widget/windows/nsNativeDragTarget.h

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5 #ifndef _nsNativeDragTarget_h_
   6 #define _nsNativeDragTarget_h_
   7
   8 #include "nsCOMPtr.h"
   9 #include "nsIDragSession.h"
  10 #include <ole2.h>
  11 #include <shlobj.h>
  12
  13 #ifndef IDropTargetHelper
  14 #include <shobjidl.h> // Vista drag image interfaces
  15 #undef LogSeverity // SetupAPI.h #defines this as DWORD
  16 #endif
  17
  18 #include "mozilla/Attributes.h"
  19
  20 class nsIDragService;
  21 class nsIWidget;
  22
  23 struct IDataObject;
  24
  25 /*
  26  * nsNativeDragTarget implements the IDropTarget interface and gets most of its
  27  * behavior from the associated adapter (m_dragDrop).
  28  */
  29
  30 class nsNativeDragTarget MOZ_FINAL : public IDropTarget
  31 {
  32 public:
  33   nsNativeDragTarget(nsIWidget * aWidget);
  34   ~nsNativeDragTarget();
  35
  36   // IUnknown members - see iunknown.h for documentation
  37   STDMETHODIMP QueryInterface(REFIID, void**);
  38   STDMETHODIMP_(ULONG) AddRef();
  39   STDMETHODIMP_(ULONG) Release();
  40
  41   // IDataTarget members
  42
  43   // Set pEffect based on whether this object can support a drop based on
  44   // the data available from pSource, the key and mouse states specified
  45   // in grfKeyState, and the coordinates specified by point. This is
  46   // called by OLE when a drag enters this object's window (as registered
  47   // by Initialize).
  48   STDMETHODIMP DragEnter(LPDATAOBJECT pSource, DWORD grfKeyState,
  49                          POINTL point, DWORD* pEffect);
  50
  51   // Similar to DragEnter except it is called frequently while the drag
  52   // is over this object's window.
  53   STDMETHODIMP DragOver(DWORD grfKeyState, POINTL point, DWORD* pEffect);
  54
  55   // Release the drag-drop source and put internal state back to the point
  56   // before the call to DragEnter. This is called when the drag leaves
  57   // without a drop occurring.
  58   STDMETHODIMP DragLeave();
  59
  60   // If point is within our region of interest and pSource's data supports
  61   // one of our formats, get the data and set pEffect according to
  62   // grfKeyState (DROPEFFECT_MOVE if the control key was not pressed,
  63   // DROPEFFECT_COPY if the control key was pressed). Otherwise return
  64   // E_FAIL.
  65   STDMETHODIMP Drop(LPDATAOBJECT pSource, DWORD grfKeyState,
  66                     POINTL point, DWORD* pEffect);
  67   /**
  68    * Cancel the current drag session, if any.
  69    */
  70   void DragCancel();
  71
  72 protected:
  73
  74   void GetGeckoDragAction(DWORD grfKeyState, LPDWORD pdwEffect,
  75                           uint32_t * aGeckoAction);
  76   void ProcessDrag(uint32_t aEventType, DWORD grfKeyState,
  77                    POINTL pt, DWORD* pdwEffect);
  78   void DispatchDragDropEvent(uint32_t aType, POINTL pt);
  79   void AddLinkSupportIfCanBeGenerated(LPDATAOBJECT aIDataSource);
  80
  81   // Native Stuff
  82   ULONG            m_cRef;      // reference count
  83   HWND             mHWnd;
  84   DWORD            mEffectsAllowed;
  85   DWORD            mEffectsPreferred;
  86   bool             mTookOwnRef;
  87
  88   // Gecko Stuff
  89   nsIWidget      * mWidget;
  90   nsIDragService * mDragService;
  91   // Drag target helper
  92   IDropTargetHelper * GetDropTargetHelper();
  93
  94
  95 private:
  96   // Drag target helper
  97   IDropTargetHelper * mDropTargetHelper;
  98 };
  99
 100 #endif // _nsNativeDragTarget_h_
 101
 102