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how insert loading animation during a function in python kivy?

I'm a beginner and would like to insert an MDSpinner while executing a loop, or a mysql query, or some process that takes time. I made this example below to illustrate my problem:
from kivy.lang import Builder
from kivymd.app import MDApp
from kivy.clock import Clock
import threading
KV = '''
MDScreen:
ScreenManager:
id: screen_manager
MDScreen:
name: 'a'
BoxLayout:
orientation: 'vertical'
MDLabel:
text: 'test - screen a'
pos_hint: {"center_x": .5, "center_y": .5}
Button:
id: btn
text: 'screen a'
size_hint: 0.5, 0.1
pos_hint: {"center_x": .5, "center_y": .5}
on_press:
load.active = True
app.aperta()
MDScreen:
name: 'b'
BoxLayout:
orientation: 'vertical'
MDLabel:
text: 'test - screen b'
pos_hint: {"center_x": .5}
Button:
id: btn2
text: 'screen b'
size_hint: 0.5, 0.5
pos_hint: {"center_x": .5, "center_y": .5}
MDSpinner:
id: load
active: False
size: dp(64), dp(64)
size_hint: None, None
pos_hint: {'center_x': 0.5, "center_y": .5}
'''
class Example(MDApp):
def build(self):
self.tela = Builder.load_string(KV)
return self.tela
def aperta(self):
threading.Thread(target=self.op_1).start()
def op_1(self, *args):
cont = 0
while cont < 1000000:
cont += 1
print(cont)
self.tela.ids.load.active = False
self.tela.ids.screen_manager.current = 'b'
Example().run()
however, when I change the screen, the following error appears and all the elements of the two screens overlap...
TypeError: Cannot change graphics instruction outside the main Kivy thread

You can also use the mainthread decorator, which is the equivalent to what #ApuCoder suggested:
class Example(MDApp):
def build(self):
self.tela = Builder.load_string(KV)
return self.tela
def aperta(self):
threading.Thread(target=self.op_1).start()
def op_1(self, *args):
cont = 0
while cont < 1000000:
cont += 1
print(cont)
self.go_to_b()
#mainthread
def go_to_b(self):
self.tela.ids.load.active = False
self.tela.ids.screen_manager.current = 'b'

Either the class "FourthWindow" doesn't show stacklayout or its the only thing on the screen

from kivy.app import App
from kivy.graphics import Line
from kivy.metrics import dp
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.dropdown import DropDown
from kivy.uix.relativelayout import RelativeLayout
from kivy.uix.screenmanager import ScreenManager, Screen
from kivy.uix.scrollview import ScrollView
from kivy.uix.stacklayout import StackLayout
from kivy.uix.widget import Widget
from kivy.lang import Builder
from kivymd.app import MDApp
class ScrollViewExample(ScrollView):
pass
class FirstWindow(Screen):
def set_text(self):
my_title_input = self.ids.note_title
my_details = self.ids.note_details
fo = open("notes.txt", "a")
fo.write('\n'+'\n'+my_title_input.text)
fo.write('\n'+my_details.text)
fo.close()
class SecondWindow(Screen):
pass
class ThirdWindow(Screen):
def on_toggle_button_state(self):
dark_mode = self.ids.dark_mode
dark_mode.text = 'Feature not available'
pass
class FourthWindow(Screen):
#This class displays notes from a file in buttons
#works but only the notes showup
def build(self):
root = FourthWindow()
root.add_widget(FourthWindow(name='StackLayout'))
class StackLayoutExample(StackLayout):
class ScrollView(ScrollView):
pass
def __init__(self, **kwargs):
super().__init__(**kwargs)
layout = StackLayout(orientation='lr-tb')
with open('notes.txt', 'r') as fp:
data = fp.read()
splat = data.split("\n\n")
notes = []
for i, note in enumerate(splat, 0):
notes.append(note)
for i in range(0, len(notes)):
b = Button(text=notes[i], size_hint=(.25, .4))
self.add_widget(b)
class WindowManager(ScreenManager):
pass
class RelativeLayoutExample(RelativeLayout):
pass
class ScreeManager(ScreenManager):
pass
class LineMaker(Widget):
pass
class Noteit(App):
pass
Noteit().run()
Noteit.kv <---The kv file begins here
WindowManager:
FirstWindow:
SecondWindow:
ThirdWindow:
FourthWindow:
<FirstWindow>:
id: first_window
name: "Notes"
RelativeLayout:
Label:
text: "Notes"
size_hint: None,None
pos_hint: {'top':1,'center_x':.5}
font_size: 35
Button:
text: 'Account'
size_hint: None,None
pos_hint: {'top':1,'right':1}
on_release:
app.root.current = "Account"
root.manager.transition.direction= "left"
Button:
text: 'Preferences'
size_hint: None,None
pos_hint: {'top':1,'left':1}
on_release:
app.root.current = "Preferences"
root.manager.transition.direction= "right"
Label:
text: "Title:"
size_hint: None,None
pos_hint: {'top':.85,'center_x':.5}
font_size: 20
TextInput:
id: note_title
size_hint: .45,.08
pos_hint: {'top':.75,'center_x':.5}
multiline: False
Label:
text: "Details:"
size_hint: None,None
pos_hint: {'top':.65,'center_x':.5}
font_size: 20
TextInput:
id: note_details
size_hint: .45,.3
pos_hint: {'top':.55,'center_x':.5}
multiline: True
Button:
text: "Submit"
size_hint: .25,.1
length: "100dp"
pos_hint: {'top':.25,'center_x':.5}
on_release:
root.set_text()
LineMaker:
canvas:
Color:
rgba: 1, 1, 1, 1
Line:
width: 2.
points: (self.width,self.height*.83,0,self.height*.83)
Button:
text: 'View All Notes'
size_hint:.25,.15
pos_hint: {'bottom':1,'center_x':.5}
on_release:
app.root.current = "View"
root.manager.transition.direction= "up"
<SecondWindow>:
name: "Account"
RelativeLayout:
Label:
text: "Account"
size_hint: None,None
pos_hint: {'top':1,'center_x':.5}
font_size: 35
Button:
text: 'Notes'
size_hint: None,None
pos_hint: {'top':1,'left':1}
on_release:
app.root.current = "Notes"
root.manager.transition.direction= "right"
Button:
text: 'Preferences'
size_hint: None,None
pos_hint: {'top':1,'right':1}
on_release:
app.root.current = "Preferences"
root.manager.transition.direction= "left"
Label:
text: "Username:"
size_hint: None,None
pos_hint: {'top':.85}
font_size: 20
TextInput:
size_hint: .5,.1
pos_hint: {'top':.55,'left':.3}
multiline: False
Label:
text: "Password:"
size_hint: None,None
pos_hint: {'top':.65}
font_size: 20
TextInput:
size_hint: .5,.1
pos_hint: {'top':.75,'left':.3}
multiline: False
Button:
text: "Log In"
size_hint: .25,.1
length: "100dp"
pos_hint: {'top':.45}
Button:
text: "Sign Up"
size_hint: .25,.1
length: "100dp"
pos_hint: {'top':.45,'center_x':.375}
LineMaker:
canvas:
Color:
rgba: 1, 1, 1, 1
Line:
width: 2.
points: (self.width,self.height*.83,0,self.height*.83)
<ThirdWindow>:
name: "Preferences"
RelativeLayout:
Label:
text: "Preferences"
size_hint: None,None
pos_hint: {'top':1,'center_x':.5}
font_size: 35
Button:
text: 'Notes'
size_hint: None,None
pos_hint: {'top':1,'right':1}
on_release:
app.root.current = "Notes"
root.manager.transition.direction= "left"
Button:
text: 'Account'
size_hint: None,None
pos_hint: {'top':1,'left':1}
on_release:
app.root.current = "Account"
root.manager.transition.direction= "right"
ToggleButton:
text: 'Dark Mode'
size_hint: .25,.1
pos_hint: {'top':.75,'center_x':.25}
on_state: root.on_toggle_button_state()
Label:
id: dark_mode
text: ''
LineMaker:
canvas:
Color:
rgba: 1, 1, 1, 1
Line:
width: 2.
points: (self.width,self.height*.83,0,self.height*.83)
<FourthWindow>:
name: "View"
RelativeLayout:
Button:
text: 'Note Submission'
size_hint:.25,.15
pos_hint: {'top':1,'center_x':.5}
on_release:
app.root.current = "Notes"
root.manager.transition.direction= "down"
Label:
text: 'All Notes'
size_hint: None,None
pos_hint: {'top':1,'right':.9}
font_size: 35
How do I make the stacklayout code showup with the kv file code? Or at least make the stacklayout part of the screen.
Right now the only option I have is either take the screen as output or the stack layout as output.
Replacing the def build(self) inside the class FourthWindow(Screen) will show the whole application. The code inside the def build(self) also works but they do not work together.
I am new to kivy and object oriented programming so I do not know much about this topic so I could be missing something really basic.

Programmable timer in Kivy and Python

I'm pretty new to Python and even more new to Kivy. My goal is to make a timer which I can set beforehand (which later shall control the GPIOs of my Raspberry, but that's another topic). I'm not really sure how I can do that. This ist my code so far:
Python Code: (Left away most imports for more cleanness)
import Global
Builder.load_file("screens.kv")
class ScreenOne(Screen):
pass
class ScreenTwo(Screen):
pass
class ScreenThree(Screen):
def pressPlus(self):
Global.DTIME = Global.DTIME + 0.5
self.ids.lbl1.text = str(Global.DTIME) + "h"
def pressMinus(self):
if Global.DTIME > 0:
Global.DTIME = Global.DTIME - 0.5
else:
pass
self.ids.lbl1.text = str(Global.DTIME) + "h"
def showTime(self):
self.ids.lbl1.text = str(Global.DTIME) + "h"
def printTime(self):
app = App.get_running_app()
print(app.TIME)
class Manager(ScreenManager):
screen_one = ObjectProperty(None)
screen_two = ObjectProperty(None)
screen_three = ObjectProperty(None)
class Trockner(App):
def build(self):
m = Manager(transition=WipeTransition())
return m
def furz(self, *args):
print("Fuuuuurz")
Trockner().run()
.kv File:
<ScreenOne>:
Button:
text: "Manuell"
on_press:
root.manager.current = 'screen2'
app.furz()
size_hint: 0.15, 0.15
pos_hint: {'center_x': 0.075, 'center_y': 0.9225}
Button:
text: "Zeiteingabe"
on_press:
root.manager.current = 'screen3'
size_hint: 0.15, 0.15
pos_hint: {'center_x': 0.25, 'center_y': 0.9225}
Label:
#text: "Eingestellte Zeit: "
id: lbl1
size_hint: 0.15, 0.15
pos_hint: {'center_x': 0.5, 'center_y': 0.9225}
<ScreenTwo>:
Button:
text: "Automatik"
on_press: root.manager.current = 'screen1'
size: 100, 100
size_hint: None, None
pos_hint: {'center_x': 0.075, 'center_y': 0.9}
<ScreenThree>:
FloatLayout:
Label:
id: lbl1
size_hint:[.5,.5]
pos_hint: {'right':1, 'top':1}
font_size: 100
Button:
text: "+"
size_hint:[.5,.5]
on_press:
root.pressPlus()
Button:
text: "-"
size_hint:[.5,.5]
pos_hint: {'right': 1}
on_press:
root.pressMinus()
Button:
text: "Enter"
size_hint:[.5,.5]
pos_hint: {'top':1, 'left':1}
on_press:
root.manager.current = 'screen1'
<Manager>:
id: screen_manager
screen_one: screen_one
screen_two: screen_two
screen_three: screen_three
ScreenOne:
id: screen_one
name: 'screen1'
manager: screen_manager
ScreenTwo:
id: screen_two
name: 'screen2'
manager: screen_manager
ScreenThree:
id: screen_three
name: 'screen3'
manager: screen_manager
Right now, the Global.py which I'm importing is only holding the DTIME variable, so I can access it from Python and Kivy.
Plan is, that on Screen Three I can set a time which is then used on screen one again to start my countdown timer from set time. I also have to have access to the set time from my python code to switch the GPIOs after said time. The timer progress should also be visible on screen one then, which probably works with Kivy clock and animation. But I'm not really sure about that either, so help would be very much appreciated!

How to get user input from an MDTextField in KivyMD

Please I keep getting an attribute error when I try to get the text a user input into an MDTextField, tried everything I could think of, researched and couldn't get anything. Please I need your help.
I try to get the text with this argument of self.root.ids.MyId.text
This is the error I get:
File "C:/Users/user/Documents/KmD/Webma/main_webma.py", line 120, in login
email_addr = self.root.ids.email.text
File "kivy\properties.pyx", line 864, in kivy.properties.ObservableDict.__getattr__
AttributeError: 'super' object has no attribute '__getattr__'
And this is my main.py code
from kivymd.app import MDApp
from kivy.clock import Clock
from kivy.lang import Builder
from home_page_strings import toolbar
import sqlite3
from kivy.uix.screenmanager import Screen, ScreenManager
from kivymd.uix.picker import MDThemePicker
from kivy.uix.popup import Popup
from kivymd.uix.textfield import MDTextField
# calling of screen classes and addition to the screen_manager
class Friend1(Screen):
pass
class WelcomeScreen(Screen):
def __init__(self, **kwargs):
super(WelcomeScreen, self).__init__(**kwargs)
Clock.schedule_once(self.callNext, 5)
def callNext(self, dt):
self.manager.current = 'account'
class AccountScreen(Screen):
pass
class HomeScreen(Screen):
pass
class RoomScreen(Screen):
pass
class ContactsScreen(Screen):
pass
class CallsScreen(Screen):
pass
class SettingsScreen(Screen):
pass
class FaqScreen(Screen):
pass
class InviteScreen(Screen):
pass
manager = ScreenManager()
manager.add_widget(Friend1(name='friend1'))
manager.add_widget(HomeScreen(name='home'))
manager.add_widget(WelcomeScreen(name='welcome'))
manager.add_widget(RoomScreen(name='room'))
manager.add_widget(ContactsScreen(name='contacts'))
manager.add_widget(CallsScreen(name='calls'))
manager.add_widget(SettingsScreen(name='settings'))
manager.add_widget(FaqScreen(name='faq'))
manager.add_widget(InviteScreen(name='invite'))
manager.add_widget(AccountScreen(name='account'))
# end of call of screen classes and addition to screenmanager
class EMC_WebmaApp(MDApp):
def __init__(self, **kwargs):
super().__init__(**kwargs)
# -------------------------- CODE FOR THE DATABASE ---------------------------------- #
conn = sqlite3.connect('webma_database.db')
cursor = conn.cursor()
# cursor.execute('''CREATE TABLE users (
# email text,
# password integer
# )''')
def sign_up(self, cursor):
cursor.execute('INSERT INTO users VALUES('', '')')
conn.commit()
conn.close()
# -------------------------- END OF CODE FOR THE DATABASE ---------------------------------- #
# BUILDER FUNCTION AND SCREEN
def build(self):
screen = Screen()
# theme settings
self.theme_cls.primary_palette = 'DeepPurple'
self.theme_cls.theme_style = 'Dark'
# end of theme declaration
# loaded strings
navigation_bar = Builder.load_string(toolbar)
# end of loaded strings
# addition of loaded strings to screen + return screen
screen.add_widget(navigation_bar)
return screen
# end of addition
# END OF BUILDER FUNCTION
# USER VALIDATION FUNCTION
def login(self):
email_addr = self.root.ids.email.text
if email_addr == str(''):
print('Invalid Email Address')
# END OF USER VALIDATION
def change(self, dt):
self.root.manager.current = 'home'
# App theme manager
def change_theme(self):
picker = MDThemePicker()
picker.open()
# End of app theme manager
# home page search bar
def search_bar(self, dt):
searchbar = Popup(
title='Search',
content=MDTextField(
helper_text='Input values to be searched for',
helper_text_mode='on_focus'
),
auto_dismiss=True,
# size_hint=(None, None),
# size=(400, 98)
size_hint=(0.7, 0.17),
pos_hint={'center_x': 0.5, 'center_y': 0.8}
)
searchbar.open()
# APP RUN
if __name__ == '__main__':
EMC_WebmaApp().run()
# WELL... THIS IS THE END OF EVERYTHING
Then my string code where I try to get my text from
toolbar = '''
ScreenManager:
WelcomeScreen:
HomeScreen:
RoomScreen:
ContactsScreen
CallsScreen:
SettingsScreen:
FaqScreen:
InviteScreen:
AccountScreen:
Friend1:
<WelcomeScreen>:
name: 'welcome'
Image:
source: 'logo.png'
size_hint: 0.4, 0.4
pos_hint: {'center_x': 0.5, 'center_y':0.6}
MDLabel:
text: 'Webma'
halign: 'center'
font_style: 'H3'
color: (1, 1, 1, 1)
pos_hint: {'center_x': 0.5, 'center_y':0.8}
MDLabel:
text: 'Powered by emc_codes'
halign: 'center'
bold: 'True'
italic: True
pos_hint: {'center_x': 0.5, 'center_y':0.1}
<HomeScreen>:
name: 'home'
NavigationLayout:
ScreenManager:
Screen:
BoxLayout:
orientation: 'vertical'
spacing: '8dp'
MDToolbar:
title: 'EMC_Webma'
left_action_items: [['menu', lambda x: navigation.set_state('open')]]
right_action_items: [['card-search', app.search_bar]]
elevation: 10
ScrollView:
MDList:
TwoLineAvatarIconListItem:
text: 'Friend 1'
ImageLeftWidget:
source: 'einstein.jpg'
IconRightWidget:
icon: 'dots-vertical'
MDNavigationDrawer:
id: navigation
BoxLayout:
orientation: 'vertical'
spacing: '8dp'
padding: '8dp'
Image:
source: 'einstein.jpg'
MDLabel:
text: 'Enwerem Melvin Confidence'
font_style: 'Subtitle2'
size_hint_y: None
height: self.texture_size[1]
MDLabel:
text: 'enweremmelvinconfidence#gmail.com'
font_style: 'Caption'
size_hint_y: None
height: self.texture_size[1]
ScrollView:
MDList:
OneLineIconListItem:
text: 'Room'
on_release: root.manager.current = 'room'
IconLeftWidget:
icon: 'theater'
on_release: root.manager.current = 'room'
OneLineIconListItem:
text: 'Contacts'
on_release: root.manager.current = 'contacts'
IconLeftWidget:
icon: 'contacts'
on_release: root.manager.current = 'contacts'
OneLineIconListItem:
text: 'Calls'
on_release: root.manager.current = 'calls'
IconLeftWidget:
icon: 'cellphone-android'
on_release: root.manager.current = 'calls'
OneLineIconListItem:
text: 'Settings'
on_release: root.manager.current = 'settings'
IconLeftWidget:
icon: 'settings'
on_release: root.manager.current = 'settings'
OneLineIconListItem:
text: 'FAQ'
on_release: root.manager.current = 'faq'
IconLeftWidget:
icon: 'frequently-asked-questions'
on_release: root.manager.current = 'faq'
OneLineIconListItem:
text: 'Invite Friends'
on_release: root.manager.current = 'invite'
IconLeftWidget:
icon: 'account-plus'
on_release: root.manager.current = 'invite'
OneLineIconListItem:
text: 'Theme Manager'
on_release:
app.change_theme()
IconLeftWidget:
icon: 'theme-light-dark'
<RoomScreen>:
name: 'room'
MDLabel:
text: 'Welcome to the Room Screen'
halign: 'center'
bold: True
font_size: 50
MDIconButton:
icon: 'keyboard-backspace'
pos_hint: {'center_x': 0.06, 'center_y': 0.96}
on_release: root.manager.current = 'home'
size_hint: None, None
<ContactsScreen>:
name: 'contacts'
MDLabel:
text: 'Welcome to the Contacts Screen'
halign: 'center'
bold: True
font_size: 50
MDIconButton:
icon: 'keyboard-backspace'
pos_hint: {'center_x': 0.06, 'center_y': 0.96}
on_release: root.manager.current = 'home'
size_hint: None, None
<CallsScreen>:
name: 'calls'
MDLabel:
text: 'Welcome to the Calls Screen'
halign: 'center'
bold: True
font_size: 50
MDIconButton:
icon: 'keyboard-backspace'
pos_hint: {'center_x': 0.06, 'center_y': 0.96}
on_release: root.manager.current = 'home'
size_hint: None, None
<SettingsScreen>:
name: 'settings'
MDLabel:
text: 'Welcome to the Settings Screen'
halign: 'center'
bold: True
font_size: 50
MDIconButton:
icon: 'keyboard-backspace'
pos_hint: {'center_x': 0.06, 'center_y': 0.96}
on_release: root.manager.current = 'home'
size_hint: None, None
<FaqScreen>:
name: 'faq'
MDLabel:
text: 'Welcome to the Faq Screen'
halign: 'center'
bold: True
font_size: 50
MDIconButton:
icon: 'keyboard-backspace'
pos_hint: {'center_x': 0.06, 'center_y': 0.96}
on_release: root.manager.current = 'home'
size_hint: None, None
<InviteScreen>:
name: 'invite'
MDLabel:
text: 'Welcome to the Invite Screen'
halign: 'center'
bold: True
font_size: 50
MDIconButton:
icon: 'keyboard-backspace'
pos_hint: {'center_x': 0.06, 'center_y': 0.96}
on_release: root.manager.current = 'home'
size_hint: None, None
<AccountScreen>:
name: 'account'
BoxLayout:
MDLabel:
text: 'Account Login'
pos_hint: {'center_x': 0.6, 'center_y': 0.9}
color: (1, 1, 1, 1)
font_size: 40
MDTextFieldRound:
id: email
hint_text: 'Email Address'
icon_right: 'email'
icon_right_color: app.theme_cls.primary_color
pos_hint: {'center_x': 0.5, 'center_y': 0.7}
size_hint_x: None
width: 300
MDTextFieldRound:
id: password
hint_text: 'Enter Password'
icon_right: 'lock'
icon_right_color: app.theme_cls.primary_color
password: True
pos_hint: {'center_x': 0.5, 'center_y': 0.5}
size_hint_x: None
width: 300
MDRaisedButton:
text: 'Login'
md_bg_color: app.theme_cls.primary_color
pos_hint: {'center_x': 0.5, 'center_y': 0.2}
on_release: app.login() # root.manager.current = 'home'
<Friend1>
name: 'friend1'
BoxLayout:
orientation: 'vertical'
MDToolbar:
title: 'Friend 1'
left_action_items: [['keyboard-backspace', app.change]]
right_action_items: [['phone', lambda x: print('go ahead and make a call')], ['video', lambda x: print('Video')], ['dots-vertical', lambda x: print('dots')]]
MDLabel:
text: 'This is a test screen for our Chat'
halign: 'center'
'''
Please guys I really appreciate the help. Thanks in advance...

The email id only appears in the ids for the AccountScreen. Any id appearing in a kv gets inserted into the ids of the widget that is the root of the rule that contains the id. So, you must access the AccountScreen instance to get to the email id:
# BUILDER FUNCTION AND SCREEN
def build(self):
screen = Screen()
# theme settings
self.theme_cls.primary_palette = 'DeepPurple'
self.theme_cls.theme_style = 'Dark'
# end of theme declaration
# loaded strings
self.navigation_bar = Builder.load_string(toolbar) # save a reference to the loaded ScreenManager
# end of loaded strings
# addition of loaded strings to screen + return screen
screen.add_widget(self.navigation_bar)
return screen
# end of addition
# END OF BUILDER FUNCTION
# USER VALIDATION FUNCTION
def login(self):
# use the saved reference to access the email address
email_addr = self.navigation_bar.get_screen('account').ids.email.text
if email_addr == str(''):
print('Invalid Email Address')
# END OF USER VALIDATION

value = self.root.get_screen('nameofscreen').ids.username.text
print("What you typed is: ", value)
syntax = self.root.get_screen('name').ids.id.text

KivyMD App ScrollView exceeding the boundaries

I have a kivy app I built, that receives a message from a server, saves it into a text file, and displays the text file onto the screen. However, the text always exceeds the ScrollView widget and goes onto some other widgets like the picture below.
Is there any ways to solve this? Any help will be appreciated. Thank You.
This is my code:
#Todo: fix line 334 AttributeError
#Remove the upload button also
#Error Fixed
#Todo: fix message received exceeds border error
from kivy.app import App
from kivy.lang import Builder
from kivy.properties import ObjectProperty, StringProperty
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.image import Image
from kivymd.dialog import MDDialog
from kivymd.theming import ThemeManager
from kivymd.navigationdrawer import NavigationLayout
from kivymd.list import OneLineAvatarListItem, ILeftBody
from kivymd.toast import toast
from kivymd.dialog import MDDialog
from kivy.uix.popup import Popup
from threading import Thread
import socket
sock = socket.socket()
sock.connect(('127.0.0.1', 6818))
sock.sendall(b"add_contact hello llo")
sock = socket.socket()
sock.connect(('127.0.0.1', 6818))
sock.sendall(b'new llo')
class MyLayout(BoxLayout):
scr_mngr = ObjectProperty(None)
def check_data_login(self):
username = self.scr_mngr.screen1.username.text
password = self.scr_mngr.screen1.password.text
print(username)
print(password)
if username == "KivyMD" and password == "kivy":
self.ids["wrongpass"].text = ""
self.change_screen("screen2")
else:
self.ids["wrongpass"].text = "Wrong username or password, please try again"
def change_screen(self, screen, *args):
self.scr_mngr.transition.direction = 'left'
self.scr_mngr.current = screen
def back_to_chat(self):
self.scr_mngr.transition.direction = 'right'
self.scr_mngr.current = 'screen2'
class nav_layout(NavigationLayout):
def print_text(self):
print('hello')
def check_data_login(self):
username = self.ids.screen1.username.text
password = self.ids.screen1.password.text
print(username)
print(password)
if username == "KivyMD" and password == "kivy":
Thread(target=self.recover_data).start()
self.change_screen("screen2")
self.ids.wrongpass.text = ""
else:
self.ids.wrongpass.text = \
"Wrong username or password, please try again"
def recover_data(self):
print('started')
while True:
data = sock.recv(1024)
data = data.decode()
if data:
print(data)
data = data.split()
data = data[-1] + ": " + ' '.join(data[:-1])
r = data + '\n'
open('chat1.txt', 'a+').write(r)#Fix The the Attribute Error that occurs when a message is sent!!!!!
e = open('chat1.txt', 'r').readlines()
self.ids.Chat_String.text = '\n\r'.join(e)
print(data)
def change_screen(self, screen, *args):
self.ids.scr_mngr.transition.direction = 'left'
self.ids.scr_mngr.current = screen
def back_to_chat(self):
self.ids.scr_mngr.transition.direction = 'right'
self.ids.scr_mngr.current = 'screen2'
def logout(self):
# logout function, returns to screen 1
self.ids.scr_mngr.current = 'screen1'
class UploadPopup(Popup):
def load(self, path, selection):
print(path, selection)
KV = """
#:import Toolbar kivymd.toolbar.Toolbar
#:import MDNavigationDrawer kivymd.navigationdrawer.MDNavigationDrawer
#:import NavigationLayout kivymd.navigationdrawer.NavigationLayout
#:import NavigationDrawerDivider kivymd.navigationdrawer.NavigationDrawerDivider
#:import NavigationDrawerToolbar kivymd.navigationdrawer.NavigationDrawerToolbar
#:import MDTextField kivymd.textfields.MDTextField
#:import MDSeparator kivymd.card.MDSeparator
#:import MDThemePicker kivymd.theme_picker.MDThemePicker
#:import CardTransition kivy.uix.screenmanager.CardTransition
#:import Factory kivy.factory.Factory
<MDCustomIconItem>:
text: root.text
AvatarSampleWidget:
source: root.icon
<UploadPopup>:
id: popup
title: "Upload"
BoxLayout:
FileChooserIconView:
id: FileChoose
pos_hint_x: 0.5
pos_hint_y: 0.5
on_selection: root.load(FileChoose.path, FileChoose.selection)
MDRaisedButton:
text: "Upload"
text_color: (0,0,0,1)
on_release: root.load(FileChoose.path, FileChoose.selection)
on_release: popup.dismiss()
MDRaisedButton:
text: "Close"
text_color: (0,0,0,1)
on_release: popup.dismiss()
nav_layout:
id: nav_layout
MDNavigationDrawer:
id: nav_drawer
drawer_logo: 'logo.png'
NavigationDrawerToolbar:
title: 'hello'
NavigationDrawerIconButton:
icon: 'settings'
text: 'Account Settings'
on_release: root.change_screen('screen3')
NavigationDrawerIconButton:
icon: 'face'
text: 'Friends'
on_release: root.print_text()
NavigationDrawerIconButton:
icon: 'logout'
text: 'Logout'
on_release: root.logout()
NavigationDrawerDivider:
height: dp(1)
MyLayout:
scr_mngr: scr_mngr
orientation: 'vertical'
ScreenManager:
transition: CardTransition()
id: scr_mngr
screen1: screen1
Screen:
id: screen1
name: 'screen1'
username: username
password: password
BoxLayout:
size_hint: None, None
size: dp(520), dp(340)
pos_hint: {'center_x': 0.5, 'center_y': 0.5}
BoxLayout:
orientation:'vertical'
padding: dp(20)
spacing:20
MDLabel:
text: 'Chat App'
theme_text_color: 'Secondary'
font_style:"Title"
size_hint_y: None
height: dp(36)
MDSeparator:
height: dp(1)
MDTextField:
id: username
hint_text: "Username "
size_hint_y: 0.9
helper_text_mode: "on_focus"
MDTextField:
id: password
hint_text: "Password "
helper_text_mode: "on_focus"
size_hint_y: 0.9
password: True
MDFlatButton:
text: "Login"
pos_hint: {'center_x': 0.5}
on_release: root.check_data_login()
MDLabel:
id: wrongpass
color: 1,0,1,1
text: ""
Screen:
name: 'screen2'
id: screen2
Toolbar:
id: toolbar
title: "Welcome ! "
pos_hint: {'center_x': 0.5, 'center_y': 0.96}
md_bg_color: app.theme_cls.primary_color
background_palette: 'DeepPurple'
background_hue: 'A400'
left_action_items: [['menu', lambda x: app.root.toggle_nav_drawer() ]]
right_action_items: [['animation', lambda x: MDThemePicker().open()], ['camera', lambda x: print('hello')]]
MDLabel:
id: data
font_style: 'Title'
theme_text_color: 'Primary'
text: "Data :"
height: self.texture_size[1] + dp(3)
halign: 'center'
pos_hint: {'center_x': 0.5, 'center_y': 0.5}
Screen:
name: 'screen3'
id: screen3
Toolbar:
id: tools
title: "Your Profile"
pos_hint: {'center_x': 0.5, 'center_y': 0.96}
md_bg_color: app.theme_cls.primary_color
background_palette: 'DeepPurple'
background_hue: 'A400'
left_action_items: [['arrow-left', lambda x: root.back_to_chat()]]
MDLabel:
id: Profile_String
font_size: 90
text: "XXX"
halign: 'center'
pos_hint: {'center_x': 0.5, 'center_y': 0.85}
Screen:
name: 'screen4'
id: screen4
Toolbar:
id: tools
title: "XXX"
pos_hint: {'center_x': 0.5, 'center_y': 0.96}
md_bg_color: app.theme_cls.primary_color
background_palette: 'DeepPurple'
background_hue: 'A400'
left_action_items: [['menu', lambda x: app.root.toggle_nav_drawer() ]]
right_action_items: [['animation', lambda x: MDThemePicker().open()], ['camera', lambda x: print('hello')]]
ScrollView:
pos_hint: {'center_x': .55, 'y': .35}
MDLabel:
size_hint: 1, None
id: Chat_String
font_size: 40
text: "XXX"
MDTextField:
id: Input_String
hint_text: 'Enter Your Message...'
helper_text_mode: 'on_focus'
pos_hint: {'center_x': 0.35, 'center_y': 0.2}
size_hint_x: 0.6
multiline: True
MDRaisedButton:
id: Send_Button
text: 'Send'
pos_hint: {'center_x': 0.75, 'center_y': 0.2}
MDRaisedButton:
id: Choose_Image
text: 'Attach File'
pos_hint: {'center_x': 0.9, 'center_y': 0.2}
on_release: Factory.UploadPopup().open()
"""
class MDCustomIconItem(OneLineAvatarListItem):
icon = StringProperty('')
text = StringProperty()
def _set_active(self, active, list):
pass
class AvatarSampleWidget(ILeftBody, Image):
pass
class MyApp(App):
theme_cls = ThemeManager()
theme_cls.primary_palette = 'Blue'
title = "Navigation Drawer"
main_widget = None
def __getattr__(self, attr):
return super().__getattr__(attr)
def build(self):
self.main_widget = Builder.load_string(KV)
return self.main_widget
def callback(self, instance, value):
self.main_widget.ids.scr_mngr.current = 'screen4'
def on_start(self):
for i in range(15):
self.main_widget.ids.nav_drawer.add_widget(
MDCustomIconItem(
text="Item menu %d" % i,
icon='logo.png',
on_release=lambda x, y=i: self.callback(x, y)))
MyApp().run()

You need to set the size of the ScrollView. Add size_hint: (0.85, 0.55)
Snippets
ScrollView:
size_hint: (0.85, 0.55)
pos_hint: {'center_x': .55, 'y': .35}
MDLabel:
id: Chat_String
font_size: 40
Output