Develop Reference

setText changes every QTextEdit even if specified to focus on one

I'm trying to put text into a QTextEdit in PyQT5, but every time I set the text for one text field it copies the same value into the other text fields on the same page. Even though I specified that it has to only change the contents of the QTextEdit field of which I have given the ID. Is this normal behavior, or is there a workaround? Any advice would be appreciated.
class NodeUIDScanner(QObject):
rfidTag = pyqtSignal(str)
scanEnabled = bool
def init(self):
self.scanEnabled = False
def run(self):
self.scanEnabled = True
dev = rfid_scanner.init('COM7') #change depending on usb port
while self.scanEnabled:
rfid = rfid_scanner.read(dev)
if rfid is None:
continue
if 'rfid' not in rfid:
continue
rfid = rfid['rfid']
self.scanEnabled = False
self.rfidTag.emit(rfid)
def stop(self):
self.scanEnabled = False
class Main:
def __init__(self):
self.main_win = QMainWindow()
self.ui = RFIDScannerDesign.Ui_MainWindow()
self.ui.setupUi(self.main_win)
#default page on load is the create page
self.ui.stackedWidget.setCurrentWidget(self.ui.pageCreate)
#nav buttons
self.ui.buttonCreate.clicked.connect(self.showCreate)
self.ui.buttonRead.clicked.connect(self.showRead)
self.ui.buttonUpdate.clicked.connect(self.showUpdate)
self.ui.buttonDelete.clicked.connect(self.showDelete)
self.ui.read_editButton.clicked.connect(self.showEdit)
#scan buttons
self.ui.create_buttonScan.clicked.connect(self.scanNodeUidCreate)
self.ui.read_buttonScan.clicked.connect(self.scanNodeUidRead)
self.ui.update_buttonScanOld.clicked.connect(self.scanNodeUidOld)
self.ui.update_buttonScanNew.clicked.connect(self.scanNodeUidNew)
self.ui.delete_buttonScan.clicked.connect(self.scanNodeUidDelete)
#submit button gives alert asking if you're sure you have the right input
self.ui.create_buttonSubmit.clicked.connect(self.alertCreate)
self.ui.edit_buttonSubmit.clicked.connect(self.alertEdit)
self.ui.update_buttonSubmit.clicked.connect(self.alertUpdate)
self.ui.delete_buttonSubmit.clicked.connect(self.alertDelete)
#yes or no buttons with alert. Yes sends info to db. No keeps you on the page
self.ui.create_buttonSubmitYes.clicked.connect(self.submitCreate)
self.ui.create_buttonSubmitNo.clicked.connect(self.hideCreateAlert)
self.ui.edit_buttonSubmitYes.clicked.connect(self.submitEdit)
self.ui.edit_buttonSubmitNo.clicked.connect(self.hideEditAlert)
self.ui.update_buttonSubmitYes.clicked.connect(self.submitUpdate)
self.ui.update_buttonSubmitNo.clicked.connect(self.hideUpdateAlert)
self.ui.delete_buttonSubmitYes.clicked.connect(self.submitDelete)
self.ui.delete_buttonSubmitNo.clicked.connect(self.hideDeleteAlert)
#define QThread here so it can be used
self.main_win.thread = QThread()
self.worker = NodeUIDScanner()
self.worker.moveToThread(self.main_win.thread)
self.main_win.thread.started.connect(self.worker.run)
def show(self):
self.main_win.show()
#Functions for nav buttons to show the right page
def showCreate(self):
self.ui.stackedWidget.setCurrentWidget(self.ui.pageCreate)
self.ui.create_buttonSubmit.show()
self.ui.create_alert.hide()
self.ui.create_buttonSubmitYes.hide()
self.ui.create_buttonSubmitNo.hide()
def showRead(self):
self.ui.stackedWidget.setCurrentWidget(self.ui.pageRead)
self.ui.read_editButton.show()
def showUpdate(self):
self.ui.stackedWidget.setCurrentWidget(self.ui.pageUpdate)
self.ui.update_buttonSubmit.show()
self.ui.update_alert.hide()
self.ui.update_buttonSubmitYes.hide()
self.ui.update_buttonSubmitNo.hide()
def showDelete(self):
self.ui.stackedWidget.setCurrentWidget(self.ui.pageDelete)
self.ui.delete_buttonSubmit.show()
self.ui.delete_alert.hide()
self.ui.delete_buttonSubmitYes.hide()
self.ui.delete_buttonSubmitNo.hide()
def showEdit(self):
self.ui.stackedWidget.setCurrentWidget(self.ui.pageEdit)
self.ui.edit_buttonSubmit.show()
self.ui.edit_alert.hide()
self.ui.edit_buttonSubmitYes.hide()
self.ui.edit_buttonSubmitNo.hide()
#Threads for scanning nodeUIDs asynchronously
def readRFID(self, rfid):
try:
response_rfid = database.query(IndexName='rfid-index',
KeyConditionExpression=Key('rfid').eq(rfid))
if response_rfid['Count'] > 0:
print('RFID already in database', rfid)
print('Node uid:', int(response_rfid['Items'][0]['node_uid']))
return int(response_rfid['Items'][0]['node_uid'])
except Exception as e:
print(e)
def scanNodeUidCreate(self):
if self.ui.create_buttonScan.clicked:
self.worker.stop()
self.worker.rfidTag.connect(self.displayNodeCreate)
self.main_win.thread.start()
def scanNodeUidRead(self):
if self.ui.read_buttonScan.clicked:
self.worker.stop()
self.worker.rfidTag.connect(self.displayNodeRead)
self.main_win.thread.start()
def scanNodeUidOld(self):
if self.ui.update_buttonScanOld.clicked:
self.worker.stop()
self.worker.rfidTag.connect(self.displayNodeOld)
self.main_win.thread.start()
def scanNodeUidNew(self):
if self.ui.update_buttonScanNew.clicked:
self.worker.stop()
self.worker.rfidTag.connect(self.displayNodeNew)
self.main_win.thread.start()
def scanNodeUidDelete(self):
if self.ui.delete_buttonScan.clicked:
self.worker.stop()
self.worker.rfidTag.connect(self.displayNodeDelete)
self.main_win.thread.start()
#Slot for passing signal from worker thread to keep it asynchronous
def displayNodeCreate(self, node):
if self.ui.stackedWidget.currentWidget() == self.ui.pageCreate:
self.ui.create_nodeUid.setText(str(self.readRFID(node)))
self.ui.create_buttonScan.setChecked(False)
self.worker.stop()
self.main_win.thread.quit()
self.main_win.thread.wait()
def displayNodeRead(self, node):
if self.ui.stackedWidget.currentWidget() == self.ui.pageRead:
self.ui.read_nodeUid.setText(str(self.readRFID(node)))
self.ui.edit_nodeUid.setText(str(self.readRFID(node)))
self.ui.read_buttonScan.setChecked(False)
self.worker.stop()
self.main_win.thread.quit()
self.main_win.thread.wait()
def displayNodeOld(self, node):
if self.ui.stackedWidget.currentWidget() == self.ui.pageUpdate:
self.ui.update_nodeUidOld.setText(str(self.readRFID(node)))
self.ui.update_buttonScanOld.setChecked(False)
self.worker.stop()
self.main_win.thread.quit()
self.main_win.thread.wait()
def displayNodeNew(self, node):
if self.ui.stackedWidget.currentWidget() == self.ui.pageUpdate:
self.ui.update_nodeUidNew.setText(str(self.readRFID(node)))
self.ui.update_buttonScanNew.setChecked(False)
self.worker.stop()
self.main_win.thread.quit()
self.main_win.thread.wait()
def displayNodeDelete(self, node):
if self.ui.stackedWidget.currentWidget() == self.ui.pageDelete:
self.ui.delete_nodeUid.setText(str(self.readRFID(node)))
self.ui.delete_buttonScan.setChecked(False)
self.worker.stop()
self.main_win.thread.quit()
self.main_win.thread.wait()
#Submit button, when pressed gives alerts
def alertCreate(self):
self.ui.create_buttonSubmit.hide()
self.ui.create_alert.show()
self.ui.create_buttonSubmitYes.show()
self.ui.create_buttonSubmitNo.show()
def alertEdit(self):
self.ui.edit_buttonSubmit.hide()
self.ui.edit_alert.show()
self.ui.edit_buttonSubmitYes.show()
self.ui.edit_buttonSubmitNo.show()
def alertUpdate(self):
self.ui.update_buttonSubmit.hide()
self.ui.update_alert.show()
self.ui.update_buttonSubmitYes.show()
self.ui.update_buttonSubmitNo.show()
def alertDelete(self):
self.ui.delete_buttonSubmit.hide()
self.ui.delete_alert.show()
self.ui.delete_buttonSubmitYes.show()
self.ui.delete_buttonSubmitNo.show()
#TODO add db connection
def submitCreate(self):
self.showCreate()
self.ui.create_alertSucces.show()
self.fade(self.ui.create_alertSucces)
def submitEdit(self):
self.showRead()
self.ui.read_alertSucces.show()
self.fade(self.ui.read_alertSucces)
def submitUpdate(self):
self.showUpdate()
self.ui.update_alertSucces.show()
self.fade(self.ui.update_alertSucces)
def submitDelete(self):
self.showDelete()
self.ui.delete_alertSucces.show()
self.fade(self.ui.delete_alertSucces)
def hideCreateAlert(self):
self.ui.create_buttonSubmit.show()
self.ui.create_alert.hide()
self.ui.create_buttonSubmitYes.hide()
self.ui.create_buttonSubmitNo.hide()
def hideEditAlert(self):
self.ui.edit_buttonSubmit.show()
self.ui.edit_alert.hide()
self.ui.edit_buttonSubmitYes.hide()
self.ui.edit_buttonSubmitNo.hide()
def hideUpdateAlert(self):
self.ui.update_buttonSubmit.show()
self.ui.update_alert.hide()
self.ui.update_buttonSubmitYes.hide()
self.ui.update_buttonSubmitNo.hide()
def hideDeleteAlert(self):
self.ui.delete_buttonSubmit.show()
self.ui.delete_alert.hide()
self.ui.delete_buttonSubmitYes.hide()
self.ui.delete_buttonSubmitNo.hide()
#fade effect for animations on labels and alerts
def fade(self, widget):
self.effect = QGraphicsOpacityEffect()
widget.setGraphicsEffect(self.effect)
self.animation = QtCore.QPropertyAnimation(self.effect, b"opacity")
self.animation.setDuration(3000)
self.animation.setStartValue(1)
self.animation.setEndValue(0)
self.animation.start()
if __name__ == '__main__':
app = QApplication(sys.argv)
main_win = Main()
main_win.show()
sys.exit(app.exec_())

The problem is that every time a "buttonScan" is clicked, you connect it to a slot. Signals can be connected to an indefinite number of functions, and it is also possible to connect a signal to the same function more than once.
Stopping the worker won't change anything, as the object still exists, and when the signal will be emitted every (previously) connected function will be called as well.
Since all functions do practically the same thing, a better choice is to connect the signal to a single function, and set the target widgets when switching between pages.
Note that there are other problems in your code, most importantly:
clicked is a signal, using if someObject.someSignal: is pointless as it will always be considered valid, and since the function is already connected to that signal there would be no point in checking it anyway;
calling wait() of an external thread in the main thread is wrong, since it is blocking; I won't address the issue here as it's off topic to the question;
Unfortunately, your code is quite convoluted, so I'm only providing modifications for a single page, then you have to implement the rest on your own.
class Main:
def __init__(self):
# ...
self.ui.create_buttonScan.clicked.connect(self.startScan)
# ...
self.worker.rfidTag.connect(self.rfidReceived)
def showCreate(self):
if self.ui.stackedWidget.currentWidget == self.ui.pageCreate:
return
# ...
self.worker.stop() # just to be sure...
self.targetField = self.ui.create_nodeUid
self.targetCheck = self.ui.create_buttonScan
def startScan(self):
self.worker.stop()
self.main_win.thread.start()
def rfidReceived(self, node):
self.targetField.setText(str(self.readRFID(node))
self.targetCheck.setChecked(False)
self.worker.stop()
self.main_win.thread.quit()
self.main_win.thread.wait()
Note that more than half of your code is boilerplate just like the functions that update the text edits: they always do the same thing, just for different targets. This makes your code unnecessarily long and convoluted, so, prone to errors and annoying editing whenever you need to change its behavior. Since it seems clear that almost all your pages have the same interface (except for the read page) it's pointless to have functions that do the same thing repeated 5 times, especially considering that you're using very similar names that might be easily confused; each function is repeated for its 5 "targets" (the page and its buttons), that makes 30 functions, while you could just have 4 or 5. A better modularization and usage of classes will certainly be a smarter choice, will cut down your code by at least half the size, and will make debugging and maintenance much easier.

Why does running mainloop() cause my whole computer to freeze?

I'm building a large, complicated program, one half of which involves a GUI, which I'm building using Tkinter.
Previous iterations of this GUI seemed to work as intended. However, in the latest version, when I try to run a demonstration (see the demo() function in the code below), my whole computer freezes, and my only option is to carry out a hard reset.
Does anyone have any ideas as to why this might be happening? Some points which might be useful:
If I run the code below with the line self.gui.mainloop() commented out, the desired window appears on the screen for long enough for the toaster message to be displayed, and then closes without any freezing.
The ArrivalsManagerDaughter and DeparturesManagerDaughter objects transmit data wirelessly to another device, but they shouldn't be doing anything, other than being initialised, in the code which is causing the freezing. I don't believe that these are the cause of the problem, although I could well be wrong.
Here's the whole Python file which I'm trying to run. I'm happy to post more code if requested.
"""
This code holds a class which manages transitions between the
"recommendations" and "custom placement" windows, and also oversees their
interactions with Erebus.
"""
# GUI imports.
from tkinter import *
# Non-standard imports.
import ptoaster
# Custom imports.
from erebus.arrivals_manager_daughter import ArrivalsManagerDaughter
from erebus.departures_manager_daughter import DeparturesManagerDaughter
# Local imports.
from charon.custom_placement_window import Custom_Placement_Window
from charon.recommendations_window import Recommendations_Window
# Local constants.
REFRESH_INTERVAL = 1000
# ^^^ in miliseconds ^^^
##############
# MAIN CLASS #
##############
class Comptroller:
""" The class in question. """
def __init__(self, welcome=False, delete_existing_ledger=False,
internal=False, diagnostics=False, path_to_icon=None):
self.close_requested = False
self.path_to_icon = path_to_icon
self.recommendations = dict()
self.arrivals_manager = ArrivalsManagerDaughter(self,
diagnostics=diagnostics)
self.departures_manager = DeparturesManagerDaughter(
delete_existing=delete_existing_ledger, internal=internal,
diagnostics=diagnostics)
self.gui = Tk()
self.top = Frame(self.gui)
self.window = Recommendations_Window(self)
self.is_on_recommendations_window = True
self.arrange()
if welcome:
print_welcome()
def add_recommendation(self, ticket, epc, column, row):
""" Add a recommendation to the dictionary. """
recommendation = dict()
recommendation["ticket"] = ticket
recommendation["epc"] = epc
recommendation["column"] = column
recommendation["row"] = row
self.recommendations[ticket] = recommendation
def remove_recommendation(self, ticket):
""" Delete a recommendation from the dictionary. """
del self.recommendations[ticket]
def get_top(self):
""" Return the top-level GUI object. """
return self.top
def arrange(self):
""" Arrange the widgets. """
self.window.get_top().pack()
self.top.pack()
def switch_to_custom_placement(self, ticket, epc):
""" Switch window from "Recommendations" to "Custom Placement". """
columns = self.arrivals_manager.columns
rows = self.arrivals_manager.rows
self.window.get_top().pack_forget()
self.window = Custom_Placement_Window(self, ticket, epc, columns,
rows)
self.window.get_top().pack()
self.is_on_recommendations_window = False
def switch_to_recommendations(self):
""" Switch window from "Custom Placement" to "Recommendations". """
self.window.get_top().pack_forget()
self.window = Recommendations_Window(self)
self.window.get_top().pack()
self.is_on_recommendations_window = True
def refresh(self):
""" Refresh the "recommendations" window, as necessary. """
if (self.is_on_recommendations_window and
self.arrivals_manager.clear_quanta()):
self.window.refresh_rec_table()
self.departures_manager.clear_backlog()
if self.close_requested:
self.kill_me()
else:
self.gui.after(REFRESH_INTERVAL, self.refresh)
def simulate_recommendation(self, ticket, epc, column, row):
""" Simulate receiving a transmission from the Pi. """
self.add_recommendation(ticket, epc, column, row)
self.window.refresh_rec_table()
def request_close(self):
self.close_requested = True
def run_me(self):
""" Run the "mainloop" method on the GUI object. """
self.gui.after(REFRESH_INTERVAL, self.refresh)
self.gui.title("Charon")
if self.path_to_icon:
self.gui.iconphoto(True, PhotoImage(file=self.path_to_icon))
self.gui.protocol("WM_DELETE_WINDOW", self.request_close)
self.gui.mainloop()
def kill_me(self):
""" Kill the mainloop process, and shut the window. """
self.gui.destroy()
####################
# HELPER FUNCTIONS #
####################
def print_welcome():
""" Print a welcome "toaster" message. """
message = ("Notifications about boxes leaving the coldstore will be "+
"posted here.")
ptoaster.notify("Welcome to Charon", message,
display_duration_in_ms=REFRESH_INTERVAL)
def print_exit(epc):
""" Print an exit "toaster" message. """
message = "Box with EPC "+epc+" has left the coldstore."
ptoaster.notify("Exit", message)
###########
# TESTING #
###########
def demo():
""" Run a demonstration. """
comptroller = Comptroller(welcome=True, delete_existing_ledger=True,
internal=True, diagnostics=True)
comptroller.simulate_recommendation(1, "rumpelstiltskin", 0, 0)
comptroller.simulate_recommendation(2, "beetlejuice", 0, 0)
comptroller.run_me()
###################
# RUN AND WRAP UP #
###################
def run():
demo()
if __name__ == "__main__":
run()
FOUND THE PROBLEM: the culprit was actually calling a ptoaster function from within a Tkinter GUI. Which leads me on to my next question: Is it possible to combine ptoaster and Tkinter in an elegant fashion, and, if so, how?

The problem ocurred when calling print_welcome(), which in turn calls one of the ptoaster functions. It seems that Tkinter and ptoaster do not play together nicely. Removing the reference to print_welcome() from the Comptroller class put a stop to any freezing.
(On a side note: I'd be very grateful to anyone who could suggest an elegant method of combing ptoaster with Tkinter.)

Try changing
def demo():
""" Run a demonstration. """
comptroller = Comptroller(welcome=True, delete_existing_ledger=True,
internal=True, diagnostics=True)
comptroller.simulate_recommendation(1, "rumpelstiltskin", 0, 0)
comptroller.simulate_recommendation(2, "beetlejuice", 0, 0)
comptroller.run_me()
###################
# RUN AND WRAP UP #
###################
def run():
demo()
if __name__ == "__main__":
run()
To simply
if __name__ == "__main__":
""" Run a demonstration. """
comptroller = Comptroller(welcome=True, delete_existing_ledger=True,
internal=True, diagnostics=True)
comptroller.simulate_recommendation(1, "rumpelstiltskin", 0, 0)
comptroller.simulate_recommendation(2, "beetlejuice", 0, 0)
comptroller.run_me()
As to why this might happening, since you're creating an object by instantiating Comptroller inside a regular function demo, the object is not being "retained" after the demo exits.
EDIT
If you would like to still maintain demo and run you could create a class Demo and store the instance globally.
Or maybe a simple global variable inside demo to retain a "reference" to the instance Comptroller.

Threading, multiprocessing shared memory and asyncio

I am having trouble implementing the following scheme :
class A:
def __init__(self):
self.content = []
self.current_len = 0
def __len__(self):
return self.current_len
def update(self, new_content):
self.content.append(new_content)
self.current_len += 1
class B:
def __init__(self, id):
self.id = id
And I also have these 2 functions that will be called later in the main :
async def do_stuff(first_var, second_var):
""" this function is ideally called from the main in another
process. Also, first_var and second_var are not modified so it
would be nice if they could be given by reference without
having to copy them """
### used for first call
yield None
while len(first_var) < CERTAIN_NUMBER:
time.sleep(10)
while True:
## do stuff
if condition_met:
yield new_second_var ## which is a new instance of B
## continue doing stuff
def do_other_stuff(first_var, second_var):
while True:
queue = multiprocessing.JoinableQueue()
results = multiprocessing.Queue()
### do stuff
first_var.update(results)
The main looks like this at the moment :
first_var = A()
second_var = B()
while True:
async for new_second_var in do_stuff(first_var, second_var):
if new_second_var:
## stop the do_other_stuff that is currently running
## to re-launch it with the updated new_var
do_other_stuff(first_var, new_second_var)
else: ## used for the first call
do_other_stuff(first_var, second_var)
Here are my questions :
Is there a better solution to make this scheme work?
How can I implement the "stopping" part since there is a while True loop that fills first_var by reference?
Will the instance of A (first_var) be passed by reference to do_stuff if first_var doesn't get modified inside it?
Is it even possible to have an asynchronous generator in another process?
Is it even possible at all?
This is using Python 3.6 for the async generators.
I hope this is somewhat clear! Thanks a lot!

Child calling parent's method without calling parent's __init__ in python

I have a program that have a gui in PyQt in the main thread. It communicates to a photo-detector and gets power readings in another thread, which sends a signal to the main thread to update the gui's power value.
Now I want to use a motor to automatically align my optical fiber, getting feedback from the photo-detector.
So I created a class that controls the motors, but I have to somehow pass the photo-detector readings to that class. First, I tried to access parent's power variable but it didn't work.
Then I created a method in my gui to return the variable's value and tried to access it from the motor class. I got a problem saying that I couldn't use parent's method without using its __init__ first. Is there a way to bypass it? I can't call the gui __init__ again, I just want to use one of its methods from within the child class.
If there is an alternative way to do this, I'd be happy as well.
PS: I guess I can't give the child class the photo-detector object because it is in another thread, right?
--Edit--
The gui code is:
class MyApp(QtGui.QMainWindow, Ui_MainWindow):
self.PDvalue = 0 #initial PD value
self.PDState = 0 #control the PD state (on-off)
self.PDport = self.dialog.pm100d.itemText(self.dialog.pm100d.currentIndex()) #gets pot info
def __init__(self):
... #a lot of other stuff
self.nano = AlgoNanoMax.NanoMax('COM12') #creates the motor object
self.nano_maxX.clicked.connect(self.NanoMaximizeX) #connect its fun to a buttom
self.actionConnect_PM100D.triggered.connect(self.ActionConnect_PM100D) #PD buttom
def NanoMaximizeX(self):
self.nano.maximize_nano_x() #uses motor object function
def ActionConnect_PM100D(self):
if self.PDState == 0: #check if PD is on
self.PD = PDThread(self.PDState, self.PDport) #creates thread
self.PD.valueupdate.connect(self.PDHandler) #signal connect
self.PD.dialogSignal.connect(self.PDdialog) #create error dialog
self.threads = []
self.threads.append(self.PD)
self.PD.start() #start thread
else:
self.PDState = 0
self.PD.state = 0 #stop thread
self.startpd.setText('Start PD') #change buttom name
def PDHandler(self, value):
self.PDvalue = value #slot to get pow from thread
def ReturnPow(self):
return self.PDvalue #return pow (I tried to use this to pass to the motor class)
def PDdialog(self):
self.dialog.set_instrument('PM100D') #I have a dialog that says error and asks you to type the right port
if self.dialog.exec_() == QtGui.QDialog.Accepted: #if Ok buttom try again
ret = self.dialog.pm100d.itemText(self.dialog.pm100d.currentIndex()) #new port
self.PD.port = str(ret)
self.PD.flagWhile = False #change PD stop loop condition to try again
else: #pressed cancel, so it gives up
self.PD.photodetector.__del__() #delete objects
self.PD.terminate() #stop thread
self.PD.quit()
Now the PD class, which is in another thread but in the same file as gui:
class PDThread(QtCore.QThread):
valueupdate = QtCore.pyqtSignal(float) #creating signals
dialogSignal = QtCore.pyqtSignal() #signal in case of error
state = 1 #used to stop thread
def __init__(self, state, port):
QtCore.QThread.__init__(self)
self.photodetector = PM100D() #creates the PD object
self.port = port
def run(self):
while True:
self.flagWhile = True #used to leave while
try:
self.photodetector.connect(self.port) #try to connect
except:
self.dialogSignal.emit() #emit error signal
while self.flagWhile == True:
time.sleep(0.5) #wait here until user press something in the dialog, which is in another thread
else:
break #leave loop when connected
window.PDState = 1 #change state of main gui buttom (change functionality to turn off if pressed again)
window.startpd.setText('Stop PD') #change buttom label
while self.state == 1:
time.sleep(0.016)
value = self.photodetector.get_pow() #get PD pow
self.valueupdate.emit(value) #emit it
The AlgoNanoMax file:
import gui
from NanoMax import Nano
class NanoMax(gui.MyApp): #inheriting parent
def __init__(self, mcontroller_port):
self.mcontroller = Nano(mcontroller_port) #mcontroller is the communication to the motor
def maximize_nano_x(self, step=0.001, spiral_number=3):
''' Alignment procedure with the nano motor X'''
print 'Optimizing X'
power = super(NanoMax, self).ReturnPow() #here I try to read from the photodetector
xpos = self.mcontroller.initial_position_x
position = []
position = [[power, xpos]]
xsign = 1
self.mcontroller.move_relative(self.mcontroller.xaxis, (-1) * spiral_number * step)
print 'X nano move: '+ str((-1) * spiral_number * step * 1000) + ' micrometers'
time.sleep(4)
power = super(NanoMax, self).ReturnPow()
xpos += (-1) * spiral_number * step
position.append([power, xpos])
for _ in xrange(2*spiral_number):
self.mcontroller.move_relative(self.mcontroller.xaxis, xsign * step)
print 'X nano move: '+ str(xsign * step * 1000) + ' micrometers'
time.sleep(5)
power = super(NanoMax, self).ReturnPow()
xpos += xsign * step
position.append([power, xpos])
pospower = [position[i][0] for i in xrange(len(position))]
optimalpoint = pospower.index(max(pospower))
x_shift = (-1) * (xpos - position[optimalpoint][1])
print 'Maximum power: ' + str(max(pospower)) + ' dBm'
print 'Current power: ' + str(super(NanoMax, self).ReturnPow()) + ' dBm'
self.mcontroller.move_relative(self.mcontroller.xaxis, x_shift)

The __init__ for NanoMax and MyApp should call super().__init__() to ensure initialization is done for all levels (if this is Python 2, you can't use no-arg super, so it would be super(NanoMax, self).__init__() and super(MyApp, self).__init__() respectively). This assumes the PyQT was properly written with new-style classes, and correct use of super itself; you're using super in other places, so presumably at least the former is true. Using super appropriately in all classes will ensure all levels are __init__-ed once, while manually listing super classes won't work in certain inheritance patterns, or might call some __init__s multiple times or not at all.
If there is a possibility that many levels might take arguments, you should also accept *args/**kwargs and forward them to the super().__init__ call so the arguments are forwarded where then need to go.
Combining the two, your code should look like:
class MyApp(QtGui.QMainWindow, Ui_MainWindow):
def __init__(self, *args, **kwargs):
super(MyApp, self).__init__(*args, **kwargs)
... rest of __init__ ...
class PDThread(QtCore.QThread):
def __init__(self, state, port, *args, **kwargs):
super(PDThread, self).__init__(*args, **kwargs)
...
class NanoMax(gui.MyApp): #inheriting parent
def __init__(self, mcontroller_port, *args, **kwargs):
super(NanoMax, self).__init__(*args, **kwargs)
self.mcontroller = Nano(mcontroller_port) #mcontroller is the communication to the motor
Note: If you've overloaded methods that the super class might call in its __init__ and your overloads depend on state set in your own __init__, you'll need to set up that state before, rather than after the super().__init__(...) call. Cooperative multiple inheritance can be a pain that way. Also note that using positional arguments for anything but the lowest level class can be ugly with multiple inheritance, so it may make sense to pass all arguments by keyword, and only accept and forward **kwargs, not *args, so people don't pass positional arguments in ways that break if the inheritance hierarchy changes slightly.

class MyApp(QtGui.QMainWindow, Ui_MainWindow):
self.PDvalue = 0 #initial PD value
self.PDState = 0 #control the PD state (on-off)
In the above code it is setting a variable outside of a function. To do this in a class don't put the self keyword in front of it. This way you can just have in the class definition
class MyApp(QtGui.QMainWindow, Ui_MainWindow):
PDvalue = 0 #initial PD value
PDState = 0 #control the PD state (on-off)
and in the super line
power = super(NanoMax, self).PDvalue
For example:
>>> class Hi:
H = 5
def __init__(self):
self.g = 6
>>> class Bye(Hi):
def H(self):
print(super(Bye, self).H)
>>> e = Bye()
>>> e.H()
5
>>>

Python GTK3 - TreeView not being updated properly

I have issue with GTK's TreeView with ListStore. Records are updated, but sometime only when I hover it.
Bigger problem are new records - It's like it stops to displaying new ones unless I scroll to bottom all the time - which is weird.
I use Glade.
My code (slightly simplified)
class UI(SampleUI):
gladefile = 'ui.glade'
iterdict = {}
def __init__(self, module):
super().__init__(module)
def start(self):
self.fetch_widgets()
self.connect_events()
self.window.show()
def fetch_widgets(self):
self.window = self.builder.get_object('window')
self.liststore = self.builder.get_object('store')
def connect_events(self):
handlers = {
"on_window_close" : Gtk.main_quit,
"on_start_working": self.start_working,
"on_stop_working": self.stop_working
}
self.builder.connect_signals(handlers)
self.module.url_pending_action = self.url_pending
self.module.url_succeed_action = self.url_update
def start_working(self, button):
self.module.start()
def stop_stop(self, button):
self.module.stop()
def url_pending(self, data):
self.iterdict[data['url']] = self.liststore.append([0, data['url'], 0, '', data['text']])
def url_update(self, data):
_iter = self.iterdict[data['url']]
self.liststore[_iter][1] = data['some_field1']
self.liststore[_iter][2] = data['some_field2']
Methods self.url_pending and self.url_update are called by threads (at most 30 running at the same time) created in self.module
I checked and new records are correctly appended into ListStore - I can read data from it. Window is working fine, but there are no new items at the bottom.
Ideas?

Ok, I made research and I figured out that GTK don't like being called from outside of main thread.
There was methods in Gdk to lock GTK calls
Gtk.threads_enter()
...
Gtk.threads_leave()
But now it's deprecated and GTK documentation says that every GTK call should be in main thread.
My workaround:
# [...]
def start(self):
# [...]
GObject.timeout_add(100, self.query_do)
# [...]
def query_do(self):
while len(self.gtk_calls):
self.gtk_calls.pop()()
GObject.timeout_add(100, self.query_do)
And I'm just adding into query
self.gtk_calls.insert(0, lambda: anything())
The code isn't as clear as it was before, but works perfect.