docs/latex/wx/screendc.tex

   1 \section{\class{wxScreenDC}}\label{wxscreendc}
   2
   3 A wxScreenDC can be used to paint on the screen.
   4 This should normally be constructed as a temporary stack object; don't store
   5 a wxScreenDC object.
   6
   7 \wxheading{Derived from}
   8
   9 \helpref{wxDC}{wxdc}
  10
  11 \wxheading{See also}
  12
  13 \helpref{wxDC}{wxdc}, \helpref{wxMemoryDC}{wxmemorydc}, \helpref{wxPaintDC}{wxpaintdc},\rtfsp
  14 \helpref{wxClientDC}{wxclientdc}, \helpref{wxWindowDC}{wxwindowdc}
  15
  16 \latexignore{\rtfignore{\wxheading{Members}}}
  17
  18 \membersection{wxScreenDC::wxScreenDC}
  19
  20 \func{}{wxScreenDC}{\void}
  21
  22 Constructor.
  23
  24 \membersection{wxScreenDC::StartDrawingOnTop}\label{wxscreendcstartdrawingontop}
  25
  26 \func{bool}{StartDrawingOnTop}{\param{wxWindow*}{ window}}
  27
  28 \func{bool}{StartDrawingOnTop}{\param{wxRect*}{ rect = NULL}}
  29
  30 Use this in conjunction with \helpref{EndDrawingOnTop}{wxscreendcenddrawingontop} to
  31 ensure that drawing to the screen occurs on top of existing windows. Without this,
  32 some window systems (such as X) only allow drawing to take place underneath
  33 other windows.
  34
  35 By using the first form of this function, an application is specifying that
  36 the area that will be drawn on coincides with the given window.
  37
  38 By using the second form, an application can specify an area of the screen
  39 which is to be drawn on. If NULL is passed, the whole screen is available.
  40
  41 It is recommended that an area of the screen is specified because with large regions,
  42 flickering effects are noticeable when destroying the temporary transparent window used
  43 to implement this feature.
  44
  45 You might use this pair of functions when implementing a drag feature, for example
  46 as in the \helpref{wxSplitterWindow}{wxsplitterwindow} implementation.
  47
  48 \membersection{wxScreenDC::EndDrawingOnTop}\label{wxscreendcenddrawingontop}
  49
  50 \func{bool}{EndDrawingOnTop}{\void}
  51
  52 Use this in conjunction with \helpref{StartDrawingOnTop}{wxscreendcstartdrawingontop}.
  53
  54 This function destroys the temporary window created to implement on-top drawing (X only).
  55