I hope I got to understand your question. You are asking for methods to do this. The plain answer is that you have the whole Python to do all the operations you want. Kivy is a library that provides a lot of components to design GUI. It also provides you with a language that is parsed by the Builder.load_string()
. Here is an example that might be more or less what you are looking for. It is sort of a calculator on the first screen. The second screen is empty and you can move between them with the bottom buttons.
The calculator on the first screen has two InputTexts
and two buttons (Sum
and Product
). The Sum Button has the implementation of a sum directly on the kivy language. The Product Button calls a method in the root (an instance of Calc). The method doesn't exist by itself. I created in the python code below the kivy section. There is some comments on the code for what I am saying.
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout
Builder.load_string("""
<Calc>:
# This are attributes of the class Calc now
a: _a
b: _b
result: _result
AnchorLayout:
anchor_x: 'center'
anchor_y: 'top'
ScreenManager:
size_hint: 1, .9
id: _screen_manager
Screen:
name: 'screen1'
GridLayout:
cols:1
TextInput:
id: _a
text: '3'
TextInput:
id: _b
text: '5'
Label:
id: _result
Button:
text: 'sum'
# You can do the opertion directly
on_press: _result.text = str(int(_a.text) + int(_b.text))
Button:
text: 'product'
# Or you can call a method from the root class (instance of calc)
on_press: root.product(*args)
Screen:
name: 'screen2'
Label:
text: 'The second screen'
AnchorLayout:
anchor_x: 'center'
anchor_y: 'bottom'
BoxLayout:
orientation: 'horizontal'
size_hint: 1, .1
Button:
text: 'Go to Screen 1'
on_press: _screen_manager.current = 'screen1'
Button:
text: 'Go to Screen 2'
on_press: _screen_manager.current = 'screen2'""")
class Calc(FloatLayout):
# define the multiplication of a function
def product(self, instance):
# self.result, self.a and self.b where defined explicitely in the kv
self.result.text = str(int(self.a.text) * int(self.b.text))
class TestApp(App):
def build(self):
return Calc()
if __name__ == '__main__':
TestApp().run()