/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */

/* vim: set ts=8 sts=2 et sw=2 tw=80: */

/* 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/. */

#ifndef nsContentAreaDragDrop_h__

#define nsContentAreaDragDrop_h__

#include "nsCOMPtr.h"

#include "nsIDOMEventListener.h"

#include "nsITransferable.h"

class nsPIDOMWindowOuter;

class nsITransferable;

class nsIContent;

class nsIFile;

namespace mozilla {

namespace dom {

class DataTransfer;

class Selection;

} // namespace dom

} // namespace mozilla

//

// class nsContentAreaDragDrop, used to generate the dragdata

//

class nsContentAreaDragDrop

{

public:

  /**

   * Determine what data in the content area, if any, is being dragged.

   *

   * aWindow - the window containing the target node

   * aTarget - the mousedown event target that started the drag

   * aSelectionTargetNode - the node where the drag event should be fired

   * aIsAltKeyPressed - true if the Alt key is pressed. In some cases, this

   *                    will prevent the drag from occuring. For example,

   *                    holding down Alt over a link should select the text,

   *                    not drag the link.

   * aDataTransfer - the dataTransfer for the drag event.

   * aCanDrag - [out] set to true if the drag may proceed, false to stop the

   *            drag entirely

   * aSelection - [out] set to the selection being dragged, or null if no

   *                    selection is being dragged.

   * aDragNode - [out] the link, image or area being dragged, or null if the

   *             drag occurred on another element.

   * aPrincipalURISpec - [out] set to the URI of the triggering principal of

   *                           the drag, or empty string if it's from

   *                           browser chrome or OS

   */

  static nsresult GetDragData(nsPIDOMWindowOuter* aWindow,

                              nsIContent* aTarget,

                              nsIContent* aSelectionTargetNode,

                              bool aIsAltKeyPressed,

                              mozilla::dom::DataTransfer* aDataTransfer,

                              bool* aCanDrag,

                              mozilla::dom::Selection** aSelection,

                              nsIContent** aDragNode,

                              nsACString& aPrincipalURISpec);

};

// this is used to save images to disk lazily when the image data is asked for

// during the drop instead of when it is added to the drag data transfer. This

// ensures that the image data is only created when an image drop is allowed.

class nsContentAreaDragDropDataProvider : public nsIFlavorDataProvider

{

  virtual ~nsContentAreaDragDropDataProvider() {}

public:

  NS_DECL_ISUPPORTS

  NS_DECL_NSIFLAVORDATAPROVIDER

  nsresult SaveURIToFile(nsIURI* inSourceURI,

                         nsIPrincipal* inTriggeringPrincipal,

                         nsIFile* inDestFile, bool isPrivate);

};

#endif /* nsContentAreaDragDrop_h__ */