Fix Enabling/Disabling MDTextField (#1651)

kivymd/tests/list/test_disable.py

@@ -0,0 +1,78 @@
+from kivy.clock import Clock
+from kivy.core.clipboard import Clipboard
+from kivy.input.providers.mouse import MouseMotionEvent
+from kivy.lang.builder import Builder
+
+from kivymd.app import MDApp
+
+KV = """
+MDScreen:
+
+    MDBoxLayout:
+        orientation: 'vertical'
+
+        MDListItem:
+            id: item1
+
+            MDListItemLeadingIcon:
+                icon: "account"
+
+            MDListItemHeadlineText:
+                text: "Headline1"
+
+            MDListItemSupportingText:
+                text: "Supporting text"
+
+            MDListItemTertiaryText:
+                text: "Tertiary text"
+
+            MDListItemTrailingCheckbox:
+
+        MDListItem:
+            id: item2
+
+            MDListItemHeadlineText:
+                text: "Headline2"
+
+            MDListItemSupportingText:
+                text: "Supporting text"
+
+            MDListItemTertiaryText:
+                text: "Tertiary text"
+
+        MDListItem:
+            id: item3
+
+            MDListItemHeadlineText:
+                text: "Headline3"
+
+        MDListItem:
+            id: item4
+
+"""
+
+
+class TestDisableList(MDApp):
+    def build(self):
+        return Builder.load_string(KV)
+
+    def on_start(self):
+        def _enabled(*args):
+            self.root.ids.item1.disabled = False
+            self.root.ids.item2.disabled = False
+            self.root.ids.item3.disabled = False
+            self.root.ids.item4.disabled = False
+            self.stop()
+
+        def _disable(*args):
+            self.root.ids.item1.disabled = True
+            self.root.ids.item2.disabled = True
+            self.root.ids.item3.disabled = True
+            self.root.ids.item4.disabled = True
+            Clock.schedule_once(_enabled, 1)
+
+        super().on_start()
+        Clock.schedule_once(_disable, 1)
+
+
+TestDisableList().run()

kivymd/uix/list/list.kv

@@ -49,6 +49,7 @@
         } \
         [len(text_container.children)]
     on_disabled:
+        if leading_container.children: \
         leading_container.children[0].disabled = args[1]