content/base/src/nsContentAreaDragDrop.h
author David Anderson <danderson@mozilla.com>
Tue, 21 Feb 2012 15:08:22 -0800
changeset 105908 61980734d3a21c29f3783ae946733af29ebcd2bd
parent 105276 8cfeba5239a9e4f20c462d6fb20421b4e4e7c735
parent 87095 788b8d367cb56fcb34d9018b7c0d4887ce2f74ea
child 106274 80e4ab0d24bc64ceaa7693ab5def36faffde7a40
permissions -rw-r--r--
Merge from mozilla-central.

/* ***** BEGIN LICENSE BLOCK *****
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 * 1.1 (the "License"); you may not use this file except in compliance with
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 *
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 * for the specific language governing rights and limitations under the
 * License.
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 * The Original Code is Mozilla Communicator.
 *
 * The Initial Developer of the Original Code is
 * Netscape Communications.
 * Portions created by the Initial Developer are Copyright (C) 2002
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *  Mike Pinkerton <pinkerton@netscape.com>
 *
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 * either the GNU General Public License Version 2 or later (the "GPL"), or
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#ifndef nsContentAreaDragDrop_h__
#define nsContentAreaDragDrop_h__


#include "nsCOMPtr.h"

#include "nsIDOMEventTarget.h"
#include "nsIDOMEventListener.h"
#include "nsITransferable.h"

class nsIDOMNode;
class nsIDOMWindow;
class nsIDOMDocument;
class nsIDOMDragEvent;
class nsISelection;
class nsITransferable;
class nsIContent;
class nsIURI;
class nsIFile;
class nsISimpleEnumerator;
class nsDOMDataTransfer;

//
// 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.
   */
  static nsresult GetDragData(nsIDOMWindow* aWindow,
                              nsIContent* aTarget,
                              nsIContent* aSelectionTargetNode,
                              bool aIsAltKeyPressed,
                              nsDOMDataTransfer* aDataTransfer,
                              bool* aCanDrag,
                              nsISelection** aSelection,
                              nsIContent** aDragNode);
};

// 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
{
public:
  NS_DECL_ISUPPORTS
  NS_DECL_NSIFLAVORDATAPROVIDER

  virtual ~nsContentAreaDragDropDataProvider() {}

  nsresult SaveURIToFile(nsAString& inSourceURIString,
                         nsIFile* inDestFile);
};


#endif /* nsContentAreaDragDrop_h__ */