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How would I switch screens from a .py file while the screens are managed in a main .kv file?

I have three codes, I am confused with how I would navigate to the next screen in my Organize.kv from my login.py, I have the main kv file that has all the screens saved and the login python and kv file that manages the login screen, the login kv file balances two different tabs, so far I have the create tab that sends you to the create class of the login python file which is connected to mysql, how would I switch screens to the Main Menu which is in the main Organize.kv file from the login python file? Sorry if this doesn't make sense, I'm super warn out from trying to figure this out.
Anything helps, thank you
The main Organize.kv that has all the screens
#:import organize organize
#:import navigation_screen_manager navigation_screen_manager
#:import anchorlayout_with_action_bar anchorlayout_with_action_bar
#:import sharpen_skills sharpen_skills
#:import login login
<MainMenu#BoxLayout>:
orientation: "vertical"
padding: "40dp"
spacing: "20dp"
size_hint: .7, .9
pos_hint: {"center_x": .5}
Button:
text: "Organize"
on_press: app.manager.push("screen2")
Button:
text: "Journal"
on_press: app.manager.push("screen3")
Button:
text: "Sharpen Skills"
on_press: app.manager.push("SkillsExamplesTabs")
Button:
text: "Exit"
on_press: app.stop()
<MyScreenManager>:
Screen:
name: "Login"
title: "login"
LoginTabs:
Screen:
name: "MainMenu"
MainMenu:
Screen:
name: "screen2"
AnchorLayoutWithActionBar:
title: "Organize"
Screen:
name: "screen3"
AnchorLayoutWithActionBar:
title: "Journal"
Screen:
name: "SkillsExamplesTabs"
AnchorLayoutWithActionBar:
title: "Sharpen Skills"
SkillsExamplesTabs:
My login.kv file
<LoginTabs#TabbedPanel>:
do_default_tab: False
TabbedPanelItem:
text: "Create Account"
Create:
TabbedPanelItem:
text: "Login"
Login:
and finally my login.py file
from kivy.lang import Builder
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.screenmanager import ScreenManager
from kivy.uix.stacklayout import StackLayout
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.widget import Widget
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput
from kivy.uix.label import Label
from kivy.graphics import Color, Rectangle
import mysql.connector
import navigation_screen_manager
from kivy.uix.screenmanager import ScreenManager, Screen
from navigation_screen_manager import NavigationScreenManager
Builder.load_file("login.kv")
Builder.load_file("Organize.kv")
sm = ScreenManager()
class MyScreenManager(NavigationScreenManager):
pass
class Create(BoxLayout):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.orientation = "vertical"
self.build()
def build(self):
self.warning = Label(text="", pos_hint={'center_x': .5, 'center_y': .5})
user_label = Label(text="Username", size_hint=(.5, .5),
pos_hint={'center_x': .5, 'center_y': .5})
self.user_textinput = TextInput(text='Enter Username')
pas_label = Label(text="Password", size_hint=(.5, .5),
pos_hint={'center_x': .5, 'center_y': .5})
self.pas_textinput = TextInput(text="enter Password")
enter_button = Button(text="Create")
with user_label.canvas:
Color(0, .25, 1, .25)
enter_button.bind(on_press=self.Add)
self.add_widget(self.warning)
self.add_widget(user_label)
self.add_widget(self.user_textinput)
self.add_widget(pas_label)
self.add_widget(self.pas_textinput)
self.add_widget(enter_button)
def Add(self, btn):
print("Working")
t1 = self.user_textinput.text
t2 = self.pas_textinput.text
print(f"T1 = {t1} and {t2}")
conn = mysql.connector.connect(
user='root',
password='*******',
host='127.0.0.1',
database='Usersdb')
mycursor = conn.cursor()
try:
sql = "INSERT INTO user_info (user_name, user_pass) VALUES (%s, %s)"
val = (t1,t2)
mycursor.execute(sql,val)
conn.commit()
except:
self.warning = "Username Already Taken"
class Login(StackLayout):
pass
And finally my App class
from kivy.app import App
from kivy.uix.label import Label
from kivy.metrics import dp
from kivy.properties import StringProperty, BooleanProperty, ObjectProperty
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.gridlayout import GridLayout
from kivy.uix.popup import Popup
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.stacklayout import StackLayout
from kivy.uix.widget import Widget
from navigation_screen_manager import NavigationScreenManager
class MyScreenManager(NavigationScreenManager):
pass
class Organizer(App):
manager = ObjectProperty(None)
def build(self):
self.manager = MyScreenManager()
return self.manager
Organizer().run()
And my Navigation Screen Manager
from kivy.uix.screenmanager import ScreenManager
class NavigationScreenManager(ScreenManager):
screen_stack = []
def push(self, screen_name):
self.screen_stack.append(self.current)
self.transition.direction = "left"
self.current = screen_name
def pop(self):
if len(self.screen_stack) > 0:
screen_name = self.screen_stack[-1]
del self.screen_stack[-1]
self.transition.direction = "right"
self.current = screen_name

Good day. You must access your screen manager in order to set the current screen which is your active screen. In your App class, I recommend saving your screen manager as an attribute via the on_start function.
class MyApp(App):
def on_start(self):
screen_manager = self.root
From there, you could set your current screen using callback methods in kivy or python.
#in kv
on_release: setattr(app.screen_manager, 'current', 'the next screen name')
#in python
def set_screen_callback(self, instance *args):
app.screen_manager.current = "the next screen name"

Your post does not include your App class, so a specific answer is impossible. The fact that you have multiple kv files is irrelevant once those kv files are loaded. In general, you just set the current property of the ScreenManager to the name of the Screen that you want displayed.
Again, the fact that you have multiple kv files is irrelevant once those kv files are loaded. So in any of the kv files, I believe that you should be able to use:
app.manager.push("MainMenu")
or:
app.manager.current = "MainMenu"
to get to the MainMenu Screen.

kivymd Card scroll list items with the help of loop?

I am working on a mobile app and I want to create multiple of scoll items by using for loop but whenever I use for loop, gives me some error It has already parent widget. how can I make list of MDCard?
My App:
Click here
My Code:
from kivymd.app import MDApp
from kivy.lang import Builder
from kivy.core.window import Window
from kivy.uix.screenmanager import Screen, ScreenManager
from kivymd.uix.boxlayout import BoxLayout
from kivy.uix.image import AsyncImage
from kivymd.uix.card import MDCard
from kivymd.uix.label import MDLabel
Window.size = (450, 740)
kv = '''
ScreenManager:
Main:
<main>:
name: 'main'
video_list: video_list
BoxLayout:
orientation: 'vertical'
MDToolbar:
title: 'Video downloader'
ScrollView:
Screen:
id: video_list
'''
class Main(Screen):
pass
sm = ScreenManager()
sm.add_widget(Main(name='main'))
class Ytube(MDApp):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.theme_cls.colors = 'Red'
self.theme_cls.primary_palette = "Red"
self.root = Builder.load_string(kv)
image = AsyncImage(
source='https://static.hub.91mobiles.com/wp-content/uploads/2020/05/How-to-download-youtube-videos.jpg', size_hint=(1, .7), )
screen_id = self.root.get_screen('main').ids.video_list
for i in range(1):
card = MDCard(orientation='vertical', pos_hint={
'center_x': .5, 'center_y': .7}, size_hint=(.9, .4))
card.add_widget(image)
card.add_widget(MDLabel(
text='Phishing attacks are SCARY easy to do!! (let me show you!)', size_hint=(.6, .2), ))
screen_id.add_widget(card)
def build(self):
return self.root
if __name__ == "__main__":
Ytube().run()
Is there any way to make it
look like this.

The problem is that you are trying to use the same image widget for every MDCard. Any widget can only have one parent. You can only use that image widget once. You can fix that by moving the creation of the image widget inside the loop.
Also, a BoxLayout is a better choice for the child of a ScrollView, since it has a minimum_height property that you can use. Here is a modified version of your code that applies both those suggestions:
from kivymd.app import MDApp
from kivy.lang import Builder
from kivy.core.window import Window
from kivy.uix.screenmanager import Screen, ScreenManager
from kivy.uix.image import AsyncImage
from kivymd.uix.card import MDCard
from kivymd.uix.label import MDLabel
Window.size = (450, 740)
kv = '''
ScreenManager:
Main:
<main>:
name: 'main'
video_list: video_list
BoxLayout:
orientation: 'vertical'
MDToolbar:
title: 'Video downloader'
ScrollView:
do_scroll_x: False
BoxLayout:
id: video_list
orientation: 'vertical'
size_hint_y: None
height: self.minimum_height
'''
class Main(Screen):
pass
sm = ScreenManager()
sm.add_widget(Main(name='main'))
class Ytube(MDApp):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.theme_cls.colors = 'Red'
self.theme_cls.primary_palette = "Red"
self.root = Builder.load_string(kv)
screen_id = self.root.get_screen('main').ids.video_list
for i in range(5):
# Make a new image widget for each MDCard
image = AsyncImage(
source='https://static.hub.91mobiles.com/wp-content/uploads/2020/05/How-to-download-youtube-videos.jpg', size_hint=(1, .7), )
card = MDCard(orientation='vertical', pos_hint={
'center_x': .5, 'center_y': .7}, size_hint=(.9, None), height=200)
card.add_widget(image)
card.add_widget(MDLabel(
text='Phishing attacks are SCARY easy to do!! (let me show you!)', size_hint=(.6, .2), ))
screen_id.add_widget(card)
def build(self):
return self.root
if __name__ == "__main__":
Ytube().run()

Problem about kivy.uix.widget.WidgetException

I am new to python and kivymd and I am trying to develop a program for data entry. However, when I create a drop-down menu for a selection, an error occurred and I can't update the value of the text field after I select an item.
Here is the python code:
from kivymd.app import MDApp
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.properties import ObjectProperty
from kivy.lang import Builder
from kivy.clock import Clock
from kivy.properties import ObjectProperty
from kivymd.uix.menu import MDDropdownMenu
class AMRMenu(Screen):
def GIbutton(self):
sm.current = 'GI'
class GIWindow(Screen):
weather = ObjectProperty(None)
menu_weather_items = [{"text":"Sunny"},{"text":"Cloudy"},{"text":"Raining"}]
menu_FeedResponse_items=[{"text":"High"},{"text":"Medium"},{"text":"Low"}]
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.menu = MDDropdownMenu(
items=self.menu_weather_items,
width_mult=4,
caller = self.weather,
callback=self.set_item)
def set_item(self, instance):
def set_item(interval):
self.weather.text = instance.text
self.menu.dismiss()
Clock.schedule_once(set_item, 0.5)
class WindowManager(ScreenManager):
pass
sm = WindowManager()
class MainApp(MDApp):
def __init__(self, **kwargs):
super().__init__(**kwargs)
kv = Builder.load_file("FR.kv")
def build(self):
screens = [AMRMenu(name = "menu"), GIWindow(name = "GI")]
for screen in screens:
sm.add_widget(screen)
sm.current = "menu"
return sm
if __name__ == "__main__":
MainApp().run()
And here is the kv. file:
<AMRMenu>:
name:"menu"
BoxLayout:
orientation: "vertical"
MDToolbar:
title: "Main Menu"
MDList:
OneLineListItem:
text: "General Information"
on_press: root.GIbutton()
OneLineListItem:
text: "Water Temperature"
OneLineListItem
text: "Feeding Amount"
OneLineListItem:
text: "Residue and Feeding response"
OneLineListItem:
text: "Dead fish"
OneLineListItem:
text: "Sell/Use"
<GIWindow>
name: "GI"
weather: weather
ScrollView:
id: screen
MDBoxLayout:
orientation: 'vertical'
adaptive_height: True
MDTextField:
id: weather
pos_hint: {'center_x': .5, 'center_y': .5}
hint_text: "Weather"
icon_right: "arrow-down-drop-circle-outline"
input_filter: lambda text, from_undo: text[:5 - len(self.text)]
on_focus: root.menu.open()
Here is the error message:
File "/Library/Frameworks/Python.framework/Versions/3.7/lib/python3.7/site-packages/kivy/core/window/__init__.py", line 1297, in add_widget
(widget, widget.parent)
kivy.uix.widget.WidgetException: Cannot add <kivymd.uix.menu.MDDropdownMenu object at 0x7fd2fa31a6e0> to window, it already has a parent <kivy.core.window.window_sdl2.WindowSDL object at 0x7fd2f65826e0>
I don't know why I made this happen. It helps a lot if someone figures it out. Thank you for reading this question

The problem is that your kv line:
on_focus: root.menu.open()
is opening the menu every time the focus changes. So, it tries to open the menu even when the focus becomes false. An easy fix is to just open the menu when focus is True`:
on_focus: if self.focus: root.menu.open()

Kivy content sizes adjustment

I have been started to work in kivy recently. The thing what I am doing now is, i have a blank page with a button, when I click that button it navigates to an user input screen. It works fine, but the content comes in a very small input boxes and text as in the picture.
My question is that I want it bigger and centred.
Here is my code:
In python:
from kivy.app import App
from kivy.uix.label import Label
from kivy.uix.gridlayout import GridLayout
from kivy.uix.textinput import TextInput
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition
from kivy.uix.widget import Widget
from kivy.lang import Builder
class LoginScreen(GridLayout):
def __init__(self, **kwargs):
super(LoginScreen, self).__init__(**kwargs)
self.cols = 2
self.add_widget(Label(text="Username:"))
self.username = TextInput(multiline=False)
self.add_widget(self.username)
self.add_widget(Label(text="Password:"))
self.password = TextInput(multiline=False, password=True)
self.add_widget(self.password)
self.add_widget(Label(text="Two Factor Auth:"))
self.tfa = TextInput(multiline=False)
self.add_widget(self.tfa)
class MainScreen(Screen):
pass
class AnotherScreen(Screen):
pass
class ScreenManagement(ScreenManager):
pass
presentation = Builder.load_file("screen.kv")
class SimpleKivy(App):
def build(self):
return presentation
if __name__ == "__main__":
SimpleKivy().run()
In kv:
#: import FadeTransition kivy.uix.screenmanager.FadeTransition
ScreenManagement:
transition: FadeTransition()
MainScreen:
AnotherScreen:
<MainScreen>:
name: "main"
Button:
color: 0,1,0,1
font_size: 25
size_hint: 0.3,0.2
text: "Click"
on_release: app.root.current = "other"
pos_hint: {"right":1, "top":1}
<AnotherScreen>:
name: "other"
GridLayout:
LoginScreen

In your screen.kv, you have the LoginScreen inside a GridLayout. Since the LoginSCreen is a GridLayout, you do not need that extra GridLayout.
Just change:
<AnotherScreen>:
name: "other"
GridLayout:
LoginScreen
to:
<AnotherScreen>:
name: "other"
LoginScreen:

Scrollview to display different videos in kivy lags after a while

I'm a beginner in kivy and python. I've been trying to create a scrollview in a page that displays selected video on the screen. But after a while when i selected 5-6 videos to display even though i delete the video widget it starts to lag. And i'm open to any suggestions to better way to handle this kind of application.
from kivy.config import Config
Config.set('graphics', 'width', '1920')
Config.set('graphics', 'height', '1080')
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition
from kivy.uix.widget import Widget
from kivy.uix.image import Image
from kivy.properties import StringProperty
from kivy.uix.scrollview import ScrollView
from kivy.uix.label import Label
from kivy.clock import Clock
from kivy.uix.button import Button
import os
from kivy.uix.video import Video
from kivy.uix.videoplayer import VideoPlayer
from kivy.clock import mainthread
from functools import partial
from kivy.core.window import Window
Window.clearcolor = (0, 0, 0, 0)
isThereVideo=False
picture_path="/home/linux/kivyFiles/kivyLogin/assets"
video_path="/home/linux/kivyFiles/kivyLogin/videoAssets/"
class Image(Image):
pass
class MainScreen(Screen):
pass
class AnotherScreen(Screen):
pass
class Selfie(Screen):
pass
class RootWidget(Widget):
def __init__(self, **kwargs):
super(RootWidget, self).__init__(**kwargs)
Clock.schedule_once(self.createMultipleButton)
#mainthread
def createMultipleButton(self, dt):
self.root = Widget()
size_y=150;
size_x=150;
for i in range(1):
folderList = os.listdir(picture_path)
if len(folderList)==0:
time.sleep(1)
break
fileList = os.listdir(picture_path)
print fileList
for file in fileList:
x = (picture_path+"/"+file)
button = Button(id=str(file),text="" + str(file),size_hint=(None, None),height=size_y,width=size_x, pos_hint={'x': 0, 'y': 1},background_normal=x)
button.bind(on_release=partial(self.VideoContainer, file))
print file
self.scrollview.content_layout.add_widget(button)
print button.id
print("Parent of ScreenTwo: {}".format(self.parent))
#print(button.pos)
def VideoContainer(self,name,btn):
global isThereVideo
if isThereVideo==True:
#self.videocontainer.video_layout.unload()
self.videocontainer.clear_widgets()
mylist=name.split('.')
emailButton = Button(id='email')
video = Video(source="/home/linux/kivyFiles/kivyLogin/videoAssets/"+mylist[0]+".mp4", state='play',options={'eos': 'loop'})
video.size=(self.parent.width,self.parent.height)
video_pos=(self.parent.x,self.parent.y)
#video.pos_hint={'x': self.parent.width /2, 'y': self.parent.height/2}
video.play=True
#video.pos=(self.parent.width /2 , self.parent.height/2)
#self.videocontainer.video_layout.add_widget(emailButton)
self.videocontainer.add_widget(emailButton)
emailButton.add_widget(video)
isThereVideo=True
print("Parent of ScreenTwo: {}".format(self.parent))
return 0
class ScreenManagement(ScreenManager):
pass
class VideoContain(Widget):
pass
class ScrollableContainer(ScrollView):
pass
presentation = Builder.load_file("login.kv")
class MainApp(App):
def build(self):
return presentation
if __name__ == '__main__':
Window.fullscreen = True
app=MainApp()
app.run()
And my Kv file
ScreenManagement:
MainScreen:
Selfie:
<MainScreen>:
name: 'main'
Button:
on_release: app.root.current = 'selfie'
text: 'Another Screen'
font_size: 50
<Selfie>:
name: 'selfie'
Button:
on_release: app.root.current = 'login'
text: 'Selfie Screen'
font_size: 10
pos_hint: {"right": 1, 'top':1}
size_hint: (0.1, 0.1)
RootWidget:
<RootWidget>
size_hint: (0.1, None)
scrollview: scrollview
videocontainer:videocontainer
size:(self.parent.width, self.parent.height)
VideoContain:
id:videocontainer
##size:(self.parent.width, self.parent.height)
size:(root.width, root.height)
ScrollableContainer:
id: scrollview
size: root.size
pos: root.pos
<VideoContain>
video_layout:video_layout
FloatLayout:
cols:1
id: video_layout
<ScrollableContainer>:
scroll_timeout: 75
scroll_distance: 10
app: app
content_layout: content_layout
GridLayout:
id: content_layout
cols: 1
size_hint: (0.1, None)
pos: root.pos
height: self.minimum_height
padding: 25
spacing: 25
I posted all my code since i don't know which part may causing the problem i'm facing.

Solved it.
def VideoContainer(self,name,btn):
global isThereVideo
if isThereVideo:
# self.videocontainer.video_layout.unload()
self.videocontainer.clear_widgets()
In this part i'm clearing the widgets but i also need to unload the video somehow.
self.video.unload() solved my problem