CODEWITHSUNDEEP
python-3.xbuttonkivy
B. Moore
B. Moore

Reputation: 109

How do I create a button with Kivy?

I am hoping to eventually create a button to pause/start/end a pong app I built as a learning exercise. However, to understand the basics of how to create a button in the first place, and assign a response to it I am just wanting to create a button that notifies me every time the button state changes. Here is the python code I have so far:

import kivy.uix.button as kb
from kivy.app import App
from kivy.uix.widget import Widget

class Button_Widget(Widget):
    def callback(instance, value):
        print('The button <%s> state is <%s>' % (instance, value))

    btn1 = kb.Button(text='Hello World 1')
    btn1.bind(on_press=callback)

class ButtonApp(App):
    def build(self):
        button = Button_Widget()
        return button

with the associated kv file:

#:kivy 1.0.9

<Button_Widget>:
    size: 100, 100
    canvas:
        Rectangle:
            pos = self.pos
            size = self.size

So far the only resources I have found are these (1 and 2) Kivy turorials, which aren't too helpful. Or at least, I don't understand their language enough yet for them to be useful

Upvotes: 0

Views: 9570

Answers (2)

Saffron-codes
Saffron-codes

Reputation: 188

Let's see the simplest code to create a button in kivy

   from kivy.app import App
   from kivy.uix.button import Button
   class your_app_name(App):
       def build(self):
           button = Button(text="Button")
           return button
   your_app_name().run()

You can also add command or event to a button by adding on_press= function_name

Upvotes: 2

ikolim
ikolim

Reputation: 16001

Solution

In the class Button_Widget(), you have to override the constructor, __init__() so that you can add the button widget to the root widget. Please refer to the example for details.

References

Programming Guide » Kivy Basics » Create an application

Programming Guide » Kv language

Kivy Language

Event dispatcher » bind() Bind an event type or a property to a callback.

Example

main.py

import kivy.uix.button as kb
from kivy.app import App
from kivy.uix.widget import Widget


class Button_Widget(Widget):

    def __init__(self, **kwargs):
        super(Button_Widget, self).__init__(**kwargs)
        btn1 = kb.Button(text='Hello World 1')
        btn1.bind(on_press=self.callback)
        self.add_widget(btn1)

    def callback(self, instance):
        print('The button %s state is <%s>' % (instance, instance.state))


class ButtonApp(App):

    def build(self):
        return Button_Widget()


if __name__ == "__main__":
    ButtonApp().run()

button.kv

#:kivy 1.10.1

<Button_Widget>:
    size: 100, 100
    canvas:
        Rectangle:
            pos: self.pos
            size: self.size

Output

Img01

Upvotes: 0

Related Questions