Python GUI guizero: Text Edit prototype with Colour Picker

# This Python code implements a prototype Text Editor with basic Colour Picker.
# Colours are specified in RGB format. Text can be written to / read from file.
# It is a demo of the GUI guizero (with Slider command)
#
# guizero works with tkinter but simpler with extra widgets eg. Slider
# https://lawsie.github.io/guizero/slider/

# This code is refactored / fixed by JD.
from guizero import *
app = App( width=700, height=600, title='Chochi Chode')

#----------------------------------
def showColor():
    # get current values from Sliders
    red   = c1Slider.value
    green = c2Slider.value
    blue  = c3Slider.value
    # notify Views ..
    colorSelect.value = "("+str(red)+", "+str(green)+", "+str(blue)+")"

    nombre =  [red,green,blue] # specify color in list format [ iR, iG, iB ]
    colorBox.bg = nombre
    txt_archive.text_color = nombre # set color of font in edit area
#----------------------------------

def open_file():
    if ( not (txt_name.value)):
        app.error("NO filename provided", "Please provide a filename to Open ..")
    else:
        with open(txt_name.value, 'r') as f:
            txt_archive.value = f.read()

def save_file():
    if ( not (txt_name.value)):
        app.error("NO filename provided", "Please provide a filename to Save to ..")
    else:
        with open(txt_name.value, 'w') as f:
            f.write(txt_archive.value)

#----------------------------------------
editFontSize = 14 # global value in Model : font size initial value

def incFontSize(): # increment + 2
    global editFontSize
    editFontSize += 2
    # notify View ..
    txt_archive.text_size = editFontSize

def decFontSize(): # decrement - 2
    global editFontSize
    editFontSize -= 2
    if (editFontSize < 6 ): editFontSize = 6  # min limit
    # notify View ..
    txt_archive.text_size = editFontSize
#----------------------------------------
""" REPLACED WITH CODE ABOVE.
# CALLED FROM PushButton: command = myFunctionName
# .. NO ARGUMENT is passed.
# myFunctionName evaluates to a "reference to the function" so named. This ref can then be used to call the function later eg. on event ..
# myFunctionName() is a direct call to execute the function and evaluates to the return value of the function.
#-----------------

def fontSize(font):
    print("in fontSize") # debug
    if font == 'b':
        txt_archive.text_size = archive_txt_size+2
    else:
        txt_archive.text_size = archive_txt_size-2
"""
def fontColor():
    colors.visible = True

def clear_text():
    if ( app.yesno("RESET editor text", "Clear ALL editor text ?") ): txt_archive.value = ""

###################
# declare Widgets #
# --------------- #
colors = Window( app, title='Color Select', width=300, height=300, visible=False )  # pop-up: initially NOT VISIBLE
colorSelect = Text(colors, size=16, align='top', text='El color creado se vera aqui')
colorBox    = Box(colors, width=100,height=100)

t1Slider = Text(colors, text='Red',align='left')
c1Slider = Slider(colors,start=0,end=255,horizontal=False,align='left',command=showColor)
t2Slider = Text(colors, text='Green',align='left')
c2Slider = Slider(colors,start=0,end=255,horizontal=False,align='left',command=showColor)
t3Slider = Text(colors, text='Blue',align='left')
c3Slider = Slider(colors,start=0,end=255,horizontal=False,align='left',command=showColor)
#----------------

caja_header = Box(app,align='top',width='fill')

label_name = Text(caja_header, text='Nombre del archivo - FILE PATH', align='left')
txt_name   = TextBox(caja_header, align='left',width=20)
btn_open   = PushButton(caja_header, command=open_file, text='Abrir - OPEN',align='right')
btn_save   = PushButton(caja_header, command=save_file, text='Guardar - SAVE',align='right')
btn_clear  = PushButton(caja_header, command=clear_text, text='Clear ALL',align='right')  # reset text

#----------------
viewOptions = Box(app, width='fill', align='bottom' ) # new Box for bottom alignment of View controls
btn_font_bigger  = PushButton(viewOptions, command=incFontSize, text='A+',align='left')
btn_font_smaller = PushButton(viewOptions, command=decFontSize, text='A-',align='left')
#btn_font_smaller = PushButton(app, fontColor, text='FC',align='left') # paste error .. rename follows ...
btn_color_window = PushButton(viewOptions, fontColor, text='FC - COLOR',align='left')
#=======================
# finally, the EDIT area .. take all available space. Maybe align='bottom' to stack on top of viewOptions Box
startTxt = "Template text for initial styling.\n\n" +\
           "After choosing View options below, please click [Clear ALL] or [Abrir - OPEN] to continue .."
txt_archive = TextBox(app, height='fill', width='fill', multiline=True, scrollbar=True, text=startTxt ) # scrollbar is handy !
txt_archive.text_size = editFontSize # SET INITIAL SIZE of font in the EDIT area
txt_archive.focus() # ready for input ..


app.display()