from tkinter import *

def setupGUI() :
    global canvas, name_field, slider1
    window = Tk()
    canvas = Canvas(window, height=300, width=400, bg="white")
    canvas.bind("<Button-1>", do_mousepress)
    canvas.bind("<ButtonRelease-1>", do_mouserelease)
    canvas.pack()
    button1 = Button(window, text="Action 1", command=do_action1)
    button1.pack()
    name_label = Label(window, text="Enter name")
    name_label.pack()
    name_field = Entry(window)
    name_field.pack()
    slider1 = Scale(window, from_=1, to=100, orient=HORIZONTAL, command=do_slider1, showvalue=20)
    slider1.pack()
    window.mainloop()

def do_mousepress(event) :
    # respond to mouse press event  (position at event.x, event.y)
    canvas.create_oval(event.x, event.y, event.x+20, event.y+20, fill="green")
    canvas.update()

def do_mouserelease(event) :
    # respond to mouse press event  (position at event.x, event.y)
    canvas.create_rectangle(event.x, event.y, event.x+10, event.y+10, fill="red")
    canvas.update()

def do_action1() :
    # respond to button 1
    # possibly accessing the text entry using: name_field.get()
    canvas.create_text(30, 200, text=name_field.get())
    canvas.update()

def do_slider1(event) :
   # respond to slider being changed, using new value: slider1.get()
    canvas.delete(ALL)
    canvas.create_rectangle(10, 10, slider1.get(), slider1.get(), fill="blue")
    canvas.update()

setupGUI()