Kivy. Position of GridLayout inside ScrollView - kivy

Question

I give up. I think I have tried everything I possibly could. I need some explatanion how to position nested layouts classes. In below code I need these labels to be positioned in the center of the screen. Anything I've tried leaves the Labels on the left side.
from kivy.app import App
from kivy.lang import Builder
kv = """
<StorageLabel#Label>
background_normal: ''
size_hint: None, None
size: 65, 50
canvas.before:
Color:
rgba: (1, 0, 0.5, 1)
Rectangle:
pos: self.pos
size: self.size
halign: "left"
valign: "middle"
<Storage#BoxLayout>
ScrollView:
size_hint_x: 1
bar_width: 10
scroll_type: ['bars', 'content']
bar_color: [0, 0, 0, 1]
bar_inactive_color: [0, 0, 0, 1]
pos_hint: {'center_x': 0.5}
GridLayout:
cols: 3
size_hint_y: None
size: self.minimum_size
height: self.minimum_height
StorageLabel:
text: '1m'
StorageLabel:
text: '2m'
StorageLabel:
text: '3m'
Storage:
"""
sm = Builder.load_string(kv)
class Main(App):
def build(self):
return sm
if __name__ == '__main__':
Main().run()

Answer 1

The easiest way to center the Labels is to let the GridLayout size and position them. This results in a larger width for each Label, but they are centered:
from kivy.app import App
from kivy.lang import Builder
kv = """
<StorageLabel#Label>
background_normal: ''
# leave size_hint_x at default of 1
size_hint_y: None
height: 50
canvas.before:
Color:
rgba: (1, 0, 0.5, 1)
Rectangle:
pos: self.pos
size: self.size
<Storage#BoxLayout>
ScrollView:
size_hint_x: 1
bar_width: 10
scroll_type: ['bars', 'content']
bar_color: [0, 0, 0, 1]
bar_inactive_color: [0, 0, 0, 1]
pos_hint: {'center_x': 0.5}
GridLayout:
cols: 3
# add some padding and spacing
padding: 5
spacing: 5
size_hint_y: None
height: self.minimum_height
StorageLabel:
text: '1m'
StorageLabel:
text: '2m'
StorageLabel:
text: '3m'
Storage:
"""
sm = Builder.load_string(kv)
class Main(App):
def build(self):
return sm
if __name__ == '__main__':
Main().run()
If you want the labels to be your original size, then you can place each in its own Layout (perhaps a FloatLayout), and let the GridLayout size and position those Layouts:
from kivy.app import App
from kivy.lang import Builder
kv = """
<StorageLabel#Label>
background_normal: ''
size_hint: None, None
size: 65, 50
# position the label in the center of its FloatLayout
pos_hint: {'center_x':0.5}
canvas.before:
Color:
rgba: (1, 0, 0.5, 1)
Rectangle:
pos: self.pos
size: self.size
<Storage#BoxLayout>
ScrollView:
size_hint_x: 1
bar_width: 10
scroll_type: ['bars', 'content']
bar_color: [0, 0, 0, 1]
bar_inactive_color: [0, 0, 0, 1]
pos_hint: {'center_x': 0.5}
GridLayout:
cols: 3
size_hint_y: None
height: self.minimum_height
# set the default row height to the height of the Labels
row_default_height: 50
FloatLayout:
StorageLabel:
text: '1m'
FloatLayout:
StorageLabel:
text: '2m'
FloatLayout:
StorageLabel:
text: '3m'
Storage:
"""
sm = Builder.load_string(kv)
class Main(App):
def build(self):
return sm
if __name__ == '__main__':
Main().run()