execute the usual cleanup code from EVT_END_SESSION handler under MSW, otherwise...

[wxWidgets.git] / interface / dcscreen.h

/////////////////////////////////////////////////////////////////////////////
// Name:        dcscreen.h
// Purpose:     interface of wxScreenDC
// Author:      wxWidgets team
// RCS-ID:      $Id$
// Licence:     wxWindows license
/////////////////////////////////////////////////////////////////////////////

/**
    @class wxScreenDC
    @wxheader{dcscreen.h}

    A wxScreenDC can be used to paint on the screen.
    This should normally be constructed as a temporary stack object; don't store
    a wxScreenDC object.

    @library{wxcore}
    @category{dc}

    @see wxDC, wxMemoryDC, wxPaintDC, wxClientDC, wxWindowDC
*/
class wxScreenDC : public wxDC
{
public:
    /**
        Constructor.
    */
    wxScreenDC();

    /**
        Use this in conjunction with StartDrawingOnTop().
        This function destroys the temporary window created to implement on-top drawing
        (X only).
    */
    bool EndDrawingOnTop();

    //@{
    /**
        Use this in conjunction with EndDrawingOnTop() to
        ensure that drawing to the screen occurs on top of existing windows. Without
        this,
        some window systems (such as X) only allow drawing to take place underneath
        other windows.
        By using the first form of this function, an application is specifying that
        the area that will be drawn on coincides with the given window.
        By using the second form, an application can specify an area of the screen
        which is to be drawn on. If @NULL is passed, the whole screen is available.
        It is recommended that an area of the screen is specified because with large
        regions,
        flickering effects are noticeable when destroying the temporary transparent
        window used
        to implement this feature.
        You might use this pair of functions when implementing a drag feature, for
        example
        as in the wxSplitterWindow implementation.

        @remarks This function is probably obsolete since the X implementations
                 allow drawing directly on the screen now. However, the
                 fact that this function allows the screen to be
                 refreshed afterwards, may be useful to some
                 applications.
    */
    bool StartDrawingOnTop(wxWindow* window);
    bool StartDrawingOnTop(wxRect* rect = NULL);
    //@}
};