Floating Action Button in Kivy

Kivy is a Python framework for building multi-touch applications that run on various platforms including Windows, macOS, Linux, Android, and iOS. One of the key components in building interactive user interfaces in Kivy is the Floating Action Button (FAB). A Floating Action Button is a circular button that hovers above the content and provides quick access to primary actions in the application. In this tutorial, we will learn how to create a Floating Action Button in Kivy.

Step 1: Install Kivy
Before we start creating the Floating Action Button, make sure you have Kivy installed on your system. You can install Kivy using pip by running the following command in your terminal or command prompt:

pip install kivy

Step 2: Import the necessary modules
To create a Floating Action Button in Kivy, we need to import the necessary modules. Create a new Python file and import the following modules:

from kivy.app import App
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.fab import FAB

Step 3: Create the Floating Action Button class
Next, we need to create a class for the Floating Action Button. We will subclass the FAB class provided by Kivy and customize it to suit our needs. Add the following code to your Python file:

class MyFAB(FAB):
def init(self, kwargs):
super(MyFAB, self).init(kwargs)
self.icon = ‘plus’
self.size_hint = None, None
self.size = 60, 60
self.pos = 20, 20

Step 4: Create the main application class
Now, we will create the main application class that will display the Floating Action Button. Add the following code to your Python file:

class MyApp(App):
def build(self):
layout = FloatLayout()
fab = MyFAB()
layout.add_widget(fab)
return layout

Step 5: Run the application
To run the application and see the Floating Action Button in action, add the following code at the end of your Python file:

if name == ‘main‘:
MyApp().run()

Now, save your Python file and run it using the Python interpreter. You should see a circular button with a plus icon hovering above the content of the application.

Step 6: Customize the FAB
You can customize the Floating Action Button by changing its properties such as icon, size, position, background color, and more. Experiment with different values to achieve the desired look and behavior.

Step 7: Handling click events
To handle click events on the Floating Action Button, you can bind a callback function to the on_release event. Add the following code to your Python file:

fab.bind(on_release=self.callback_function)

def callback_function(self, instance):
print(‘Button clicked!’)

Now, when you click on the Floating Action Button, the callback function will be executed, and ‘Button clicked!’ will be printed to the console.

In conclusion, the Floating Action Button is a great way to provide quick access to primary actions in your Kivy application. By following this tutorial, you should now have a good understanding of how to create and customize a Floating Action Button in Kivy. Experiment with different properties and events to create a unique and interactive user interface for your application.