Created a common method for empty screen label

src/bitmessagekivy/baseclass/addressbook.py

@@ -26,7 +26,7 @@ import state
 from bitmessagekivy.get_platform import platform
 from bitmessagekivy import kivy_helper_search
 from bitmessagekivy.baseclass.common import (
-    avatarImageFirstLetter, toast,
+    avatarImageFirstLetter, toast, empty_screen_label,
     ThemeClsColor, SwipeToDeleteItem
 )
 from bitmessagekivy.baseclass.popup import AddbookDetailPopup
@@ -42,6 +42,8 @@ class AddressBook(Screen, HelperAddressBook):
     has_refreshed = True
     address_label = StringProperty()
     address = StringProperty()
+    label_str = "No contact Address found yet......"
+    no_search_res_found = "No search result found"
 
     def __init__(self, *args, **kwargs):
         """Getting AddressBook Details"""
@@ -71,7 +73,7 @@ class AddressBook(Screen, HelperAddressBook):
             self.set_mdList(0, 20)
             self.ids.scroll_y.bind(scroll_y=self.check_scroll_y)
         else:
-            self.ids.ml.add_widget(self.default_label_when_empty())
+            self.ids.ml.add_widget(empty_screen_label(self.label_str, self.no_search_res_found))
 
     def set_mdList(self, start_index, end_index):
         """Creating the mdList"""

src/bitmessagekivy/baseclass/addressbook_widgets.py

@@ -6,31 +6,11 @@ Addressbook widgets are here.
 
 from kivymd.uix.button import MDRaisedButton
 from kivymd.uix.dialog import MDDialog
-from kivymd.uix.label import MDLabel
 
 import state
 
-no_address_found = "No contact found yet......"
-empty_search_label = "No contact found!"
 
-
-# pylint: disable=no-init, old-style-class
-class DefaultLabelMixin:
-    """Common label on blank screen"""
-
-    @staticmethod
-    def default_label_when_empty():
-        """This function returns default message while no address is there."""
-        content = MDLabel(
-            font_style='Caption',
-            theme_text_color='Primary',
-            # FIXME: searching_text supposed to be inside kivy_sate.py, typo and need to create a PR for kivy_state.py
-            text=empty_search_label if state.searching_text else no_address_found,
-            halign='center', size_hint_y=None, valign='top')
-        return content
-
-
-class HelperAddressBook(DefaultLabelMixin):
+class HelperAddressBook(object):
     """Widget used in Addressbook are here"""
 
     @staticmethod