How to avouid duplicate entries into QlistWidget when adding new item

bidd

Re: Remove duplicate entries from QListWidget?

When add item button is clicked, for the first time one item is added to the list. On the second occasion two items are added to the existing list (2* second item) . How can this behavior be avoided. I am not sure how to add minimal reproducible code here.

JonB

@bidd said in How to avouid duplicate entries into QlistWidget when adding new item:

    self.dialog_TL.show()
    self.ui_Tl.tl_confirm.clicked.connect(lambda: self.parse_data('North_South_List'))

Here is my guess. tl_prop() is a slot, called each time add is clicked. It does not just show a dialog, it also seems to connect a button's clicked signal. If that is called multiple times there will be multiple connects on the button. So parse_data() will be called multiple times, and that does the item = QListWidgetItem().

Which is as I suggested might be the case originally. You should essentially only do object.signal.connect() once, at the time the object is created (or at the time the slot object is created, whichever is later). I think you can move it into your connectSignalsSlots().

Quite separately: You do not need the str() in all those str(....[current]text()) expressions. Qt C++'s QStrings will be converted to strs for you in Python.

jsulm

@bidd said in How to avouid duplicate entries into QlistWidget when adding new item:

I am not sure how to add minimal reproducible code here

Show the code where you add entries.
You're apparently doing something wrong if second time two items are added.

JonB

@bidd said in How to avouid duplicate entries into QlistWidget when adding new item:

or the first time one item is added to the list. On the second occasion two items are added

Are you perchance doing a new connect() where you added the (first) item? If you have multiple connects from same signal->slot the slot gets executed multiple times.

bidd

This post is deleted!

JonB

@bidd
Maybe someone else will look through this length of code. Otherwise, at least for my part, please produce a minimal example which illustrates the issue. Literally 90+% of the above looks irrelevant.

bidd

@JonB hope this is minimal

import sys
from PyQt5 import QtCore

from PyQt5.QtWidgets import (

QApplication, QDialog, QMainWindow, QMessageBox,QListWidget,QListWidgetItem

)

from tl_cluster_dialog_ui import Ui_tl_cluster_define
from tl_prop_dialog_ui import Ui_Trafficlightproperty

class Virtual_TL_details:
def init(self):
self.id = None
self.state = None
self.arduino_id = None
self.vehicle = None
self.desired = None
self.time = None

class Window(QMainWindow, Ui_tl_cluster_define):

def __init__(self, parent=None):
    super().__init__(parent)
    self.setupUi(self)
    self.connectSignalsSlots()
    self.msg = QMessageBox()
    self.msg.setIcon(QMessageBox.Warning)
    self.msg.setWindowTitle("Warning Message")
    self.dialog_TL = QDialog()
    self.ui_Tl = Ui_Trafficlightproperty()
    self.ui_Tl.setupUi(self.dialog_TL)
    self.to_check = [self.ui_Tl.tl_id_value, self.ui_Tl.tl_arduino_value]
    self.to_check_v_t = [self.ui_Tl.tl_vehicle_value, self.ui_Tl.tl_time_value]
    self.modify_TL = False

def connectSignalsSlots(self):
    self.add.clicked.connect(self.tl_prop)
    # self.delete_2.clicked.connect(self.delete_selected)
    # self.view.clicked.connect(self.view_selected)

def tl_prop(self):
    self.dialog_TL.show()
    self.ui_Tl.tl_confirm.clicked.connect(lambda: self.parse_data('North_South_List'))

def parse_data(self, name):
    #selected_index = getattr(self, name).selectedIndexes()
    self.dialog_TL.close()
    item = QListWidgetItem()
    item.setFlags(QtCore.Qt.ItemIsSelectable | QtCore.Qt.ItemIsUserCheckable | QtCore.Qt.ItemIsEnabled )
    item.setCheckState(QtCore.Qt.Unchecked)
    item.setText('TL - ' + str(self.ui_Tl.tl_id_value.text()))
    item.details = Virtual_TL_details()
    item.details.id = str(self.ui_Tl.tl_id_value.text())
    item.details.state = str(self.ui_Tl.tl_state_value.currentText())
    item.details.arduino_id = str(self.ui_Tl.tl_arduino_value.text())
    try:
        item.details.vehicle = str(self.ui_Tl.tl_vehicle_value.text())
        item.details.time = float(self.ui_Tl.tl_time_value.text())
        item.details.desired = str(self.ui_Tl.tl_desired_value.currentText())
    except Exception:
        pass
    if getattr(self, name.rsplit("_", 1)[0]).isChecked():
        getattr(self, name).addItem(item)
        getattr(self, name).clearSelection()

if name == "main":
app = QApplication(sys.argv)
win = Window()
win.show()
sys.exit(app.exec_())

JonB

@bidd said in How to avouid duplicate entries into QlistWidget when adding new item:

    self.dialog_TL.show()
    self.ui_Tl.tl_confirm.clicked.connect(lambda: self.parse_data('North_South_List'))

Here is my guess. tl_prop() is a slot, called each time add is clicked. It does not just show a dialog, it also seems to connect a button's clicked signal. If that is called multiple times there will be multiple connects on the button. So parse_data() will be called multiple times, and that does the item = QListWidgetItem().

Which is as I suggested might be the case originally. You should essentially only do object.signal.connect() once, at the time the object is created (or at the time the slot object is created, whichever is later). I think you can move it into your connectSignalsSlots().

Quite separately: You do not need the str() in all those str(....[current]text()) expressions. Qt C++'s QStrings will be converted to strs for you in Python.

bidd

@JonB

Thank you. your guidance helped have a closer look and redefine things. Cheers