Preventing cursor movement via mouse in GtkTextView

[Douglas Vechinski <douglas vechinski dynetics com>]

I'm attempting to create a "command line" input area for a GTK
application using a GtkTextView with GtkTextBuffer.  The user will type
in commands and some output may be sent to the text buffer.  After a
command line is entered I make the text and any output "not editable"
with a tag so they can not go back and delete some of the text.  I also
catch each keystroke to see if they are attempting to move the cursor to
previous lines and prevent to the keystroke from going through if it
would move the cursor to the previous commands and output.  However, one
can currently use the mouse to click in a "non-editable" area and the
cursor is moved to there.  Is there a way to prevent the user from being
able to use the mouse to move the cursor into this unchangeable area.
However I would still like to allow them to select text in this "not
editable" area.  Also, I would still want to allow them to move the
cursor via the mouse on the current command line (such as they are in
the process of entering a string but have not yet pressed <Return>).