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 #if defined(__GNUG__) && !defined(__APPLE__)
  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 #include "wx/log.h"
  26
  27 /*
  28   To use this class, create a wxDragImage when you start dragging, for example:
  29
  30   void MyTreeCtrl::OnBeginDrag(wxTreeEvent& event)
  31   {
  32 #ifdef __WXMSW__
  33     ::UpdateWindow((HWND) GetHWND()); // We need to implement this in wxWindows
  34 #endif
  35
  36     CaptureMouse();
  37
  38     m_dragImage = new wxDragImage(* this, itemId);
  39     m_dragImage->BeginDrag(wxPoint(0, 0), this);
  40     m_dragImage->Move(pt, this);
  41     m_dragImage->Show(this);
  42     ...
  43   }
  44
  45   In your OnMouseMove function, hide the image, do any display updating required,
  46   then move and show the image again:
  47
  48   void MyTreeCtrl::OnMouseMove(wxMouseEvent& event)
  49   {
  50     if (m_dragMode == MY_TREE_DRAG_NONE)
  51     {
  52         event.Skip();
  53         return;
  54     }
  55
  56     // Prevent screen corruption by hiding the image
  57     if (m_dragImage)
  58         m_dragImage->Hide(this);
  59
  60     // Do some updating of the window, such as highlighting the drop target
  61     ...
  62
  63 #ifdef __WXMSW__
  64     if (updateWindow)
  65         ::UpdateWindow((HWND) GetHWND());
  66 #endif
  67
  68     // Move and show the image again
  69     m_dragImage->Move(event.GetPosition(), this);
  70     m_dragImage->Show(this);
  71  }
  72
  73  Eventually we end the drag and delete the drag image.
  74
  75  void MyTreeCtrl::OnLeftUp(wxMouseEvent& event)
  76  {
  77     ...
  78
  79     // End the drag and delete the drag image
  80     if (m_dragImage)
  81     {
  82         m_dragImage->EndDrag(this);
  83         delete m_dragImage;
  84         m_dragImage = NULL;
  85     }
  86     ReleaseMouse();
  87  }
  88 */
  89
  90 /*
  91  * wxGenericDragImage
  92  */
  93
  94 class WXDLLEXPORT wxGenericDragImage: public wxObject
  95 {
  96 public:
  97
  98     // Ctors & dtor
  99     ////////////////////////////////////////////////////////////////////////////
 100
 101     wxGenericDragImage(const wxCursor& cursor = wxNullCursor)
 102     {
 103         Init();
 104         Create(cursor);
 105     }
 106
 107     // Deprecated version of the above
 108     wxGenericDragImage(const wxCursor& cursor, const wxPoint& cursorHotspot)
 109     {
 110         Init();
 111         Create(cursor, cursorHotspot);
 112     }
 113
 114     wxGenericDragImage(const wxBitmap& image, const wxCursor& cursor = wxNullCursor)
 115     {
 116         Init();
 117
 118         Create(image, cursor);
 119     }
 120
 121     // Deprecated version of the above
 122     wxGenericDragImage(const wxBitmap& image, const wxCursor& cursor, const wxPoint& cursorHotspot)
 123     {
 124         Init();
 125
 126         Create(image, cursor, cursorHotspot);
 127     }
 128
 129     wxGenericDragImage(const wxIcon& image, const wxCursor& cursor = wxNullCursor)
 130     {
 131         Init();
 132
 133         Create(image, cursor);
 134     }
 135
 136     // Deprecated version of the above
 137     wxGenericDragImage(const wxIcon& image, const wxCursor& cursor, const wxPoint& cursorHotspot)
 138     {
 139         Init();
 140
 141         Create(image, cursor, cursorHotspot);
 142     }
 143
 144     wxGenericDragImage(const wxString& str, const wxCursor& cursor = wxNullCursor)
 145     {
 146         Init();
 147
 148         Create(str, cursor);
 149     }
 150
 151     // Deprecated version of the above
 152     wxGenericDragImage(const wxString& str, const wxCursor& cursor, const wxPoint& cursorHotspot)
 153     {
 154         Init();
 155
 156         Create(str, cursor, cursorHotspot);
 157     }
 158
 159     wxGenericDragImage(const wxTreeCtrl& treeCtrl, wxTreeItemId& id)
 160     {
 161         Init();
 162
 163         Create(treeCtrl, id);
 164     }
 165
 166     wxGenericDragImage(const wxListCtrl& listCtrl, long id)
 167     {
 168         Init();
 169
 170         Create(listCtrl, id);
 171     }
 172     ~wxGenericDragImage();
 173
 174     // Attributes
 175     ////////////////////////////////////////////////////////////////////////////
 176
 177     // For efficiency, tell wxGenericDragImage to use a bitmap that's already
 178     // created (e.g. from last drag)
 179     void SetBackingBitmap(wxBitmap* bitmap) { m_pBackingBitmap = bitmap; }
 180
 181     // Operations
 182     ////////////////////////////////////////////////////////////////////////////
 183
 184     // Create a drag image with a virtual image (need to override DoDrawImage, GetImageRect)
 185     bool Create(const wxCursor& cursor = wxNullCursor);
 186     bool Create(const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 187     {
 188         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 189         return Create(cursor);
 190     }
 191
 192     // Create a drag image from a bitmap and optional cursor
 193     bool Create(const wxBitmap& image, const wxCursor& cursor = wxNullCursor);
 194     bool Create(const wxBitmap& image, const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 195     {
 196         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 197         return Create(image, cursor);
 198     }
 199
 200     // Create a drag image from an icon and optional cursor
 201     bool Create(const wxIcon& image, const wxCursor& cursor = wxNullCursor);
 202     bool Create(const wxIcon& image, const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 203     {
 204         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 205         return Create(image, cursor);
 206     }
 207
 208     // Create a drag image from a string and optional cursor
 209     bool Create(const wxString& str, const wxCursor& cursor = wxNullCursor);
 210     bool Create(const wxString& str, const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 211     {
 212         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 213         return Create(str, cursor);
 214     }
 215
 216     // Create a drag image for the given tree control item
 217     bool Create(const wxTreeCtrl& treeCtrl, wxTreeItemId& id);
 218
 219     // Create a drag image for the given list control item
 220     bool Create(const wxListCtrl& listCtrl, long id);
 221
 222     // Begin drag. hotspot is the location of the drag position relative to the upper-left
 223     // corner of the image.
 224     bool BeginDrag(const wxPoint& hotspot, wxWindow* window, bool fullScreen = FALSE, wxRect* rect = (wxRect*) NULL);
 225
 226     // Begin drag. hotspot is the location of the drag position relative to the upper-left
 227     // corner of the image. This is full screen only. fullScreenRect gives the
 228     // position of the window on the screen, to restrict the drag to.
 229     bool BeginDrag(const wxPoint& hotspot, wxWindow* window, wxWindow* fullScreenRect);
 230
 231     // End drag
 232     bool EndDrag();
 233
 234     // Move the image: call from OnMouseMove. Pt is in window client coordinates if window
 235     // is non-NULL, or in screen coordinates if NULL.
 236     bool Move(const wxPoint& pt);
 237
 238     // Show the image
 239     bool Show();
 240
 241     // Hide the image
 242     bool Hide();
 243
 244     // Implementation
 245     ////////////////////////////////////////////////////////////////////////////
 246
 247     void Init();
 248
 249     // Override this if you are using a virtual image (drawing your own image)
 250     virtual wxRect GetImageRect(const wxPoint& pos) const;
 251
 252     // Override this if you are using a virtual image (drawing your own image)
 253     virtual bool DoDrawImage(wxDC& dc, const wxPoint& pos) const;
 254
 255     // Override this if you wish to draw the window contents to the backing bitmap
 256     // yourself. This can be desirable if you wish to avoid flicker by not having to
 257     // redraw the window itself before dragging in order to be graphic-minus-dragged-objects.
 258     // Instead, paint the drag image's backing bitmap to be correct, and leave the window
 259     // to be updated only when dragging the objects away (thus giving a smoother appearance).
 260     virtual bool UpdateBackingFromWindow(wxDC& windowDC, wxMemoryDC& destDC,
 261         const wxRect& sourceRect, const wxRect& destRect) const;
 262
 263     // Erase and redraw simultaneously if possible
 264     virtual bool RedrawImage(const wxPoint& oldPos, const wxPoint& newPos, bool eraseOld, bool drawNew);
 265
 266 protected:
 267     wxBitmap        m_bitmap;
 268     wxIcon          m_icon;
 269     wxCursor        m_cursor;
 270     wxCursor        m_oldCursor;
 271 //    wxPoint         m_hotspot;
 272     wxPoint         m_offset; // The hostpot value passed to BeginDrag
 273     wxPoint         m_position;
 274     bool            m_isDirty;
 275     bool            m_isShown;
 276     wxWindow*       m_window;
 277     wxDC*           m_windowDC;
 278
 279     // Stores the window contents while we're dragging the image around
 280     wxBitmap        m_backingBitmap;
 281     wxBitmap*       m_pBackingBitmap; // Pointer to existing backing bitmap
 282                                       // (pass to wxGenericDragImage as an efficiency measure)
 283     // A temporary bitmap for repairing/redrawing
 284     wxBitmap        m_repairBitmap;
 285
 286     wxRect          m_boundingRect;
 287     bool            m_fullScreen;
 288
 289 private:
 290     DECLARE_DYNAMIC_CLASS(wxGenericDragImage)
 291     DECLARE_NO_COPY_CLASS(wxGenericDragImage)
 292 };
 293
 294 #endif
 295     // _WX_DRAGIMGG_H_