diagram1.py

#!/usr/bin/env python3
# Copyright © 2012-13 Qtrac Ltd. All rights reserved.
# This program or module is free software: you can redistribute it
# and/or modify it under the terms of the GNU General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version. It is provided for
# educational purposes and is distributed in the hope that it will be
# useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
# General Public License for more details.

import os
import sys
import tempfile


def main():
    if len(sys.argv) > 1 and sys.argv[1] == "-P": # For regression testing
        create_diagram(DiagramFactory()).save(sys.stdout)
        create_diagram(SvgDiagramFactory()).save(sys.stdout)
        return
    textFilename = os.path.join(tempfile.gettempdir(), "diagram.txt")
    svgFilename = os.path.join(tempfile.gettempdir(), "diagram.svg")

    txtDiagram = create_diagram(DiagramFactory())
    txtDiagram.save(textFilename)
    print("wrote", textFilename)

    svgDiagram = create_diagram(SvgDiagramFactory())
    svgDiagram.save(svgFilename)
    print("wrote", svgFilename)


def create_diagram(factory):
    diagram = factory.make_diagram(30, 7)
    rectangle = factory.make_rectangle(4, 1, 22, 5, "yellow")
    text = factory.make_text(7, 3, "Abstract Factory")
    diagram.add(rectangle)
    diagram.add(text)
    return diagram


class DiagramFactory:

    def make_diagram(self, width, height):
        return Diagram(width, height)


    def make_rectangle(self, x, y, width, height, fill="white",
            stroke="black"):
        return Rectangle(x, y, width, height, fill, stroke)


    def make_text(self, x, y, text, fontsize=12):
        return Text(x, y, text, fontsize)



class SvgDiagramFactory(DiagramFactory):

    def make_diagram(self, width, height):
        return SvgDiagram(width, height)


    def make_rectangle(self, x, y, width, height, fill="white",
            stroke="black"):
        return SvgRectangle(x, y, width, height, fill, stroke)


    def make_text(self, x, y, text, fontsize=12):
        return SvgText(x, y, text, fontsize)


BLANK = " "
CORNER = "+"
HORIZONTAL = "-"
VERTICAL = "|"


class Diagram:

    def __init__(self, width, height):
        self.width = width
        self.height = height
        self.diagram = _create_rectangle(self.width, self.height, BLANK)


    def add(self, component):
        for y, row in enumerate(component.rows):
            for x, char in enumerate(row):
                self.diagram[y + component.y][x + component.x] = char


    def save(self, filenameOrFile):
        file = None if isinstance(filenameOrFile, str) else filenameOrFile
        try:
            if file is None:
                file = open(filenameOrFile, "w", encoding="utf-8")
            for row in self.diagram:
                print("".join(row), file=file)
        finally:
            if isinstance(filenameOrFile, str) and file is not None:
                file.close()


def _create_rectangle(width, height, fill):
    rows = [[fill for _ in range(width)] for _ in range(height)]
    for x in range(1, width - 1):
        rows[0][x] = HORIZONTAL
        rows[height - 1][x] = HORIZONTAL
    for y in range(1, height - 1):
        rows[y][0] = VERTICAL
        rows[y][width - 1] = VERTICAL
    for y, x in ((0, 0), (0, width - 1), (height - 1, 0),
            (height - 1, width -1)):
        rows[y][x] = CORNER
    return rows


class Rectangle:

    def __init__(self, x, y, width, height, fill, stroke):
        self.x = x
        self.y = y
        self.rows = _create_rectangle(width, height,
                BLANK if fill == "white" else "%")


class Text:

    def __init__(self, x, y, text, fontsize):
        self.x = x
        self.y = y
        self.rows = [list(text)]


SVG_START = """<?xml version="1.0" encoding="UTF-8" standalone="no"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 20010904//EN"
    "http://www.w3.org/TR/2001/REC-SVG-20010904/DTD/svg10.dtd">
<svg xmlns="http://www.w3.org/2000/svg"
    xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve"
    width="{pxwidth}px" height="{pxheight}px">"""

SVG_END = "</svg>\n"

SVG_RECTANGLE = """<rect x="{x}" y="{y}" width="{width}" \
height="{height}" fill="{fill}" stroke="{stroke}"/>"""

SVG_TEXT = """<text x="{x}" y="{y}" text-anchor="left" \
font-family="sans-serif" font-size="{fontsize}">{text}</text>"""

SVG_SCALE = 20


class SvgDiagram:


    def __init__(self, width, height):
        pxwidth = width * SVG_SCALE
        pxheight = height * SVG_SCALE
        self.diagram = [SVG_START.format(**locals())]
        outline = SvgRectangle(0, 0, width, height, "lightgreen", "black")
        self.diagram.append(outline.svg)


    def add(self, component):
        self.diagram.append(component.svg)


    def save(self, filenameOrFile):
        file = None if isinstance(filenameOrFile, str) else filenameOrFile
        try:
            if file is None:
                file = open(filenameOrFile, "w", encoding="utf-8")
            file.write("\n".join(self.diagram))
            file.write("\n" + SVG_END)
        finally:
            if isinstance(filenameOrFile, str) and file is not None:
                file.close()


class SvgRectangle:

    def __init__(self, x, y, width, height, fill, stroke):
        x *= SVG_SCALE
        y *= SVG_SCALE
        width *= SVG_SCALE
        height *= SVG_SCALE
        self.svg = SVG_RECTANGLE.format(**locals())


class SvgText:

    def __init__(self, x, y, text, fontsize):
        x *= SVG_SCALE
        y *= SVG_SCALE
        fontsize *= SVG_SCALE // 10
        self.svg = SVG_TEXT.format(**locals())


if __name__ == "__main__":
    main()