include/wx/msw/dragimag.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        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     DECLARE_DYNAMIC_CLASS(wxDragImage)
 104 public:
 105
 106     // Ctors & dtor
 107     ////////////////////////////////////////////////////////////////////////////
 108
 109     wxDragImage();
 110     wxDragImage(const wxBitmap& image, const wxCursor& cursor = wxNullCursor, const wxPoint& hotspot = wxPoint(0, 0))
 111     {
 112         m_hImageList = 0;
 113         Create(image, cursor);
 114     }
 115     wxDragImage(const wxIcon& image, const wxCursor& cursor = wxNullCursor, const wxPoint& hotspot = wxPoint(0, 0))
 116     {
 117         m_hImageList = 0;
 118         Create(image, cursor);
 119     }
 120     wxDragImage(const wxString& str, const wxCursor& cursor = wxNullCursor, const wxPoint& hotspot = wxPoint(0, 0))
 121     {
 122         m_hImageList = 0;
 123         Create(str, cursor);
 124     }
 125     wxDragImage(const wxTreeCtrl& treeCtrl, wxTreeItemId& id)
 126     {
 127         m_hImageList = 0;
 128         Create(treeCtrl, id);
 129     }
 130     wxDragImage(const wxListCtrl& listCtrl, long id)
 131     {
 132         m_hImageList = 0;
 133         Create(listCtrl, id);
 134     }
 135     ~wxDragImage();
 136
 137     // Attributes
 138     ////////////////////////////////////////////////////////////////////////////
 139
 140     // Operations
 141     ////////////////////////////////////////////////////////////////////////////
 142
 143     // Create a drag image from a bitmap and optional cursor
 144     bool Create(const wxBitmap& image, const wxCursor& cursor = wxNullCursor, const wxPoint& hotspot = wxPoint(0, 0));
 145
 146     // Create a drag image from an icon and optional cursor
 147     bool Create(const wxIcon& image, const wxCursor& cursor = wxNullCursor, const wxPoint& hotspot = wxPoint(0, 0));
 148
 149     // Create a drag image from a string and optional cursor
 150     bool Create(const wxString& str, const wxCursor& cursor = wxNullCursor, const wxPoint& hotspot = wxPoint(0, 0));
 151
 152     // Create a drag image for the given tree control item
 153     bool Create(const wxTreeCtrl& treeCtrl, wxTreeItemId& id);
 154
 155     // Create a drag image for the given list control item
 156     bool Create(const wxListCtrl& listCtrl, long id);
 157
 158     // Begin drag. hotspot is the location of the drag position relative to the upper-left
 159     // corner of the image.
 160     bool BeginDrag(const wxPoint& hotspot, wxWindow* window);
 161
 162     // End drag
 163     bool EndDrag(wxWindow* window);
 164
 165     // Move the image: call from OnMouseMove. Pt is in window client coordinates if window
 166     // is non-NULL, or in screen coordinates if NULL.
 167     bool Move(const wxPoint& pt, wxWindow* window);
 168
 169     // Show the image
 170     bool Show(wxWindow* window);
 171
 172     // Hide the image
 173     bool Hide(wxWindow* window);
 174
 175     // Implementation
 176     ////////////////////////////////////////////////////////////////////////////
 177
 178     // Returns the native image list handle
 179     inline WXHIMAGELIST GetHIMAGELIST() const { return m_hImageList; }
 180
 181 protected:
 182     WXHIMAGELIST    m_hImageList;
 183     wxCursor        m_cursor;
 184     wxPoint         m_hotspot;
 185     wxPoint         m_position;
 186 };
 187
 188 #endif
 189     // _WX_DRAGIMAG_H_