Creating Rounded Buttons in Kivy: The Ultimate Guide to 3 Simple Methods

Kivy is a powerful open-source Python framework used for developing cross-platform applications. One common requirement for many applications is the use of rounded buttons. In this tutorial, I will show you the only three ways to create round buttons with Kivy: using the background_color property, using the canvas feature, and using custom widget classes.

1. Using the background_color property:
   One simple way to create round buttons in Kivy is by adjusting the background_color property of a Button widget. This can be done by setting the color to a circular gradient.

Here is an example of how to create a round button using the background_color property:

from kivy.app import App
from kivy.uix.button import Button

class RoundButtonApp(App):
    def build(self):
        btn = Button(text='Round Button', size_hint=(None, None), size=(200, 200))
        btn.background_color = [0, 0, 1, 1] # Blue color
        btn.border_radius = [20]
        return btn

RoundButtonApp().run()

In this example, we create a Button widget with a size of 200×200 pixels and set the background_color property to blue. We also set the border_radius property to 20 to make the button round.

1. Using the canvas feature:
   Another way to create round buttons in Kivy is by using the canvas feature. This allows us to draw custom shapes on a widget using graphics instructions.

Here is an example of how to create a round button using the canvas feature:

from kivy.app import App
from kivy.uix.button import Button
from kivy.graphics import RoundedRectangle

class RoundButtonApp(App):
    def build(self):
        btn = Button(text='Round Button', size_hint=(None, None), size=(200, 200))
        with btn.canvas:
            RoundedRectangle(pos=btn.pos, size=btn.size, radius=[20,])
        return btn

RoundButtonApp().run()

In this example, we create a Button widget and use the canvas feature to draw a RoundedRectangle with a radius of 20 pixels, making the button round.

1. Using custom widget classes:
   Finally, we can create round buttons in Kivy by subclassing the Button widget and customizing its appearance.

Here is an example of how to create a custom round button class:

from kivy.uix.button import Button
from kivy.graphics import RoundedRectangle

class RoundButton(Button):
    def __init__(self, **kwargs):
        super(RoundButton, self).__init__(**kwargs)
        with self.canvas:
            RoundedRectangle(pos=self.pos, size=self.size, radius=[20,])

# Usage
from kivy.app import App

class RoundButtonApp(App):
    def build(self):
        return RoundButton(text='Round Button', size_hint=(None, None), size=(200, 200))

RoundButtonApp().run()

In this example, we create a custom RoundButton class that subclasses the Button widget and draws a RoundedRectangle with a radius of 20 pixels in its constructor. We then use the custom RoundButton class to create a round button in the Kivy application.

In conclusion, these are the only three ways to create round buttons with Kivy: using the background_color property, using the canvas feature, and using custom widget classes. Choose the method that best fits your application requirements and design preferences. I hope this tutorial helps you create beautiful round buttons in your Kivy applications.