Quite new with UI and python, I am wondering if it's possible to have a window (in my case with wxPython) which stays alive all the time until we destroy it, to perform many other actions in the meantime. If so, where the main running code should be? Here is an example where it is wrong and doesn't work of course:
from time import sleep
import wx
def do_actions(g):
for i in range(100):
print('Iteration: ', i)
g.SetValue(i)
sleep(1)
class MyFrame(wx.Frame):
def __init__(self, parent, id, title):
wx.Frame.__init__(self, parent, id, title)
panel = wx.Panel(self, -1)
self.gauge = wx.Gauge(panel, -1, 50, size=(250, 25))
do_actions(self.gauge)
class MyApp(wx.App):
def OnInit(self):
frame = MyFrame(None, -1, 'wx.Gauge')
frame.Show(True)
app = MyApp(0)
app.MainLoop()
CodePudding user response：
You are probably trying to run, before you've learnt to walk but there's nothing wrong with ambition.
You will need to read up on threading/multiprocessing i.e. running separate processes at the same time.
wxPython has a single main event loop, which is used to monitor all of the the GUI events, so that has to be in control at all times.
We fire up a thread to run each job and the GUI updates are issued as events.
That's probably not a very good explanation so here is a bit of simplistic test code, which illustrates one way of setting this up. The threads only run for a limited time but obviously, you can adjust that.
Hopefully, you can pick the bones out of this enough to get you started.
import time
import wx
from threading import Thread
import wx.lib.newevent
progress_event, EVT_PROGRESS_EVENT = wx.lib.newevent.NewEvent()
class MainFrame(wx.Frame):
def __init__(self):
wx.Frame.__init__(self, None, title='Main Frame', size=(400,400))
panel = MyPanel(self)
self.Show()
class MyPanel(wx.Panel):
def __init__(self, parent):
wx.Panel.__init__(self, parent)
self.text_count = 0
self.parent=parent
self.process1 = None
self.process2 = None
self.jobs = []
self.btn_start = wx.Button(self, wx.ID_ANY, label='Start Long running process', size=(180,30), pos=(10,10))
btn_test = wx.Button(self, wx.ID_ANY, label='Is the GUI still active?', size=(180,30), pos=(10,50))
self.txt = wx.TextCtrl(self, wx.ID_ANY, style= wx.TE_MULTILINE, pos=(10,90),size=(300,100))
self.btn_start.Bind(wx.EVT_BUTTON, self.Start_Process)
btn_test.Bind(wx.EVT_BUTTON, self.ActiveText)
def Start_Process(self, event):
self.process1 = ProcessingFrame(title='Threaded Task 1', parent=self, job_no=1)
self.jobs.append(1)
self.process2 = ProcessingFrame(title='Threaded Task 2', parent=self, job_no=2)
self.jobs.append(2)
self.btn_start.Enable(False)
def ActiveText(self,event):
self.text_count = 1
txt = "Gui is still active " str(self.text_count) "\n"
self.txt.write(txt)
if self.process1:
txt = "process1 alive " str(self.process1.mythread.is_alive()) "\n"
else:
txt = "process1 is dead\n"
if self.process2:
txt = "process2 alive " str(self.process2.mythread.is_alive()) "\n"
else:
txt = "process2 is dead\n"
self.txt.write(txt)
class ProcessingFrame(wx.Frame):
def __init__(self, title, parent=None,job_no=None):
wx.Frame.__init__(self, parent=parent, title=title, size=(400,400))
panel = wx.Panel(self)
self.parent = parent
self.job_no = job_no
self.btn = wx.Button(panel,label='Stop processing', size=(200,30), pos=(10,10))
self.btn.Bind(wx.EVT_BUTTON, self.OnExit)
self.btn_pause = wx.Button(panel,label='Pause processing', size=(200,30), pos=(10,50))
self.btn_pause.Bind(wx.EVT_BUTTON, self.OnPause)
self.progress = wx.Gauge(panel,size=(200,10), pos=(10,90), range=60)
self.process = wx.TextCtrl(panel,size = (200,250), pos=(10,120), style = wx.TE_MULTILINE)
#Bind to the progress event issued by the thread
self.Bind(EVT_PROGRESS_EVENT, self.OnProgress)
#Bind to Exit on frame close
self.Bind(wx.EVT_CLOSE, self.OnExit)
self.Show()
self.mythread = TestThread(self)
def OnProgress(self, event):
self.progress.SetValue(event.count)
self.process.write(event.process "\n")
self.Refresh()
if event.count >= 60:
self.OnExit(None)
def OnExit(self, event):
if self.mythread.is_alive():
self.mythread.terminate() # Shutdown the thread
self.mythread.join() # Wait for it to finish
self.parent.jobs.remove(self.job_no)
if not self.parent.jobs:
self.parent.btn_start.Enable(True)
self.Destroy()
def OnPause(self, event):
if self.mythread.is_alive():
self.mythread.pause() # Pause the thread
class TestThread(Thread):
def __init__(self,parent_target):
Thread.__init__(self)
self.target = parent_target
self.stopthread = False
self.process = 1 # Testing only - mock process id
self.start() # start the thread
def run(self):
# A selectable test loop that will run for 60 loops then terminate
if self.target.job_no == 1:
self.run1()
else:
self.run2()
def run1(self):
curr_loop = 0
while self.stopthread != True:
if self.stopthread == "Pause":
time.sleep(1)
continue
curr_loop = 1
self.process = 10 # Testing only - mock process id
if curr_loop <= 60: # Update progress bar
time.sleep(1.0)
evt = progress_event(count=curr_loop,process="Envoking process " str(self.process))
#Send back current count for the progress bar
try:
wx.PostEvent(self.target, evt)
except: # The parent frame has probably been destroyed
self.terminate()
self.terminate()
def run2(self):
curr_loop = 0
while self.stopthread != True:
if self.stopthread == "Pause":
time.sleep(1)
continue
curr_loop = 1
self.process = 100 # Testing only - mock process id
if curr_loop <= 60: # Update progress bar
time.sleep(1.0)
evt = progress_event(count=curr_loop,process="Checking process" str(self.process))
#Send back current count for the progress bar
try:
wx.PostEvent(self.target, evt)
except: # The parent frame has probably been destroyed
self.terminate()
self.terminate()
def terminate(self):
self.stopthread = True
def pause(self):
if self.stopthread == "Pause":
self.stopthread = False
self.target.btn_pause.SetLabel('Pause processing')
else:
self.stopthread = "Pause"
self.target.btn_pause.SetLabel('Continue processing')
if __name__ == '__main__':
app = wx.App(False)
frame = MainFrame()
app.MainLoop()
