How can I bind the spacebar to 2 functions on Tkinter?

Question

so I'm trying to make a timer (like cstimer.net) and I got this problem

I have binded the spacebar to start the timer, and then, once you started the timer, hitting it again would stop it. The problem is that when I hit the spacebar, it starts and finishes the timer. And the time, would not reset, it would just add the elapsed time to the last time.

Here's what I've done:

import pyglet
import os
import time
from tkinter import *

# Import scripts
import sys
sys.path.insert(1, './scripts')

import scrambler
import timer
import saver

class Application():
    def __init__(self, app):
        self.app = app

        pyglet.font.add_file('./data/fonts/DS-DIGIB.TTF')  # Add the time font
        # Add the body (used for scramble and more elements) font
        pyglet.font.add_file('./data/fonts/OverPassMono-Light.ttf')

        # Create side panel
        self.sidepanel = Frame(self.app, bg='red', width=200, height=800)

        # Generate scramble
        self.scramble_output = scrambler.gen_333scramble()

        #Bind spacebar to start timer
        self.app.bind('<Key>', self.updater_start)

        # Define button, start time and scramble Widget and show them
        self.display = Label(self.app, text='0.00', bg='#232931', fg='white', anchor=CENTER, font=('DS-DIGITAL', 64), pady=100)
        self.scramble = Label(self.app, text=self.scramble_output, bg='#232931', fg='white', font=('Overpass Mono Light', 12), anchor=NW)
        self.start_button = Button(self.app, text='Start', fg='white', bg='#4ecca3', command=self.start, anchor=CENTER)
            
        #Show in grid
        self.display.grid(row=1, column=1, sticky=EW, padx=275, pady=150)
        self.start_button.grid(row=2, column=1, columnspan=2, padx=275, sticky=N, ipadx=20)
        self.scramble.grid(row=0, column=1, sticky=EW, padx=275)


    def start(self):
        # Unshow last time or starting time
        self.display.grid_remove()

        # Start counting time
        self.start_time = timer.start()

        #Bind spacebar to stop timer

        self.app.bind('<Key>', self.updater_stop)

         # Create widgets to show the timer is running and finish button
        self.state = Label(self.app, text='.', bg='#232931', fg='white', font=('DS-DIGITAL', 32))
        self.state.grid(row=1, column=1, sticky=EW, padx=560, pady=300)
        self.finish_button = Button(self.app, text='FINISH', fg='white', bg='#4ecca3', command=self.finish)
        self.finish_button.grid(row=2, column=1, columnspan=2, padx=275, sticky=N, ipadx=20)

        # Unshow start button and scramble widgets

        self.start_button.grid_remove()
        self.scramble.grid_remove()

    def updater_start(self, e):  
        if e.keysym=='space':
            print('Hitted spacebar')
            self.start()

    def updater_stop(self, e):
        if e.keysym=='space':
            print('Hitted spacebar')
            self.finish()

    def finish(self):
        self.message = timer.finish(self.start_time)
        # Display formatted time
        self.display = Label(self.app, text=self.message, bg='#232931', fg='white', font=('DS-DIGITAL', 64), pady=100)


        #Save time on times.json
        saver.save_time(self.message, self.scramble_output)

        # Unshow state and finish button widgets
        self.finish_button.grid_remove()
        self.state.grid_remove()

        # Redefine widgets
        self.start_button = Button(self.app, text='Start', fg='white', bg='#4ecca3', command=self.start)
        self.scramble_output = scrambler.gen_333scramble()
        self.scramble = Label(self.app, text=self.scramble_output, bg='#232931', fg='white', font=('Overpass Mono Light', 12), anchor=NW)

        # Show widgets on screen and formatted time
        self.display.grid(row=1, column=1, sticky=EW, padx=275, pady=150)
        self.start_button.grid(row=2, column=1, columnspan=2, padx=275, sticky=N, ipadx=20)
        self.scramble.grid(row=0, column=1, sticky=EW, padx=275)

Just so you can know, saver , timer and scrambler modules are scripts I made so I can slice the code. Timer script just takes the time.time() variable at the start and subtracts it with the current time, and then it format its as hours:seconds:minutes.

Answer 1

I recommend making a variable for the number of space bar presses. When you bind the space bar, check if it is even (0, 2, 4, etc.). That means it should start . Otherwise, it should end .

from tkinter import *

root = Tk()
NUM_SPACE_PRESS = 0


def space_press(e):
    global NUM_SPACE_PRESS
    if NUM_SPACE_PRESS % 2 == 0:
        Label(text='<start here>').pack()
        NUM_SPACE_PRESS += 1
    else:
        Label(text='<end here>').pack()
        NUM_SPACE_PRESS += 1


root.bind("<space>", space_press)

root.mainloop()

Answer 2

You should use one function with variable ie. running with True/False to inform what to do - stop or start timer.

import tkinter as tk

def space_press(event):
    global running
        
    if running:
        l['text'] = 'timer stoped'
    else:
        l['text'] = 'timer started'

    # switch state
    running = not running

# --- main ---

running = False

root = tk.Tk()

l = tk.Label(root, text='press space')
l.pack()

root.bind("<space>", space_press)

root.mainloop()

Answer 3

You need to reset the "<space>" binding in finish() function.

Below is a modified example based on yours:

class Application():
    def __init__(self, app):
        ...
        self.bind(self.start) # replace self.app.bind("<Key>", self.updater_start)
        ...

    # added function
    def bind(self, callback=None):
        self.app.bind("<space>", callback)

    def start(self, event=None):
        self.bind()  # disable space binding when busy
        ...
        # removed self.app.bind("<Key>", self.updater_stop)
        ...
        self.bind(self.finish)

    def finish(self, event=None):
        self.bind()  # disable space binding when busy
        ...
        self.bind(self.start)

Note that I have removed updater_start() and updater_stop() functions.

Answer 4

Rather than create new widgets, update the values of the existing ones. I used a tk.after to update the timer and a True/False to start/stop the timer. Note certain imports are commented out for me to run it.

# import pyglet
# import os
import time
from datetime import timedelta
from tkinter import *


# Import scripts
# import sys
# sys.path.insert(1, './scripts')

# import scrambler
# import timer
# import saver

class Application():
    def __init__(self, app):
        self.app = app

        # pyglet.font.add_file('./data/fonts/DS-DIGIB.TTF')  # Add the time font
        # Add the body (used for scramble and more elements) font
        # pyglet.font.add_file('./data/fonts/OverPassMono-Light.ttf')

        # Create side panel
        self.sidepanel = Frame(self.app, bg='red', width=200, height=800)

        # Generate scramble
        self.scramble_output = 'scramble_output goes here' # scrambler.gen_333scramble()

        #Bind spacebar to start timer
        self.app.bind('<space>', self.toggle_timer_running)

        # Define button, start time and scramble Widget and show them
        self.display = Label(self.app, text='0.00', bg='#232931', fg='white', anchor=CENTER, font=('DS-DIGITAL', 64), pady=100)
        self.scramble = Label(self.app, text=self.scramble_output, bg='#232931', fg='white', font=('Overpass Mono Light', 12), anchor=NW)
        self.start_button = Button(self.app, text='Start', fg='white', bg='#4ecca3', command=self.toggle_timer_running, anchor=CENTER)
            
        #Show in grid
        self.display.grid(row=1, column=1, sticky=EW, padx=275, pady=150)
        self.start_button.grid(row=2, column=1, columnspan=2, padx=275, sticky=N, ipadx=20)
        self.scramble.grid(row=0, column=1, sticky=EW, padx=275)

        self._timer_running = False
        self.start_time = self.end_time = time.time()
        self.update()

    def toggle_timer_running(self, event=None):
        self._timer_running = not self._timer_running
        
        if self._timer_running:
            self.start_time = time.time()
            self.start_button.config(text='Finish')
        else:
            self.start_button.config(text='Start')

    def update(self):
        if self._timer_running:
            self.end_time = time.time()
        duration = self.end_time - self.start_time
        self.display.configure(text=timedelta(seconds= duration))
        self.app.after(100, self.update)


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