/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

#include "nsISupports.idl"
#include "nsISupportsArray.idl"
#include "nsIFormatConverter.idl"


%{ C++

// these probably shouldn't live here, but in some central repository shared
// by the entire app.
#define kTextMime                   "text/plain"
#define kUnicodeMime                "text/unicode"
#define kMozTextInternal          "text/x-moz-text-internal"  // text data which isn't suppoed to be parsed by other apps.
#define kHTMLMime                   "text/html"
#define kAOLMailMime                "AOLMAIL"
#define kPNGImageMime               "image/png"
#define kJPEGImageMime              "image/jpeg"
#define kJPGImageMime               "image/jpg"
#define kGIFImageMime               "image/gif"
#define kFileMime                   "application/x-moz-file"

#define kURLMime                    "text/x-moz-url"        // data contains url\ntitle
#define kURLDataMime                "text/x-moz-url-data"   // data contains url only
#define kURLDescriptionMime         "text/x-moz-url-desc"   // data contains description
#define kURLPrivateMime             "text/x-moz-url-priv"   // same as kURLDataMime but for private uses
#define kNativeImageMime            "application/x-moz-nativeimage"
#define kNativeHTMLMime             "application/x-moz-nativehtml"

// These are used to indicate the context for a fragment of HTML source, such
// that some parent structure and style can be preserved. kHTMLContext
// contains the serialized ancestor elements, whereas kHTMLInfo are numbers
// identifying where in the context the fragment was from.
#define kHTMLContext   "text/_moz_htmlcontext"
#define kHTMLInfo      "text/_moz_htmlinfo"

// the source URL for a file promise
#define kFilePromiseURLMime         "application/x-moz-file-promise-url"
// the destination filename for a file promise
#define kFilePromiseDestFilename    "application/x-moz-file-promise-dest-filename"
// a dataless flavor used to interact with the OS during file drags
#define kFilePromiseMime            "application/x-moz-file-promise"
// a synthetic flavor, put into the transferable once we know the destination directory of a file drag
#define kFilePromiseDirectoryMime   "application/x-moz-file-promise-dir"

%}


/**
  * nsIFlavorDataProvider allows a flavor to 'promise' data later,
  * supplying the data lazily.
  * 
  * To use it, call setTransferData, passing the flavor string,
  * a nsIFlavorDataProvider QI'd to nsISupports, and a data size of 0.
  *
  * When someone calls getTransferData later, if the data size is
  * stored as 0, the nsISupports will be QI'd to nsIFlavorDataProvider,
  * and its getFlavorData called.
  *
  */
interface nsITransferable;
interface nsILoadContext;

[scriptable, uuid(7E225E5F-711C-11D7-9FAE-000393636592)]
interface nsIFlavorDataProvider : nsISupports
{

  /**
    * Retrieve the data from this data provider.
    *
    * @param  aTransferable (in parameter) the transferable we're being called for.
    * @param  aFlavor (in parameter) the flavor of data to retrieve
    * @param  aData the data. Some variant of class in nsISupportsPrimitives.idl
    * @param  aDataLen the length of the data
    */
  void getFlavorData(in nsITransferable aTransferable, in string aFlavor, out nsISupports aData, out unsigned long aDataLen);
};


[scriptable, uuid(5a611a60-e5b5-11e1-aff1-0800200c9a66)]
interface nsITransferable : nsISupports
{
  const long kFlavorHasDataProvider = 0;

  /**
   * Initializes a transferable object.  This should be called on all
   * transferable objects.  Failure to do so will result in fatal assertions in
   * debug builds.
   *
   * @param aContext the load context associated with the transferable object.
   *        This can be set to null if a load context is not available.
   */
  void init(in nsILoadContext aContext);

  /**
    * Computes a list of flavors (mime types as nsISupportsCString) that the transferable 
    * can export, either through intrinsic knowledge or output data converters.
    *
    * @param  aDataFlavorList fills list with supported flavors. This is a copy of
    *          the internal list, so it may be edited w/out affecting the transferable.
    */
  nsISupportsArray flavorsTransferableCanExport ( ) ;

  /**
    * Given a flavor retrieve the data. 
    *
    * @param  aFlavor (in parameter) the flavor of data to retrieve
    * @param  aData the data. Some variant of class in nsISupportsPrimitives.idl
    * @param  aDataLen the length of the data
    */
  void getTransferData ( in string aFlavor, out nsISupports aData, out unsigned long aDataLen ) ;

  /**
    * Returns the best flavor in the transferable, given those that have
    * been added to it with |AddFlavor()|
    *
    * @param  aFlavor (out parameter) the flavor of data that was retrieved
    * @param  aData the data. Some variant of class in nsISupportsPrimitives.idl
    * @param  aDataLen the length of the data
    */
  void getAnyTransferData ( out string aFlavor, out nsISupports aData, out unsigned long aDataLen ) ;

  /**
    * Returns true if the data is large.
    */
  boolean isLargeDataSet ( ) ;
  

    ///////////////////////////////
    // Setter part of interface 
    ///////////////////////////////

  /**
    * Computes a list of flavors (mime types as nsISupportsCString) that the transferable can
    * accept into it, either through intrinsic knowledge or input data converters.
    *
    * @param  outFlavorList fills list with supported flavors. This is a copy of
    *          the internal list, so it may be edited w/out affecting the transferable.
    */
  nsISupportsArray flavorsTransferableCanImport ( ) ;

  /**
    * Sets the data in the transferable with the specified flavor. The transferable
    * will maintain its own copy the data, so it is not necessary to do that beforehand.
    *
    * @param  aFlavor the flavor of data that is being set
    * @param  aData the data, either some variant of class in nsISupportsPrimitives.idl,
    *         an nsIFile, or an nsIFlavorDataProvider (see above)
    * @param  aDataLen the length of the data, or 0 if passing a nsIFlavorDataProvider
    */
  void setTransferData ( in string aFlavor, in nsISupports aData, in unsigned long aDataLen ) ;

  /**
    * Add the data flavor, indicating that this transferable 
    * can receive this type of flavor
    *
    * @param  aDataFlavor a new data flavor to handle
    */
  void addDataFlavor ( in string aDataFlavor ) ;

  /**
    * Removes the data flavor matching the given one (string compare) and the data
    * that goes along with it.
    *
    * @param  aDataFlavor a data flavor to remove
    */
  void removeDataFlavor ( in string aDataFlavor ) ;

  attribute nsIFormatConverter converter;

  /**
   * Use of the SetIsPrivateData() method generated by isPrivateData attribute should 
   * be avoided as much as possible because the value set may not reflect the status 
   * of the context in which the transferable was created.
   */
  [noscript] attribute boolean isPrivateData;

};

