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python kivy app stops functioning after adding widget (on PC)

I removed everything superfluous, leaving only what was necessary to reproduce the same behavior.
There is an MD Text Field in which, when entering text, if there are matches, MDDropdownMenu appears with options to choose from. The options are stored in the P_LIST list. If you don't enter text into this Mytextfield, everything works. As soon as you enter the text, the function is triggered, a menu appears, you select. After that, the application does not function.
I determined that this is happening because of the line: self.add_widget(list drop down) # <----------- marked in the code
The menu appears without add_widget, but if you enter more than one letter, a new instance of the ListDropdownValue class is created each time and the menus overlap.
#kivymd 0.104.2
#kivy 2.0.0
from kivy.clock import Clock
from kivy.lang import Builder
from kivy.metrics import dp
from kivy.properties import ObjectProperty
from kivymd.app import MDApp
from kivy.uix.boxlayout import BoxLayout
from kivymd.uix.menu import MDDropdownMenu
kv_str = """
<StartScreen>:
startscreen_textfield_1: textfield_id
BoxLayout:
orientation: "vertical"
BoxLayout:
size_hint: 1, 0.5
BoxLayout:
size_hint: 1, 0.5
orientation: "vertical"
BoxLayout:
MDTextField:
id: textfield_id
on_text:
root.open_listdropdown(textfield_id)#
BoxLayout:
MDTextField:
BoxLayout:
MDTextField:
"""
P_LIST = ["ASD", "SDF", "AASD"]
def search_product(prefix):
filtered_list = []
filtered_list = list(filter(lambda l: l.startswith(prefix), P_LIST))
return filtered_list
class MyListDropdownValue(MDDropdownMenu):
def __init__(self, dropdown_list, **kwargs):
super().__init__(**kwargs)
self.dropdown_list_id = dropdown_list
def list_dropdown(self):
if len(self.dropdown_list_id.text) != 0:
prefix = self.dropdown_list_id.text.upper()
filtered_list = search_product(prefix)
menu_items = [{'text':f'{value}',
"height": dp(56),
"viewclass": "OneLineListItem",
"on_release": lambda x= f"{value}": self.set_item(x)}
for value in filtered_list]
self.menu = MDDropdownMenu(
caller=self.dropdown_list_id,
items=menu_items,
width_mult=5,
)
self.menu.open()
def set_item(self, value):
def set_item(interval):
self.dropdown_list_id.text = value
self.menu.dismiss()
Clock.schedule_once(set_item, 0.1)
class StartScreen(BoxLayout):
startscreen_textfield_1 = ObjectProperty()
def open_listdropdown(self, id):
if len(self.children) == 1:
listdropdown = MyListDropdownProduct(id)
self.add_widget(listdropdown)
self.children[0].list_dropdown()
else:
self.children[0].menu.dismiss()
self.children[0].list_dropdown()
kv = Builder.load_string(kv_str)
class Program(MDApp):
def build(self):
self.screen = StartScreen()
return self.screen
def main():
app = Program()
app.run()
if __name__ == "__main__":
main()

Your MyListDropdownValue(MDDropdownMenu) class inherits from a MDDropdownMenu.
Then you make dropdown instance with
openlistdrop_down = MyDropdownValue(id)
Then you add that instance every time you "on_text" with
self.add_widget(listdropdown)
So you are adding multiple dropdowns.
In Kv try changing
on_text:
root.open_listdropdown(textfield_id)
To
on_validate:
root.open_listdropdown(textfield_id)
Then the user will need to hit enter before the list is made instead of with every letter added.

how to print the text inputs from the loop in kivy

i want to print all user text inputs when i press the button. the problem when i press the button to print the inputs appear the error TypeError: p() takes 1 positional argument but 2 were given. just to know the number to text inputs may vary from user to other
from kivy.uix.textinput import TextInput
from kivy.app import App
from kivy.uix.button import Button
from kivy.lang.builder import Builder
kv=Builder.load_string('''
ScrollView:
GridLayout:
id:inputs
cols:1
row_force_default:True
row_default_height:30
size_hint_y:None
height:self.minimum_height
''')
class Accounting(App):
def build(self):return kv
def on_start(self):
self.return_list = [] #print this list
w = Button(text='print all the text inputs',on_press=self.p)
self.return_list.append(w)
self.root.ids.inputs.add_widget(w)
for i in range(5):
w = TextInput()
self.return_list.append(w)
self.root.ids.inputs.add_widget(w)
return self.return_list
def p(self):print(self.return_list)#here
Accounting().run()

When you click button then Kivy runs it with extra argument p(widget) so you can assign function to many buttons and you will see which button was clicked.
But it means you have to get this value in function
def p(self, widget):
Minimal working code.
If you want text only from TextInput then removed Button from return_list.
from kivy.uix.textinput import TextInput
from kivy.app import App
from kivy.uix.button import Button
from kivy.lang.builder import Builder
kv = Builder.load_string('''
ScrollView:
GridLayout:
id:inputs
cols:1
row_force_default:True
row_default_height:30
size_hint_y:None
height:self.minimum_height
''')
class Accounting(App):
def build(self):
return kv
def on_start(self):
self.return_list = [] #print this list
w = Button(text='print all the text inputs', on_press=self.p)
self.return_list.append(w)
self.root.ids.inputs.add_widget(w)
for i in range(5):
w = TextInput()
self.return_list.append(w)
self.root.ids.inputs.add_widget(w)
return self.return_list
def p(self, widget):
print('widget:', widget)
print('text :', widget.text)
for item in self.return_list:
print(item.text)
Accounting().run()

Kivy change label text [duplicate]

This question already has answers here:
What is the purpose of the `self` parameter? Why is it needed?
(26 answers)
Closed 3 years ago.
I would like to change a Label-text in Python/Kivy after a swipe event has been detected. Changing the text works basically via the following line
self.Translation.text = "test"
but I have to change the text after detecting a swipe event from another class, in which I call a function to change the label text:
MyWidget.ThisDoesntWork("self_dummy")
In this function the exact same line as above gives me an error.
How can I change the Label-text from class "Swiping_class" calling function "MyWidget.ThisDoesntWork("self_dummy")"?
from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.anchorlayout import AnchorLayout
from kivy.uix.button import Button
from kivy.uix.label import Label
from kivy.uix.textinput import TextInput
from kivy.base import EventLoop
from kivy.clock import Clock
from kivy.factory import Factory
from kivy.uix.stacklayout import StackLayout
from kivy.uix.image import Image
from kivy.uix.floatlayout import FloatLayout
from kivy.graphics import *
from kivy.properties import ListProperty
from kivy.lang import Builder
from kivy.core.window import Window
from kivy.uix.screenmanager import ScreenManager, Screen
from random import random
import pickle
import random
kv = '''
<ColoredLabel>:
size: (self.size_x,self.size_y)
pos: (0,0) # no effect
background_color:
canvas.before:
Color:
rgba: self.background_color
Rectangle:
pos: self.pos
size: (self.size_x,self.size_y)
'''
Builder.load_string(kv)
class ColoredLabel(Label):
background_color = ListProperty((0,0,0,1))
s_global = Window.size
size_x = s_global[0]
size_y = s_global[1]/3
class MyWidget(BoxLayout):
#init
def __init__(self, **kwargs):
super().__init__(**kwargs)
s_global = Window.size
size_x = s_global[0]
size_y = s_global[1]/3
self.ForeignLanguage = ColoredLabel(text="str_fl", size_hint=(None, None),size = (size_x,size_y), background_color=(0/255,171/255,169/255, 1))
self.Translation = ColoredLabel(text="str_tr", size_hint=(None, None),size = (size_x,size_y), background_color=(45/255,137/255,239/255, 1))
self.Example = ColoredLabel(text="str_ex", size_hint=(None, None),size = (size_x,size_y), background_color=(43/255,87/255,151/255, 1))
self.verticalBox = BoxLayout(orientation='vertical')
self.verticalBox.add_widget(self.ForeignLanguage)
self.verticalBox.add_widget(self.Translation)
self.verticalBox.add_widget(self.Example)
self.Translation.text = "test"
s=Swiping_class()
s.add_widget(self.verticalBox)
self.add_widget(s)
def ThisDoesntWork(self):
print("this is printed")
self.Translation.text = "I wanna change this via fucntion"
print("this is not printed anymore")
class Swiping_class(Screen):
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.initial = 0
def on_touch_down(self, touch):
self.initial = touch.x
def on_touch_up(self, touch):
if touch.x < self.initial:
print("swiped left")
MyWidget.ThisDoesntWork("self_dummy")
else:
print("swiped right")
class BoxLayoutDemo(App):
def build(self):
return MyWidget()
if __name__ == '__main__':
BoxLayoutDemo().run()

I think I found a solution. Within your Swiping_class, replace this line:
MyWidget.ThisDoesntWork("self_dummy")
with this line:
MyWidget.ThisDoesntWork(self.parent)
That way, instead of passing a string to your method, you pass the label object, which contains the text attribute you are trying to modify.

Python/Kivy passing variables

Struggling to pass a variable to kivy window. I have read similar threads all over the place but none of the fixes seem to work for me. Im sure this is simple to someone who knows their way around tiny, unfortunately I don't.
main.py
import kivy
from kivy.uix.togglebutton import ToggleButton
from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.clock import Clock
from kivy.lang import Builder
from kivy.app import App
kivy.require('1.10.0')
from phue import Bridge
import nest
b = Bridge('xxx.xxx.x.xxx')
b.connect()
b.get_api()
lights = b.lights
class Controller(GridLayout):
print("launching")
def __init__(self):
super(Controller, self).__init__()
def KitchenSpot1(self,state):
lights[0].name
lights[0].on = state
def update(dt):
if b.get_light(1, 'on')== True:
#print("down") # When this line is commented out I get an continuous accurate update on the status of the light, showing that its working.
return 'down' # This is the part I want passed to the state criteria in the ivy window
else:
#print("up")# When this line is commented out I get an continuous accurate update on the status of the light, showing that its working.
return 'down' # This is the part I want passed to the state criteria in the ivy window
class ActionApp(App):
def build(self):
Clock.schedule_interval(Controller.update, 1.0 / 60.0)
return Controller()
myApp = ActionApp()
myApp.run()
action.kv
<Controller>:
cols: 4
rows: 3
spacing: 10
ToggleButton:
id: KitchenSpot1Toggle
text: "Kitchen Spot 1"
on_press: root.KitchenSpot1(True)
#on_release: root.KitchenSpot1(False)
#state1 = app.update.h
state: Controller.update # This is the part that is throwing up the error.
The error:
11: #on_release: root.KitchenSpot1(False)
12: #state1 = app.update.h
>> 13: state: Controller.update
14:
15:
...
NameError: name 'Controller' is not defined
Thanks in advance to anyone that can help me.

Make update an instance method and use a StringProperty to update state property in your kv:
main.py:
import kivy
kivy.require('1.10.0')
from kivy.app import App
from kivy.clock import Clock
from kivy.lang import Builder
from kivy.properties import StringProperty
from kivy.uix.gridlayout import GridLayout
from kivy.uix.togglebutton import ToggleButton
from phue import Bridge
import nest
b = Bridge('xxx.xxx.x.xxx')
b.connect()
b.get_api()
lights = b.lights
class Controller(GridLayout):
state = StringProperty('normal') # <<<<<<<<<<<<
def __init__(self, **kwargs):
super(Controller, self).__init__(**kwargs)
Clock.schedule_interval(self.update, 1.0 / 60.0)
def KitchenSpot1(self,state):
lights[0].name
lights[0].on = state
def update(self, dt):
if b.get_light(1, 'on'):
self.state = 'down' # <<<<<<<<<<<<
else:
self.state = 'normal' # <<<<<<<<<<<<
class ActionApp(App):
def build(self):
return Controller()
if __name__ == "__main__":
myApp = ActionApp()
myApp.run()
action.kv:
<Controller>:
cols: 4
rows: 3
spacing: 10
state: "normal" # <<<<<<<<<<<<
ToggleButton:
id: KitchenSpot1Toggle
text: "Kitchen Spot 1"
on_press: root.KitchenSpot1(True)
#on_release: root.KitchenSpot1(False)
#state1 = app.update.h
state: root.state # <<<<<<<<<<<<

Here is a more generic simplified answer from the kivy documentation, look for the section called "Keyword arguments and init()" because there are some other ways to do it as well.
The following code passes myvar to the build() method of MyApp. It does this by over-riding the init() of the Kivy App class by a new init() that calls App.init() and then continues with whatever extra initialisation you want. You can then store variables in the MyApp class instances and use them in build().
from kivy.app import App
from kivy.uix.label import Label
myvar = 'Hello Kivy'
class MyApp(App):
def __init__(self, myvar, **kwargs):
super(MyApp, self).__init__(**kwargs)
self.myvar = myvar
def build(self):
widget = Label(text=self.myvar)
return widget
if __name__ == '__main__':
MyApp(myvar).run()

Kivy - Update a label with sensor data?

New to kivy, and OOP.
I'm trying to update a label in kivy with data I pull from a temp sensor. The code that pulls in the sensor data is in labeltempmod. I created a function getTheTemp() that is called every second. In the function I try to assign the text of the label via Label(text=(format(thetemp)), font_size=80). The program ignores this. What am I doing wrong here?
#This is a test to see if I can write the temp to label
import labeltempmod
import kivy
from kivy.app import App
from kivy.clock import Clock
from kivy.uix.label import Label
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.textinput import TextInput
from kivy.uix.boxlayout import BoxLayout
def getTheTemp(dt):
thetemp = labeltempmod.readtemp()
Label(text=(format(thetemp)), font_size=80)
print thetemp
class LabelWidget(BoxLayout):
pass
class labeltestApp(App):
def build(self):
# call get_temp 0.5 seconds
Clock.schedule_interval(getTheTemp, 1)
return LabelWidget()
if __name__ == "__main__":
labeltestApp().run()
Here is the kivy language file:
<LabelWidget>:
orientation: 'vertical'
TextInput:
id: my_textinput
font_size: 80
size_hint_y: None
height: 100
text: 'default'
FloatLayout:
Label:
id: TempLabel
font_size: 150
text: 'Temp Test'
Thanks.

Sorry but you never update something You are just creating another label
Try this:
class LabelWidget(BoxLayout):
def __init__(self, **kwargs):
super(LabelWidget, self).__init__(**kwargs)
Clock.schedule_interval(self.getTheTemp, 1)
def getTheTemp(self, dt):
thetemp = labeltempmod.readtemp()
self.ids.TempLabel.text = thetemp
print thetemp
class labeltestApp(App):
def build(self):
return LabelWidget()
if __name__ == "__main__":
labeltestApp().run()
Update : for your last request, I think the best way to do that is:
...
class LabelWidget(BoxLayout):
def __init__(self, **kwargs):
super(LabelWidget, self).__init__(**kwargs)
self.Thetemp = None
Clock.schedule_interval(self.getTheTemp, 1)
def getTheTemp(self, dt):
if self.Thetemp is None:
self.thetemp = labeltempmod.readtemp()
else:
self.thetemp = labeltempmod.readtemp(self.theTemp)
self.ids.TempLabel.text = str(self.thetemp)