added wxMessageQueue class for inter-thread communications

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

diff --git a/docs/latex/wx/memorydc.tex b/docs/latex/wx/memorydc.tex
index c3e4f16ce9375ab2100ccbd2695ded6a8351cb4d..e71262b954304a2cdea653263c94e76784989fa1 100644 (file)
--- a/docs/latex/wx/memorydc.tex
+++ b/docs/latex/wx/memorydc.tex
@@ -15,6 +15,10 @@ foreground colour (i.e. 1).
 
 <wx/dcmemory.h>
 
+\wxheading{Library}
+
+\helpref{wxCore}{librarieslist}
+
 \wxheading{Remarks}
 
 A bitmap must be selected into the new memory DC before it may be used
@@ -33,6 +37,16 @@ for anything.  Typical usage is as follows:
 Note that the memory DC {\it must} be deleted (or the bitmap selected out of it) before a bitmap
 can be reselected into another memory DC.
 
+And, before performing any other operations on the bitmap data, the bitmap must
+be selected out of the memory DC:
+
+\begin{verbatim}
+    temp_dc.SelectObject(wxNullBitmap)
+\end{verbatim}
+
+(this happens automatically when wxMemoryDC object goes out of scope).
+
+
 \wxheading{See also}
 
 \helpref{wxBitmap}{wxbitmap}, \helpref{wxDC}{wxdc}
@@ -65,11 +79,13 @@ Works exactly like \helpref{SelectObjectAsSource}{wxmemorydcselectobjectassource
 this is the function you should use when you select a bitmap because you want to modify
 it, e.g. drawing on this DC.
 
-Be careful to use this function and not \helpref{SelectObjectAsSource}{wxmemorydcselectobjectassource}
-when you want to modify the bitmap you are selecting otherwise you may incurr in some
-problems related to wxBitmap being a reference counted object
+Using \helpref{SelectObjectAsSource}{wxmemorydcselectobjectassource} when modifying
+the bitmap may incurr some problems related to wxBitmap being a reference counted object
 (see \helpref{reference counting overview}{trefcount}).
 
+Also, before using the updated bitmap data, make sure to select it out of context first
+(for example by selecting wxNullBitmap into the device context).
+
 \wxheading{See also}
 
 \helpref{wxDC::DrawBitmap}{wxdcdrawbitmap}