dom/base/nsContentAreaDragDrop.h

   1 /* This Source Code Form is subject to the terms of the Mozilla Public
   2  * License, v. 2.0. If a copy of the MPL was not distributed with this
   3  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   4
   5
   6 #ifndef nsContentAreaDragDrop_h__
   7 #define nsContentAreaDragDrop_h__
   8
   9
  10 #include "nsCOMPtr.h"
  11
  12 #include "nsIDOMEventListener.h"
  13 #include "nsITransferable.h"
  14
  15 class nsIDOMNode;
  16 class nsPIDOMWindow;
  17 class nsIDOMDragEvent;
  18 class nsISelection;
  19 class nsITransferable;
  20 class nsIContent;
  21 class nsIURI;
  22 class nsIFile;
  23 class nsISimpleEnumerator;
  24
  25 namespace mozilla {
  26 namespace dom {
  27 class DataTransfer;
  28 }
  29 }
  30
  31 //
  32 // class nsContentAreaDragDrop, used to generate the dragdata
  33 //
  34 class nsContentAreaDragDrop
  35 {
  36 public:
  37
  38   /**
  39    * Determine what data in the content area, if any, is being dragged.
  40    *
  41    * aWindow - the window containing the target node
  42    * aTarget - the mousedown event target that started the drag
  43    * aSelectionTargetNode - the node where the drag event should be fired
  44    * aIsAltKeyPressed - true if the Alt key is pressed. In some cases, this
  45    *                    will prevent the drag from occuring. For example,
  46    *                    holding down Alt over a link should select the text,
  47    *                    not drag the link.
  48    * aDataTransfer - the dataTransfer for the drag event.
  49    * aCanDrag - [out] set to true if the drag may proceed, false to stop the
  50    *            drag entirely
  51    * aSelection - [out] set to the selection being dragged, or null if no
  52    *                    selection is being dragged.
  53    * aDragNode - [out] the link, image or area being dragged, or null if the
  54    *             drag occurred on another element.
  55    */
  56   static nsresult GetDragData(nsPIDOMWindow* aWindow,
  57                               nsIContent* aTarget,
  58                               nsIContent* aSelectionTargetNode,
  59                               bool aIsAltKeyPressed,
  60                               mozilla::dom::DataTransfer* aDataTransfer,
  61                               bool* aCanDrag,
  62                               nsISelection** aSelection,
  63                               nsIContent** aDragNode);
  64 };
  65
  66 // this is used to save images to disk lazily when the image data is asked for
  67 // during the drop instead of when it is added to the drag data transfer. This
  68 // ensures that the image data is only created when an image drop is allowed.
  69 class nsContentAreaDragDropDataProvider : public nsIFlavorDataProvider
  70 {
  71   virtual ~nsContentAreaDragDropDataProvider() {}
  72
  73 public:
  74   NS_DECL_ISUPPORTS
  75   NS_DECL_NSIFLAVORDATAPROVIDER
  76
  77   nsresult SaveURIToFile(nsAString& inSourceURIString,
  78                          nsIFile* inDestFile, bool isPrivate);
  79 };
  80
  81
  82 #endif /* nsContentAreaDragDrop_h__ */
  83