Initial Checkin of Button Toggle Demo

DemoPrograms/Demo_Button_Toggle.py

@@ -0,0 +1,24 @@
+import PySimpleGUI as sg
+
+"""
+    Toggle Button Demo
+    The background color of the button toggles between red and green
+    The text of the button toggles between Off and On
+"""
+
+layout = [[sg.Text('A toggle button example')],
+          [sg.Button('On', size=(3,1), button_color=('white', 'green'), key='_B_'), sg.Button('Exit')]]
+
+window = sg.Window('Toggle Button Example', layout)
+
+down = True
+
+while True:             # Event Loop
+    event, values = window.Read()
+    if event in (None, 'Exit'):
+        break
+    elif event == '_B_':
+        down = not down
+        window.Element('_B_').Update(('Off','On')[down], button_color=(('white', ('red', 'green')[down])))
+
+window.Close()