Timer Widget

This simple data entry form accepts user input and then prints it to the screen when submitted. The overall theme is flatly and various styles are applied to the buttons depending on state and function:

Start

style="info.TButton"

Pause

style="info.Outline.TButton"

Reset

style="success.TButton"

Exit

style="danger.TButton"

timer is running

timer is paused

Run this code live on repl.it

"""
    Author: Israe Dryer
    Modified: 2021-04-07
    Adapted for ttkbootstrap from: https://github.com/PySimpleGUI/PySimpleGUI/blob/master/DemoPrograms/Demo_Desktop_Widget_Timer.py
"""
import tkinter
from tkinter import ttk
from ttkbootstrap import Style


class Application(tkinter.Tk):

    def __init__(self):
        super().__init__()
        self.title('Timer')
        self.style = Style()
        self.timer = TimerWidget(self)
        self.timer.pack(fill='both', expand='yes')


class TimerWidget(ttk.Frame):

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)

        # variables
        self.running = tkinter.BooleanVar(value=False)
        self.after_id = tkinter.StringVar()
        self.time_elapsed = tkinter.IntVar()
        self.time_text = tkinter.StringVar(value='00:00:00')

        # timer label
        self.timer_lbl = ttk.Label(self, font='-size 32', anchor='center', textvariable=self.time_text)
        self.timer_lbl.pack(side='top', fill='x', padx=60, pady=20)

        # control buttons
        self.toggle_btn = ttk.Button(self, text='Start', width=10, style='info.TButton', command=self.toggle)
        self.toggle_btn.pack(side='left', fill='x', expand='yes', padx=10, pady=10)

        self.reset_btn = ttk.Button(self, text='Reset', width=10, style='success.TButton', command=self.reset)
        self.reset_btn.pack(side='left', fill='x', expand='yes', pady=10)

        self.quit_btn = ttk.Button(self, text='Quit', width=10, style='danger.TButton', command=self.quit)
        self.quit_btn.pack(side='left', fill='x', expand='yes', padx=10, pady=10)

    def toggle(self):
        if self.running.get():
            self.pause()
            self.running.set(False)
            self.toggle_btn.configure(text='Start', style='info.TButton')
        else:
            self.start()
            self.running.set(True)
            self.toggle_btn.configure(text='Pause', style='info.Outline.TButton')

    def pause(self):
        self.after_cancel(self.after_id.get())

    def start(self):
        self.after_id.set(self.after(1, self.increment))

    def increment(self):
        current = self.time_elapsed.get() + 1
        self.time_elapsed.set(current)
        time_str = '{:02d}:{:02d}:{:02d}'.format((current // 100) // 60, (current // 100) % 60, current % 100)
        self.time_text.set(time_str)
        self.after_id.set(self.after(100, self.increment))

    def reset(self):
        self.time_elapsed.set(0)
        self.time_text.set('00:00:00')


if __name__ == '__main__':
    Application().mainloop()