MDExpansionPanel without async kivy unexpected behaviour with 100 widgets

[Sahil-pixel]

Description of the Bug

Your text when no of widgets is 10 or some thing then it works fine , i have tested 100 widgets it is not behaving as expected .

Screencast from 19-05-24 12:09:48 PM IST.webm

Code and Logs

import asynckivy
from kivy.animation import Animation
from kivy.lang import Builder
from kivy.metrics import dp
from kivy.uix.behaviors import ButtonBehavior

from kivymd.app import MDApp
from kivymd.uix.behaviors import RotateBehavior
from kivymd.uix.expansionpanel import MDExpansionPanel
from kivymd.uix.list import MDListItemTrailingIcon

KV = '''
<ExpansionPanelItem>

    MDExpansionPanelHeader:

        MDListItem:
            theme_bg_color: "Custom"
            md_bg_color: self.theme_cls.surfaceContainerLowColor
            ripple_effect: False

            MDListItemSupportingText:
                text: "Supporting text"

            TrailingPressedIconButton:
                id: chevron
                icon: "chevron-right"
                on_release: app.tap_expansion_chevron(root, chevron)

    MDExpansionPanelContent:
        orientation: "vertical"
        padding: "12dp", 0, "12dp", "12dp"
        md_bg_color: self.theme_cls.surfaceContainerLowestColor

        MDLabel:
            text: "Channel information"
            adaptive_height: True
            padding_x: "16dp"
            padding_y: "12dp"

        MDListItem:
            theme_bg_color: "Custom"
            md_bg_color: self.theme_cls.surfaceContainerLowestColor

            MDListItemLeadingIcon:
                icon: "email"

            MDListItemHeadlineText:
                text: "Email"

            MDListItemSupportingText:
                text: "[email protected]"

        MDListItem:
            theme_bg_color: "Custom"
            md_bg_color: self.theme_cls.surfaceContainerLowestColor

            MDListItemLeadingIcon:
                icon: "instagram"

            MDListItemHeadlineText:
                text: "Instagram"

            MDListItemSupportingText:
                text: "Account"

            MDListItemTertiaryText:
                text: "www.instagram.com/KivyMD"


MDScreen:
    md_bg_color: self.theme_cls.backgroundColor

    ScrollView:
        size_hint_x: .5
        pos_hint: {"center_x": .5, "center_y": .5}

        BoxLayout:
            size_hint_y:None
            height:self.minimum_height
            orientation:'vertical'
            id: container
            padding:'50dp'
'''


class ExpansionPanelItem(MDExpansionPanel):
    ...


class TrailingPressedIconButton(
    ButtonBehavior, RotateBehavior, MDListItemTrailingIcon
):
    ...


class Example(MDApp):
    def on_start(self):
        def set_panel_list():
            for i in range(100):
                #await asynckivy.sleep(0)
                self.root.ids.container.add_widget(ExpansionPanelItem())

        #asynckivy.start(set_panel_list())
        set_panel_list()

    def build(self):
        self.theme_cls.theme_style = "Dark"
        return Builder.load_string(KV)

    def tap_expansion_chevron(
        self, panel: MDExpansionPanel, chevron: TrailingPressedIconButton
    ):
        Animation(
            padding=[0, dp(12), 0, dp(12)]
            if not panel.is_open
            else [0, 0, 0, 0],
            d=0.2,
        ).start(panel)
        panel.open() if not panel.is_open else panel.close()
        panel.set_chevron_down(
            chevron
        ) if not panel.is_open else panel.set_chevron_up(chevron)


Example().run()

Screenshots

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Versions

• OS: ubuntu 22.04
• Python: 3.11
• Kivy: 2.3.0
• KivyMD: 2.0.1.dev0