\section{\class{wxBufferedDC}}\label{wxbuffereddc}
This simple class provides a simple way to avoid flicker: when drawing on it,
-everything is in fact drawn on an in-memory buffer (a
-\helpref{wxBitmap}{wxbitmap}) and copied to the screen only once, when this
+everything is in fact first drawn on an in-memory buffer (a
+\helpref{wxBitmap}{wxbitmap}) and then copied to the screen only once, when this
object is destroyed.
It can be used in the same way as any other device context. wxBufferedDC itself
\func{}{wxBufferedDC}{\void}
-\func{}{wxBufferedDC}{\param{wxDC *}{dc}, \param{const wxSize\& }{area}, \param{int }{flags}}
+\func{}{wxBufferedDC}{\param{wxDC *}{dc}, \param{const wxSize\& }{area}, \param{int }{style = wxBUFFER\_CLIENT\_AREA}}
-\func{}{wxBufferedDC}{\param{wxDC *}{dc}, \param{const wxBitmap\& }{buffer}}
+\func{}{wxBufferedDC}{\param{wxDC *}{dc}, \param{const wxBitmap\& }{buffer}, \param{int }{style = wxBUFFER\_CLIENT\_AREA}}
If you use the first, default, constructor, you must call one of the
\helpref{Init}{wxbuffereddcinit} methods later in order to use the object.
\wxheading{Parameters}
\docparam{dc}{The underlying DC: everything drawn to this object will be
-flushed to this DC when this object is destroyed.}
+flushed to this DC when this object is destroyed. You may pass NULL
+in order to just initialize the buffer, and not flush it.}
\docparam{area}{The size of the bitmap to be used for buffering (this bitmap is
-created internally when it is not given explicitely).}
-
-\docparam{flags}{Can currently only include the flag
-\texttt{wxBUFFER\_DC\_PRESERVE\_BG} which means that the existing background
-of \arg{dc} must be copied to this object before doing anything else, otherwise
-the background is overwritten (which is more efficient).}
+created internally when it is not given explicitly).}
\docparam{buffer}{Explicitly provided bitmap to be used for buffering: this is
the most efficient solution as the bitmap doesn't have to be recreated each
time but it also requires more memory as the bitmap is never freed. The bitmap
should have appropriate size, anything drawn outside of its bounds is clipped.}
+\docparam{style}{wxBUFFER\_CLIENT\_AREA to indicate that just the client area of
+the window is buffered, or wxBUFFER\_VIRTUAL\_AREA to indicate that the buffer bitmap
+covers the virtual area (in which case PrepareDC is automatically called for the actual window
+device context).}
\membersection{wxBufferedDC::Init}\label{wxbuffereddcinit}
-\func{void}{Init}{\param{wxDC *}{dc}, \param{const wxSize\& }{area}, \param{int }{flags}}
+\func{void}{Init}{\param{wxDC *}{dc}, \param{const wxSize\& }{area}, \param{int }{style = wxBUFFER\_CLIENT\_AREA}}
-\func{void}{Init}{\param{wxDC *}{dc}, \param{const wxBitmap\& }{buffer}}
+\func{void}{Init}{\param{wxDC *}{dc}, \param{const wxBitmap\& }{buffer}, \param{int }{style = wxBUFFER\_CLIENT\_AREA}}
These functions initialize the object created using the default constructor.
Please see \helpref{constructors documentation}{wxbuffereddcctor} for details.
\membersection{wxBufferedDC::\destruct{wxBufferedDC}}\label{wxbuffereddcdtor}
Copies everything drawn on the DC so far to the underlying DC associated with
-this object.
+this object, if any.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\section{\class{wxBufferedPaintDC}}\label{wxbufferedpaintdc}
This is a subclass of \helpref{wxBufferedDC}{wxbuffereddc} which can be used
-inside \texttt{OnPaint()} handler. Just create an object of this class instead
+inside of an \texttt{OnPaint()} event handler. Just create an object of this class instead
of \helpref{wxPaintDC}{wxpaintdc} and that's all you have to do to (mostly)
avoid flicker. The only thing to watch out for is that if you are using this
class together with \helpref{wxScrolledWindow}{wxscrolledwindow}, you probably
\membersection{wxBufferedPaintDC::wxBufferedPaintDC}\label{wxbufferedpaintdcctor}
-\func{}{wxBufferedPaintDC}{\param{wxWindow *}{window}, \param{int }{flags}}
+\func{}{wxBufferedPaintDC}{\param{wxWindow *}{window}, \param{const wxBitmap\& }{buffer}, \param{int }{style = wxBUFFER\_CLIENT\_AREA}}
-\func{}{wxBufferedPaintDC}{\param{wxWindow *}{window}, \param{const wxBitmap\& }{buffer}}
+\func{}{wxBufferedPaintDC}{\param{wxWindow *}{window}, \param{int }{style = wxBUFFER\_CLIENT\_AREA}}
As with \helpref{wxBufferedDC}{wxbuffereddcctor}, you may either provide the
bitmap to be used for buffering or let this object create one internally (in
the latter case, the size of the client part of the window is used).
+Pass wxBUFFER\_CLIENT\_AREA for the {\it style} parameter to indicate that just the client area of
+the window is buffered, or wxBUFFER\_VIRTUAL\_AREA to indicate that the buffer bitmap
+covers the virtual area (in which case PrepareDC is automatically called for the actual window
+device context).
\membersection{wxBufferedPaintDC::\destruct{wxBufferedPaintDC}}\label{wxbufferedpaintdcdtor}
Copies everything drawn on the DC so far to the window associated with this
-object.
+object, using a \helpref{wxPaintDC}{wxpaintdc}.
projects / wxWidgets.git / blobdiff