Added python JSON generation script.

README.md

@@ -135,6 +135,8 @@ Then a `MultiStateAnimationOjbect` can be created in Java:
 
 ```
 
+Included in the repo is a [Python 3 script](scripts/generate_animation_json.py) that can assist in generating the JSON for an animation.
+
 ### Playing animations
 
 Once the animation object is created via one of the above methods, you can use `queueTransition` and `transitionNow` 

scripts/generate_animation_json.py

@@ -0,0 +1,112 @@
+#!/usr/bin/env python3
+import argparse
+import collections
+import json
+import pathlib
+import re
+import sys
+
+class Spec(collections.OrderedDict):
+    """An ordered defaultdict(dict)."""
+    def __missing__(self, key):
+        self[key] = ret = {}
+        return ret
+
+
+# A list of image filetypes used to filter out hidden files etc. from section
+# directories
+VALID_EXTENSITONS = {'.png', '.gif', '.bmp', '.jpg', '.jpeg'}
+
+def answer_to_bool(answer):
+    """Convert a string to a boolean."""
+    a = answer.lower()
+    if any(w.startswith(a) for w in ('yes', 'true', '1')):
+        return True
+    elif any(w.startswith(a) for w in ('no', 'false', '0')):
+        return False
+
+def get_answer(question, allow_empty=False):
+    """Ask the user a question until they enter input."""
+    ans = ''
+    while not ans:
+        ans = input(question.strip() + ' ')
+        if allow_empty: 
+            break
+    return ans.strip()
+
+def main():
+    parser = argparse.ArgumentParser(
+        description='Generate an animation specification file.'
+        'e.x.\n`%(prog)s 01-start-image/  02-working/  03-end-transition/  04-end-image/`',
+        epilog='''The arguments to this program are a series of directories.
+        Each directory must contain the frames of a section of an overall
+        animation. Frames can be any image file, but the names of the files
+        must consist only of letters, numbers, and underscores. The program
+        will ask a series of questions about each directory to generate the
+        final specification. Each section must be given an ID, which does not
+        have to match the directory name.''')
+    parser.add_argument('directories', metavar='DIRS', nargs='+', type=pathlib.Path,
+                       help='Directories of animation sequence. Each directory '
+                       'should contain all of the frames for one section.')
+    parser.add_argument('-d', '--frame-duration', type=int, default=33, metavar='INT',
+                        help='Milliseconds per frame of the animation '
+                        '(16 = 60fps, 33 = 30fps) [default: %(default)s]')
+    parser.add_argument('-o', '--output', metavar='FILE', type=pathlib.Path,
+                        help='If given, write output to %(metavar)s isntead of stdout.')
+
+    args = parser.parse_args()
+
+    spec = Spec()
+
+    for path in args.directories:
+        if not path.is_dir():
+            print('Directory %s does not exist' % dirname)
+            sys.exit(1)
+
+        print('Working on directory %s...' % path)
+
+        # The frames are the file names in the directory without path or extenstions
+        frames = [f.stem for f in path.iterdir() if f.suffix in VALID_EXTENSITONS]
+        for frame in frames:
+            if re.search(r'^\w+$', frame) is None:
+                print('ERROR: filename %s is not valid. Filenames must consist '
+                      'only of letters, numbers and underscores' % frame)
+                sys.exit(1)
+
+        if len(frames) > 1:
+            if answer_to_bool(get_answer('Are these frames a transition [y/n]?')):
+                from_id = get_answer(
+                    'What is the ID that these frames are a transition FROM '
+                    '(leave empty for initial transition)?', allow_empty=True)
+                section_id = get_answer('What is the ID that these frames are a transition TO?')
+                # Create the section if it doesn't exist yet.
+                spec[section_id].setdefault('transitions_from', {})[from_id] = {
+                    'frame_duration': args.frame_duration,
+                    'frames': frames
+                }
+                print()
+                continue
+
+        section_id = get_answer('What is the name of this section?')
+
+        # Single-frame sections are automatically oneshot with default duration.
+        if len(frames) == 1:
+            oneshot = True
+        else:
+            spec[section_id]['frame_duration'] = args.frame_duration
+            oneshot = answer_to_bool(get_answer('Is this section a oneshot [y/n]?'))
+
+        spec[section_id]['oneshot'] = oneshot
+        spec[section_id]['frames'] = frames
+
+        print()
+
+    if args.output:
+        with open(args.output, 'w') as f:
+            json.dump(spec, f, indent=4)
+    else:
+        print(json.dumps(spec, indent=4))
+
+
+if __name__ == '__main__':
+    main()