The SBJ MVC Framework - The Model, from Abstraction to Realization

//------------------------------------------------------------------------------
// $Workfile: DropTarget.cpp $
// $Header: /SbjDev/SbjCore/DropTarget.cpp 2     11/12/08 2:22p Steve $
//
//	Copyright � 2008 SbjCat
// All rights reserved.
//
//
// *** Authors ***
//	 Steve Johnson
//
// $Revision: 2 $
//
//-----------------------------------------------------------------------------

#include "stdafx.h"
#include "DropTarget.h"
#include "DataHandler.h"

#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif

namespace SbjCore
{
	namespace DragNDrop
	{
		struct DropTargetImpl
		{
			typedef std::map<CLIPFORMAT, DataHandler*> t_mapCFToDataHandler;
		
			t_mapCFToDataHandler theDataHandlers;
			DataHandler* pTheDataHandler;
			IDropTargetHelper* pDropHelper;

			DropTargetImpl() :
				pTheDataHandler(NULL),
				pDropHelper(NULL)
			{
				CoCreateInstance(CLSID_DragDropHelper, NULL, CLSCTX_INPROC_SERVER, IID_IDropTargetHelper, (void**) &pDropHelper);
			}

			virtual ~DropTargetImpl()
			{
				try 
				{
					if (pDropHelper != NULL)
					{
						pDropHelper->Release();
					}
				}
				catch (...)
				{
					ASSERT(FALSE);
				}
			}
			
			bool GetDataHandler(COleDataObject* pDataObject)
			{
				bool bRslt = false;
				
				pTheDataHandler = NULL;
				
				t_mapCFToDataHandler::iterator iter;
				
				for (iter = theDataHandlers.begin(); iter != theDataHandlers.end(); iter++)
				{
					CLIPFORMAT nCF = iter->first;
					
					if (pDataObject->GetGlobalData(nCF) != NULL)
					{
						pTheDataHandler = iter->second;
						bRslt = true;
						break;
					}
				}
				return bRslt;
			}
		};
		
		

		DropTarget::DropTarget() : 
			m_pImpl(new DropTargetImpl)
		{

		}

		DropTarget::~DropTarget()
		{
			try 
			{
				delete m_pImpl;
			}
			catch (...)
			{
				ASSERT(FALSE);
			}
		}


		DROPEFFECT DropTarget::OnDragEnter(CWnd* pWnd, COleDataObject* pDataObject, DWORD dwKeyState, CPoint point)
		{
			dwKeyState;
			DROPEFFECT dwEffect = DROPEFFECT_NONE;

			if (m_pImpl->GetDataHandler(pDataObject))
			{
				dwEffect = m_pImpl->pTheDataHandler->GetDropEffect(pDataObject, dwKeyState, point);
			}

			if (m_pImpl->pDropHelper)
			{
				IDataObject* piDataObj = pDataObject->GetIDataObject(FALSE); 
				pWnd->ClientToScreen(&point);
				m_pImpl->pDropHelper->DragEnter(pWnd->GetSafeHwnd(), piDataObj, &point, dwEffect);
			}

			return dwEffect;
		}

		DROPEFFECT DropTarget::OnDragOver(CWnd* pWnd, COleDataObject* pDataObject, DWORD dwKeyState, CPoint point)
		{
			dwKeyState;
			pDataObject;
			DROPEFFECT dwEffect = DROPEFFECT_NONE;
			
			if (m_pImpl->pTheDataHandler != NULL)
			{
				dwEffect = m_pImpl->pTheDataHandler->GetDropEffect(pDataObject, dwKeyState, point);;
			}

			if (m_pImpl->pDropHelper)
			{
				pWnd->ClientToScreen(&point);
				m_pImpl->pDropHelper->DragOver(&point, dwEffect);
			}

			return dwEffect;
		}

		BOOL DropTarget::OnDrop(CWnd* pWnd, COleDataObject* pDataObject,
			DROPEFFECT dropEffect, CPoint point)
		{
			pWnd;
			bool bRslt = m_pImpl->pTheDataHandler->Handle(pDataObject, dropEffect, point);
			
			m_pImpl->pTheDataHandler = NULL; // done with it

			if (m_pImpl->pDropHelper)
			{
				IDataObject* piDataObj = pDataObject->GetIDataObject(FALSE); 
				pWnd->ClientToScreen(&point);
				m_pImpl->pDropHelper->Drop(piDataObj, &point, dropEffect);
			}

			return bRslt;
		}

		void DropTarget::OnDragLeave(CWnd* pWnd)
		{
			pWnd;
			if (m_pImpl->pDropHelper)
			{
				m_pImpl->pDropHelper->DragLeave();
			}
		}
		

		

		void DropTarget::AddHandler(CLIPFORMAT nCF, DataHandler* pHandler)
		{
			m_pImpl->theDataHandlers[nCF] = pHandler;
		}

	}
}

//*** Modification History ***
// $Log: /SbjDev/SbjCore/DropTarget.cpp $
// 
// 2     11/12/08 2:22p Steve
// Finished Generalization of Model  v2.0.1