\wxheading{Remarks}
Note that even empty text controls have one line (where the insertion point
-is), so GetNumberOfLines() never returns 0.
+is), so GetNumberOfLines() never returns $0$.
-For gtk\_text (multi-line) controls, the number of lines is
-calculated by actually counting newline characters in the buffer. You
-may wish to avoid using functions that work with line numbers if you are
-working with controls that contain large amounts of text.
+For wxGTK using GTK+ 1.2.x and earlier, the number of lines in a multi-line
+text control is calculated by actually counting newline characters in the
+buffer, i.e. this function returns the number of logical lines and doesn't
+depend on whether any of them are wrapped. For all the other platforms, the
+number of physical lines in the control is returned.
+
+Also note that you may wish to avoid using functions that work with line
+numbers if you are working with controls that contain large amounts of text as
+this function has $O(N)$ complexity for $N$ being the number of lines.
\membersection{wxTextCtrl::GetRange}\label{wxtextctrlgetrange}
\wxheading{Return value}
-The position value.
+The position value, or -1 if {\tt x} or {\tt y} was invalid.
\membersection{wxTextCtrl::operator \cinsert}\label{wxtextctrlinsert}