GUIs 2.12

from guizero import App, TextBox, PushButton, Box, Combo, CheckBox, Slider, MenuBar

def open_file():
    with open(file_name.value, "r") as f:
        editor.value = f.read()

def save_file():
    with open(file_name.value, "w") as f:
        f.write(editor.value)
    # Disable the save_button
    save_button.disable()
    # Enable the open_button
    open_button.enable()

def change_font():
    editor.font = font.value

def change_text_size():
    editor.text_size = size.value
    editor.resize(1, 1)
    editor.resize("fill", "fill")

def change_font_colour():
    editor.text_color = font_colour.value

def change_bg_color(col):
    editor.bg = col

def enable_save():
    save_button.enable()
    open_button.disable()

def preference_control_toggle():
    if preference_chkbox.value == True:
        preferences_controls.show()
    else:
        preferences_controls.hide()

def dark_mode():
    if dark_chkbox.value == True:
        editor.bg = "black"
        editor.text_color = "white"
        dark_chkbox.value = False
    else:
        editor.bg = "white"
        editor.text_color = "black"
        dark_chkbox.value = True

def exit_app():
    if save_button.enabled == True:
        app.warn("Warning!", "You have not saved the changes")
    else:
        app.destroy()

app = App(title="textzero")

# Menu bar
menubar = MenuBar(app,
        # These are the menu options
        toplevel=["File", "Edit", "Background"],
        # The options are recorded in a nested lists, one list for each menu option
        # Each option is a list containing a name and a function
        options=[[ ["Open file", open_file], ["Save file", save_file], ["Exit",exit_app] ],
                 [ ["Change font", change_font], ["Change text size", change_text_size], ["Change font colour", change_font_colour] ],
                 [["Orange",lambda: change_bg_color('orange')], ["Yellow",lambda: change_bg_color('yellow')],
                  ["magenta",lambda: change_bg_color('magenta')], ["Reset",lambda: change_bg_color('white')]]
                 ])

# One box to house the controls
file_controls = Box(app, align="bottom", width="fill", border=True)
preferences_controls = Box(app, align="top", width="fill", border=True, visible=False)
preference_chkbox = CheckBox(file_controls, text="View options", align="left", command=preference_control_toggle)
dark_chkbox = CheckBox(file_controls, text="Dark", align="right", command=dark_mode)

# One slider for font sizes
size = Slider(preferences_controls,  align="left", start = 8, end = 18, command=change_text_size)

# Font controls
font = Combo(preferences_controls, options=["Courier", "Century Gothic", "Verdana"], align="left", command=change_font)
font_colour = Combo(preferences_controls, options=["black", "orange", "purple"], align="right", command=change_font_colour)

# File name text box
file_name = TextBox(file_controls, text="text_file.txt", width=24, align="left")

# Buttons
save_button = PushButton(file_controls, text="Save", command=save_file, align="right", enabled=False)
open_button = PushButton(file_controls, text="Open", command=open_file, align="right")

# TextBox to fill remainder of GUI
editor = TextBox(app, multiline=True, height="fill", width="fill", command=enable_save)

app.display()