added interface headers with latest discussed changes

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@52381 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

interface/dcscreen.h

@@ -0,0 +1,72 @@
+/////////////////////////////////////////////////////////////////////////////
+// Name:        dcscreen.h
+// Purpose:     documentation for wxScreenDC class
+// 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}
+    
+    @seealso
+    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);
+    //@}
+};