added null pointer check and assert

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

diff --git a/docs/latex/wx/paintdc.tex b/docs/latex/wx/paintdc.tex
index e1c416044bfc31324088a0debb71c5433b90a2ef..2884b3a6d6274ed69c749fecaf7292e4e0db96cb 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.
 
@@ -12,7 +17,17 @@ To draw on the whole window including decorations, construct a \helpref{wxWindow
 
 \wxheading{Derived from}
 
-\helpref{wxDC}{wxdc}
+\helpref{wxWindowDC}{wxwindowdc}\\
+\helpref{wxDC}{wxdc}\\
+\helpref{wxObject}{wxobject}
+
+\wxheading{Include files}
+
+<wx/dcclient.h>
+
+\wxheading{Library}
+
+\helpref{wxCore}{librarieslist}
 
 \wxheading{See also}
 
@@ -21,7 +36,7 @@ To draw on the whole window including decorations, construct a \helpref{wxWindow
 
 \latexignore{\rtfignore{\wxheading{Members}}}
 
-\membersection{wxPaintDC::wxPaintDC}
+\membersection{wxPaintDC::wxPaintDC}\label{wxpaintdcctor}
 
 \func{}{wxPaintDC}{\param{wxWindow*}{ window}}