include/wx/generic/dragimgg.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/generic/dragimgg.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:     29/2/2000
   8 // RCS-ID:      $Id$
   9 // Copyright:   (c) Julian Smart
  10 // Licence:     wxWindows licence
  11 /////////////////////////////////////////////////////////////////////////////
  12
  13 #ifndef _WX_DRAGIMGG_H_
  14 #define _WX_DRAGIMGG_H_
  15
  16 #ifdef __GNUG__
  17 #pragma interface "dragimgg.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  * wxGenericDragImage
  91  */
  92
  93 class WXDLLEXPORT wxGenericDragImage: public wxObject
  94 {
  95 public:
  96
  97     // Ctors & dtor
  98     ////////////////////////////////////////////////////////////////////////////
  99
 100     wxGenericDragImage(const wxCursor& cursor = wxNullCursor)
 101     {
 102         Init();
 103         Create(cursor);
 104     }
 105
 106     // Deprecated version of the above
 107     wxGenericDragImage(const wxCursor& cursor, const wxPoint& cursorHotspot)
 108     {
 109         Init();
 110         Create(cursor, cursorHotspot);
 111     }
 112
 113     wxGenericDragImage(const wxBitmap& image, const wxCursor& cursor = wxNullCursor)
 114     {
 115         Init();
 116
 117         Create(image, cursor);
 118     }
 119
 120     // Deprecated version of the above
 121     wxGenericDragImage(const wxBitmap& image, const wxCursor& cursor, const wxPoint& cursorHotspot)
 122     {
 123         Init();
 124
 125         Create(image, cursor, cursorHotspot);
 126     }
 127
 128     wxGenericDragImage(const wxIcon& image, const wxCursor& cursor = wxNullCursor)
 129     {
 130         Init();
 131
 132         Create(image, cursor);
 133     }
 134
 135     // Deprecated version of the above
 136     wxGenericDragImage(const wxIcon& image, const wxCursor& cursor, const wxPoint& cursorHotspot)
 137     {
 138         Init();
 139
 140         Create(image, cursor, cursorHotspot);
 141     }
 142
 143     wxGenericDragImage(const wxString& str, const wxCursor& cursor = wxNullCursor)
 144     {
 145         Init();
 146
 147         Create(str, cursor);
 148     }
 149
 150     // Deprecated version of the above
 151     wxGenericDragImage(const wxString& str, const wxCursor& cursor, const wxPoint& cursorHotspot)
 152     {
 153         Init();
 154
 155         Create(str, cursor, cursorHotspot);
 156     }
 157
 158     wxGenericDragImage(const wxTreeCtrl& treeCtrl, wxTreeItemId& id)
 159     {
 160         Init();
 161
 162         Create(treeCtrl, id);
 163     }
 164
 165     wxGenericDragImage(const wxListCtrl& listCtrl, long id)
 166     {
 167         Init();
 168
 169         Create(listCtrl, id);
 170     }
 171     ~wxGenericDragImage();
 172
 173     // Attributes
 174     ////////////////////////////////////////////////////////////////////////////
 175
 176     // For efficiency, tell wxGenericDragImage to use a bitmap that's already
 177     // created (e.g. from last drag)
 178     void SetBackingBitmap(wxBitmap* bitmap) { m_pBackingBitmap = bitmap; }
 179
 180     // Operations
 181     ////////////////////////////////////////////////////////////////////////////
 182
 183     // Create a drag image with a virtual image (need to override DoDrawImage, GetImageRect)
 184     bool Create(const wxCursor& cursor = wxNullCursor);
 185     bool Create(const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 186     {
 187         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 188         return Create(cursor);
 189     }
 190
 191     // Create a drag image from a bitmap and optional cursor
 192     bool Create(const wxBitmap& image, const wxCursor& cursor = wxNullCursor);
 193     bool Create(const wxBitmap& image, const wxCursor& cursor, const wxPoint& cursorHotspot)
 194     {
 195         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 196         return Create(image, cursor);
 197     }
 198
 199     // Create a drag image from an icon and optional cursor
 200     bool Create(const wxIcon& image, const wxCursor& cursor = wxNullCursor);
 201     bool Create(const wxIcon& image, const wxCursor& cursor, const wxPoint& cursorHotspot)
 202     {
 203         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 204         return Create(image, cursor);
 205     }
 206
 207     // Create a drag image from a string and optional cursor
 208     bool Create(const wxString& str, const wxCursor& cursor = wxNullCursor);
 209     bool Create(const wxString& str, const wxCursor& cursor, const wxPoint& cursorHotspot)
 210     {
 211         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 212         return Create(str, cursor);
 213     }
 214
 215     // Create a drag image for the given tree control item
 216     bool Create(const wxTreeCtrl& treeCtrl, wxTreeItemId& id);
 217
 218     // Create a drag image for the given list control item
 219     bool Create(const wxListCtrl& listCtrl, long id);
 220
 221     // Begin drag. hotspot is the location of the drag position relative to the upper-left
 222     // corner of the image.
 223     bool BeginDrag(const wxPoint& hotspot, wxWindow* window, bool fullScreen = FALSE, wxRect* rect = (wxRect*) NULL);
 224
 225     // Begin drag. hotspot is the location of the drag position relative to the upper-left
 226     // corner of the image. This is full screen only. fullScreenRect gives the
 227     // position of the window on the screen, to restrict the drag to.
 228     bool BeginDrag(const wxPoint& hotspot, wxWindow* window, wxWindow* fullScreenRect);
 229
 230     // End drag
 231     bool EndDrag();
 232
 233     // Move the image: call from OnMouseMove. Pt is in window client coordinates if window
 234     // is non-NULL, or in screen coordinates if NULL.
 235     bool Move(const wxPoint& pt);
 236
 237     // Show the image
 238     bool Show();
 239
 240     // Hide the image
 241     bool Hide();
 242
 243     // Implementation
 244     ////////////////////////////////////////////////////////////////////////////
 245
 246     void Init();
 247
 248     // Override this if you are using a virtual image (drawing your own image)
 249     virtual wxRect GetImageRect(const wxPoint& pos) const;
 250
 251     // Override this if you are using a virtual image (drawing your own image)
 252     virtual bool DoDrawImage(wxDC& dc, const wxPoint& pos) const;
 253
 254     // Override this if you wish to draw the window contents to the backing bitmap
 255     // yourself. This can be desirable if you wish to avoid flicker by not having to
 256     // redraw the window itself before dragging in order to be graphic-minus-dragged-objects.
 257     // Instead, paint the drag image's backing bitmap to be correct, and leave the window
 258     // to be updated only when dragging the objects away (thus giving a smoother appearance).
 259     virtual bool UpdateBackingFromWindow(wxDC& windowDC, wxMemoryDC& destDC,
 260         const wxRect& sourceRect, const wxRect& destRect) const;
 261
 262     // Erase and redraw simultaneously if possible
 263     virtual bool RedrawImage(const wxPoint& oldPos, const wxPoint& newPos, bool eraseOld, bool drawNew);
 264
 265 protected:
 266     wxBitmap        m_bitmap;
 267     wxIcon          m_icon;
 268     wxCursor        m_cursor;
 269     wxCursor        m_oldCursor;
 270 //    wxPoint         m_hotspot;
 271     wxPoint         m_offset; // The hostpot value passed to BeginDrag
 272     wxPoint         m_position;
 273     bool            m_isDirty;
 274     bool            m_isShown;
 275     wxWindow*       m_window;
 276     wxDC*           m_windowDC;
 277
 278     // Stores the window contents while we're dragging the image around
 279     wxBitmap        m_backingBitmap;
 280     wxBitmap*       m_pBackingBitmap; // Pointer to existing backing bitmap
 281                                       // (pass to wxGenericDragImage as an efficiency measure)
 282     // A temporary bitmap for repairing/redrawing
 283     wxBitmap        m_repairBitmap;
 284
 285     wxRect          m_boundingRect;
 286     bool            m_fullScreen;
 287
 288 private:
 289     DECLARE_DYNAMIC_CLASS(wxGenericDragImage)
 290 };
 291
 292 #endif
 293     // _WX_DRAGIMGG_H_