/* -*- Mode: C++; 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>
 *   Akkana Peck <akkana@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 "nsAString.h"

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;

  readonly attribute nsISelection selection;

  /**
   * 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 AString sourceAttrName,
                                in AString sourceAttrValue,
                                in boolean aSuppressTransaction);
  void removeAttributeOrEquivalent(in nsIDOMElement element,
                                   in DOMString sourceAttrName,
                                   in boolean aSuppressTransaction);

  /**
   * 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();

  /** edit flags for this editor.  May be set at any time. */
  attribute unsigned long flags;

  /**
   * the MimeType of the document
   */
  attribute string contentsMIMEType;

  /** Returns true if we have a document that is not marked read-only */
  readonly attribute boolean isDocumentEditable;

  /**
   * the DOM Document this editor is associated with, refcounted.
   */
  readonly attribute nsIDOMDocument document;

  /** the body element, i.e. the root of the editable document.
   */
  readonly attribute  nsIDOMElement rootElement;

  /**
   * the selection controller for the current presentation, refcounted.
   */
  readonly attribute nsISelectionController selectionController;


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

  /** 
   * DeleteSelection removes all nodes in the current selection.
   * @param aDir  if eNext, delete to the right (for example, the DEL key)
   *              if ePrevious, 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 */
  readonly attribute boolean documentIsEmpty;
  
  /** Returns true if the document is modifed and needs saving */
  readonly attribute boolean documentModified;

  /** Sets the current 'Save' document character set */
  attribute ACString documentCharacterSet;

  /** 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.
    * @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 by which
    *                    to increase or decrease the count
    */
  void incrementModificationCount(in long aModCount);
  
  /* ------------ Transaction methods -------------- */

  /** transactionManager Get the transaction manager the editor is using.
    */
  readonly attribute nsITransactionManager transactionManager;

  /** doTransaction() 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 doTransaction(in nsITransaction txn);


  /** turn the undo system on or off
    * @param aEnable  if PR_TRUE, the undo system is turned on if 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();
  boolean shouldTxnSetSelection();

  /** 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.
    */
  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.
    */
  boolean canCopy();
  
  /** 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.
    */
  boolean canPaste(in long aSelectionType);

  /* ------------ 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();

   /* ------------ Drag/Drop methods -------------- */
  
   /** 
    * canDrag decides if a drag should be started
    * (for example, based on the current selection and mousepoint).
    */
  boolean canDrag(in nsIDOMEvent aEvent);
 
   /** 
    * 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 AString attributestr,
                    in AString 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  [OUT] the value of aAttribute.
   *                      Only valid if aResultIsSet is PR_TRUE
   * @return              PR_TRUE if aAttribute is set on the current node,
   *                      PR_FALSE if it is not.
   */
  boolean getAttributeValue(in nsIDOMElement aElement, 
                            in AString attributestr, 
                            out AString resultValue);

  /**
   * 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 AString aAttribute);

  /**
   * cloneAttribute() copies the attribute from the source node to
   * the destination node and delete those not in the source.
   *
   * The supplied nodes MUST BE ELEMENTS (most callers are working with nodes)
   * @param aAttribute    the name of the attribute to copy
   * @param aDestNode     the destination element to operate on
   * @param aSourceNode   the source element to copy attributes from
   * @exception NS_ERROR_NULL_POINTER at least one of the nodes is null
   * @exception NS_ERROR_NO_INTERFACE at least one of the nodes is not an
   *                                  element
   */
  void cloneAttribute(in AString aAttribute,
                      in nsIDOMNode aDestNode, in nsIDOMNode aSourceNode);

  /**
   * 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
   * @return          The node created.  Caller must release aNewNode.
   */
  nsIDOMNode createNode(in AString tag,
                        in nsIDOMNode parent,
                        in long position);

  /** 
   * 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 node,
                  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);

  /** 
   * markNodeDirty() 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.
   */
  AString outputToString(in AString formatType,
                         in unsigned long flags);
  void outputToStream(in nsIOutputStream aStream,
                      in AString formatType,
                      in ACString 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);
};