PySimpleGUI/DemoPrograms/Demo_PIL_Toggle_Button.py

from io import BytesIO
from PIL import Image, ImageDraw, ImageFont
import PySimpleGUI as sg

"""
    Demo Toggle Buttons created using PIL

    A BIG thank you to @jason990420 for his talented work creating this demo.

    Demonstrates how you can draw buttons rather than using the built-in buttons
    with the help of the PIL module.

    One advantage is that the buttons will match your window's theme.

    You'll find more PySimpleGUI programs featured in 
    Mike Driscoll's PIL book - "Pillow: Image Processing with Python"

    Copyright 2021 PySimpleGUI, @jason990420 
"""


def im_to_data(im):
    """
    Convert a PIL.Image.Image to a bytes image
    :param im: Image
    :type: PIL.Image.Image object
    :return image in bytes
    :type: bytes
    """
    with BytesIO() as buffer:
        im.save(buffer, format='PNG')
        data = buffer.getvalue()
    return data


def toggle_button(button_color=None, size=(100, 40), on=True):
    """

    :return image in bytes
    :type: bytes
    """
    pad, radius, spacing = 5, 10, 5
    w, h = size
    c1, c2 = button_color if button_color else (sg.theme_input_background_color(), sg.theme_background_color())
    im = Image.new("RGBA", (w, h), (255, 255, 255, 0))
    draw = ImageDraw.Draw(im)
    draw.rounded_rectangle((0, 0, w - 1, h - 1), fill=c1, width=3, radius=radius)
    if on:
        draw.rounded_rectangle((2, 2, w - size[1], h - 3), fill=c2, width=3, radius=radius)
    else:
        draw.rounded_rectangle((size[1], 2, w - 2, h - 3), fill=c2, width=3, radius=radius)

    return im_to_data(im)




sg.theme("dark red")
# sg.theme("dark green 7")
# sg.theme("dark gray 13")
button_on = toggle_button()
button_off = toggle_button(on=False)
layout = [[sg.T('PIL Made Toggle Buttons')],
          [sg.T('On'), sg.Button(image_data=button_on, button_color=(sg.theme_background_color(), sg.theme_background_color()), border_width=0, k='-B1-', metadata=True), sg.T('Off')],
          [sg.Button(image_data=button_off, button_color=(sg.theme_background_color(), sg.theme_background_color()), border_width=0,  k='-B2-', metadata=False)]]


window = sg.Window('PIL Buttons', layout, finalize=True, element_justification='c', use_custom_titlebar=True, font='_ 18', keep_on_top=True)

while True:

    event, values = window.read()
    if event in (sg.WINDOW_CLOSED, "Exit"):
        break
    window[event].metadata = not window[event].metadata
    window[event].update(image_data=button_on if window[event].metadata else button_off)

window.close()