I am working on a Kivy project, and I need to display a label when there is no elements in a list. Otherwise, I need to display a list view.
These are the two scenarios I am describing:
When no friends to show:
When list contains friends:
This is my Kivy file:
#: kivy 1.9.1
#: import ListAdapter kivy.adapters.listadapter.ListAdapter
#: import FriendItemButton gui.FriendItemButton
ChumMeRoot:
<ChumMeRoot>:
friend_list_view: friend_list_view
FriendList:
id: friend_list_view
<FriendItemButton>:
text: self.full_name
height: "40dp"
size_hint_y: None
<FriendList>:
orientation: 'vertical'
friend_list: friend_list_view
Button:
height: '45dp'
size_hint_y: None
text: 'Add Friend'
on_press: app.root.show_add_friend_form()
ListView:
id: friend_list_view
adapter:
ListAdapter(
data=[],
cls=FriendItemButton,
args_converter=root.args_converter)
<AddFriendFormInput@BoxLayout>
height: '30dp'
size_hint_y: None
<AddFriendForm>:
orientation: 'vertical'
first_name_input: first_name
last_name_input: last_name
AddFriendFormInput:
Label:
text: 'First Name'
TextInput:
id: first_name
AddFriendFormInput:
Label:
text: 'Middle Name'
TextInput:
AddFriendFormInput:
Label:
text: 'Last Name'
TextInput:
id: last_name
AddFriendFormInput:
Label:
text: 'Birthdate'
TextInput:
AddFriendFormInput:
Label:
text: 'Email'
TextInput:
AddFriendFormInput:
Label:
text: 'Cell Phone'
TextInput:
BoxLayout:
BoxLayout:
height: '40dp'
size_hint_y: None
Button:
text: 'Cancel'
on_press: app.root.show_friend_list()
Button:
text: 'Add friend'
on_press: app.root.add_friend()
and this is my Python code:
import os
from kivy.app import App
from kivy.properties import ObjectProperty, StringProperty
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.listview import ListItemButton
from friend import Friend
from friend_manager import FriendManager
def get_friend_manager():
db_path = '{}/{}'.format(
os.path.dirname(os.path.abspath(__file__)),
'chumme.db'
)
return FriendManager(db_path)
def get_friends():
return [(friend.full_name,)
for friend in get_friend_manager().get_friends()]
class ChumMeRoot(BoxLayout):
add_friend_form = ObjectProperty()
friend_list_view = ObjectProperty()
def __init__(self, **kwargs):
super().__init__(**kwargs)
self.update_friend_list_view()
def update_friend_list_view(self):
friend_list = self.friend_list_view.friend_list
friend_list.adapter.data.clear()
friend_list.adapter.data.extend(get_friends())
friend_list._trigger_reset_populate()
def show_add_friend_form(self):
self.clear_widgets()
self.add_friend_form = AddFriendForm()
self.add_widget(self.add_friend_form)
def show_friend_list(self):
self.clear_widgets()
self.update_friend_list_view()
self.add_widget(self.friend_list_view)
def add_friend(self):
friend = Friend(first_name=self.add_friend_form.first_name_input.text,
last_name=self.add_friend_form.last_name_input.text)
get_friend_manager().add_friend(friend)
self.show_friend_list()
class AddFriendForm(BoxLayout):
first_name_input = ObjectProperty()
last_name_input = ObjectProperty()
class FriendList(BoxLayout):
friend_list = ObjectProperty()
def args_converter(self, index, data_item):
return {'full_name': (data_item[0])}
class FriendItemButton(ListItemButton):
full_name = StringProperty()
class ChumMeApp(App):
pass
def main():
ChumMeApp().run()
if __name__ == '__main__':
main()
So far, I have found this solution which basically says to avoid removing widgets from the root, and though I have tried it, I lost references and my app crashes. I don't also want to put the element in a position out of the visible screen, so I wonder if somebody knows a way to hide and show widgets as 'self.widget_name.hide()orself.widget_name.hide = True`, or can somebody tell me a good way to achieve this task?
