#!/usr/bin/env python
import PySimpleGUI as sg


# Demonstrates a number of PySimpleGUI features including:
# Default element size
# auto_size_buttons
# Button
# Dictionary return values
# update of elements in form (Text, Input)


layout = [[sg.Text('Enter Your Passcode')],
 [sg.Input('', size=(10, 1), key='input')],
 [sg.Button('1'), sg.Button('2'), sg.Button('3')],
 [sg.Button('4'), sg.Button('5'), sg.Button('6')],
 [sg.Button('7'), sg.Button('8'), sg.Button('9')],
 [sg.Button('Submit'), sg.Button('0'), sg.Button('Clear')],
 [sg.Text('', size=(15, 1), font=('Helvetica', 18),
 text_color='red', key='out')],
 ]

window = sg.Window('Keypad', layout,
 default_button_element_size=(5, 2),
 auto_size_buttons=False,
 grab_anywhere=False)

# Loop forever reading the form's values, updating the Input field
keys_entered = ''
while True:
 event, values = window.read() # read the form
 if event is None: # if the X button clicked, just exit
 break
 if event == 'Clear': # clear keys if clear button
 keys_entered = ''
 elif event in '1234567890':
 keys_entered = values['input'] # get what's been entered so far
 keys_entered += event # add the new digit
 elif event == 'Submit':
 keys_entered = values['input']
 window['out'].update(keys_entered) # output the final string

 # change the form to reflect current key string
 window['input'].update(keys_entered)
window.close()