1. New classes documented: wxCriticalSection, wxMutexLocker,

[wxWidgets.git] / docs / latex / wx / paintdc.tex

diff --git a/docs/latex/wx/paintdc.tex b/docs/latex/wx/paintdc.tex
index e1c416044bfc31324088a0debb71c5433b90a2ef..05842fb646b9f4d5167ca6194963c9a047a20040 100644 (file)
--- a/docs/latex/wx/paintdc.tex
+++ b/docs/latex/wx/paintdc.tex
@@ -3,7 +3,12 @@
 A wxPaintDC must be constructed if an application wishes to paint on the
 client area of a window from within an {\bf OnPaint} event.
 This should normally be constructed as a temporary stack object; don't store
-a wxPaintDC object.
+a wxPaintDC object. If you have an OnPaint handler, you {\it must} create a wxPaintDC
+object within it even if you don't actually use it.
+
+Using wxPaintDC within OnPaint is important because it automatically
+sets the clipping area to the damaged area of the window. Attempts to draw
+outside this area do not appear.
 
 To draw on a window from outside {\bf OnPaint}, construct a \helpref{wxClientDC}{wxclientdc} object.