Resets the cached best size value so it will be recalculated the next time it is needed.
+\membersection{wxWindow::IsDoubleBuffered}\label{wxwindowisdoublebuffered}
+
+\constfunc{virtual bool}{IsDoubleBuffered}{\void}
+
+Returns \true if the window contents is double-buffered by the system, i.e. if
+any drawing done on the window is really done on a temporary backing surface
+and transferred to the screen all at once later.
+
+\wxheading{See also}
+
+\helpref{wxBufferedDC}{wxbuffereddc}
+
+
\membersection{wxWindow::IsEnabled}\label{wxwindowisenabled}
\constfunc{virtual bool}{IsEnabled}{\void}
\end{twocollist}}}
+\membersection{wxWindow::IsFrozen}\label{wxwindowisfrozen}
+
+\constfunc{virtual bool}{IsFrozen}{\void}
+
+Returns \true if the window is currently frozen by a call to
+\helpref{Freeze()}{wxwindowfreeze}.
+
+\wxheading{See also}
+
+\helpref{Thaw()}{wxwindowthaw}
+
+
\membersection{wxWindow::IsRetained}\label{wxwindowisretained}
\constfunc{virtual bool}{IsRetained}{\void}
Returns {\tt true} if the window is shown, {\tt false} if it has been hidden.
+\wxheading{See also}
+
+\helpref{wxWindow::IsShownOnScreen}{wxwindowisshownonscreen}
+
+
+\membersection{wxWindow::IsShownOnScreen}\label{wxwindowisshownonscreen}
+
+\constfunc{virtual bool}{IsShownOnScreen}{\void}
+
+Returns {\tt true} if the window is physically visible on the screen, i.e. it
+is shown and all its parents up to the toplevel window are shown as well.
+
+\wxheading{See also}
+
+\helpref{wxWindow::IsShown}{wxwindowisshown}
+
\membersection{wxWindow::IsTopLevel}\label{wxwindowistoplevel}