Text Editor enable widgets V4

### Text Editor V4 enable widgets 05/05/2022
from guizero import App, TextBox, PushButton, Box, Combo, Slider

# function for reading files
def open_file():
    with open(file_name.value, "r") as f:
        editor.value = f.read()

def enable_save():
    save_button.enable()

def disable_save():
    save_button.disable()

# function for writing files
def save_file():
    with open(file_name.value, "w") as f:
        f.write(editor.value)
    save_button.disable()

# function for changing fonts
def change_font():
    editor.font = font.value

def change_text_size():
    editor.text_size = size.value
    '''
    resize the widget because if the text is made bigger,
    this might affect the size of the TextBox so guizero
    needs to know how to maintain the intended layout
    '''
    editor.resize(1, 1)
    editor.resize("fill", "fill")

# function for changing text colour
def change_font_color():
    choice = font_color.value
    if choice == "Red":
        editor.text_color = "Red"
    if choice == "Green":
        editor.text_color = "Green"
    if choice == "Blue":
        editor.text_color = "Blue"
    if choice == "None":
        editor.text_color = None


app = App(title="texteditor")

# create a box to house the controls, we want the box to span the entire width of the app
file_controls = Box(app, align="top", width="fill")

# create a TextBox for the file name
file_name = TextBox(file_controls, text="text_file.txt", width=50, align="left")

# create a save button which uses the save_file function
save_button = PushButton(file_controls, text="Save", command=save_file, align="right", enabled=False)

# create an open button which uses the open_file function
open_button = PushButton(file_controls, text="Open", command=open_file, align="right")

# create a TextBox which is not in the box and fills the rest of the GUI
editor = TextBox(app, multiline=True, height="fill", width="fill", command=enable_save)

# create a box to house the controls at the bottom, add a font combobox and size slider
preferences_controls = Box(app, align="bottom", width="fill", border=True)

font = Combo(preferences_controls, options=["courier", "times new roman", "verdana"], align="left", command=change_font)
size = Slider(preferences_controls,  align="right", command=change_text_size, start=8, end=42)
font_color = Combo(preferences_controls, options=["Red", "Green", "Blue", "Reset"], align="bottom", command=change_font_color)

app.display()