src/Utils/DragDropImpl.h

   1 // IDataObjectImpl.h: interface for the CIDataObjectImpl class.
   2 /**************************************************************************
   3    THIS CODE AND INFORMATION IS PROVIDED 'AS IS' WITHOUT WARRANTY OF
   4    ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING BUT NOT LIMITED TO
   5    THE IMPLIED WARRANTIES OF MERCHANTABILITY AND/OR FITNESS FOR A
   6    PARTICULAR PURPOSE.
   7    Author: Leon Finker  1/2001
   8 **************************************************************************/
   9 #ifndef __DRAGDROPIMPL_H__
  10 #define __DRAGDROPIMPL_H__
  11 //#include <ShlDisp.h>
  12 #include <shobjidl.h>
  13 #include <shlobj.h>
  14
  15 ///////////////////////////////////////////////////////////////////////////////////////////////
  16 class CDragSourceNotify : IDropSourceNotify
  17 {
  18 private:
  19         LONG refCount;
  20
  21 public:
  22
  23         CDragSourceNotify(void)
  24         {
  25                 refCount = 0;
  26         }
  27
  28         ~CDragSourceNotify(void)
  29         {
  30         }
  31
  32         HRESULT STDMETHODCALLTYPE QueryInterface(REFIID riid, void** ppvObject) override
  33         {
  34                 if(!ppvObject)
  35                         return E_POINTER;
  36
  37                 if (IsEqualIID(riid, IID_IUnknown))
  38                         *ppvObject = static_cast<IUnknown*>(this);
  39                 else if (IsEqualIID(riid, IID_IDropSourceNotify))
  40                         *ppvObject = static_cast<IDropSourceNotify*>(this);
  41                 else
  42                 {
  43                         *ppvObject = nullptr;
  44                         return E_NOINTERFACE;
  45                 }
  46
  47                 AddRef();
  48                 return S_OK;
  49         }
  50
  51         ULONG STDMETHODCALLTYPE AddRef(void) override
  52         {
  53                 return InterlockedIncrement(&refCount);
  54         }
  55
  56         ULONG STDMETHODCALLTYPE Release(void) override
  57         {
  58                 ULONG ret = InterlockedDecrement(&refCount);
  59                 if(!ret) {
  60                         delete this;
  61                 }
  62                 return ret;
  63         }
  64
  65         HRESULT STDMETHODCALLTYPE DragEnterTarget(HWND /*hWndTarget*/) override
  66         {
  67                 return S_OK;
  68         }
  69
  70         HRESULT STDMETHODCALLTYPE DragLeaveTarget(void) override
  71         {
  72                 return S_OK;
  73         }
  74 };
  75
  76
  77 ///////////////////////////////////////////////////////////////////////////////////////////////
  78 class CEnumFormatEtc : public IEnumFORMATETC
  79 {
  80    private:
  81          ULONG           m_cRefCount;
  82          CSimpleArray<FORMATETC>  m_pFmtEtc;
  83          int           m_iCur;
  84
  85    public:
  86          CEnumFormatEtc(const CSimpleArray<FORMATETC>& ArrFE);
  87          CEnumFormatEtc(const CSimpleArray<FORMATETC*>& ArrFE);
  88          //IUnknown members
  89          STDMETHOD(QueryInterface)(REFIID, void FAR* FAR*) override;
  90          STDMETHOD_(ULONG, AddRef)(void) override;
  91          STDMETHOD_(ULONG, Release)(void) override;
  92
  93          //IEnumFORMATETC members
  94          STDMETHOD(Next)(ULONG, LPFORMATETC, ULONG FAR *) override;
  95          STDMETHOD(Skip)(ULONG) override;
  96          STDMETHOD(Reset)(void) override;
  97          STDMETHOD(Clone)(IEnumFORMATETC FAR* FAR*) override;
  98 };
  99
 100 ///////////////////////////////////////////////////////////////////////////////////////////////
 101 class CIDropSource : public IDropSource
 102 {
 103         long m_cRefCount;
 104 public:
 105         bool m_bDropped;
 106         IDataObject * m_pIDataObj;
 107         CDragSourceNotify* pDragSourceNotify;
 108
 109
 110         CIDropSource()
 111         : m_cRefCount(0)
 112         , m_bDropped(false)
 113         , m_pIDataObj(nullptr)
 114         {
 115                 pDragSourceNotify = new CDragSourceNotify();
 116                 pDragSourceNotify->AddRef();
 117         }
 118         ~CIDropSource()
 119         {
 120                 if (m_pIDataObj)
 121                 {
 122                         m_pIDataObj->Release();
 123                         m_pIDataObj = nullptr;
 124                 }
 125                 if (pDragSourceNotify)
 126                 {
 127                         pDragSourceNotify->Release();
 128                         pDragSourceNotify = nullptr;
 129                 }
 130         }
 131         //IUnknown
 132         virtual HRESULT STDMETHODCALLTYPE QueryInterface(
 133                         /* [in] */ REFIID riid,
 134                         /* [iid_is][out] */ void __RPC_FAR *__RPC_FAR *ppvObject) override;
 135         virtual ULONG STDMETHODCALLTYPE AddRef( void) override;
 136         virtual ULONG STDMETHODCALLTYPE Release( void) override;
 137         //IDropSource
 138         virtual HRESULT STDMETHODCALLTYPE QueryContinueDrag(
 139                 /* [in] */ BOOL fEscapePressed,
 140                 /* [in] */ DWORD grfKeyState) override;
 141
 142         virtual HRESULT STDMETHODCALLTYPE GiveFeedback(
 143                 /* [in] */ DWORD dwEffect) override;
 144 };
 145
 146 ///////////////////////////////////////////////////////////////////////////////////////////////
 147 class CIDataObject : public IDataObject//,public IAsyncOperation
 148 {
 149         CIDropSource* m_pDropSource;
 150         long m_cRefCount;
 151         CSimpleArray<FORMATETC*> m_ArrFormatEtc;
 152         CSimpleArray<STGMEDIUM*> m_StgMedium;
 153 public:
 154         CIDataObject(CIDropSource* pDropSource);
 155         ~CIDataObject();
 156         void CopyMedium(STGMEDIUM* pMedDest, STGMEDIUM* pMedSrc, FORMATETC* pFmtSrc);
 157         //IUnknown
 158         virtual HRESULT STDMETHODCALLTYPE QueryInterface(
 159                         /* [in] */ REFIID riid,
 160                         /* [iid_is][out] */ void __RPC_FAR *__RPC_FAR *ppvObject) override;
 161         virtual ULONG STDMETHODCALLTYPE AddRef( void) override;
 162         virtual ULONG STDMETHODCALLTYPE Release( void) override;
 163
 164         //IDataObject
 165         virtual /* [local] */ HRESULT STDMETHODCALLTYPE GetData(
 166                 /* [unique][in] */ FORMATETC __RPC_FAR *pformatetcIn,
 167                 /* [out] */ STGMEDIUM __RPC_FAR *pmedium) override;
 168
 169         virtual /* [local] */ HRESULT STDMETHODCALLTYPE GetDataHere(
 170                 /* [unique][in] */ FORMATETC __RPC_FAR *pformatetc,
 171                 /* [out][in] */ STGMEDIUM __RPC_FAR *pmedium) override;
 172
 173         virtual HRESULT STDMETHODCALLTYPE QueryGetData(
 174                 /* [unique][in] */ FORMATETC __RPC_FAR *pformatetc) override;
 175
 176         virtual HRESULT STDMETHODCALLTYPE GetCanonicalFormatEtc(
 177                 /* [unique][in] */ FORMATETC __RPC_FAR *pformatectIn,
 178                 /* [out] */ FORMATETC __RPC_FAR *pformatetcOut) override;
 179
 180         virtual /* [local] */ HRESULT STDMETHODCALLTYPE SetData(
 181                 /* [unique][in] */ FORMATETC __RPC_FAR *pformatetc,
 182                 /* [unique][in] */ STGMEDIUM __RPC_FAR *pmedium,
 183                 /* [in] */ BOOL fRelease) override;
 184
 185         virtual HRESULT STDMETHODCALLTYPE EnumFormatEtc(
 186                 /* [in] */ DWORD dwDirection,
 187                 /* [out] */ IEnumFORMATETC __RPC_FAR *__RPC_FAR *ppenumFormatEtc) override;
 188
 189         virtual HRESULT STDMETHODCALLTYPE DAdvise(
 190                 /* [in] */ FORMATETC __RPC_FAR *pformatetc,
 191                 /* [in] */ DWORD advf,
 192                 /* [unique][in] */ IAdviseSink __RPC_FAR *pAdvSink,
 193                 /* [out] */ DWORD __RPC_FAR *pdwConnection) override;
 194
 195         virtual HRESULT STDMETHODCALLTYPE DUnadvise(
 196                 /* [in] */ DWORD dwConnection) override;
 197
 198         virtual HRESULT STDMETHODCALLTYPE EnumDAdvise(
 199                 /* [out] */ IEnumSTATDATA __RPC_FAR *__RPC_FAR *ppenumAdvise) override;
 200
 201         //IAsyncOperation
 202         //virtual HRESULT STDMETHODCALLTYPE SetAsyncMode(
 203         //    /* [in] */ BOOL fDoOpAsync)
 204         //{
 205         //      return E_NOTIMPL;
 206         //}
 207         //
 208         //virtual HRESULT STDMETHODCALLTYPE GetAsyncMode(
 209         //    /* [out] */ BOOL __RPC_FAR *pfIsOpAsync)
 210         //{
 211         //      return E_NOTIMPL;
 212         //}
 213         //
 214         //virtual HRESULT STDMETHODCALLTYPE StartOperation(
 215         //    /* [optional][unique][in] */ IBindCtx __RPC_FAR *pbcReserved)
 216         //{
 217         //      return E_NOTIMPL;
 218         //}
 219         //
 220         //virtual HRESULT STDMETHODCALLTYPE InOperation(
 221         //    /* [out] */ BOOL __RPC_FAR *pfInAsyncOp)
 222         //{
 223         //      return E_NOTIMPL;
 224         //}
 225         //
 226         //virtual HRESULT STDMETHODCALLTYPE EndOperation(
 227         //    /* [in] */ HRESULT hResult,
 228         //    /* [unique][in] */ IBindCtx __RPC_FAR *pbcReserved,
 229         //    /* [in] */ DWORD dwEffects)
 230         //{
 231         //      return E_NOTIMPL;
 232         //}
 233
 234
 235         // helper function
 236         HRESULT SetDropDescription(DROPIMAGETYPE image, LPCTSTR format, LPCTSTR insert);
 237 };
 238
 239 ///////////////////////////////////////////////////////////////////////////////////////////////
 240 class CIDropTarget : public IDropTarget
 241 {
 242         DWORD m_cRefCount;
 243         bool m_bAllowDrop;
 244         IDropTargetHelper *m_pDropTargetHelper;
 245         CSimpleArray<FORMATETC> m_formatetc;
 246         FORMATETC* m_pSupportedFrmt;
 247 protected:
 248         HWND m_hTargetWnd;
 249         IDataObject *           m_pIDataObject;
 250 public:
 251
 252         CIDropTarget(HWND m_hTargetWnd);
 253         virtual ~CIDropTarget();
 254         void AddSuportedFormat(FORMATETC& ftetc) { m_formatetc.Add(ftetc); }
 255
 256         //return values: true - release the medium. false - don't release the medium
 257         virtual bool OnDrop(FORMATETC* pFmtEtc, STGMEDIUM& medium,DWORD *pdwEffect, POINTL pt) = 0;
 258
 259         virtual HRESULT STDMETHODCALLTYPE QueryInterface(
 260                 /* [in] */ REFIID riid,
 261                 /* [iid_is][out] */ void __RPC_FAR *__RPC_FAR *ppvObject) override;
 262         virtual ULONG STDMETHODCALLTYPE AddRef( void) override { ATLTRACE("CIDropTarget::AddRef\n"); return ++m_cRefCount; }
 263         virtual ULONG STDMETHODCALLTYPE Release( void) override;
 264
 265         bool QueryDrop(DWORD grfKeyState, LPDWORD pdwEffect);
 266         virtual HRESULT STDMETHODCALLTYPE DragEnter(
 267                 /* [unique][in] */ IDataObject __RPC_FAR *pDataObj,
 268                 /* [in] */ DWORD grfKeyState,
 269                 /* [in] */ POINTL pt,
 270                 /* [out][in] */ DWORD __RPC_FAR *pdwEffect) override;
 271         virtual HRESULT STDMETHODCALLTYPE DragOver(
 272                 /* [in] */ DWORD grfKeyState,
 273                 /* [in] */ POINTL pt,
 274                 /* [out][in] */ DWORD __RPC_FAR *pdwEffect) override;
 275         virtual HRESULT STDMETHODCALLTYPE DragLeave( void) override;
 276         virtual HRESULT STDMETHODCALLTYPE Drop(
 277                 /* [unique][in] */ IDataObject __RPC_FAR *pDataObj,
 278                 /* [in] */ DWORD grfKeyState,
 279                 /* [in] */ POINTL pt,
 280                 /* [out][in] */ DWORD __RPC_FAR *pdwEffect) override;
 281
 282         // helper function
 283         HRESULT SetDropDescription(DROPIMAGETYPE image, LPCTSTR format, LPCTSTR insert);
 284 };
 285
 286 class CDragSourceHelper
 287 {
 288         IDragSourceHelper2* pDragSourceHelper2;
 289         IDragSourceHelper* pDragSourceHelper;
 290
 291 public:
 292         CDragSourceHelper()
 293         {
 294                 pDragSourceHelper = nullptr;
 295                 pDragSourceHelper2 = nullptr;
 296                 if(FAILED(CoCreateInstance(CLSID_DragDropHelper,
 297                                                 nullptr,
 298                                                 CLSCTX_INPROC_SERVER,
 299                                                 IID_IDragSourceHelper2,
 300                                                 (void**)&pDragSourceHelper2)))
 301                 {
 302                         pDragSourceHelper2 = nullptr;
 303                         if(FAILED(CoCreateInstance(CLSID_DragDropHelper,
 304                                 nullptr,
 305                                 CLSCTX_INPROC_SERVER,
 306                                 IID_IDragSourceHelper,
 307                                 (void**)&pDragSourceHelper)))
 308                                 pDragSourceHelper = nullptr;
 309                 }
 310         }
 311         virtual ~CDragSourceHelper()
 312         {
 313                 if (pDragSourceHelper2)
 314                 {
 315                         pDragSourceHelper2->Release();
 316                         pDragSourceHelper2 = nullptr;
 317                 }
 318                 if (pDragSourceHelper)
 319                 {
 320                         pDragSourceHelper->Release();
 321                         pDragSourceHelper = nullptr;
 322                 }
 323         }
 324
 325         // IDragSourceHelper
 326         HRESULT InitializeFromBitmap(HBITMAP hBitmap,
 327                 POINT& pt,  // cursor position in client coords of the window
 328                 RECT& rc,   // selected item's bounding rect
 329                 IDataObject* pDataObject,
 330                 BOOL allowDropDescription=TRUE,
 331                 COLORREF crColorKey=GetSysColor(COLOR_WINDOW)// color of the window used for transparent effect.
 332                 )
 333         {
 334                 if (!pDragSourceHelper && !pDragSourceHelper2)
 335                         return E_FAIL;
 336
 337                 if ((allowDropDescription)&&(pDragSourceHelper2))
 338                         pDragSourceHelper2->SetFlags(DSH_ALLOWDROPDESCRIPTIONTEXT);
 339
 340                 SHDRAGIMAGE di;
 341                 BITMAP      bm;
 342                 GetObject(hBitmap, sizeof(bm), &bm);
 343                 di.sizeDragImage.cx = bm.bmWidth;
 344                 di.sizeDragImage.cy = bm.bmHeight;
 345                 di.hbmpDragImage = hBitmap;
 346                 di.crColorKey = crColorKey;
 347                 di.ptOffset.x = pt.x - rc.left;
 348                 di.ptOffset.y = pt.y - rc.top;
 349                 if (pDragSourceHelper2)
 350                         return pDragSourceHelper2->InitializeFromBitmap(&di, pDataObject);
 351                 if (!pDragSourceHelper)
 352                         return E_FAIL;
 353                 return pDragSourceHelper->InitializeFromBitmap(&di, pDataObject);
 354         }
 355         HRESULT InitializeFromWindow(HWND hwnd, POINT& pt, IDataObject* pDataObject, BOOL allowDropDescription=TRUE)
 356         {
 357                 if (!pDragSourceHelper && !pDragSourceHelper2)
 358                         return E_FAIL;
 359                 if ((allowDropDescription)&&(pDragSourceHelper2))
 360                         pDragSourceHelper2->SetFlags(DSH_ALLOWDROPDESCRIPTIONTEXT);
 361                 if (pDragSourceHelper2)
 362                         return pDragSourceHelper2->InitializeFromWindow(hwnd, &pt, pDataObject);
 363                 if (!pDragSourceHelper)
 364                         return E_FAIL;
 365                 return pDragSourceHelper->InitializeFromWindow(hwnd, &pt, pDataObject);
 366         }
 367 };
 368 #endif //__DRAGDROPIMPL_H__