Pygame text editing example

# Pygame text editing example
# Author: Weeble
# License: http://www.opensource.org/licenses/MIT

import pygame

pygame.init()

screen = pygame.display.set_mode((1024,200))

text = u"Is this effective?"
cursorpos = 10
times = pygame.font.SysFont("Times New Roman", 100, False, True)
pygame.key.set_repeat(300,50)

while True:
    screen.fill((255,255,255))

    # Draw the text
    textsurf = times.render(text, True, (0,0,0))
    screen.blit(textsurf, (0,40))

    # Draw the cursor
    lefttext = text[:cursorpos]
    lefttextwidth = times.size(lefttext)[0]
    if cursorpos > 0 and len(text) > 0:
        leftchar = text[cursorpos - 1]
        _, xmax, _, _, advance = times.metrics(leftchar)[0]
        if xmax > advance:
            # Character immediately left of the cursor has
            # an overhang.
            lefttextwidth -= xmax - advance
    screen.fill((0,0,0),(lefttextwidth, 40, 2, times.get_height()))

    pygame.display.flip()

    ev = pygame.event.wait()
    if ev.type == pygame.QUIT:
        break
    elif ev.type == pygame.KEYDOWN:
        if ev.key == pygame.K_BACKSPACE and cursorpos > 0:
            cursorpos -= 1
            text = text[:cursorpos] + text[cursorpos+1:]
        if ev.key == pygame.K_DELETE and cursorpos < len(text):
            text = text[:cursorpos] + text[cursorpos+1:]
        if ev.key == pygame.K_LEFT and cursorpos > 0:
            cursorpos -= 1
        if ev.key == pygame.K_RIGHT and cursorpos < len(text):
            cursorpos += 1
        if ev.key == pygame.K_ESCAPE:
            break
        if ev.unicode != '' and not (0<=ord(ev.unicode)<=31) and not (127<=ord(ev.unicode)<=159):
            text = text[:cursorpos] + ev.unicode + text[cursorpos:]
            cursorpos+=1