interface/dcscreen.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        dcscreen.h
   3 // Purpose:     documentation for wxScreenDC class
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     @class wxScreenDC
  11     @wxheader{dcscreen.h}
  12
  13     A wxScreenDC can be used to paint on the screen.
  14     This should normally be constructed as a temporary stack object; don't store
  15     a wxScreenDC object.
  16
  17     @library{wxcore}
  18     @category{dc}
  19
  20     @seealso
  21     wxDC, wxMemoryDC, wxPaintDC, wxClientDC, wxWindowDC
  22 */
  23 class wxScreenDC : public wxDC
  24 {
  25 public:
  26     /**
  27         Constructor.
  28     */
  29     wxScreenDC();
  30
  31     /**
  32         Use this in conjunction with StartDrawingOnTop().
  33
  34         This function destroys the temporary window created to implement on-top drawing
  35         (X only).
  36     */
  37     bool EndDrawingOnTop();
  38
  39     //@{
  40     /**
  41         Use this in conjunction with EndDrawingOnTop() to
  42         ensure that drawing to the screen occurs on top of existing windows. Without
  43         this,
  44         some window systems (such as X) only allow drawing to take place underneath
  45         other windows.
  46
  47         By using the first form of this function, an application is specifying that
  48         the area that will be drawn on coincides with the given window.
  49
  50         By using the second form, an application can specify an area of the screen
  51         which is to be drawn on. If @NULL is passed, the whole screen is available.
  52
  53         It is recommended that an area of the screen is specified because with large
  54         regions,
  55         flickering effects are noticeable when destroying the temporary transparent
  56         window used
  57         to implement this feature.
  58
  59         You might use this pair of functions when implementing a drag feature, for
  60         example
  61         as in the wxSplitterWindow implementation.
  62
  63         @remarks This function is probably obsolete since the X implementations
  64                    allow drawing directly on the screen now. However,
  65                    the fact that this function allows the screen to be
  66                    refreshed afterwards, may be useful to some
  67                    applications.
  68     */
  69     bool StartDrawingOnTop(wxWindow* window);
  70     bool StartDrawingOnTop(wxRect* rect = @NULL);
  71     //@}
  72 };