Calculator

# Calculator
# a simple calculator using pygame
# Version 1.21
# Bobby Clarke

# Change log:

# 1.0 initial relaese with numbers and basic operators, no decimals
# 1.1 added decimal answers and Error messages
# 1.2 added decimal input

# Upcoming:

# Ability to use keyboard for input
# 10 digit limit

# Imports
import pygame, math, sys
from pygame.locals import *
pygame.init()

#   #   #   #   #

screen = pygame.display.set_mode((180, 300))

clock = pygame.time.Clock()

interface = pygame.image.load("calc.png") # the GUI image for the calculator
errormsg = pygame.image.load("error.png") # The error message

# All the number and operator images

#numbers
img0 = pygame.image.load("Numbers/0.png")
img1 = pygame.image.load("Numbers/1.png")
img2 = pygame.image.load("Numbers/2.png")
img3 = pygame.image.load("Numbers/3.png")
img4 = pygame.image.load("Numbers/4.png")
img5 = pygame.image.load("Numbers/5.png")
img6 = pygame.image.load("Numbers/6.png")
img7 = pygame.image.load("Numbers/7.png")
img8 = pygame.image.load("Numbers/8.png")
img9 = pygame.image.load("Numbers/9.png")

# operators
plus = pygame.image.load("Numbers/+.png")
minus = pygame.image.load("Numbers/-.png")
multiply = pygame.image.load("Numbers/multiply.png")
divide = pygame.image.load("Numbers/divide.png")
dot = pygame.image.load("Numbers/dot.png")

#   #   #   #   #

# The dictionary showing which images coresponds to which operation

op2img = {# Numbers
          "0" : img0,
          "1" : img1,
          "2" : img2,
          "3" : img3,
          "4" : img4,
          "5" : img5,
          "6" : img6,
          "7" : img7,
          "8" : img8,
          "9" : img9,

          #Operators
          "+" : plus,
          "-" : minus,
          "*" : multiply,
          "/" : divide,
          "." : dot}

#   #   #   #   #

num = False # a variable to temporarily hold a number
op = False # a variable to temporarily hold an operator
back = False # will clear the last operation when true
equals = False # when this is true it will find the solution to the question
answer = False # will become the answer
mousepress = False # True if mouse button is pressed
error = False # true if there is an error

operations = "" # a list of operations

while True:

    #reset the variables
    num = False
    op = False
    back = False
    equals = False

    if mousepress:
        # Decides what the mouse press means, if anything
        # this is done by determining whether the mouse was on a button when pressed
        # the ranges are the x and y positions of the buttons
        # and are being compared to the position of the mouse at the time of being pressed

        if mouse_x in range(13, 44):
            if mouse_y in range(126, 146):
                num = "1"
            elif mouse_y in range(151, 171):
                num = "4"
            elif mouse_y in range(179, 199):
                num = "7"
            elif mouse_y in range(208, 228):
                num = "0"

            is_number = True

        elif mouse_x in range(47, 79):
            if mouse_y in range(126, 146):
                num = "2"
            elif mouse_y in range(151, 171):
                num = "5"
            elif mouse_y in range(179, 199):
                num = "8"
            is_number = True

        elif mouse_x in range(80, 113):
            if mouse_y in range(126, 146):
                num = "3"
            elif mouse_y in range(151, 171):
                num = "6"
            elif mouse_y in range(179, 199):
                num = "9"

        elif mouse_x in range(132, 164):
            if mouse_y in range(126, 146):
                op = "+"
            elif mouse_y in range(151, 171):
                op = "-"
            elif mouse_y in range(179, 199):
                op = "*"
            elif mouse_y in range(208, 228):
                op = "/"
            elif mouse_y in range(232, 252):
                op = "."

        elif mouse_x in range (15, 70) and mouse_y in range (258, 288):
            back = True

        elif mouse_x in range(89, 167) and mouse_y in range(258, 288):
            equals = True

        else:
            pass

        mousepress = False


    if num:
        # adds a number to the operations
        operations += num
    elif op:
        # adds an operator to the operations
        operations += op
    elif back:
        # This removes the last Item in operations
        if len(operations) > 1:
            operations = operations[0 : len(operations) - 1]
        else:
            operations = ""

    elif equals:
        # find an answer by evaluating the operations
        try:
            if len(operations) > 1:
                answer = str(eval(operations))
            else:
                answer = 0

        except:
            error = True

    if len(operations) > 10:
        operations = operations[0 : 10]



    screen.fill((255, 255, 255))

    if answer:
        count = 0
        for i in answer:
            count += 1
            img = op2img[i]
            screen.blit(img, (0 + (count * 15), 78))

    elif error:
        screen.blit(errormsg, (15, 78))

    else:
        count = 0
        for operation in operations:
            count += 1
            img = op2img[operation]
            screen.blit(img, (0 + (count * 15), 78))

    screen.blit(interface, (0, 0))

    pygame.display.update()

    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            sys.exit()

        elif event.type == MOUSEBUTTONDOWN:
            mouse_x, mouse_y = pygame.mouse.get_pos()
            mousepress = True

            if answer:
                answer = False
                operations = ""

            elif error:
                error = False
                operations = ""