interface/wx/dcscreen.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        dcscreen.h
   3 // Purpose:     interface of wxScreenDC
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     @class wxScreenDC
  11
  12     A wxScreenDC can be used to paint on the screen. This should normally be
  13     constructed as a temporary stack object; don't store a wxScreenDC object.
  14
  15     @library{wxcore}
  16     @category{dc}
  17
  18     @see wxDC, wxMemoryDC, wxPaintDC, wxClientDC, wxWindowDC
  19 */
  20 class wxScreenDC : public wxDC
  21 {
  22 public:
  23     /**
  24         Constructor.
  25     */
  26     wxScreenDC();
  27
  28     /**
  29         Use this in conjunction with StartDrawingOnTop().
  30
  31         This function destroys the temporary window created to implement on-top
  32         drawing (X only).
  33     */
  34     static bool EndDrawingOnTop();
  35
  36     /**
  37         Use this in conjunction with EndDrawingOnTop() to ensure that drawing
  38         to the screen occurs on top of existing windows. Without this, some
  39         window systems (such as X) only allow drawing to take place underneath
  40         other windows.
  41
  42         This version of StartDrawingOnTop() is used to specify that the area
  43         that will be drawn on coincides with the given window. It is
  44         recommended that an area of the screen is specified with
  45         StartDrawingOnTop(wxRect*) because with large regions, flickering
  46         effects are noticeable when destroying the temporary transparent window
  47         used to implement this feature.
  48
  49         You might use this function when implementing a drag feature, for
  50         example as in the wxSplitterWindow implementation.
  51
  52         @remarks This function is probably obsolete since the X implementations
  53                  allow drawing directly on the screen now. However, the fact
  54                  that this function allows the screen to be refreshed
  55                  afterwards, may be useful to some applications.
  56     */
  57     static bool StartDrawingOnTop(wxWindow* window);
  58     /**
  59         Use this in conjunction with EndDrawingOnTop() to ensure that drawing
  60         to the screen occurs on top of existing windows. Without this, some
  61         window systems (such as X) only allow drawing to take place underneath
  62         other windows.
  63
  64         This version of StartDrawingOnTop() is used to specify an area of the
  65         screen which is to be drawn on. If @NULL is passed, the whole screen is
  66         available. It is recommended that an area of the screen is specified
  67         with this function rather than with StartDrawingOnTop(wxWindow*),
  68         because with large regions, flickering effects are noticeable when
  69         destroying the temporary transparent window used to implement this
  70         feature.
  71
  72         You might use this function when implementing a drag feature, for
  73         example as in the wxSplitterWindow implementation.
  74
  75         @remarks This function is probably obsolete since the X implementations
  76                  allow drawing directly on the screen now. However, the fact
  77                  that this function allows the screen to be refreshed
  78                  afterwards, may be useful to some applications.
  79     */
  80     static bool StartDrawingOnTop(wxRect* rect = NULL);
  81 };
  82