Python GUI for reMarkable sync script

sync_gui.py

#!/usr/bin/env python3

import os
import tkinter as tk
from tkinter import filedialog
from tkinter import ttk
from tkinter import scrolledtext
import time
import threading

class DirectoryPicker(tk.Button):
    """
    Subclass of tkinter button.
    Button that shows folder selection dialog on click and selected folder path as text.
    """
    def __init__(self, root, *args, **kwargs):
        super().__init__(root, *args, **kwargs)
        self.directory = None
        self.root = root
        self.placeholder = 'Select a folder'
        self.configure(text=self.placeholder)
        self.configure(command=self.openDirectory)

    def openDirectory(self):
        home = os.path.expanduser('~')
        path = filedialog.askdirectory(parent=self.root, initialdir=home, title=self.placeholder)
        self["text"] = str(path) if path else self.placeholder
        self.directory = path

class App():
    """
    GUI using tkinter. Shows main window with .show().
    Pass a function in the constructor to be executed when the start button is clicked.
    The function is passed a dictionary of the arguments set in the GUI elements.
    """
    def __init__(self, worker_function):
        self.root = tk.Tk()
        self.root.title('reSyncable')
        self.setupWidgets()
        self.worker_function = worker_function

    def show(self):
        # Place window in middle of screen
        self.root.eval('tk::PlaceWindow %s center' % self.root.winfo_pathname(self.root.winfo_id()))
        self.root.mainloop()

    def run(self):
        """
        Function that is called when the start button is clicked.
        Collects all the arguments to be passed to the worked function
        and runs it in a spearate thread, so the main UI remains responsive.
        """
        args = {
            'sync_dir': self.sync_dir_btn["text"],
            'another_dir': self.another_dir_btn['text'],
            'third_dir': self.third_dir_btn['text']
        }
        threading.Thread(target=self.worker_function, args=[args]).start()

    def set_active(self, bool_val):
        if bool_val:
            self.start_btn['state'] = 'disabled'
            self.progress.grid(column=0, row=6, columnspan=2, sticky=tk.W+tk.E)
            self.progress.start()
        else:
            self.start_btn['state'] = 'normal'
            self.progress.stop()
            self.progress.grid_forget()

    def write(self, text):
        """
        Write to the text area at the bottom of the GUI.
        """
        self.log.configure(state='normal')
        self.log.insert(tk.END, text + '\n')
        self.log.yview(tk.END) # Autoscroll to the bottom
        self.log.configure(state='disabled')

    def setupWidgets(self):
        # Folder selection dialog
        tk.Label(self.root, text="Sync directory").grid(row=0, sticky=tk.W)
        self.sync_dir_btn = DirectoryPicker(self.root, padx=10)
        self.sync_dir_btn.grid(row=0, column=1, padx=(10, 0), sticky=tk.W)

        tk.Label(self.root, text="Another directory").grid(row=1, sticky=tk.W)
        self.another_dir_btn = DirectoryPicker(self.root, padx=10)
        self.another_dir_btn.grid(row=1, column=1, padx=(10, 0), sticky=tk.W)

        tk.Label(self.root, text="A third directory").grid(row=2, sticky=tk.W)
        self.third_dir_btn = DirectoryPicker(self.root, padx=10)
        self.third_dir_btn.grid(row=2, column=1, padx=(10, 0), sticky=tk.W)

        self.start_btn = tk.Button(self.root, text="Start syncing", padx=20, command=self.run)
        self.start_btn.grid(column=0, row=4, columnspan=2, pady=10)

        self.log = scrolledtext.ScrolledText(self.root, width=40, height=10)
        self.log.configure(font='TkFixedFont')
        self.log.configure(state='disabled')
        self.log.grid(column=0, row=5, columnspan=2, sticky=tk.W+tk.E)

        self.progress = ttk.Progressbar(self.root, orient="horizontal", mode="indeterminate")


if __name__ == "__main__":

    def worker(args):
        app.set_active(True)
        # this is where the actual work is being done
        app.write('Started syncing')
        app.write('Got args: {}'.format(args))
        for _ in range(3):
            # Report time / date at 1-second intervals
            app.write('Current time: ' + time.asctime())
            time.sleep(1)
        app.write('Done syncing')
        app.set_active(False)

    app = App(worker)
    app.show()