Adding Kivy recycleview to screenmanager breaks example - python-3.x

Question

I'm trying to combine this recycleview example with this screenmanager example so that the recycleview example can be one of the screens in my app. The app runs but all the control buttons display at the bottom of the UI (They're supposed to be at the top) and are either disabled or obscured, disallowing input. Consequently, the recycleview cannot be populated and/or viewed.
Here's my attempt:
import asyncio
from random import sample, randint
from string import ascii_lowercase
from kivy.app import App
from kivy.lang import Builder
from kivy.uix.screenmanager import ScreenManager, Screen, FadeTransition
from kivy.uix.boxlayout import BoxLayout
from kivy.uix.recycleview.views import RecycleDataViewBehavior
kv = '''
#:import FadeTransition kivy.uix.screenmanager.FadeTransition
#:import BoxLayout kivy.uix.boxlayout.BoxLayout
#:import RecycleDataViewBehavior kivy.uix.recycleview.views.RecycleDataViewBehavior
ScreenManagement:
transition: FadeTransition()
ContactsScreen:
name: 'contacts'
MessengerScreen:
name: 'messenger'
<Row#RecycleKVIDsDataViewBehavior+BoxLayout>:
canvas.before:
Color:
rgba: 0.5, 0.5, 0.5, 1
Rectangle:
size: self.size
pos: self.pos
value: ''
Label:
id: name
Label:
text: root.value
<ContactsScreen>:
canvas:
Color:
rgba: 0.3, 0.3, 0.3, 1
Rectangle:
size: self.size
pos: self.pos
rv: rv
orientation: 'vertical'
GridLayout:
cols: 3
rows: 2
size_hint_y: None
height: dp(108)
padding: dp(8)
spacing: dp(16)
Button:
text: 'Populate list'
on_press: root.populate()
Button:
text: 'Sort list'
on_press: root.sort()
Button:
text: 'Clear list'
on_press: root.clear()
BoxLayout:
spacing: dp(8)
Button:
text: 'Insert new item'
on_press: root.insert(new_item_input.text)
TextInput:
id: new_item_input
size_hint_x: 0.6
hint_text: 'value'
padding: dp(10), dp(10), 0, 0
BoxLayout:
spacing: dp(8)
Button:
text: 'Update first item'
on_press: root.update(update_item_input.text)
TextInput:
id: update_item_input
size_hint_x: 0.6
hint_text: 'new value'
padding: dp(10), dp(10), 0, 0
Button:
text: 'Remove first item'
on_press: root.remove()
RecycleView:
id: rv
scroll_type: ['bars', 'content']
scroll_wheel_distance: dp(114)
bar_width: dp(10)
viewclass: 'Row'
RecycleBoxLayout:
default_size: None, dp(56)
default_size_hint: 1, None
size_hint_y: None
height: self.minimum_height
orientation: 'vertical'
spacing: dp(2)
<MessengerScreen>:
Button:
on_release: app.root.current = 'contacts'
text: 'back to the home screen'
font_size: 50
'''
class ContactsScreen(Screen):
def populate(self):
self.rv.data = [
{'name.text': ''.join(sample(ascii_lowercase, 6)),
'value': str(randint(0, 2000))}
for x in range(50)]
def sort(self):
self.rv.data = sorted(self.rv.data, key=lambda x: x['name.text'])
def clear(self):
self.rv.data = []
def insert(self, value):
self.rv.data.insert(0, {
'name.text': value or 'default value', 'value': 'unknown'})
def update(self, value):
if self.rv.data:
self.rv.data[0]['name.text'] = value or 'default new value'
self.rv.refresh_from_data()
def remove(self):
if self.rv.data:
self.rv.data.pop(0)
class MessengerScreen(Screen):
pass
class ScreenManagement(ScreenManager):
pass
presentation = Builder.load_string(kv)
class MainApp(App):
def build(self):
return presentation
def main_runner(self):
async def run_wrapper():
# we don't actually need to set asyncio as the lib because it is
# the default, but it doesn't hurt to be explicit
await self.async_run(async_lib='asyncio')
print('App done')
#self.other_task.cancel()
return asyncio.gather(run_wrapper())
if __name__ == '__main__':
loop = asyncio.get_event_loop()
loop.run_until_complete(MainApp().main_runner())
loop.close()
The trouble seems to come from the <Row#RecycleKVIDsDataViewBehavior+BoxLayout> directive but I can't seem to fix it no matter where I place it.

Answer 1

You can position the Buttons using pos_hint, like this:
GridLayout:
id: grid
pos_hint: {'center_x': 0.5, 'top': 1}
Then, you need to size the RecycleView so that it is not over the Buttons, like this:
RecycleView:
id: rv
size_hint_y: None
height: root.height - grid.height