import pygame

pygame.init()
pygame.font.init()

# Setup pygame screen
screen_size = (800, 600)
screen = pygame.display.set_mode(screen_size)
pygame.display.set_caption('Pygame Button')

# Setup some colors
screen_bg = 'ivory2'

# Set framerate
fps = 60
framerate = pygame.time.Clock()

# Load and define button images. Three states normal, hover, and pressed
normal = pygame.image.load('normal.png')
hover = pygame.image.load('hover.png')
pressed = pygame.image.load('pressed.png')

# change cursor on hover
hand = pygame.SYSTEM_CURSOR_HAND

# Create Button class
class Button:
    def __init__(self, image, pos, callback):
        '''
            Create a animated button from images
            self.callback is for a funtion for the button to do - set to None
        '''
        self.image = image
        self.rect = self.image.get_rect(topleft=pos)
        self.callback = callback


    # Define function for normal button state
    def normal(self):
        self.image = normal
        pygame.mouse.set_cursor()

    # Define function for mouse hover state
    def hover(self):
        self.image = hover
        pygame.mouse.set_cursor(hand)

    # Define function for pressed state
    def pressed(self):
        self.image = pressed


# Set a variabe to True and enter loop
running = True
while running:

    # Fill screen with background color
    screen.fill(screen_bg)

    # Start event loop
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            running = False

    # Create a button from the Button class with args for state, position, and callback
    button = Button(normal, (100, 100), None)

    # Get mouse button from pygame
    left, middle, right = pygame.mouse.get_pressed()

    # If cursor is over button change state to hover else state is normal
    if button.rect.collidepoint(pygame.mouse.get_pos()):
        button.hover()

        # If left mouse button pressed change state to pressed else hover
        if left and button.rect.collidepoint(pygame.mouse.get_pos()):
            button.pressed()
        else:
            button.hover()
    else:
        button.normal()

    # Blit button to screen
    screen.blit(button.image, button.rect)

    # Set framerate and update
    framerate.tick(fps)
    pygame.display.update()