PyGame basic TestProgram

"""

        TestProgram

    A testprogram made to test out
    the pygame module.

    ~Piorjade

"""

# Imports
import sys, pygame
from UI import Element
from UI import Button

# Code
pygame.init()

size = (800, 600)

screen = pygame.display.set_mode(size)

#Objects
btn = Button(0.05, 0.05, 0.9, 0.9, (255, 0, 0), "Click Me!", pygame.font.SysFont("monospace", 15))
lastbtn = None

# Main Loop
while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()
        elif event.type == pygame.MOUSEBUTTONUP:
            pos = pygame.mouse.get_pos()
            if btn.isClick(screen, pos[0], pos[1]):
                btn.setColor((255, 0, 0))
                lastbtn = None
                # Your code
        elif event.type == pygame.MOUSEBUTTONDOWN:
            pos = pygame.mouse.get_pos()
            if btn.isClick(screen, pos[0], pos[1]):
                btn.setColor((180, 0, 0))
                lastbtn = btn
            else:
                if lastbtn != None:
                    lastbtn.setColor((255, 0, 0))
                lastbtn = None

    screen.fill((255, 255, 255))
    btn.draw(screen)
    pygame.display.update()