X-Git-Url: https://git.saurik.com/wxWidgets.git/blobdiff_plain/12f5e1e78fe906050ff2fee9529476db332633f0..2a8312bced9d3f3415383a79a15cad2acf447b7e:/interface/wx/scrolwin.h?ds=sidebyside

diff --git a/interface/wx/scrolwin.h b/interface/wx/scrolwin.h
index b73f8464b4..873a2182cc 100644
--- a/interface/wx/scrolwin.h
+++ b/interface/wx/scrolwin.h
@@ -181,11 +181,11 @@ public:
         image.
 
         It sets the device origin according to the current scroll position.
-        DoPrepareDC() is called automatically within the default OnPaint()
-        event handler, so your OnDraw() override will be passed a
+        DoPrepareDC() is called automatically within the default @c wxEVT_PAINT
+        event handler, so your OnDraw() override will be passed an already
         'pre-scrolled' device context. However, if you wish to draw from
-        outside of OnDraw() (via OnPaint()), or you wish to implement OnPaint()
-        yourself, you must call this function yourself.
+        outside of OnDraw() (e.g. from your own @c wxEVT_PAINT handler), you
+        must call this function yourself.
 
         For example:
         @code
@@ -206,6 +206,12 @@ public:
         }
         @endcode
 
+        Notice that the function sets the origin by moving it relatively to the
+        current origin position, so you shouldn't change the origin before
+        calling DoPrepareDC() or, if you do, reset it to (0, 0) later. If you
+        call DoPrepareDC() immediately after device context creation, as in the
+        example above, this problem doesn't arise, of course, so it is
+        customary to do it like this.
     */
     void DoPrepareDC(wxDC& dc);