GHOST_DropTargetWin32.h

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/*
 * ***** BEGIN GPL LICENSE BLOCK *****
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 * The Original Code is Copyright (C) 2001-2002 by NaN Holding BV.
 * All rights reserved.
 *
 * The Original Code is: all of this file.
 *
 * Contributor(s): none yet.
 *
 * ***** END GPL LICENSE BLOCK *****
 */

#ifndef _GHOST_DROP_TARGET_WIN32_H_
#define _GHOST_DROP_TARGET_WIN32_H_

#include <string.h>
#include <GHOST_Types.h>
#include "GHOST_WindowWin32.h"
#include "GHOST_SystemWin32.h"

class GHOST_DropTargetWin32 : public IDropTarget
{
public:
    /* IUnknownd implementation.
     * Enables clients to get pointers to other interfaces on a given object 
     * through the QueryInterface method, and manage the existence of the object
     * through the AddRef and Release methods. All other COM interfaces are 
     * inherited, directly or indirectly, from IUnknown. Therefore, the three 
     * methods in IUnknown are the first entries in the VTable for every interface. 
     */
    HRESULT __stdcall QueryInterface (REFIID riid, void ** ppvObj);
    ULONG   __stdcall AddRef (void);
    ULONG   __stdcall Release (void);

    /* IDropTarget implementation
     + The IDropTarget interface is one of the interfaces you implement to
     provide drag-and-drop operations in your application. It contains methods 
     used in any application that can be a target for data during a 
     drag-and-drop operation. A drop-target application is responsible for:
     * 
     *  - Determining the effect of the drop on the target application.
     *  - Incorporating any valid dropped data when the drop occurs.
     *  - Communicating target feedback to the source so the source application
     *    can provide appropriate visual feedback such as setting the cursor.
     *  - Implementing drag scrolling.
     *  - Registering and revoking its application windows as drop targets.
     * 
     * The IDropTarget interface contains methods that handle all these 
     * responsibilities except registering and revoking the application window 
     * as a drop target, for which you must call the RegisterDragDrop and the 
     * RevokeDragDrop functions.
     */
    
    HRESULT __stdcall DragEnter (IDataObject * pDataObject, DWORD grfKeyState, POINTL pt, DWORD * pdwEffect);
    HRESULT __stdcall DragOver (DWORD grfKeyState, POINTL pt, DWORD * pdwEffect);
    HRESULT __stdcall DragLeave (void);
    HRESULT __stdcall Drop (IDataObject * pDataObject, DWORD grfKeyState, POINTL pt, DWORD * pdwEffect);

    GHOST_DropTargetWin32(GHOST_WindowWin32 * window, GHOST_SystemWin32 * system);

    ~GHOST_DropTargetWin32();

private:

    /* Internal helper functions */

    DWORD allowedDropEffect(DWORD dwAllowed);

    GHOST_TDragnDropTypes getGhostType(IDataObject * pDataObject);

    void * getGhostData(IDataObject * pDataObject);

    void * getDropDataAsFilenames(IDataObject * pDataObject);

    void * getDropDataAsString(IDataObject * pDataObject);

    int WideCharToANSI(LPCWSTR in, char * &out);

    /* Private member variables */
    /* COM reference count. */
    LONG    m_cRef; 
    /* Handle of the associated window. */
    HWND    m_hWnd;
    /* The associated GHOST_WindowWin32. */
    GHOST_WindowWin32 * m_window;
    /* The System. */
    GHOST_SystemWin32 * m_system;
    /* Data type of the dragged object */
    GHOST_TDragnDropTypes m_draggedObjectType;

};

#endif  // _GHOST_DROP_TARGET_WIN32_H_