[Tutor] moving objects in only one direction at a time

[Tudor, Bogdan - tudby001]

Hi,

Sorry if this sends twice.
I am using python 3.4.3 on windows 7 64bit.

I'm using John M. Zelle graphics module.

Graphics module:
http://mcsp.wartburg.edu/zelle/python/graphics/graphics/graphics.html

I am trying to create user movable blocks that can only move in one direction at a time. The arrow keys are used to move left or right.
Currently while moving left, pressing the right arrow key will change the blocks direction and vice versa. I'm trying to get the block to continue moving in only one direction determined by the arrow keys, i.e. pressing right should not move the blocks right if they already moving left.

How can I fix my code to do this?

I expected adding True/False variables (moveLEFT, moveRIGHT) would allow me to disable one key press while another is in action, unfortunately has not worked.

I hope its OK that I attached files as they are long.

--> blockgame.py

import graphics
import game_functions
import time

def handleKeys(event):
    global direction
    global moveLEFT
    global moveRIGHT
    print('Key pressed', event.keysym, event.keycode)

    if event.keysym == 'Left':
        direction = 'Left'
        moveLEFT = True
        moveRIGHT = False
    elif event.keysym == 'Right':
        direction = 'Right'
        moveLEFT = False
        moveRIGHT = True

    elif event.keysym == 'q':
        win.close()

def game():
    global direction
    global square
    global moveLEFT
    global moveRIGHT

    block = game_functions.GameBlock(WIN_WIDTH//2,
                                     WIN_HEIGHT//2, BLOCK_SIZE,
                                     BLOCK_SIZE, 'Red', None, None, 0)
    block.draw(win)
    square.append(block)
    block = game_functions.GameBlock(WIN_WIDTH//2,
                                     WIN_HEIGHT//2, BLOCK_SIZE,
                                     BLOCK_SIZE, 'Red', None, None, 0)
    block.draw(win)
    square.append(block)
    speed = 0.1
    playing = True
    while playing:

        # Move squares
        for k in range(len(square)-1, 0, -1):
            moveX = square[k-1].getCentreX() - square[k].getCentreX()
            moveY = square[k-1].getCentreY() - square[k].getCentreY()
            square[k].move(moveX, moveY)

        # Update pos
        if moveLEFT == True and moveRIGHT == False:
            square[0].move(-20, 0)
        if moveRIGHT and moveLEFT == False:
            square[0].move(20, 0)

        time.sleep(speed)
moveLEFT = False
moveRIGHT = False

WIN_WIDTH = 500
WIN_HEIGHT = 500
BLOCK_SIZE = 20
direction = ""
square = []
win = graphics.GraphWin("Snake", WIN_WIDTH, WIN_HEIGHT)
win.setBackground("white")
win.bind_all('<Key>', handleKeys)
game()
win.mainloop()
win.getMouse()
win.close()

--> game_functions.py

import graphics

class GameBlock():
    def __init__(self, dx, dy, width, height, colour, imageName, blockType, points):
        self.centreX = dx
        self.centreY = dy
        self.width  = width
        self.height = height
        self.colour = colour
        self.imageName = imageName
        self.blockType = blockType
        self.points = points
        self.scrollSpeed = 10
        self.block = graphics.Rectangle(graphics.Point(self.centreX-self.width//2, self.centreY-self.height//2),
                                        graphics.Point(self.centreX+self.width//2, self.centreY+self.height//2))
        self.block.setFill(colour)
        if not(imageName == None):
          self.image = graphics.Image(graphics.Point(dx,dy), imageName)
        else:
          self.image = None

    def getCentreX(self):
        return self.centreX

    def getCentreY(self):
        return self.centreY

    def move(self, dx, dy):
        self.centreX = self.centreX + dx
        self.centreY = self.centreY + dy
        self.block.move(dx,dy)
        if not(self.image == None):
            self.image.move(dx,dy)

    def draw(self, canvas):
        if self.image == None:
            self.block.draw(canvas)
        else:
            self.image.draw(canvas)

__________________________
I will greatly appreciate any help!

Kind Regards