Add a script to rename fonts for SDK.

This tool is used to rename the PS name encoded inside the ttf font that we ship

with the SDK. There is bug in Java that returns incorrect results for

java.awt.Font#layoutGlyphVector() if two fonts with same name but differnt

versions are loaded. As a workaround, we rename all the fonts that we ship with

the SDK by appending the font version to its name.

The build_font.py copies all files from input_dir to output_dir while renaming

the font files (*.ttf) in the process.

#!/usr/bin/env python

# Copyright (C) 2014 The Android Open Source Project

#

# Licensed under the Apache License, Version 2.0 (the 'License');

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

#      http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License is distributed on an 'AS IS' BASIS,

# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

# See the License for the specific language governing permissions and

# limitations under the License.

"""

Rename the PS name of all fonts in the input directory and copy them to the

output directory.

Usage: build_font.py /path/to/input_fonts/ /path/to/output_fonts/

"""

import sys

# fontTools is available at platform/external/fonttools

from fontTools import ttx

import re

import os

from lxml import etree

import shutil

import glob

def main(argv):

  if len(argv) != 2:

    print "Usage: build_font.py /path/to/input_fonts/ /path/to/out/dir/"

    sys.exit(1)

  if not os.path.isdir(argv[0]):

    print argv[0] + "is not a valid directory"

    sys.exit(1)

  if not os.path.isdir(argv[1]):

    print argv[1] + "is not a valid directory"

    sys.exit(1)

  cwd = os.getcwd()

  os.chdir(argv[1])

  files = glob.glob('*')

  for filename in files:

    os.remove(filename)

  os.chdir(cwd)

  for filename in os.listdir(argv[0]):

    if not os.path.splitext(filename)[1].lower() == ".ttf":

      shutil.copy(os.path.join(argv[0], filename), argv[1])

      continue

    print os.path.join(argv[0], filename)

    old_ttf_path = os.path.join(argv[0], filename)

    # run ttx to generate an xml file in the output folder which represents all

    # its info

    ttx_args = ["-d", argv[1], old_ttf_path]

    ttx.main(ttx_args)

    # the path to the output file. The file name is the fontfilename.ttx

    ttx_path = os.path.join(argv[1], filename)

    ttx_path = ttx_path[:-1] + "x"

    # now parse the xml file to change its PS name.

    tree = etree.parse(ttx_path)

    encoding = tree.docinfo.encoding

    root = tree.getroot()

    for name in root.iter('name'):

      [old_ps_name, version] = get_font_info(name)

      new_ps_name = old_ps_name + version

      update_name(name, new_ps_name)

    tree.write(ttx_path, xml_declaration=True, encoding=encoding )

    # generate the udpated font now.

    ttx_args = ["-d", argv[1], ttx_path]

    ttx.main(ttx_args)

    # delete the temp ttx file.

    os.remove(ttx_path)

def get_font_info(tag):

  ps_name = None

  ps_version = None

  for namerecord in tag.iter('namerecord'):

    if 'nameID' in namerecord.attrib:

      # if the tag has nameID=6, it is the postscript name of the font.

      # see: http://scripts.sil.org/cms/scripts/page.php?item_id=IWS-Chapter08#3054f18b

      if namerecord.attrib['nameID'] == '6':

        if ps_name is not None:

          if not sanitize(namerecord.text) == ps_name:

            sys.exit('found multiple possibilities of the font name')

        else:

          ps_name = sanitize(namerecord.text)

      # nameID=5 means the font version

      if namerecord.attrib['nameID'] == '5':

        if ps_version is not None:

          if not ps_version == get_version(namerecord.text):

            sys.exit('found multiple possibilities of the font version')

        else:

          ps_version = get_version(namerecord.text)

  if ps_name is not None and ps_version is not None:

    return [ps_name, ps_version]

  sys.exit('didn\'t find the font name or version')

def update_name(tag, name):

  for namerecord in tag.iter('namerecord'):

    if 'nameID' in namerecord.attrib:

      if namerecord.attrib['nameID'] == '6':

        namerecord.text = name

def sanitize(string):

  return re.sub(r'[^\w-]+', '', string)

def get_version(string):

  # The string must begin with "Version n.nn "

  # to extract n.nn, we return the second entry in the split strings.

  string = string.strip()

  if not string.startswith("Version "):

    sys.exit('mal-formed font version')

  return sanitize(string.split()[1])

if __name__ == '__main__':

  main(sys.argv[1:])

#!/usr/bin/env python

"""Tests build_font.py by renaming a font.

The test copies Roboto-Regular.ttf to a tmp directory and ask build_font.py to rename it and put in another dir.

We then use ttx to dump the new font to its xml and check if rename was successful

To test locally, use:

PYTHONPATH="$PYTHONPATH:/path/to/android/checkout/external/fonttools/Lib" ./test.py

"""

import unittest

import build_font

from fontTools import ttx

import os

from lxml import etree

import shutil

import tempfile

class MyTest(unittest.TestCase):

  def test(self):

    font_name = "Roboto-Regular.ttf"

    srcdir = tempfile.mkdtemp()

    print "srcdir: " + srcdir

    shutil.copy(font_name, srcdir)

    destdir = tempfile.mkdtemp()

    print "destdir: " + destdir

    self.assertTrue(build_font.main([srcdir, destdir]) is None)

    out_path = os.path.join(destdir, font_name)

    ttx.main([out_path])

    ttx_path = out_path[:-1] + "x"

    tree = etree.parse(ttx_path)

    root = tree.getroot()

    name_tag = root.find('name')

    [f_name, f_version] = build_font.get_font_info(name_tag)

    shutil.rmtree(srcdir)

    shutil.rmtree(destdir)

    self.assertEqual(f_name, "Roboto-Regular1200310")

if __name__ == '__main__':

  unittest.main()