Text Editor v4

from guizero import App, Box, PushButton, TextBox, Combo, Text, info, Window, MenuBar, CheckBox

# Event Handlers

def btnSaveClicked():
    global fileSaved
    f =  open(txtFilename.value, "w")
    f.write(txtEditor.value)
    f.close()
    info('SAVE','Your file has been saved')
    fileSaved = True

def btnLoadClicked():
    with open(txtFilename.value, "r") as f:
        txtEditor.value = f.read()

def btnExitClicked():
    if fileSaved:
        app.destroy()
    else:
        openSaveWindow()

def ChangeBgcolour():
    boxEditor.bg = cboChangeBg.value
    bgWindow.hide()

def btnChangeFontSize():
    fontSizeWindow.show(wait=True)

def btnChangeFont():
    fontWindow.show(wait = True)

def btnChangeBg():
    bgWindow.show(wait = True)

def FontChanged():
    boxEditor.font = cboChangeFont.value
    fontWindow.hide()

def ChangeFontSize():
    boxEditor.text_size = int(cboChangeFontSize.value)
    fontSizeWindow.hide()

def cboCancel():
    fontWindow.hide()

def cboCancel2():
    fontSizeWindow.hide()

def cboCancel3():
    bgWindow.hide()

def cboCancel4():
    saveWindow.hide()

def textChanged():
    global fileSaved
    fileSaved = False

def openSaveWindow():
    saveWindow.show(wait=True)

def confirmExit():
    app.destroy()

def darkMode():
    if chkDark.value == 1:
        boxEditor.bg = 'black'
        boxEditor.text_color = 'white'
    else:
        boxEditor.bg = 'light yellow'
        boxEditor.text_color = 'black'

# Main App WIndow

app = App(title="Text Editor",width="800",height="600")
fileSaved = False

# Menu Bar
menubar = MenuBar(app,
                  toplevel=["File", "Appearance"],
                  options=[
                      [ ["Open", btnLoadClicked], ["Save", btnSaveClicked], ['Exit', btnExitClicked ] ],
                      [ ["Font", btnChangeFont], ["Font Size", btnChangeFontSize], ["Background", btnChangeBg ] ]
                  ])

# GUI widgets

boxFileControls = Box(app, align="top", width='fill', height = 30)
boxFileControls.bg = "white"
boxFileControls.text_color = 'black'
lblFilename = Text(boxFileControls, text = 'Filename: ', align = 'left' ,color = 'red')
lblFilename.text_size = 10
txtFilename = TextBox(boxFileControls, text = 'editor.txt', width = 30, height = 'fill', align = 'left')
txtFilename.text_size =10
chkDark = CheckBox(boxFileControls, text="Dark Mode", align = 'right', command = darkMode)

#..............................................................................

boxEditor = Box(app, align = 'top', width='fill', height = 'fill', border = 1)
boxEditor.bg = 'light yellow'
boxEditor.font ='Palatino Linotype'
txtEditor = TextBox(boxEditor, width = 'fill', height = 'fill', multiline = True, scrollbar = True, command = textChanged)

#..............................................................................

# Windows

# Font Window
fontWindow = Window(app,"Change Font",width = 300, height = 200)
fontWindow.bg = 'light blue'
fontWindow.font='Segoe Ui'
fontWindow.hide()

lblChangeFont = Text(fontWindow, text = "Select a font", align='top')
cboChangeFont = Combo(fontWindow, options = ['Times New Roman','Courier New', 'Palatino Linotype', 'Segoe UI'],align = 'top')
btnSubmit1 = PushButton(fontWindow, text = 'OK', align = 'left', width = 20, command = FontChanged)
btnCancel1 = PushButton(fontWindow, text = 'CANCEL', align = 'left', width = 20, command = cboCancel)

# Font Size Window
fontSizeWindow = Window(app,"Change Font Size",width = 300, height = 200)
fontSizeWindow.bg = 'light blue'
fontSizeWindow.font='Segoe Ui'
fontSizeWindow.hide()

lblChangeFontSize = Text(fontSizeWindow, text = "Select a size",align="top")
cboChangeFontSize = Combo(fontSizeWindow, options = ['10','12','14','16','18','36'],align="top")
btnSubmit2 = PushButton(fontSizeWindow, text = 'OK', align = 'left', width = 20, command = ChangeFontSize)
btnCancel2 = PushButton(fontSizeWindow, text = 'CANCEL', align = 'left', width = 20, command = cboCancel2)

# Background Colour Window
bgWindow = Window(app,"Change Background Colour",width = 300, height = 200)
bgWindow.bg = 'light blue'
bgWindow.font='Segoe Ui'
bgWindow.hide()

lblChangeBg= Text(bgWindow, text = "Select a colour",align="top")
cboChangeBg = Combo(bgWindow, options = ['light yellow','honeydew','light blue','lavender','pink'],align="top")
btnSubmit3 = PushButton(bgWindow, text = 'OK', align = 'left', width = 20, command = ChangeBgcolour)
btnCancel3 = PushButton(bgWindow, text = 'CANCEL', align = 'left', width = 20, command = cboCancel3)

# Save Window
saveWindow = Window(app,"WARNING",width = 400, height = 70)
saveWindow.bg = 'yellow2'
saveWindow.font='Segoe Ui'
saveWindow.hide()

lblWarning = Text(saveWindow, text = 'Your file has not been saved. Do you really want to exit?', color = 'red')
btnOK = PushButton(saveWindow, text = 'OK', align = 'left', width = 20, command = confirmExit)
btnCancel4 = PushButton(saveWindow, text = 'CANCEL', align = 'right', width = 20, command = cboCancel4)

#..............................................................................

# Show the GUI on the screen

app.display()