from guizero import App, TextBox, PushButton, Box

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

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

def incfont():
    editor.text_size=editor.text_size+1


def decfont():
    editor.text_size=editor.text_size-1

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", command=open_file)

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

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

label="F"+chr(8593)
#create a button that will inc the font size
fontup = PushButton(file_controls, text=label,command=incfont,  align="right")

label="F"+chr(8595)
#create a button that will inc the font size
fontdown = PushButton(file_controls, text=label,command=decfont,  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")

app.display()