Explode *.gif for Android.

explode.py

#!/usr/bin/env python3
#
# explode.py --- Explode *.gif for Android
# Copyright (C) 2013  HiHex Ltd.
#
# This program 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.
#
# This program 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.
#
# You should have received a copy of the GNU General Public License along with
# this program.  If not, see <http://www.gnu.org/licenses/>.

'''
Explode an animated *.gif file to an <animation-list> XML file usable by Android.
'''

import PIL.Image
import PIL.ImageSequence

import argparse
import os
import os.path
import re
import sys

def main():
    parser = argparse.ArgumentParser(description='Explode *.gif for Android')
    parser.add_argument('-o', '--output', default='.', help='Output folder')
    parser.add_argument('-p', '--use-path', action='store_true',
                        help='Refer to the images as path instead of drawable resource')
    parser.add_argument('-x', '--xml', help='Override the name of the XML file')
    parser.add_argument('gif', help='The GIF file to explode')

    opt = parser.parse_args()

    gif_image = PIL.Image.open(opt.gif)

    output_filename = os.path.splitext(os.path.basename(opt.gif))[0]
    if not opt.use_path:
        # Clean filename, Android's resources require /[a-z][a-z0-9_]*/.
        output_filename = re.sub('[^0-9a-z_]', '', output_filename.lower())
        if not ('a' <= output_filename[:1] <= 'z'):
            output_filename = 'anim_' + output_filename

    os.makedirs(opt.output, exist_ok=True)

    xml_name = opt.xml or output_filename + '.xml'

    with open(os.path.join(opt.output, xml_name), 'w') as f:
        f.write('<?xml version="1.0"?>\n')
        f.write('<animation-list xmlns:android="http://schemas.android.com/apk/res/android">\n')
        # TODO support non-looping gif.

        for i, frame_image in enumerate(PIL.ImageSequence.Iterator(gif_image), start=1):
            frame_filename = '{}_{}'.format(output_filename, i)
            f.write('  <item android:drawable="')
            if opt.use_path:
                f.write(frame_filename)
                f.write('.png')
            else:
                f.write('@drawable/')
                f.write(frame_filename)
            f.write('" android:duration="')
            f.write(str(frame_image.info['duration']))
            f.write('"/>\n')

            frame_image.save(os.path.join(opt.output, frame_filename + '.png'))

        f.write('</animation-list>')

if __name__ == '__main__':
    main()