Text Layouting Test 2

# coding: utf-8

import copy
import pygame
import argparse

LEFT = 1

def rint(x):
    if x % 1 >= 0.5:
        x += 1
    return int(x)

class NodeToLarge(Exception):

    def __init__(self, message, row, node):
        super(NodeToLarge, self).__init__(message)
        self.row = row
        self.node = node

text = '''This is some example text for demonstration purpose.
Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet. Lorem ipsum dolor sit amet, consetetur sadipscing elitr, sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat, sed diam voluptua. At vero eos et accusam et justo duo dolores et ea rebum. Stet clita kasd gubergren, no sea takimata sanctus est Lorem ipsum dolor sit amet.'''

class Node(object):

    width = 0
    height = 0
    margin_x = 0
    margin_y = 0
    x = 0
    y = 0
    background = None

    def __init__(self, options):
        super(Node, self).__init__()
        self.options = options

    def get_real_size(self):
        return self.width + self.margin_x * 2, self.height + self.margin_y * 2

    def add(self, node):
        return False

    def layout(self):
        pass

    def paint(self, rel_x, rel_y, screen):
        x, y = self.x + self.margin_x + rel_x, self.y + self.margin_y + rel_y
        w, h = self.width, self.height
        if self.background and self.options.colorize:
            screen.fill(self.background, pygame.Rect(x, y, w, h))

class ContainerNode(Node):

    def __init__(self, options):
        super(ContainerNode, self).__init__(options)
        self.nodes = []

    def layout(self):
        for node in self.nodes:
            node.layout()

    def paint(self, rel_x, rel_y, screen):
        super(ContainerNode, self).paint(rel_x, rel_y, screen)
        for node in self.nodes:
            node.paint(rel_x + self.x + self.margin_x, rel_y + self.y + self.margin_y, screen)

class TextNode(Node):

    background = (240, 190, 20)

    def __init__(self, word, options):
        super(TextNode, self).__init__(options)
        self.word = word

        self.width, self.height = options.font.size(word)
        self.height = options.line_height or self.height
        self.margin_x = options.font.size(' ')[0] / 2.0
        self.margin_y = 0

    def add(self, node):
        raise NotImplementedError

    def paint(self, rel_x, rel_y, screen):
        super(TextNode, self).paint(rel_x, rel_y, screen)
        options = self.options
        rel_x += self.x + self.margin_x
        rel_y += self.y + self.margin_y
        label = options.font.render(self.word, options.antialias, options.color)
        screen.blit(label, (rint(rel_x), rint(rel_y)))

class InlineNodeRow(ContainerNode):

    background = (255, 80, 50)

    def __init__(self, options):
        super(InlineNodeRow, self).__init__(options)

    def add(self, node, force=False):
        w, h = node.get_real_size()
        if (self.options.maxwidth and self.width + w > self.options.maxwidth) and not force:
            return False

        self.width += w
        if h > self.height:
            self.height = h

        self.nodes.append(node)
        return True

    def layout(self):
        if not self.nodes:
            return

        options = self.options
        justify = self.options.justify
        maxwidth = self.options.maxwidth
        if justify not in ['left', 'right', 'block', 'center']:
            raise ValueError('invalid justify value %s' % justify)
        if justify in ['right', 'center'] and not maxwidth:
            raise RuntimeError('for %s justification, a maxwidth must have been set.' % justify)
        if justify == 'block' and not maxwidth:
            justify = 'left'

        if justify == 'block':
            # Is that really okay?
            free_space = maxwidth - self.width
            self.width = maxwidth
        else:
            free_space = 0

        if len(self.nodes) > 1:
            free_space_partial = float(free_space) / (len(self.nodes) - 1)
        else:
            free_space_partial = 0

        last_x = 0
        for node in self.nodes:
            w, h = node.get_real_size()
            node.x = last_x
            last_x = last_x + w + free_space_partial

            free_space_h = self.height - h
            if options.vertical_align == 'headline':
                node.y = 0
            elif options.vertical_align == 'middle':
                node.y = free_space_h * 0.5
            elif options.vertical_align == 'baseline':
                node.y = free_space_h

        super(InlineNodeRow, self).layout()

class NodeBox(ContainerNode):

    background = (30, 100, 255)

    def __init__(self, options):
        super(NodeBox, self).__init__(options)
        self.width = options.maxwidth - self.margin_x * 2

        self.sub_options = copy.copy(options)
        self.sub_options.maxwidth = self.width
        self.c_row = InlineNodeRow(self.sub_options)

    def end_line(self):
        options = self.c_row.options
        if self.c_row.options.justify == 'block':
            options = copy.copy(options)
            options.justify = 'left'
            self.c_row.options = options
        self.nodes.append(self.c_row)
        self.height += self.c_row.height
        self.c_row = InlineNodeRow(self.sub_options)

    def add(self, node):
        if not self.c_row.add(node):
            w, h = self.c_row.get_real_size()
            self.height += h
            self.nodes.append(self.c_row)

            self.c_row = InlineNodeRow(self.sub_options)
            if not self.c_row.add(node, True):
                raise NodeToLarge('Node is too large for this NodeBox.', self.c_row, node)

        return True

    def layout(self):
        options = self.options
        last_y = 0
        for node in self.nodes:
            w, h = node.get_real_size()

            if options.justify in ['left', 'block']:
                node.x = 0
            elif options.justify == 'right':
                node.x = self.options.maxwidth - w - self.margin_x * 2
            elif options.justify == 'center':
                node.x = (self.options.maxwidth - w) * 0.5 - self.margin_x
            else:
                raise ValueError('self.options.maxwidth')

            node.y = last_y
            last_y += h

        super(NodeBox, self).layout()


class Options(object):

    def __init__(self, color, font, maxwidth, justify='left',
                 antialias=True, vertical_align='headline', line_height=None,
                 colorize=False):
        super(Options, self).__init__()
        self.color = color
        self.font = font
        self.justify = justify
        self.maxwidth = maxwidth
        self.antialias = antialias
        self.vertical_align = vertical_align
        self.line_height = line_height
        self.colorize = colorize


def convert_text(text, options):
    lines = text.split('\n')

    box = NodeBox(options)
    for line in lines:
        words = line.split()
        for word in words:
            node = TextNode(word, options)
            box.add(node)
        box.end_line()
    box.layout()

    return box

def main():
    parser = argparse.ArgumentParser()
    parser.add_argument('justify', choices=['left', 'right', 'center', 'block'])
    parser.add_argument('-c', '--colorize', action='store_true')
    parser.add_argument('-f', '--font', default='Times New Roman')
    parser.add_argument('-s', '--font-size', default=14, type=int)
    parser.add_argument('-v', '--valign', choices=['baseline', 'middle', 'headline'])
    args = parser.parse_args()

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

    screen = pygame.display.set_mode((600, 600))
    pygame.display.set_caption('Font Drawing Test')

    options = Options(
        maxwidth=600,
        color=(0, 0, 0),
        font=pygame.font.SysFont(args.font, args.font_size),
        justify=args.justify,
        vertical_align=args.valign,
        colorize=args.colorize,
    )
    position = [0, 0]

    def make_box():
        options.maxwidth = 600 - position[0]
        return convert_text(text, options)

    box = make_box()
    mouse_down = False

    clock = pygame.time.Clock()
    running = True
    while running:
        clock.tick(30)
        screen.fill((255, 255, 255))
        box = make_box()
        box.paint(position[0], position[1], screen)

        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                running = False
            elif event.type == pygame.MOUSEBUTTONDOWN and event.button == LEFT:
                mouse_down = True
            elif event.type == pygame.MOUSEBUTTONUP and event.button == LEFT:
                mouse_down = False
            elif event.type == pygame.MOUSEMOTION:
                if mouse_down:
                    position = event.pos

        pygame.display.flip()

if __name__ == '__main__':
    main()