Python | Drop-down list in kivy using .kv file

Kivy is a platform independent GUI tool in Python. As it can be run on Android, IOS, linux and Windows etc. It is basically used to develop the Android application, but it does not mean that it can not be used on Desktops applications.

Dropdown list

A drop-down list can be used with custom widgets. It allows you to display a list of widgets under a displayed widget. Unlike other toolkits, the list of widgets can contain any type of widget: simple buttons, images etc.
The positioning of the drop-down list is fully automatic: we will always try to place the dropdown list in a way that the user can select an item in the list.

To work with this widget you must have to import:
from kivy.uix.dropdown import DropDown



Basic Approach:
1) import kivy
2) import kivyApp
3) import dropdown
4) import Floatlayout(according to need)
5) Set minimum version(optional)
6) Create Layout class
7) Create App class
9) create .kv file (name same as the app class):
        1) create Dropdown
        2) create callback
        3) And many more styling as needed
10) return Layout/widget/Class(according to requirement)
11) Run an instance of the class

#.py file

filter_none

edit
close

play_arrow

link
brightness_4
code

'''
Code of How to use drop-down list with.kv file
'''
   
# Program to Show how to create a switch 
# import kivy module    
import kivy  
       
# base Class of your App inherits from the App class.    
# app:always refers to the instance of your application   
from kivy.app import App 
     
# this restrict the kivy version i.e  
# below this kivy version you cannot  
# use the app or software  
kivy.require('1.9.0'
    
# drop-down menu is a list of items that
# appear whenever a piece of text or a
# button is clicked.
# To use drop down you must have ti import it
from kivy.uix.dropdown  import DropDown
    
# module consists the floatlayout  
# to work with FloatLayout first  
# you have to import it  
from kivy.uix.floatlayout import FloatLayout
  
# The Button is a Label with associated actions that
# are triggered when the button is pressed (
# or released after a click / touch).
from kivy. uix . button  import Button
  
class CustomDropDown(DropDown):
    pass
   
   
class DropdownDemo(FloatLayout):
    '''The code of the application itself.''' 
    def __init__(self, **kwargs):
          
        '''The button at the opening of the window is created here,
        not in kv
        ''' 
        super(DropdownDemo, self).__init__(**kwargs)
        self.dropdown = CustomDropDown()
  
        # Creating a self widget bouton
        self.mainbutton = Button(text ='Do you in college?',
                                 size_hint_x = 0.6, size_hint_y = 0.15)
          
        # Added button to FloatLayout so inherits this class 
        self.add_widget(self.mainbutton)
  
        # Adding actions 
        # If click 
        self.mainbutton.bind(on_release = self.dropdown.open)
  
        # root.select on_select called
        self.dropdown.bind(on_select = lambda\
                           instance, x: setattr(self.mainbutton, 'text', x))
        self.dropdown.bind(on_select = self.callback)
   
    def callback(self, instance, x):
        '''x is self.mainbutton.text refreshed''' 
        print ( "The chosen mode is: {0}" . format ( x ) )
   
   
class MainApp(App):
    '''The build function returns root,
    here root = DropdownDemo ().
    root can only be called in the kv file.
    ''' 
    def build(self):
        return DropdownDemo()
   
   
if __name__ == '__main__':
      
    MainApp().run()

chevron_right


.kv file:

filter_none

edit
close

play_arrow

link
brightness_4
code

<CustomDropDown>:
    Button:
        text: 'College Name'
        size_hint_y: None
        height: 44
        on_release: root.select('College is')
    Label:
        text: 'Not in college'
        size_hint_y: None
        height: 44
    Button:
        text: 'KccItm'
        size_hint_y: None
        height: 44
        on_release: root.select('Kcc')

chevron_right


Output:



My Personal Notes arrow_drop_up

Competative Programmer

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.




Article Tags :

Be the First to upvote.


Please write to us at contribute@geeksforgeeks.org to report any issue with the above content.