python - How to fire one event when we release the click on a kivy switch item?

Question

Goal: when I click then release the click on the switch widget, it fires me an event on the release.

Problem: I used the on_touch_down() Switch method but:

• it release 2 event on the release of the click and not only one.
• when I release and it shows "off", it says "True" and it shows "False" when it's on "on" !

from kivymd.app import MDApp
from kivy.lang import Builder
from kivy.uix.gridlayout import GridLayout


KV = '''
MyGridLayout:
    Switch:
        id: switch_ecs
        on_touch_up:
            root.on_switch("ecs")
'''

class MyGridLayout(GridLayout):
    def __init__(self, **kwargs):
        super().__init__(**kwargs)

    def on_switch(self,element_id):
        print(self.ids["switch_" + element_id].active)

class MyApp(MDApp):
    def build(self):
        self.screen = Builder.load_string(KV)
        return self.screen



if __name__ == '__main__':
    MyApp().run()

Answer 1

Kivy has some obscure logic that results in touch up events getting dispatched twice to some widgets (like Buttons and Switches). The fix for your code is to use a different trigger for your on_switch() method. You can use:

    on_touch_down:
        root.on_switch("ecs")

or:

    on_active:
        root.on_switch("ecs")