[Tkinter] Background inactivity timer when tkinter window is not active

[deanhystad]

This works fine for me.

import tkinter as tk
from ctypes import Structure, windll, c_uint, sizeof, byref

class LASTINPUTINFO(Structure):
    _fields_ = [
        ('cbSize', c_uint),
        ('dwTime', c_uint),
    ]

def get_idle_duration():
    lastInputInfo = LASTINPUTINFO()
    lastInputInfo.cbSize = sizeof(lastInputInfo)
    windll.user32.GetLastInputInfo(byref(lastInputInfo))
    count = windll.kernel32.GetTickCount()
    return (count - lastInputInfo.dwTime) / 1000.0

class Window(tk.Tk):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.counter = tk.IntVar(self, 0)
        self.timer = tk.DoubleVar(self, 0.0)
        tk.Label(self, textvariable=self.counter, width=20).pack(padx=10, pady=10)
        tk.Button(self, text="Iconify", command=self.iconify).pack(padx=10, pady=10)
        self.update()

    def update(self):
        self.counter.set(self.counter.get() + 1)
        if get_idle_duration() > 10.0:
            print("Time to wake up!")
            self.deiconify()
        self.after(1000, self.update)

Window().mainloop()

It also works if the Iconify button calls withdraw() instead of iconify().