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 #include "wx/bitmap.h"
  17 #include "wx/icon.h"
  18 #include "wx/cursor.h"
  19 #include "wx/treectrl.h"
  20 #include "wx/listctrl.h"
  21 #include "wx/log.h"
  22
  23 /*
  24   To use this class, create a wxDragImage when you start dragging, for example:
  25
  26   void MyTreeCtrl::OnBeginDrag(wxTreeEvent& event)
  27   {
  28 #ifdef __WXMSW__
  29     ::UpdateWindow((HWND) GetHWND()); // We need to implement this in wxWidgets
  30 #endif
  31
  32     CaptureMouse();
  33
  34     m_dragImage = new wxDragImage(* this, itemId);
  35     m_dragImage->BeginDrag(wxPoint(0, 0), this);
  36     m_dragImage->Move(pt, this);
  37     m_dragImage->Show(this);
  38     ...
  39   }
  40
  41   In your OnMouseMove function, hide the image, do any display updating required,
  42   then move and show the image again:
  43
  44   void MyTreeCtrl::OnMouseMove(wxMouseEvent& event)
  45   {
  46     if (m_dragMode == MY_TREE_DRAG_NONE)
  47     {
  48         event.Skip();
  49         return;
  50     }
  51
  52     // Prevent screen corruption by hiding the image
  53     if (m_dragImage)
  54         m_dragImage->Hide(this);
  55
  56     // Do some updating of the window, such as highlighting the drop target
  57     ...
  58
  59 #ifdef __WXMSW__
  60     if (updateWindow)
  61         ::UpdateWindow((HWND) GetHWND());
  62 #endif
  63
  64     // Move and show the image again
  65     m_dragImage->Move(event.GetPosition(), this);
  66     m_dragImage->Show(this);
  67  }
  68
  69  Eventually we end the drag and delete the drag image.
  70
  71  void MyTreeCtrl::OnLeftUp(wxMouseEvent& event)
  72  {
  73     ...
  74
  75     // End the drag and delete the drag image
  76     if (m_dragImage)
  77     {
  78         m_dragImage->EndDrag(this);
  79         delete m_dragImage;
  80         m_dragImage = NULL;
  81     }
  82     ReleaseMouse();
  83  }
  84 */
  85
  86 /*
  87  * wxGenericDragImage
  88  */
  89
  90 class WXDLLEXPORT wxGenericDragImage: public wxObject
  91 {
  92 public:
  93
  94     // Ctors & dtor
  95     ////////////////////////////////////////////////////////////////////////////
  96
  97     wxGenericDragImage(const wxCursor& cursor = wxNullCursor)
  98     {
  99         Init();
 100         Create(cursor);
 101     }
 102
 103     // Deprecated version of the above
 104     wxGenericDragImage(const wxCursor& cursor, const wxPoint& cursorHotspot)
 105     {
 106         Init();
 107         Create(cursor, cursorHotspot);
 108     }
 109
 110     wxGenericDragImage(const wxBitmap& image, const wxCursor& cursor = wxNullCursor)
 111     {
 112         Init();
 113
 114         Create(image, cursor);
 115     }
 116
 117     // Deprecated version of the above
 118     wxGenericDragImage(const wxBitmap& image, const wxCursor& cursor, const wxPoint& cursorHotspot)
 119     {
 120         Init();
 121
 122         Create(image, cursor, cursorHotspot);
 123     }
 124
 125     wxGenericDragImage(const wxIcon& image, const wxCursor& cursor = wxNullCursor)
 126     {
 127         Init();
 128
 129         Create(image, cursor);
 130     }
 131
 132     // Deprecated version of the above
 133     wxGenericDragImage(const wxIcon& image, const wxCursor& cursor, const wxPoint& cursorHotspot)
 134     {
 135         Init();
 136
 137         Create(image, cursor, cursorHotspot);
 138     }
 139
 140     wxGenericDragImage(const wxString& str, const wxCursor& cursor = wxNullCursor)
 141     {
 142         Init();
 143
 144         Create(str, cursor);
 145     }
 146
 147     // Deprecated version of the above
 148     wxGenericDragImage(const wxString& str, const wxCursor& cursor, const wxPoint& cursorHotspot)
 149     {
 150         Init();
 151
 152         Create(str, cursor, cursorHotspot);
 153     }
 154
 155 #if wxUSE_TREECTRL
 156     wxGenericDragImage(const wxTreeCtrl& treeCtrl, wxTreeItemId& id)
 157     {
 158         Init();
 159
 160         Create(treeCtrl, id);
 161     }
 162 #endif
 163
 164 #if wxUSE_LISTCTRL
 165     wxGenericDragImage(const wxListCtrl& listCtrl, long id)
 166     {
 167         Init();
 168
 169         Create(listCtrl, id);
 170     }
 171 #endif
 172
 173     ~wxGenericDragImage();
 174
 175     // Attributes
 176     ////////////////////////////////////////////////////////////////////////////
 177
 178     // For efficiency, tell wxGenericDragImage to use a bitmap that's already
 179     // created (e.g. from last drag)
 180     void SetBackingBitmap(wxBitmap* bitmap) { m_pBackingBitmap = bitmap; }
 181
 182     // Operations
 183     ////////////////////////////////////////////////////////////////////////////
 184
 185     // Create a drag image with a virtual image (need to override DoDrawImage, GetImageRect)
 186     bool Create(const wxCursor& cursor = wxNullCursor);
 187     bool Create(const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 188     {
 189         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 190         return Create(cursor);
 191     }
 192
 193     // Create a drag image from a bitmap and optional cursor
 194     bool Create(const wxBitmap& image, const wxCursor& cursor = wxNullCursor);
 195     bool Create(const wxBitmap& image, const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 196     {
 197         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 198         return Create(image, cursor);
 199     }
 200
 201     // Create a drag image from an icon and optional cursor
 202     bool Create(const wxIcon& image, const wxCursor& cursor = wxNullCursor);
 203     bool Create(const wxIcon& image, const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 204     {
 205         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 206         return Create(image, cursor);
 207     }
 208
 209     // Create a drag image from a string and optional cursor
 210     bool Create(const wxString& str, const wxCursor& cursor = wxNullCursor);
 211     bool Create(const wxString& str, const wxCursor& cursor, const wxPoint& WXUNUSED(cursorHotspot))
 212     {
 213         wxLogDebug(wxT("wxDragImage::Create: use of a cursor hotspot is now deprecated. Please omit this argument."));
 214         return Create(str, cursor);
 215     }
 216
 217 #if wxUSE_TREECTRL
 218     // Create a drag image for the given tree control item
 219     bool Create(const wxTreeCtrl& treeCtrl, wxTreeItemId& id);
 220 #endif
 221
 222 #if wxUSE_LISTCTRL
 223     // Create a drag image for the given list control item
 224     bool Create(const wxListCtrl& listCtrl, long id);
 225 #endif
 226
 227     // Begin drag. hotspot is the location of the drag position relative to the upper-left
 228     // corner of the image.
 229     bool BeginDrag(const wxPoint& hotspot, wxWindow* window, bool fullScreen = false, wxRect* rect = (wxRect*) NULL);
 230
 231     // Begin drag. hotspot is the location of the drag position relative to the upper-left
 232     // corner of the image. This is full screen only. fullScreenRect gives the
 233     // position of the window on the screen, to restrict the drag to.
 234     bool BeginDrag(const wxPoint& hotspot, wxWindow* window, wxWindow* fullScreenRect);
 235
 236     // End drag
 237     bool EndDrag();
 238
 239     // Move the image: call from OnMouseMove. Pt is in window client coordinates if window
 240     // is non-NULL, or in screen coordinates if NULL.
 241     bool Move(const wxPoint& pt);
 242
 243     // Show the image
 244     bool Show();
 245
 246     // Hide the image
 247     bool Hide();
 248
 249     // Implementation
 250     ////////////////////////////////////////////////////////////////////////////
 251
 252     void Init();
 253
 254     // Override this if you are using a virtual image (drawing your own image)
 255     virtual wxRect GetImageRect(const wxPoint& pos) const;
 256
 257     // Override this if you are using a virtual image (drawing your own image)
 258     virtual bool DoDrawImage(wxDC& dc, const wxPoint& pos) const;
 259
 260     // Override this if you wish to draw the window contents to the backing bitmap
 261     // yourself. This can be desirable if you wish to avoid flicker by not having to
 262     // redraw the window itself before dragging in order to be graphic-minus-dragged-objects.
 263     // Instead, paint the drag image's backing bitmap to be correct, and leave the window
 264     // to be updated only when dragging the objects away (thus giving a smoother appearance).
 265     virtual bool UpdateBackingFromWindow(wxDC& windowDC, wxMemoryDC& destDC,
 266         const wxRect& sourceRect, const wxRect& destRect) const;
 267
 268     // Erase and redraw simultaneously if possible
 269     virtual bool RedrawImage(const wxPoint& oldPos, const wxPoint& newPos, bool eraseOld, bool drawNew);
 270
 271 protected:
 272     wxBitmap        m_bitmap;
 273     wxIcon          m_icon;
 274     wxCursor        m_cursor;
 275     wxCursor        m_oldCursor;
 276 //    wxPoint         m_hotspot;
 277     wxPoint         m_offset; // The hostpot value passed to BeginDrag
 278     wxPoint         m_position;
 279     bool            m_isDirty;
 280     bool            m_isShown;
 281     wxWindow*       m_window;
 282     wxDC*           m_windowDC;
 283
 284     // Stores the window contents while we're dragging the image around
 285     wxBitmap        m_backingBitmap;
 286     wxBitmap*       m_pBackingBitmap; // Pointer to existing backing bitmap
 287                                       // (pass to wxGenericDragImage as an efficiency measure)
 288     // A temporary bitmap for repairing/redrawing
 289     wxBitmap        m_repairBitmap;
 290
 291     wxRect          m_boundingRect;
 292     bool            m_fullScreen;
 293
 294 private:
 295     DECLARE_DYNAMIC_CLASS(wxGenericDragImage)
 296     DECLARE_NO_COPY_CLASS(wxGenericDragImage)
 297 };
 298
 299 #endif
 300     // _WX_DRAGIMGG_H_