Answer
code
Work Step by Step
# 9.14 (Draw lines using the arrow keys) Write a program that draws line segments using
# the arrow keys. The line starts from the center of the frame and draws toward east,
# north, west, or south when the Right arrow key, Up arrow key, Left arrow key, or
# Down arrow key is clicked, as shown in Figure 9.28c.
from tkinter import * # Import tkinter
width = 220
height = 100
class MainGUI:
def __init__(self):
window = Tk() # Create a window
window.title("Arrow Keys") # Set a title
self.canvas = Canvas(window, bg="white", width=width, height=height)
self.canvas.pack()
# Bind canvas with key events
self.canvas.bind("", self.up)
self.canvas.bind("", self.down)
self.canvas.bind("", self.left)
self.canvas.bind("", self.right)
self.canvas.focus_set()
self.x = width / 2
self.y = height / 2
window.mainloop() # Create an event loop
def up(self, event):
self.canvas.create_line(self.x, self.y, self.x, self.y - 5, tags="line")
self.y -= 5
def down(self, event):
self.canvas.create_line(self.x, self.y, self.x, self.y + 5, tags="line")
self.y += 5
def left(self, event):
self.canvas.create_line(self.x, self.y, self.x - 5, self.y, tags="line")
self.x -= 5
def right(self, event):
self.canvas.create_line(self.x, self.y, self.x + 5, self.y, tags="line")
self.x += 5
MainGUI()
