.kv is loaded multiples times, you might have unwanted behaviors - kivy

Question

I can run my code but I'm having such unwanted behavior enter image description here, I combined my source code with the https://dev.to/ngonidzashe/how-to-create-a-simple-to-do-list-application-with-kivymd-d89 , and I guess I didn't combine it right here are my code:
import mysql.connector
from kivy.lang import Builder
from kivymd.uix.dialog import MDDialog
from kivymd.uix.button import MDFlatButton
from kivy.uix.screenmanager import ScreenManager
from kivymd.app import MDApp
from kivymd.uix.boxlayout import MDBoxLayout
from kivymd.uix.picker import MDDatePicker
from datetime import datetime
from kivymd.uix.list import TwoLineAvatarIconListItem, ILeftBodyTouch
from kivymd.uix.selectioncontrol import MDCheckbox
from database import Database
from kivy.core.window import Window
Window.size = (350, 600)
db = Database()
class MainApp(MDApp):
def build(self):
global screen_manager
screen_manager = ScreenManager()
screen_manager.add_widget(Builder.load_file("login.kv"))
screen_manager.add_widget(Builder.load_file("register.kv"))
screen_manager.add_widget(Builder.load_file("main.kv"))
return screen_manager
database = mysql.connector.connect(host='localhost',
database='loginform',
user='root',
password='****')
cursor = database.cursor()
def send_data(self, user, password):
self.cursor.execute(f"insert into example2 values('{user.text}','{password.text}')")
self.database.commit()
def receive_data(self, user, password):
self.cursor.execute("select * from example2")
user_list = []
for i in self.cursor.fetchall():
user_list.append(i[0])
if user.text in user_list and user.text != "":
self.cursor.execute(f"select password from example2 where user='{user.text}'")
for j in self.cursor:
if password.text == j[0]:
open_button = MDFlatButton(text='Open the App', on_release=self.open_app)
close_button = MDFlatButton(text='Close', on_release=self.close_dialg)
self.dialog = MDDialog(text='Welcome to the *****',
buttons=[close_button, open_button])
self.dialog.open()
else:
try_button = MDFlatButton(text='Try Again', on_release=self.close_dialg)
self.dialog = MDDialog(title='Incorrect Password',
text='You entered wrong password please try again',
buttons=[try_button])
self.dialog.open()
else:
open_regist = MDFlatButton(text="Register", on_release=self.open_regist)
close_button = MDFlatButton(text='Close', on_release=self.close_dialg)
self.dialog = MDDialog(title='Incorrect User',
text='There are no such user',
buttons=[close_button, open_regist])
self.dialog.open()
def open_regist(self, *args):
screen_manager.current = "register"
self.dialog.dismiss()
def close_dialg(self, *args):
self.dialog.dismiss()
def open_app(self, *args):
screen_manager.current = "tasks"
self.dialog.dismiss()
task_list_dialog = None # Here
# Add the below functions
def show_task_dialog(self):
if not self.task_list_dialog:
self.task_list_dialog = MDDialog(
title="Create Task",
type="custom",
content_cls=DialogContent(),
)
self.task_list_dialog.open()
def on_start(self):
"""Load the saved tasks and add them to the MDList widget when the application starts"""
try:
completed_tasks, uncomplete_tasks = db.get_tasks()
if uncomplete_tasks != []:
for task in uncomplete_tasks:
add_task = ListItemWithCheckbox(pk=task[0], text=task[1], secondary_text=task[2])
self.root.ids.container.add_widget(add_task)
if completed_tasks != []:
for task in completed_tasks:
add_task = ListItemWithCheckbox(pk=task[0], text='[s]' + task[1] + '[/s]',
secondary_text=task[2])
add_task.ids.check.active = True
self.root.ids.container.add_widget(add_task)
except Exception as e:
print(e)
pass
def close_dialog(self, *args):
self.task_list_dialog.dismiss()
def add_task(self, task, task_date):
"""Add task to the list of tasks"""
# Add task to the db
created_task = db.create_task(task.text, task_date) # Here
# return the created task details and create a list item
self.root.ids['container'].add_widget(
ListItemWithCheckbox(pk=created_task[0], text='[b]' + created_task[1] + '[/b]',
secondary_text=created_task[2])) # Here
task.text = ''
class DialogContent(MDBoxLayout):
"""OPENS A DIALOG BOX THAT GETS THE TASK FROM THE USER"""
def __init__(self, **kwargs):
super().__init__(**kwargs)
# set the date_text label to today's date when user first opens dialog box
self.ids.date_text.text = str(datetime.now().strftime('%A %d %B %Y'))
def show_date_picker(self):
"""Opens the date picker"""
date_dialog = MDDatePicker()
date_dialog.bind(on_save=self.on_save)
date_dialog.open()
def on_save(self, instance, value, date_range):
"""This functions gets the date from the date picker and converts its it a
more friendly form then changes the date label on the dialog to that"""
date = value.strftime('%A %d %B %Y')
self.ids.date_text.text = str(date)
# create the following two classes
class ListItemWithCheckbox(TwoLineAvatarIconListItem):
"""Custom list item"""
def __init__(self, pk=None, **kwargs):
super().__init__(**kwargs)
# state a pk which we shall use link the list items with the database primary keys
self.pk = pk
def mark(self, check, the_list_item):
"""mark the task as complete or incomplete"""
if check.active == True:
# add strikethrough to the text if the checkbox is active
the_list_item.text = '[s]' + the_list_item.text + '[/s]'
db.mark_task_as_complete(the_list_item.pk) # here
else:
the_list_item.text = str(db.mark_task_as_incomplete(the_list_item.pk)) # Here
def delete_item(self, the_list_item):
"""Delete the task"""
self.parent.remove_widget(the_list_item)
db.delete_task(the_list_item.pk) # Here
class LeftCheckbox(ILeftBodyTouch, MDCheckbox):
"""Custom left container"""
if __name__ == '__main__':
app = MainApp()
app.run()
and here is my kv file with this:
MDScreen:
name: "tasks"
MDFloatLayout:
MDLabel:
id: task_label
halign: 'center'
markup: True
text: "[u][size=48][b]TASKS[/b][/size][/u]"
pos_hint: {'y': .45}
ScrollView:
pos_hint: {'center_y': .5, 'center_x': .5}
size_hint: .9, .8
MDList:
id: container
MDFloatingActionButton:
icon: 'plus-thick'
on_release: app.show_task_dialog() #functionality to be added later
elevation_normal: 12
pos_hint: {'x': .8, 'y':.05}
<DialogContent>:
orientation: "vertical"
spacing: "10dp"
size_hint: 1, None
height: "130dp"
GridLayout:
rows: 1
MDTextField:
id: task_text
hint_text: "Add Task..."
pos_hint: {"center_y": .4}
max_text_length: 50
on_text_validate: (app.add_task(task_text, date_text.text), app.close_dialog())
MDIconButton:
icon: 'calendar'
on_release: root.show_date_picker()
padding: '10dp'
MDLabel:
spacing: '10dp'
id: date_text
BoxLayout:
orientation: 'horizontal'
MDRaisedButton:
text: "SAVE"
on_release: (app.add_task(task_text, date_text.text), app.close_dialog())
MDFlatButton:
text: 'CANCEL'
on_release: app.close_dialog()
<ListItemWithCheckbox>:
id: the_list_item
markup: True
LeftCheckbox:
id: check
on_release:
root.mark(check, the_list_item)
IconRightWidget:
icon: 'trash-can-outline'
theme_text_color: "Custom"
text_color: 1, 0, 0, 1
on_release:
root.delete_item(the_list_item)
I would be very thankful if someone can help or give some tips, how to improve. I'm open to have private conversation.

Answer 1

A kv file with the name main.kv will be loaded automatically by Kivy for your application (See documentation). So your code:
screen_manager.add_widget(Builder.load_file("main.kv"))
is loading main.kv a second time. The easiest fix is to just rename the main.kv file.