GetBoundingRect() is supposed to return the logical coordinates, even in !textOnly case; also documented it

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@38604 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

docs/latex/wx/treectrl.tex

@@ -340,9 +340,13 @@ only the rectangle around the item's label will be returned, otherwise the
 item's image is also taken into account.
 
 The return value is {\tt true} if the rectangle was successfully retrieved or {\tt false}
-if it was not (in this case {\it rect} is not changed) - for example, if the
+if it was not (in this case {\it rect} is not changed) -- for example, if the
 item is currently invisible.
 
+Notice that the rectangle coordinates are logical, not physical ones. So, for
+example, the x coordinate may be negative if the tree has a horizontal
+scrollbar and its position is not $0$.
+
 \pythonnote{The wxPython version of this method requires only the
 {\tt item} and {\tt textOnly} parameters.  The return value is either a
 {\tt wxRect} object or {\tt None}.}