text: /////////////////////////////////////////////////////////////////////////////
  // Name:        wx/msw/dragimag.h
  // Purpose:     wxDragImage class: a kind of a cursor, that can cope
  //              with more sophisticated images
  // Author:      Julian Smart
  // Modified by:
  // Created:     08/04/99
  // RCS-ID:      $Id$
  // Copyright:   (c) Julian Smart
  // Licence:     wxWindows licence
  /////////////////////////////////////////////////////////////////////////////
  
  #ifndef _WX_DRAGIMAG_H_
  #define _WX_DRAGIMAG_H_
  
  #if wxUSE_DRAGIMAGE
  
  #include "wx/bitmap.h"
  #include "wx/icon.h"
  #include "wx/cursor.h"
  #include "wx/treectrl.h"
  #include "wx/listctrl.h"
  
  // If 1, use a simple wxCursor instead of ImageList_SetDragCursorImage
  #define wxUSE_SIMPLER_DRAGIMAGE 0
  
  /*
    To use this class, create a wxDragImage when you start dragging, for example:
  
    void MyTreeCtrl::OnBeginDrag(wxTreeEvent& event)
    {
  #ifdef __WXMSW__
      ::UpdateWindow((HWND) GetHWND()); // We need to implement this in wxWidgets
  #endif
  
      CaptureMouse();
  
      m_dragImage = new wxDragImage(* this, itemId);
      m_dragImage->BeginDrag(wxPoint(0, 0), this);
      m_dragImage->Move(pt, this);
      m_dragImage->Show(this);
      ...
    }
  
    In your OnMouseMove function, hide the image, do any display updating required,
    then move and show the image again:
  
    void MyTreeCtrl::OnMouseMove(wxMouseEvent& event)
    {
      if (m_dragMode == MY_TREE_DRAG_NONE)
      {
          event.Skip();
          return;
      }
  
      // Prevent screen corruption by hiding the image
      if (m_dragImage)
          m_dragImage->Hide(this);
  
      // Do some updating of the window, such as highlighting the drop target
      ...
  
  #ifdef __WXMSW__
      if (updateWindow)
          ::UpdateWindow((HWND) GetHWND());
  #endif
  
      // Move and show the image again
      m_dragImage->Move(event.GetPosition(), this);
      m_dragImage->Show(this);
   }
  
   Eventually we end the drag and delete the drag image.
  
   void MyTreeCtrl::OnLeftUp(wxMouseEvent& event)
   {
      ...
  
      // End the drag and delete the drag image
      if (m_dragImage)
      {
          m_dragImage->EndDrag(this);
          delete m_dragImage;
          m_dragImage = NULL;
      }
      ReleaseMouse();
   }
  */
  
  /*
   Notes for Unix version:
   Can we simply use cursors instead, creating a cursor dynamically, setting it into the window
   in BeginDrag, and restoring the old cursor in EndDrag?
   For a really bog-standard implementation, we could simply use a normal dragging cursor
   and ignore the image.
  */
  
  /*
   * wxDragImage
   */
  
  class WXDLLEXPORT wxDragImage: public wxObject
  {
  public:
  
      // Ctors & dtor
      ////////////////////////////////////////////////////////////////////////////
  
      wxDragImage();
      wxDragImage(const wxBitmap& image, const wxCursor& cursor = wxNullCursor)
      {
          Init();
  
          Create(image, cursor);
      }
  
      // Deprecated form of the above
      wxDragImage(const wxBitmap& image, const wxCursor& cursor, const wxPoint& cursorHotspot)
      {
          Init();
  
          Create(image, cursor, cursorHotspot);
      }
  
      wxDragImage(const wxIcon& image, const wxCursor& cursor = wxNullCursor)
      {
          Init();
  
          Create(image, cursor);
      }
  
      // Deprecated form of the above
      wxDragImage(const wxIcon& image, const wxCursor& cursor, const wxPoint& cursorHotspot)
      {
          Init();
  
          Create(image, cursor, cursorHotspot);
      }
  
      wxDragImage(const wxString& str, const wxCursor& cursor = wxNullCursor)
      {
          Init();
  
          Create(str, cursor);
      }
  
      // Deprecated form of the above
      wxDragImage(const wxString& str, const wxCursor& cursor, const wxPoint& cursorHotspot)
      {
          Init();
  
          Create(str, cursor, cursorHotspot);
      }
  
  #if wxUSE_TREECTRL
      wxDragImage(const wxTreeCtrl& treeCtrl, wxTreeItemId& id)
      {
          Init();
  
          Create(treeCtrl, id);
      }
  #endif
  
  #if wxUSE_LISTCTRL
      wxDragImage(const wxListCtrl& listCtrl, long id)
      {
          Init();
  
          Create(listCtrl, id);
      }
  #endif
  
      virtual ~wxDragImage();
  
      // Attributes
      ////////////////////////////////////////////////////////////////////////////
  
      // Operations
      ////////////////////////////////////////////////////////////////////////////
  
      // Create a drag image from a bitmap and optional cursor
      bool Create(const wxBitmap& image, const wxCursor& cursor = wxNullCursor);
      bool Create(const wxBitmap& image, const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
      {
          wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
          return Create(image, cursor);
      }
  
      // Create a drag image from an icon and optional cursor
      bool Create(const wxIcon& image, const wxCursor& cursor = wxNullCursor);
      bool Create(const wxIcon& image, const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
      {
          wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
          return Create(image, cursor);
      }
  
      // Create a drag image from a string and optional cursor
      bool Create(const wxString& str, const wxCursor& cursor = wxNullCursor);
      bool Create(const wxString& str, const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
      {
          wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
          return Create(str, cursor);
      }
  
  #if wxUSE_TREECTRL
      // Create a drag image for the given tree control item
      bool Create(const wxTreeCtrl& treeCtrl, wxTreeItemId& id);
  #endif
  
  #if wxUSE_LISTCTRL
      // Create a drag image for the given list control item
      bool Create(const wxListCtrl& listCtrl, long id);
  #endif
  
      // Begin drag. hotspot is the location of the drag position relative to the upper-left
      // corner of the image.
      bool BeginDrag(const wxPoint& hotspot, wxWindow* window, bool fullScreen = false, wxRect* rect = (wxRect*) NULL);
  
      // Begin drag. hotspot is the location of the drag position relative to the upper-left
      // corner of the image. This is full screen only. fullScreenRect gives the
      // position of the window on the screen, to restrict the drag to.
      bool BeginDrag(const wxPoint& hotspot, wxWindow* window, wxWindow* fullScreenRect);
  
      // End drag
      bool EndDrag();
  
      // Move the image: call from OnMouseMove. Pt is in window client coordinates if window
      // is non-NULL, or in screen coordinates if NULL.
      bool Move(const wxPoint& pt);
  
      // Show the image
      bool Show();
  
      // Hide the image
      bool Hide();
  
      // Implementation
      ////////////////////////////////////////////////////////////////////////////
  
      // Initialize variables
      void Init();
  
      // Returns the native image list handle
      WXHIMAGELIST GetHIMAGELIST() const { return m_hImageList; }
  
  #if !wxUSE_SIMPLER_DRAGIMAGE
      // Returns the native image list handle for the cursor
      WXHIMAGELIST GetCursorHIMAGELIST() const { return m_hCursorImageList; }
  #endif
  
  protected:
      WXHIMAGELIST    m_hImageList;
  
  #if wxUSE_SIMPLER_DRAGIMAGE
      wxCursor        m_oldCursor;
  #else
      WXHIMAGELIST    m_hCursorImageList;
  #endif
  
      wxCursor        m_cursor;
  //    wxPoint         m_cursorHotspot; // Obsolete
      wxPoint         m_position;
      wxWindow*       m_window;
      wxRect          m_boundingRect;
      bool            m_fullScreen;
  
  private:
      DECLARE_DYNAMIC_CLASS(wxDragImage)
      DECLARE_NO_COPY_CLASS(wxDragImage)
  };
  
  #endif // wxUSE_DRAGIMAGE
  #endif
      // _WX_DRAGIMAG_H_
  