nsIDOMElement aElement, 
                             in DOMString aAttribute);

  /**
   * CloneAttributes() is similar to nsIDOMNode::cloneNode(),
   *   it assures the attribute nodes of the destination are identical with the source node
   *   by copying all existing attributes from the source and deleting those not in the source.
   *   This is used when the destination node (element) already exists
   *
   * The supplied nodes MUST BE ELEMENTS (most callers are working with nodes)
   * @param aDestNode     the destination element to operate on
   * @param aSourceNode   the source element to copy attributes from
   */
  void CloneAttributes(in nsIDOMNode destNode, in nsIDOMNode sourceNode);

  /** 
   * CreateNode instantiates a new element of type aTag and inserts it into aParent at aPosition.
   * @param aTag      The type of object to create
   * @param aParent   The node to insert the new object into
   * @param aPosition The place in aParent to insert the new node
   * @param aNewNode  [OUT] The node created.  Caller must release aNewNode.
   */
  void CreateNode(in DOMString tag,
                        in nsIDOMNode parent,
                        in long         position,
                        out nsIDOMNode newNode);

  /** 
   * InsertNode inserts aNode into aParent at aPosition.
   * No checking is done to verify the legality of the insertion.  That is the 
   * responsibility of the caller.
   * @param aNode     The DOM Node to insert.
   * @param aParent   The node to insert the new object into
   * @param aPosition The place in aParent to insert the new node
   *                  0=first child, 1=second child, etc.
   *                  any number > number of current children = last child
   */
  void InsertNode(in nsIDOMNode vode,
                        in nsIDOMNode parent,
                        in long      aPosition);


  /** 
   * SplitNode() creates a new node identical to an existing node, and split the contents between the two nodes
   * @param aExistingRightNode   the node to split.  It will become the new node's next sibling.
   * @param aOffset              the offset of aExistingRightNode's content|children to do the split at
   * @param aNewLeftNode         [OUT] the new node resulting from the split, becomes aExistingRightNode's previous sibling.
   */
  void SplitNode(in nsIDOMNode existingRightNode,
                       in long      offset,
                       out nsIDOMNode newLeftNode);

  /** 
   * JoinNodes() takes 2 nodes and merge their content|children.
   * @param aLeftNode     The left node.  It will be deleted.
   * @param aRightNode    The right node. It will remain after the join.
   * @param aParent       The parent of aExistingRightNode
   *
   *                      There is no requirement that the two nodes be of the same type.
   *                      However, a text node can be merged only with another text node.
   */
  void JoinNodes(in nsIDOMNode leftNode,
                       in nsIDOMNode rightNode,
                       in nsIDOMNode parent);


  /** 
   * DeleteNode removes aChild from aParent.
   * @param aChild    The node to delete
   */
  void DeleteNode(in nsIDOMNode child);

  /** 
   * InsertFormattingForNode() sets a special dirty attribute on the node.
   * Usually this will be called immediately after creating a new node.
   * @param aNode      The node for which to insert formatting.
   */
  void MarkNodeDirty(in nsIDOMNode node);

  /* ------------ Output methods -------------- */

  /**
   * Output methods:
   * aFormatType is a mime type, like text/plain.
   */
  void OutputToString(out DOMString outputString,
                            [const]in DOMString formatType,
                            in unsigned long flags);
  void OutputToStream(in nsIOutputStream aStream,
                            [const] in DOMString formatType,
                            [const] in DOMString charsetOverride,
                            in unsigned long flags);



  /* ------------ Various listeners methods -------------- */

  /** add an EditorObserver to the editors list of observers. */
  void AddEditorObserver(in nsIEditorObserver observer);

  /** Remove an EditorObserver from the editor's list of observers. */
  void RemoveEditorObserver(in nsIEditorObserver observer);

  /** add an EditActionListener to the editors list of listeners. */
  void AddEditActionListener(in nsIEditActionListener listener);

  /** Remove an EditActionListener from the editor's list of listeners. */
  void RemoveEditActionListener(in nsIEditActionListener listener);

  /** Add a DocumentStateListener to the editors list of doc state listeners. */
  void AddDocumentStateListener(in nsIDocumentStateListener listener);

  /** Remove a DocumentStateListener to the editors list of doc state listeners. */
  void RemoveDocumentStateListener(in nsIDocumentStateListener listener);


  /* ------------ Debug methods -------------- */

  /**
   * And a debug method -- show us what the tree looks like right now
   */
  void DumpContentTree();

  /** Dumps a text representation of the content tree to standard out */
  void DebugDumpContent() ;

  /* Run unit tests. Noop in optimized builds */
  void DebugUnitTests(out long outNumTests, out long  outNumTestsFailed);

};
