('update status',lambda t: str(t)),

        ]:

        l = tk.Label(master,anchor='w',justify='left')

        l.pack(side='top',fill='x')

        dispatcher.connect(lambda val,l=l,sn=signame,tf=textfilter:

                           l.config(text=sn+": "+tf(val)),

                           signame,weak=0)

class SubtermSetView(tk.Frame):

    def __init__(self, master, *args, **kw):

        tk.Frame.__init__(self, master, *args, **kw)

        self.cur_row = 0

        self.cur_col = 0

        self.ncols = 2

    def add_subtermview(self, stv):

        stv.grid(row=self.cur_row, column=self.cur_col, sticky='news')

        self.columnconfigure(self.cur_col, weight=1)

        self.cur_col += 1

        self.cur_col %= self.ncols

        if self.cur_col == 0:

            self.cur_row += 1

def add_one_subterm(graph, subUri, curveset, subterms, root, ssv, expr=None):

    subname = graph.label(subUri)

    if expr is None:

        expr = '%s(t)' % subname

    print "req to add %r" % subUri

    for s in graph.triples((subUri, None, None)):

        print s

    term = Subterm(Submaster.Submaster(graph=graph, sub=subUri),

                   Subexpr(curveset,expr))

    subterms.append(term)

    stv=Subtermview(ssv, graph, term)

    # stv.pack(side='top',fill='x')

    ssv.add_subtermview(stv)

    return term

def sub_commands_tk(master, curveset, subterms, root, ssv, graph):

    f=tk.Frame(master,relief='raised',bd=1)

    newname = tk.StringVar()

    def add_cmd():

        add_one_subterm(graph, L9['sub/%s' % newname.get()],

        newname.set('')

    def reload_subs():

        dispatcher.send('reload all subs')

    tk.Button(f, text="reload subs (C-r)", 

        command=reload_subs).pack(side='left')

    tk.Label(f, text="new subterm named:").pack(side='left')

    entry = tk.Entry(f, textvariable=newname)

    entry.pack(side='left', fill='x', exp=1)

    entry.bind("<Key-Return>", lambda evt: add_cmd())

    return f

def savesubterms(filename,subterms):

    raise NotImplementedError

    s=""

    for st in subterms:

        s=s+"%s %s\n" % (st.submaster.name, st.subexpr.expr)

    file(filename,'w').write(s)

def createSubtermGraph(song, subterms):

    """rdf graph describing the subterms, readable by add_subterms_for_song"""

    graph = Graph()

    for subterm in subterms:

        uri = URIRef(song + "/subterm/" + subterm.submaster.name)

        graph.add((song, L9['subterm'], uri))

        graph.add((uri, RDF.type, L9['Subterm']))

        graph.add((uri, L9['sub'], L9['sub/%s' % subterm.submaster.name]))

        graph.add((uri, L9['expression'], Literal(subterm.subexpr.expr)))

    return graph

def add_subterms_for_song(graph, song, curveset, subterms, root, ssv):

    for st in graph.objects(song, L9['subterm']):

        add_one_subterm(graph, graph.value(st, L9['sub']), curveset, subterms,

                        root, ssv, graph.value(st, L9['expression']))

def graphPathForSubterms(song):

    return showconfig.subtermsForSong(showconfig.songFilenameFromURI(song)) + ".n3"

def read_all_subs(graph):

    """read all sub files into this graph so when add_one_subterm tries

    to add, the sub will be available"""

    subsDir = showconfig.subsDir()

    for filename in os.listdir(subsDir):

        graph.parse(os.path.join(subsDir, filename), format="n3")