Learn KIVY with Real Code Examples

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.label import Label

class CounterApp(App):
    def build(self):
        self.count = 0
        layout = BoxLayout(orientation='vertical', padding=20)
        self.label = Label(text=f'Count: {self.count}', font_size=32)
        inc_btn = Button(text='Increment', on_press=lambda x: self.increment())
        layout.add_widget(self.label)
        layout.add_widget(inc_btn)
        return layout

    def increment(self):
        self.count += 1
        self.label.text = f'Count: {self.count}'

if __name__ == '__main__':
    CounterApp().run()

Demonstrates a simple counter layout using Kivy widgets for interactivity.

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button
from kivy.uix.label import Label

class TodoApp(App):
    def build(self):
        self.tasks = []
        self.layout = BoxLayout(orientation='vertical', padding=20)
        self.input = TextInput(hint_text='Enter task')
        self.layout.add_widget(self.input)
        self.add_btn = Button(text='Add Task', on_press=lambda x: self.add_task())
        self.layout.add_widget(self.add_btn)
        self.task_box = BoxLayout(orientation='vertical')
        self.layout.add_widget(self.task_box)
        return self.layout

    def add_task(self):
        task = self.input.text.strip()
        if task:
        self.task_box.add_widget(Label(text=task))
        self.input.text = ''

if __name__ == '__main__':
    TodoApp().run()

A simple Todo app built with Kivy allowing users to add and view tasks.

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.graphics import Color, Rectangle

class ThemeApp(App):
    def build(self):
        self.dark = False
        self.layout = BoxLayout()
        self.button = Button(text='Switch Theme', on_press=lambda x: self.toggle_theme())
        self.layout.add_widget(self.button)
        self.update_bg()
        return self.layout

    def update_bg(self):
        self.layout.canvas.before.clear()
        with self.layout.canvas.before:
        Color(0.1, 0.1, 0.1) if self.dark else Color(1, 1, 1)
        Rectangle(size=self.layout.size, pos=self.layout.pos)

    def toggle_theme(self):
        self.dark = not self.dark
        self.update_bg()

if __name__ == '__main__':
    ThemeApp().run()

Demonstrates theme switching between light and dark using canvas colors.

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.slider import Slider
from kivy.uix.label import Label

class SliderApp(App):
    def build(self):
        self.layout = BoxLayout(orientation='vertical', padding=20)
        self.label = Label(text='Value: 0')
        self.slider = Slider(min=0, max=100, value=0)
        self.slider.bind(value=self.on_value)
        self.layout.add_widget(self.label)
        self.layout.add_widget(self.slider)
        return self.layout

    def on_value(self, instance, value):
        self.label.text = f'Value: {int(value)}'

if __name__ == '__main__':
    SliderApp().run()

Shows how to use Slider widgets and display their values dynamically.

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button

class LoginApp(App):
    def build(self):
        layout = BoxLayout(orientation='vertical', padding=20)
        self.username = TextInput(hint_text='Username')
        self.password = TextInput(hint_text='Password', password=True)
        btn = Button(text='Login', on_press=lambda x: self.login())
        layout.add_widget(self.username)
        layout.add_widget(self.password)
        layout.add_widget(btn)
        return layout

    def login(self):
        print(f'User: {self.username.text}')

if __name__ == '__main__':
    LoginApp().run()

Creates a basic login interface with username and password fields.

from kivy.app import App
from kivy.clock import Clock
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.button import Button
from kivy.uix.label import Label

class StopwatchApp(App):
    def build(self):
        self.time = 0
        self.running = False
        self.layout = BoxLayout(orientation='vertical', padding=20)
        self.label = Label(text='0.0', font_size=32)
        self.layout.add_widget(self.label)
        self.layout.add_widget(Button(text='Start', on_press=lambda x: self.start()))
        self.layout.add_widget(Button(text='Stop', on_press=lambda x: self.stop()))
        self.layout.add_widget(Button(text='Reset', on_press=lambda x: self.reset()))
        return self.layout

    def update(self, dt):
        self.time += dt
        self.label.text = f'{self.time:.1f}'

    def start(self):
        if not self.running:
        self.running = True
        Clock.schedule_interval(self.update, 0.1)

    def stop(self):
        self.running = False
        Clock.unschedule(self.update)

    def reset(self):
        self.time = 0
        self.label.text = '0.0'

if __name__ == '__main__':
    StopwatchApp().run()

A simple stopwatch that starts, stops, and resets using Clock scheduling.

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.togglebutton import ToggleButton

class ToggleExample(App):
    def build(self):
        layout = BoxLayout(padding=20)
        self.toggle = ToggleButton(text='OFF', on_press=self.toggle_state)
        layout.add_widget(self.toggle)
        return layout

    def toggle_state(self, btn):
        btn.text = 'ON' if btn.state == 'down' else 'OFF'

if __name__ == '__main__':
    ToggleExample().run()

Demonstrates Kivy’s ToggleButton for state-based interaction.

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.colorpicker import ColorPicker
from kivy.graphics import Color, Rectangle

class ColorPickerApp(App):
    def build(self):
        self.layout = BoxLayout()
        self.picker = ColorPicker()
        self.picker.bind(color=self.on_color)
        self.layout.add_widget(self.picker)
        with self.layout.canvas.before:
        self.bg = Color(1,1,1)
        self.rect = Rectangle(size=self.layout.size, pos=self.layout.pos)
        return self.layout

    def on_color(self, instance, value):
        self.bg.rgb = value[:3]

if __name__ == '__main__':
    ColorPickerApp().run()

Uses Kivy’s ColorPicker widget to change background color dynamically.

from kivy.app import App
from kivy.uix.gridlayout import GridLayout
from kivy.uix.textinput import TextInput
from kivy.uix.button import Button

class Calculator(App):
    def build(self):
        self.result = TextInput(multiline=False, readonly=True)
        layout = GridLayout(cols=4, spacing=5, padding=10)
        layout.add_widget(self.result)
        buttons = ['7','8','9','/','4','5','6','*','1','2','3','-','0','.','=','+']
        for b in buttons:
        btn = Button(text=b, on_press=self.on_button)
        layout.add_widget(btn)
        return layout

    def on_button(self, instance):
        if instance.text == '=':
        try:
        self.result.text = str(eval(self.result.text))
        except:
        self.result.text = 'Error'
        else:
        self.result.text += instance.text

if __name__ == '__main__':
    Calculator().run()

A simple calculator UI built using Kivy layout widgets.

from kivy.app import App
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.image import Image
from kivy.uix.button import Button

class ImageViewer(App):
    def build(self):
        self.images = ['1.png','2.png','3.png']
        self.index = 0
        self.layout = BoxLayout(orientation='vertical')
        self.img = Image(source=self.images[self.index])
        btn_next = Button(text='Next', on_press=lambda x: self.next_img())
        self.layout.add_widget(self.img)
        self.layout.add_widget(btn_next)
        return self.layout

    def next_img(self):
        self.index = (self.index + 1) % len(self.images)
        self.img.source = self.images[self.index]

if __name__ == '__main__':
    ImageViewer().run()

Displays and switches between images using buttons in Kivy.