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(NO_GCC_PRAGMA)
  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 wxWidgets
  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 #if wxUSE_TREECTRL
 160     wxGenericDragImage(const wxTreeCtrl& treeCtrl, wxTreeItemId& id)
 161     {
 162         Init();
 163
 164         Create(treeCtrl, id);
 165     }
 166 #endif
 167
 168 #if wxUSE_LISTCTRL
 169     wxGenericDragImage(const wxListCtrl& listCtrl, long id)
 170     {
 171         Init();
 172
 173         Create(listCtrl, id);
 174     }
 175 #endif
 176
 177     ~wxGenericDragImage();
 178
 179     // Attributes
 180     ////////////////////////////////////////////////////////////////////////////
 181
 182     // For efficiency, tell wxGenericDragImage to use a bitmap that's already
 183     // created (e.g. from last drag)
 184     void SetBackingBitmap(wxBitmap* bitmap) { m_pBackingBitmap = bitmap; }
 185
 186     // Operations
 187     ////////////////////////////////////////////////////////////////////////////
 188
 189     // Create a drag image with a virtual image (need to override DoDrawImage, GetImageRect)
 190     bool Create(const wxCursor& cursor = wxNullCursor);
 191     bool Create(const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 192     {
 193         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 194         return Create(cursor);
 195     }
 196
 197     // Create a drag image from a bitmap and optional cursor
 198     bool Create(const wxBitmap& image, const wxCursor& cursor = wxNullCursor);
 199     bool Create(const wxBitmap& image, const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 200     {
 201         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 202         return Create(image, cursor);
 203     }
 204
 205     // Create a drag image from an icon and optional cursor
 206     bool Create(const wxIcon& image, const wxCursor& cursor = wxNullCursor);
 207     bool Create(const wxIcon& image, const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 208     {
 209         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 210         return Create(image, cursor);
 211     }
 212
 213     // Create a drag image from a string and optional cursor
 214     bool Create(const wxString& str, const wxCursor& cursor = wxNullCursor);
 215     bool Create(const wxString& str, const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 216     {
 217         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 218         return Create(str, cursor);
 219     }
 220
 221 #if wxUSE_TREECTRL
 222     // Create a drag image for the given tree control item
 223     bool Create(const wxTreeCtrl& treeCtrl, wxTreeItemId& id);
 224 #endif
 225
 226 #if wxUSE_LISTCTRL
 227     // Create a drag image for the given list control item
 228     bool Create(const wxListCtrl& listCtrl, long id);
 229 #endif
 230
 231     // Begin drag. hotspot is the location of the drag position relative to the upper-left
 232     // corner of the image.
 233     bool BeginDrag(const wxPoint& hotspot, wxWindow* window, bool fullScreen = false, wxRect* rect = (wxRect*) NULL);
 234
 235     // Begin drag. hotspot is the location of the drag position relative to the upper-left
 236     // corner of the image. This is full screen only. fullScreenRect gives the
 237     // position of the window on the screen, to restrict the drag to.
 238     bool BeginDrag(const wxPoint& hotspot, wxWindow* window, wxWindow* fullScreenRect);
 239
 240     // End drag
 241     bool EndDrag();
 242
 243     // Move the image: call from OnMouseMove. Pt is in window client coordinates if window
 244     // is non-NULL, or in screen coordinates if NULL.
 245     bool Move(const wxPoint& pt);
 246
 247     // Show the image
 248     bool Show();
 249
 250     // Hide the image
 251     bool Hide();
 252
 253     // Implementation
 254     ////////////////////////////////////////////////////////////////////////////
 255
 256     void Init();
 257
 258     // Override this if you are using a virtual image (drawing your own image)
 259     virtual wxRect GetImageRect(const wxPoint& pos) const;
 260
 261     // Override this if you are using a virtual image (drawing your own image)
 262     virtual bool DoDrawImage(wxDC& dc, const wxPoint& pos) const;
 263
 264     // Override this if you wish to draw the window contents to the backing bitmap
 265     // yourself. This can be desirable if you wish to avoid flicker by not having to
 266     // redraw the window itself before dragging in order to be graphic-minus-dragged-objects.
 267     // Instead, paint the drag image's backing bitmap to be correct, and leave the window
 268     // to be updated only when dragging the objects away (thus giving a smoother appearance).
 269     virtual bool UpdateBackingFromWindow(wxDC& windowDC, wxMemoryDC& destDC,
 270         const wxRect& sourceRect, const wxRect& destRect) const;
 271
 272     // Erase and redraw simultaneously if possible
 273     virtual bool RedrawImage(const wxPoint& oldPos, const wxPoint& newPos, bool eraseOld, bool drawNew);
 274
 275 protected:
 276     wxBitmap        m_bitmap;
 277     wxIcon          m_icon;
 278     wxCursor        m_cursor;
 279     wxCursor        m_oldCursor;
 280 //    wxPoint         m_hotspot;
 281     wxPoint         m_offset; // The hostpot value passed to BeginDrag
 282     wxPoint         m_position;
 283     bool            m_isDirty;
 284     bool            m_isShown;
 285     wxWindow*       m_window;
 286     wxDC*           m_windowDC;
 287
 288     // Stores the window contents while we're dragging the image around
 289     wxBitmap        m_backingBitmap;
 290     wxBitmap*       m_pBackingBitmap; // Pointer to existing backing bitmap
 291                                       // (pass to wxGenericDragImage as an efficiency measure)
 292     // A temporary bitmap for repairing/redrawing
 293     wxBitmap        m_repairBitmap;
 294
 295     wxRect          m_boundingRect;
 296     bool            m_fullScreen;
 297
 298 private:
 299     DECLARE_DYNAMIC_CLASS(wxGenericDragImage)
 300     DECLARE_NO_COPY_CLASS(wxGenericDragImage)
 301 };
 302
 303 #endif
 304     // _WX_DRAGIMGG_H_