import ui

def button_tapped(sender):
    if sender.title == 'Hello':
    	sender.title = 'Stop that!'
    	#view.size_to_fit()

    if sender.title == 'Tap me!':
    	sender.title = 'Hello'
    	#view.size_to_fit()


view = ui.View()                                      # [1]
view.name = 'Demo'                             # [2]
view.background_color = 'white'                       # [3]
button = ui.Button(title='Tap me!')                   # [4]
button.center = (view.width * 0.5, view.height * 0.5) # [5]
button.flex = 'LRTB'                                  # [6]
button.action = button_tapped                         # [7]
view.add_subview(button)                              # [8]
view.present(style = 'sheet')                                 # [