#! /usr/bin/env python

class TextRectException:
    def __init__(self, message = None):
        self.message = message
    def __str__(self):
        return self.message

def render_textrect(string, font, rect, text_color, background_color, justification=0):
    """Returns a surface containing the passed text string, reformatted
    to fit within the given rect, word-wrapping as necessary. The text
    will be anti-aliased.

    Takes the following arguments:

    string - the text you wish to render. \n begins a new line.
    font - a Font object
    rect - a rectstyle giving the size of the surface requested.
    text_color - a three-byte tuple of the rgb value of the
                 text color. ex (0, 0, 0) = BLACK
    background_color - a three-byte tuple of the rgb value of the surface.
    justification - 0 (default) left-justified
                    1 horizontally centered
                    2 right-justified

    Returns the following values:

    Success - a surface object with the text rendered onto it.
    Failure - raises a TextRectException if the text won't fit onto the surface.
    """

    import pygame
    
    final_lines = []

    requested_lines = string.splitlines()

    # Create a series of lines that will fit on the provided
    # rectangle.

    for requested_line in requested_lines:
        if font.size(requested_line)[0] > rect.width:
            words = requested_line.split(' ')
            # if any of our words are too long to fit, return.
            for word in words:
                if font.size(word)[0] >= rect.width:
                    raise TextRectException, "The word " + word + " is too long to fit in the rect passed."
            # Start a new line
            accumulated_line = ""
            for word in words:
                test_line = accumulated_line + word + " "
                # Build the line while the words fit.    
                if font.size(test_line)[0] < rect.width:
                    accumulated_line = test_line 
                else: 
                    final_lines.append(accumulated_line) 
                    accumulated_line = word + " " 
            final_lines.append(accumulated_line)
        else: 
            final_lines.append(requested_line) 

    # Let's try to write the text out on the surface.

    surface = pygame.Surface(rect.size) 
    surface.fill(background_color) 

    accumulated_height = 0 
    for line in final_lines: 
        if accumulated_height + font.size(line)[1] >= rect.height:
            raise TextRectException, "Once word-wrapped, the text string was too tall to fit in the rect."
        if line != "":
            tempsurface = font.render(line, 1, text_color)
            if justification == 0:
                surface.blit(tempsurface, (0, accumulated_height))
            elif justification == 1:
                surface.blit(tempsurface, ((rect.width - tempsurface.get_width()) / 2, accumulated_height))
            elif justification == 2:
                surface.blit(tempsurface, (rect.width - tempsurface.get_width(), accumulated_height))
            else:
                raise TextRectException, "Invalid justification argument: " + str(justification)
        accumulated_height += font.size(line)[1]

    return surface


if __name__ == '__main__':
    import pygame
    import pygame.font
    from pygame.locals import *

    pygame.init()

    display = pygame.display.set_mode((400, 400))

    my_font = pygame.font.Font(None, 22)

    my_string = "Hi there! I'm a nice bit of wordwrapped text. Won't you be my friend? Honestly, wordwrapping is easy, with David's fancy new render_textrect () function.\nThis is a new line.\n\nThis is another one.\n\n\nAnother line, you lucky dog."

    my_rect = pygame.Rect((40, 40, 300, 300))
    
    rendered_text = render_textrect(my_string, my_font, my_rect, (216, 216, 216), (48, 48, 48), 0)

    if rendered_text:
        display.blit(rendered_text, my_rect.topleft)

    pygame.display.update()

    while not pygame.event.wait().type in (QUIT, KEYDOWN):
        pass