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+--- Thread: Update Gtk.Label in for-loop (/thread-10809.html)
Update Gtk.Label in for-loop - TimeMen - Jun-07-2018
How can I update a Gtk.Label in a foor loop?
It's not updating via .set_text("bbb").
Is there any trick to do this?
Greetings
TimeMen
RE: Update Gtk.Label in for-loop - buran - Jun-07-2018
post your code in python tags and full traceback if you get any exception
RE: Update Gtk.Label in for-loop - TimeMen - Jun-07-2018
for zahl in range(start, end+1):
function(self, zahl, steps, counter, prim_counter)
counter +=1
if not numlist:
if not divlist:
if zahl > 1:
prim_counter += 1
elif divlist:
kpt_counter += 1
elif numlist == divlist:
if (sqrt(zahl).is_integer()):
psq_counter += 1
else:
pt_counter +=1
if numlist != divlist:
gt_counter += 1
val = self.progressbar.get_fraction() + 1/end
self.progressbar.set_fraction(val)This is the code, after changing the Label to a Progressbar (as you can see.)But it won't work too.
There's no exception, It's just not working.
Only at the end, the progressbar is completely filled.
It's only kinda bar, not a "progress"bar..
RE: Update Gtk.Label in for-loop - killerrex - Jun-07-2018
The problem is that while your application is in the loop it does not allow Gtk to control the GUI (it just "freezes") so only the final modification is effective.
So if your application is going to perform a heavy operation the best option is to launch it in a different process and set a communication channel to be able to check the progress. To do this you can use the multiprocessing module (it is easier than it looks)
Now you can set a timer in the GUI that periodically check the state of your task and update the progressbar.
As the explanation is a little bit confusing, there is a demo code:
#!/usr/bin/env python3
import multiprocessing as mp
import time
import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk, GObject
def really_looong_operation(state):
"""
Do something that will block your app for a long time
"""
# tick every 200 milliseconds
tick = 0.2
state.value = 0
for k in range(100):
# In real life this might be invert a huge matrix or whatever...
time.sleep(tick)
state.value = k + 1
# Final activity...
time.sleep(2*tick)
class PBarDemo(Gtk.Window):
def __init__(self):
super().__init__(title="Progressing...")
self.connect("destroy", Gtk.main_quit)
self.set_border_width(10)
vbox = Gtk.Box(orientation=Gtk.Orientation.VERTICAL, spacing=5)
self.add(vbox)
self.pbar = Gtk.ProgressBar()
self.pbar.set_show_text(True)
vbox.pack_start(self.pbar, True, True, 0)
self.switch = Gtk.Switch()
self.switch.connect("notify::active", self.on_start_stop)
vbox.pack_start(self.switch, True, True, 0)
self.tid = None
self.proc = None
self.state = mp.Value('i', 0)
# Guarantee the start state
self._stop()
def _stop(self):
# Guarantee that everything is in "stop mode"
if self.tid is not None:
GObject.source_remove(self.tid)
if self.proc is not None and self.proc.is_alive():
self.proc.terminate()
self.tid = None
self.proc = None
self.pbar.set_fraction(0.0)
self.pbar.set_text('Ready...')
def on_start_stop(self, switch, prop):
# Check this is the right property
if prop.name != "active":
return
self._stop()
if not switch.get_active():
return
# Launch the activity... depending of what you want to do,
# it might be better to use a pool of workers or other tricks
self.proc = mp.Process(target=really_looong_operation, args=(self.state,))
self.proc.start()
# And the timer that update the progressbar
self.tid = GObject.timeout_add(250, self.running, None)
self.pbar.set_text("0%")
def running(self, ignored):
value = self.state.value
if value >= 100:
# Stop working at 100%
self.proc.join()
self._stop()
self.switch.set_active(False)
# Return false to stop the timer
return False
else:
frac = value / 100
self.pbar.set_fraction(frac)
self.pbar.set_text(f"{frac:.0%}")
# Return True so this timer is considered active
return True
if __name__ == '__main__':
win = PBarDemo()
win.show_all()
Gtk.main()