Kivy datepicker overstretches in Stacklayout

[Ronald-Saunfe]

When i open the Kivy datepicker widget it overstretches horizontally , i dont know if it uses the srollview width . here is the code, i am using kivy 1.10.0 python 3.6.4

from kivy.app import App
from kivy.uix.stacklayout import StackLayout
from kivy.uix.floatlayout import FloatLayout
from kivy.uix.scrollview import ScrollView
from kivy.uix.button import Button
import datepicker # the datepicker module or the kivy calendar

class example(FloatLayout):
    def __init__(self,**kwargs):
        super(example,self).__init__(**kwargs)
        self.scroll=ScrollView(size_hint=(1,1))
        self.layout=StackLayout(size_hint_x=(None),orientation='tb-lr')
        self.layout.bind(minimum_width=self.layout.setter('width'))
        self.scroll.add_widget(self.layout)
        self.add_widget(self.scroll)
        
        for i in range(10):
            
            a = datepicker.DatePicker(size_hint_x=(None), width=200)
            self.layout.add_widget(a)
        

class MainApp(App):
    def build(self):
        return example()

if __name__=='__main__':
    MainApp().run()