Drag & Drop im Edit erkennen und farbig markieren

[himitsu]

Dieses Interface gibt es seit Windows 2000,
und Delphi 7 stammt aus dem Jahre 2002.

Embarcadero ... ähhhhhh Borland, waren beim Importieren der WinAPI noch nie die Schnellsten.


http://msdn.microsoft.com/en-us/libr.../bb762034.aspx
usw.

Eventuell ist in den JEDI-WinAPI-Headern, bzw in der JCL noch mehr/besseres Zeugs enthalten,
wenn nicht gar ein ganzes Drag&Drop-Komponentendinges.

Delphi-Quellcode:

///////////////////////////////////////////////////////
//
// Drag and Drop helper
//
// Purpose: To expose the Shell drag images
//
// This interface is implemented in the shell by CLSID_DragDropHelper.
//
// To use:
//   If you are the source of a drag (i.e. in response to LV_DRAGBEGIN or
//    equivelent begin drag message) call
//    IDragSourceHelper::InitializeFromWindow
//              (<hwnd of window supporting DI_GETDRAGIMAGE>,
//               <pointer to POINT indicating offset to the mouse from
//                  the upper left corner of the image>,
//               <pointer to data object>)
//
//      NOTE: The Data object must support IDataObject::SetData with multiple
//            data types and GetData must implement data type cloning
//            (Including HGLOBAL), not just aliasing.
//
//   If you wish to have an image while over your application add the
//    IDragImages::Dr* calls to your IDropTarget implementation. For Example:
//
//    STDMETHODIMP CUserDropTarget::DragEnter(IDataObject* pDataObject,
//                                            DWORD grfKeyState,
//                                            POINTL pt, DWORD* pdwEffect)
//    {
//          // Process your DragEnter
//          // Call IDragImages::DragEnter last.
//          _pDropTargetHelper->DragEnter(_hwndDragOver, pDataObject,
//                                        (POINT*)&pt, *pdwEffect);
//          return hres;
//    }
//
//
//   If you wish to be able to source a drag image from a custom control,
//     implement a handler for the RegisterWindowMessage(DI_GETDRAGIMAGE).
//     The LPARAM is a pointer to an SHDRAGIMAGE structure.
//
//      sizeDragImage  -   Calculate the length and width required to render
//                          the images.
//      ptOffset       -   Calculate the offset from the upper left corner to
//                          the mouse cursor within the image
//      hbmpDragImage  -   CreateBitmap( sizeDragImage.cx, sizeDragImage.cy,
//                           GetDeviceCaps(hdcScreen, PLANES),
//                           GetDeviceCaps(hdcScreen, BITSPIXEL),
//                           NULL);
//
//   Drag Images will only be displayed on Windows NT 5.0 or later.
//
//
//   Note about IDropTargetHelper::Show - This method is provided for
//     showing/hiding the Drag image in low color depth video modes. When
//     painting to a window that is currently being dragged over (i.e. For
//     indicating a selection) you need to hide the drag image by calling this
//     method passing FALSE. After the window is done painting, Show the image
//     again by passing TRUE.

const
  SID_IDropTargetHelper  = '{4657278B-411B-11D2-839A-00C04FD918D0}';
  SID_IDragSourceHelper  = '{DE5BF786-477A-11D2-839D-00C04FD918D0}';
  SID_IDragSourceHelper2 = '{83E07D0D-0C5F-4163-BF1A-60B274051E40}';

  // This is sent to a window to get the rendered images to a bitmap
  // Call RegisterWindowMessage to get the ID
  DI_GETDRAGIMAGE = 'ShellGetDragImage';

  DSH_ALLOWDROPDESCRIPTIONTEXT = $1;

type
  LPSHDRAGIMAGE = ^SHDRAGIMAGE;
  SHDRAGIMAGE = record
      sizeDragImage: SIZE;            // OUT - The length and Width of the
                                      //        rendered image
      ptOffset: TPoint;               // OUT - The Offset from the mouse cursor to
                                      //        the upper left corner of the image
      hbmpDragImage: HBITMAP;         // OUT - The Bitmap containing the rendered
                                      //        drag images
      crColorKey: COLORREF;           // OUT - The COLORREF that has been blitted
                                      //        to the background of the images
  end;
  TShDragImage = SHDRAGIMAGE;
  PShDragImage = ^TShDragImage;

  IDropTargetHelper = interface(IUnknown)
    [SID_IDropTargetHelper]
    function DragEnter(hwndTarget: HWND; const pDataObject: IDataObject;
                       var ppt: TPoint; dwEffect: DWORD): HRESULT; stdcall;
    function DragLeave: HResult; stdcall;
    function DragOver(var ppt: TPoint; dwEffect: DWORD): HRESULT; stdcall;
    function Drop(const pDataObject: IDataObject; var ppt: TPoint;
                  dwEffect: DWORD): HRESULT; stdcall;
    function Show(fShow: BOOL): HRESULT; stdcall;
  end;

  IDragSourceHelper = interface(IUnknown)
    [SID_IDragSourceHelper]
    function InitializeFromBitmap(pshdi: LPSHDRAGIMAGE;
      const pDataObject: IDataObject): HRESULT; stdcall;
    function InitializeFromWindow(hwnd: HWND; var ppt: TPoint;
      const pDataObject: IDataObject): HRESULT; stdcall;
  end;

  IDragSourceHelper2 = interface(IDragSourceHelper)
    [SID_IDragSourceHelper2]
    function SetFlags(dwFlags: DWORD): HRESULT; stdcall;
  end;