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 #endif
  16
  17 #include "mozilla/Attributes.h"
  18
  19 class nsIDragService;
  20 class nsIWidget;
  21
  22 struct IDataObject;
  23
  24 /*
  25  * nsNativeDragTarget implements the IDropTarget interface and gets most of its
  26  * behavior from the associated adapter (m_dragDrop).
  27  */
  28
  29 class nsNativeDragTarget MOZ_FINAL : public IDropTarget
  30 {
  31 public:
  32   nsNativeDragTarget(nsIWidget * aWidget);
  33   ~nsNativeDragTarget();
  34
  35   // IUnknown members - see iunknown.h for documentation
  36   STDMETHODIMP QueryInterface(REFIID, void**);
  37   STDMETHODIMP_(ULONG) AddRef();
  38   STDMETHODIMP_(ULONG) Release();
  39
  40   // IDataTarget members
  41
  42   // Set pEffect based on whether this object can support a drop based on
  43   // the data available from pSource, the key and mouse states specified
  44   // in grfKeyState, and the coordinates specified by point. This is
  45   // called by OLE when a drag enters this object's window (as registered
  46   // by Initialize).
  47   STDMETHODIMP DragEnter(LPDATAOBJECT pSource, DWORD grfKeyState,
  48                          POINTL point, DWORD* pEffect);
  49
  50   // Similar to DragEnter except it is called frequently while the drag
  51   // is over this object's window.
  52   STDMETHODIMP DragOver(DWORD grfKeyState, POINTL point, DWORD* pEffect);
  53
  54   // Release the drag-drop source and put internal state back to the point
  55   // before the call to DragEnter. This is called when the drag leaves
  56   // without a drop occurring.
  57   STDMETHODIMP DragLeave();
  58
  59   // If point is within our region of interest and pSource's data supports
  60   // one of our formats, get the data and set pEffect according to
  61   // grfKeyState (DROPEFFECT_MOVE if the control key was not pressed,
  62   // DROPEFFECT_COPY if the control key was pressed). Otherwise return
  63   // E_FAIL.
  64   STDMETHODIMP Drop(LPDATAOBJECT pSource, DWORD grfKeyState,
  65                     POINTL point, DWORD* pEffect);
  66   /**
  67    * Cancel the current drag session, if any.
  68    */
  69   void DragCancel();
  70
  71 protected:
  72
  73   void GetGeckoDragAction(DWORD grfKeyState, LPDWORD pdwEffect,
  74                           uint32_t * aGeckoAction);
  75   void ProcessDrag(uint32_t aEventType, DWORD grfKeyState,
  76                    POINTL pt, DWORD* pdwEffect);
  77   void DispatchDragDropEvent(uint32_t aType, POINTL pt);
  78   void AddLinkSupportIfCanBeGenerated(LPDATAOBJECT aIDataSource);
  79
  80   // Native Stuff
  81   ULONG            m_cRef;      // reference count
  82   HWND             mHWnd;
  83   DWORD            mEffectsAllowed;
  84   DWORD            mEffectsPreferred;
  85   bool             mTookOwnRef;
  86
  87   // Gecko Stuff
  88   nsIWidget      * mWidget;
  89   nsIDragService * mDragService;
  90   // Drag target helper
  91   IDropTargetHelper * GetDropTargetHelper();
  92
  93
  94 private:
  95   // Drag target helper
  96   IDropTargetHelper * mDropTargetHelper;
  97 };
  98
  99 #endif // _nsNativeDragTarget_h_
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