GUIGame.py

# The Candy Monster game program
from tkinter import *
import random

# make window
window = Tk()
window.title('The Candy Monster Game')

# create a canvas to put objects on the screen
canvas = Canvas(window, width=400, height=400, bg = 'black')
canvas.pack()

# set up welcome screen with title and directions
title = canvas.create_text(200, 200, text= 'The Candy Monster', \
fill='white', font = ('Helvetica', 30))
directions = canvas.create_text(200, 300, text= 'Collect candy \
but avoid the red ones', fill='white', font = ('Helvetica', 20))

# set up score display using label widget
score = 0
score_display = Label(window, text="Score :" + str(score))
score_display.pack()

# set up level display using label widget
level = 1
level_display = Label(window, text="Level :" + str(level))
level_display.pack()

# create an image object using the gif file
player_image = PhotoImage(file="greenChar.gif")
# use image object to create a character at position 200, 360
mychar = canvas.create_image(200, 360, image = player_image)

# variables and lists needed for managing candy
candy_list = [] # list containing all candy created, empty at start
bad_candy_list = [] # list containing all bad candy created, empty at start
candy_speed = 2 # initial speed of falling candy
candy_color_list = ['red', 'yellow', 'blue', 'green', 'purple', 'pink', \
'white']
# function to make candy at random places
def make_candy():
    # pick a random x position
    xposition = random.randint(1, 400)
    # pick a random color
    candy_color = random.choice(candy_color_list)
    # create a candy of size 30 at random position and color
    candy = canvas.create_oval(xposition, 0, xposition+30, 30, fill = \
    candy_color)
    # add candy to list
    candy_list.append(candy)
    # if color of candy is red - add it to bad_candy_list
    if candy_color == 'red' :
        bad_candy_list.append(candy)
    # schedule this function to make candy again
    window.after(1000, make_candy)
    
# function moves candy downwards, and schedules call to move_candy
def move_candy():
    # loop through list of candy and change y position
    for candy in candy_list:
        canvas.move(candy, 0, candy_speed)
        # check if end of screen - restart at random position
        if canvas.coords(candy)[1] > 400:
            xposition = random.randint(1,400)
            canvas.coords(candy, xposition, 0, xposition+30,30)
    # schedule this function to move candy again
    window.after(50, move_candy)


# function updates score, level and candy_speed
def update_score_level():
    # use of global since variables are changed
    global score, level, candy_speed
    score = score + 1
    score_display.config(text="Score :" + \
    str(score))
    # determine if level needs to change
    # update level and candy speed
    if score > 5 and score <= 10:
        candy_speed = candy_speed + 1
        level = 2
        level_display.config(text="Level :" + \
        str(level))
    elif score > 10:
        candy_speed = candy_speed + 1
        level = 3
        level_display.config(text="Level :" + \
        str(level))
    
# function called to end game - destroys window
def end_game_over():
    window.destroy()
    
# this destroys the instructions on the screen
def end_title():
    canvas.delete(title) # remove title
    canvas.delete(directions) # remove directions


# check distance between 2 objects - return true if they 'touch'
def collision(item1, item2, distance):
    xdistance = abs(canvas.coords(item1)[0] - canvas.coords(item2)[0])
    ydistance = abs(canvas.coords(item1)[1] - canvas.coords(item2)[1])
    overlap = xdistance < distance and ydistance < distance
    return overlap

# checks if character hit bad candy, schedule end_game_over
# if character hits candy, remove from screen, list, update score
def check_hits():
    # check if it hit a bad candy - need to end game
    for candy in bad_candy_list:
        if collision(mychar, candy, 30):
            game_over = canvas.create_text(200, 200, text= 'Game \
            Over', fill='red', font = ('Helvetica', 30))
            # end game but after user can see score
            window.after(2000, end_game_over)
            # do not check any other candy, window to be destroyed
            return
    # check if it hit any good candy
    for candy in candy_list:
        if collision(mychar, candy, 30):
            canvas.delete(candy) # remove from canvas
            # find where in list and remove and update score
            candy_list.remove(candy)
            update_score_level()
    # schedule check Hits again
    window.after(100, check_hits)

move_direction = 0 # track which direction player is moving
# Function handles when user first presses arrow keys
def check_input(event):
    global move_direction
    key = event.keysym
    if key == "Right":
        move_direction = "Right"
    elif key == "Left":
        move_direction = "Left"
        
# Function handles when user stop pressing arrow keys
def end_input(event):
    global move_direction
    move_direction = "None"
    
# Function checks if not on edge and updates x coordinates based on right/left
def move_character():
    if move_direction == "Right" and canvas.coords(mychar)[0] < 400:
        canvas.move(mychar, 10,0)
    if move_direction == "Left" and canvas.coords(mychar)[0] > 0 :
        canvas.move(mychar, -10,0)
    window.after(16, move_character) # Move character at 60 frames per second

# bind the keys to the character
canvas.bind_all('<KeyPress>', check_input) # bind key press
canvas.bind_all('<KeyRelease>', end_input) # bind all keys to circle

# Start game loop by scheduling all the functions
window.after(1000, end_title) # destroy title and instructions
window.after(1000, make_candy) # start making candy
window.after(1000, move_candy) # start moving candy
window.after(1000, check_hits) # check if character hit a candy
window.after(1000, move_character) # handle keyboard controls

window.mainloop() # last line is the GUI main event loop