include/wx/msw/dragimag.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/msw/dragimag.h
   3 // Purpose:     wxDragImage class: a kind of a cursor, that can cope
   4 //              with more sophisticated images
   5 // Author:      Julian Smart
   6 // Modified by:
   7 // Created:     08/04/99
   8 // RCS-ID:      $Id$
   9 // Copyright:   (c) Julian Smart
  10 // Licence:     wxWindows licence
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 #ifndef _WX_DRAGIMAG_H_
  14 #define _WX_DRAGIMAG_H_
  15
  16 #ifdef __GNUG__
  17 #pragma interface "dragimag.h"
  18 #endif
  19
  20 #include "wx/bitmap.h"
  21 #include "wx/icon.h"
  22 #include "wx/cursor.h"
  23 #include "wx/treectrl.h"
  24 #include "wx/listctrl.h"
  25
  26 /*
  27   To use this class, create a wxDragImage when you start dragging, for example:
  28
  29   void MyTreeCtrl::OnBeginDrag(wxTreeEvent& event)
  30   {
  31 #ifdef __WXMSW__
  32     ::UpdateWindow((HWND) GetHWND()); // We need to implement this in wxWindows
  33 #endif
  34
  35     CaptureMouse();
  36
  37     m_dragImage = new wxDragImage(* this, itemId);
  38     m_dragImage->BeginDrag(wxPoint(0, 0), this);
  39     m_dragImage->Move(pt, this);
  40     m_dragImage->Show(this);
  41     ...
  42   }
  43
  44   In your OnMouseMove function, hide the image, do any display updating required,
  45   then move and show the image again:
  46
  47   void MyTreeCtrl::OnMouseMove(wxMouseEvent& event)
  48   {
  49     if (m_dragMode == MY_TREE_DRAG_NONE)
  50     {
  51         event.Skip();
  52         return;
  53     }
  54
  55     // Prevent screen corruption by hiding the image
  56     if (m_dragImage)
  57         m_dragImage->Hide(this);
  58
  59     // Do some updating of the window, such as highlighting the drop target
  60     ...
  61
  62 #ifdef __WXMSW__
  63     if (updateWindow)
  64         ::UpdateWindow((HWND) GetHWND());
  65 #endif
  66
  67     // Move and show the image again
  68     m_dragImage->Move(event.GetPosition(), this);
  69     m_dragImage->Show(this);
  70  }
  71
  72  Eventually we end the drag and delete the drag image.
  73
  74  void MyTreeCtrl::OnLeftUp(wxMouseEvent& event)
  75  {
  76     ...
  77
  78     // End the drag and delete the drag image
  79     if (m_dragImage)
  80     {
  81         m_dragImage->EndDrag(this);
  82         delete m_dragImage;
  83         m_dragImage = NULL;
  84     }
  85     ReleaseMouse();
  86  }
  87 */
  88
  89 /*
  90  Notes for Unix version:
  91  Can we simply use cursors instead, creating a cursor dynamically, setting it into the window
  92  in BeginDrag, and restoring the old cursor in EndDrag?
  93  For a really bog-standard implementation, we could simply use a normal dragging cursor
  94  and ignore the image.
  95 */
  96
  97 /*
  98  * wxDragImage
  99  */
 100
 101 class WXDLLEXPORT wxDragImage: public wxObject
 102 {
 103 public:
 104
 105     // Ctors & dtor
 106     ////////////////////////////////////////////////////////////////////////////
 107
 108     wxDragImage();
 109     wxDragImage(const wxBitmap& image, const wxCursor& cursor = wxNullCursor, const wxPoint& hotspot = wxPoint(0, 0))
 110     {
 111         m_hImageList = 0;
 112         Create(image, cursor);
 113     }
 114     wxDragImage(const wxIcon& image, const wxCursor& cursor = wxNullCursor, const wxPoint& hotspot = wxPoint(0, 0))
 115     {
 116         m_hImageList = 0;
 117         Create(image, cursor);
 118     }
 119     wxDragImage(const wxString& str, const wxCursor& cursor = wxNullCursor, const wxPoint& hotspot = wxPoint(0, 0))
 120     {
 121         m_hImageList = 0;
 122         Create(str, cursor);
 123     }
 124     wxDragImage(const wxTreeCtrl& treeCtrl, wxTreeItemId& id)
 125     {
 126         m_hImageList = 0;
 127         Create(treeCtrl, id);
 128     }
 129     wxDragImage(const wxListCtrl& listCtrl, long id)
 130     {
 131         m_hImageList = 0;
 132         Create(listCtrl, id);
 133     }
 134     ~wxDragImage();
 135
 136     // Attributes
 137     ////////////////////////////////////////////////////////////////////////////
 138
 139     // Operations
 140     ////////////////////////////////////////////////////////////////////////////
 141
 142     // Create a drag image from a bitmap and optional cursor
 143     bool Create(const wxBitmap& image, const wxCursor& cursor = wxNullCursor, const wxPoint& hotspot = wxPoint(0, 0));
 144
 145     // Create a drag image from an icon and optional cursor
 146     bool Create(const wxIcon& image, const wxCursor& cursor = wxNullCursor, const wxPoint& hotspot = wxPoint(0, 0));
 147
 148     // Create a drag image from a string and optional cursor
 149     bool Create(const wxString& str, const wxCursor& cursor = wxNullCursor, const wxPoint& hotspot = wxPoint(0, 0));
 150
 151     // Create a drag image for the given tree control item
 152     bool Create(const wxTreeCtrl& treeCtrl, wxTreeItemId& id);
 153
 154     // Create a drag image for the given list control item
 155     bool Create(const wxListCtrl& listCtrl, long id);
 156
 157     // Begin drag. hotspot is the location of the drag position relative to the upper-left
 158     // corner of the image.
 159     bool BeginDrag(const wxPoint& hotspot, wxWindow* window);
 160
 161     // End drag
 162     bool EndDrag(wxWindow* window);
 163
 164     // Move the image: call from OnMouseMove. Pt is in window client coordinates if window
 165     // is non-NULL, or in screen coordinates if NULL.
 166     bool Move(const wxPoint& pt, wxWindow* window);
 167
 168     // Show the image
 169     bool Show(wxWindow* window);
 170
 171     // Hide the image
 172     bool Hide(wxWindow* window);
 173
 174     // Implementation
 175     ////////////////////////////////////////////////////////////////////////////
 176
 177     // Returns the native image list handle
 178     WXHIMAGELIST GetHIMAGELIST() const { return m_hImageList; }
 179
 180 protected:
 181     WXHIMAGELIST    m_hImageList;
 182     wxCursor        m_cursor;
 183     wxPoint         m_hotspot;
 184     wxPoint         m_position;
 185
 186 private:
 187     DECLARE_DYNAMIC_CLASS(wxDragImage)
 188 };
 189
 190 #endif
 191     // _WX_DRAGIMAG_H_