Python (Kivy) - Check Value of Checkbox from .kv in python

Question

I have a checkbox in my .kv file, and I want to disable a text input associated with it when the box is not checked.

My .py Code

if self.ids.checkbox.active==False:
    self.ids.input.disabled==True
else:
    self.ids.input.disabled==False

My .kv Code

TextInput:
        id: input
        text: "2fbd3320a168d5c2e35"
        pos_hint: {"x":0.1, "y":0.4}
        size_hint: 0.5,0.05
        background_disabled_normal: ""

    CheckBox:
        id: checkbox
        pos_hint: {"x":0.6, "y":0.4}
        size_hint: 0.05,0.05

I do not know how to go about doing this, the .py code must be in a function, but checkboxes do not harbor the on_release attribute.

Answer 1

You need to associate the event (checkbox.active) with the corresponding callback. You can do it in the .py file using bind:

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout

kv_text = """\
<MyWidget>
    TextInput:
        id: input
        text: "2fbd3320a168d5c2e35"
        pos_hint: {"x":0.1, "y":0.4}
        size_hint: 0.5,0.05
        background_disabled_normal: ""
        disabled: True

    CheckBox:
        id: checkbox
        pos_hint: {"x":0.6, "y":0.4}
        size_hint: 0.05,0.05
"""

class MyWidget(FloatLayout):
    def __init__(self, **kwargs):
        super(MyWidget, self).__init__(**kwargs)
        self.ids.checkbox.bind(active=self.disable_input)

    def disable_input(self, checkbox, checked):
        self.ids.input.disabled = not checked


class MyWidgetApp(App):
    def build(self):
        return MyWidget()

def main():
    Builder.load_string(kv_text)
    app = MyWidgetApp()
    app.run()

if __name__ == '__main__':
    main()

Another option is to do it in the .kv file:

from kivy.app import App
from kivy.lang import Builder
from kivy.uix.floatlayout import FloatLayout

kv_text = """\
<MyWidget>
    TextInput:
        id: input
        text: "2fbd3320a168d5c2e35"
        pos_hint: {"x":0.1, "y":0.4}
        size_hint: 0.5,0.05
        background_disabled_normal: ""
        disabled: not checkbox.active      # <<<<<<<<<

    CheckBox:
        id: checkbox
        pos_hint: {"x":0.6, "y":0.4}
        size_hint: 0.05,0.05
"""

class MyWidget(FloatLayout):
    pass


class MyWidgetApp(App):
    def build(self):
        return MyWidget()

def main():
    Builder.load_string(kv_text)
    app = MyWidgetApp()
    app.run()

if __name__ == '__main__':
    main()