I have run into a problem with matplotlib, GTK and Threading.
The program basically gets data over RS232 and if a certain command is sent the data is plotted
So far the program is pretty mature and data can be read via RS232 and written to RS232 and the
GUI is updated (text-widgets) accordingly
The problem I have with with the non-GUI thread calling the “plot” function.
Within the GTK-GUI class I added a method that basically plots a SINE-wave
when a button is pressed it plots another SINE-wave, basically just proof-of-concept before I got onto the date via RS232
The thread-code to extract data (for plotting) via RS232 works fine but when the thread calls a GUI method to update the
graph it locks up
CODE-SNIPPITS
class low_level(threading.Thread):
def init(self,Reg,GUI):
super(low_level, self).__init__()
self.timer = threading.Timer(3.0,self.__SetTimerState)
self.Reg = Reg
self.GUI = GUI
self.RUN = True
self.timer_exp = False
self.LOCAL_LIST = []
self.WRITELIST = []
…
def __Capture(self):
DATA = [[],[],[],[],[],[],[],[],[],[],[],[],[],[],[],[],[]]
self.__Write(self.Reg.MON_Addr,self.Reg.MON
[-1])
tmp = [x for x in self.Reg.CAPTURE_REQ if x >0 and x not in locals()["_[1]"]]
tmp.insert(0,0)
for i in range(int(self.Reg.CAPTURE_SAMPLES)):
self.__Write(127)
for x in tmp:
t = self.__ReadData(
self.Reg.MON_MASK[x][1])
if t == ‘::ERROR::’:
print “Plotting data fault!!”
break
DATA[x].append(t)
DAT = [DATA[0]]
for x in self.Reg.CAPTURE_REQ:
if x <1: DAT.append(None)
else: DAT.append(DATA[x])
gtk.threads_enter()#updating GUI section
try:
self.GUI.ThreadGraph(DAT)
finally:
gtk.threads_leave()
self.Reg.CAPTURE = False
…
…
…
gtk.gdk.threads_init
()
class appgui(object):
def init(self,Reg):
super(appgui, self).init()
self.Reg = Reg
self.gladefile=GLADE_FILE
self.windowname=‘ESC’
self.wTree=gtk.glade.XML
(self.gladefile,self.windowname)
dic = {'on_quit_button_clicked' : self.QuitClicked,##callback dictionary
'on_connect_button_clicked' : self.Connect,
'on_save_conf_clicked' : self.Save
···
,
‘on_load_conf_clicked’ : self.Load,
‘on_upload_clicked’ : self.Upload
,#GetRW,
‘on_capture_clicked’ : self.Capture,
‘on_startstop_clicked’ : self.StartStop,
‘on_window_destroy’ : (gtk.main_quit)}
self.wTree.signal_autoconnect(dic)
self.f = self.wTree.get_widget
self.GraphData(INIT_G)
…
def GraphData(self,DATA):
COLOUR = [‘b’,‘g’,‘r’,‘c’,‘m’,‘y’,‘k’]
try:
self.canvas.destroy()
self.toolbar.destroy()
except:pass
self.figure = Figure(figsize=(6,3), dpi=100)#{{{
self.axis = self.figure.add_subplot
(111)
self.axis.grid(True)
self.axis.set_xlabel(‘Time (s)’)
for x in range(1,len(DATA)):
if DATA[x] == None: continue
self.axis.plot(DATA[0],DATA[x],COLOUR[x-1],linewidth=2.0)
self.canvas = FigureCanvas(self.figure) # a gtk.DrawingArea
self.canvas.show
()
self.graphview = self.wTree.get_widget(‘vboxgraph’)
self.graphview.pack_start
(self.canvas, True, True)
self.toolbar = NavigationToolbar(self.canvas,self.wTree.get_widget(‘ESC’))
self.graphview.pack_start(self.toolbar, False, False)#}}}
…
if name == ‘main’:
Reg = Register()
app=appgui(Reg)
LL = low_level(Reg,app)
LL.start()
gtk.threads_enter()
gtk.main()
gtk.threads_leave()
LL.stop
()
As it stands with this locks up, if I change the code such that when I press the widget that starts the “Capture” fn from the thread, BUT that doesn’t update the plot
and if I add another button and in pressing that (NOTE that button’s code would be part of the GUI-class) calls the GraphData function then it works.
It seems even using the gtk.threads_enter and gtk.threads_leave with a matplotlib embedded into a GTK windows does not work and any graph modifications MUST
be called directly from the GUI-Class.
Any idea how to make matplotlib work well with GTK & Threads?