# Tk_mouse_plus_key.py

# Tk_mouse_plus_key.py

from tkinter import *

root = Tk()

class Cv(): 0
cv = Cv()
cv.x = cv.y = 0
cv.ctrl = 0

def draw():
    canvas.create_oval(cv.x-5, cv.y-5, cv.x+5, cv.y+5, fill='black')

def release(e):
    key = e.keysym
    print("RELEASED:", key)
    if key in ('Control_L'):
        canvas.unbind('<B1-Motion>')

def onLeftClick(e):
    cv.x = e.x
    cv.y = e.y
    draw()

def onLeftDrag(e):
    cv.x = e.x
    cv.y = e.y
    if 1: # cv.ctrl:
        draw()

def onCTRLdown(e):
    key = e.keysym
    print("PRESSED:", key)
    canvas.bind('<B1-Motion>', onLeftDrag)

canvas = Canvas(root, width=400, height=400, bg='white')
canvas.pack()

# needed to detect all the keyboard events <<<<<
canvas.focus_set()

canvas.bind('<Button-1>', onLeftClick)

canvas.bind("<KeyRelease>", release)
canvas.bind("<KeyPress>", onCTRLdown)

mainloop()