src/youtube/thumbnail.py

   1 import yaml
   2 from PIL import Image, ImageDraw, ImageFont
   3
   4
   5 def drawbox(img, d, context, get_font_path):
   6     for version in d['versions']:
   7         if draw_version(img, version, context, get_font_path):
   8             break
   9
  10
  11 def split_to_lines(text, draw, font, max_width):
  12     words = text.split()
  13     current = ''
  14     while words:
  15         new_words = []
  16         new_words.append(words.pop(0))
  17         while len(new_words[-1]) == 1 and words:
  18             new_words.append(words.pop(0))
  19         new_words = ' '.join(new_words)
  20         new_line = ' '.join([current, new_words]).strip()
  21         width = draw.textsize(new_line, font=font)[0]
  22         if width > max_width:
  23             yield current
  24             current = new_words
  25         else:
  26             current = new_line
  27     if current:
  28         yield current
  29
  30
  31 def draw_version(img, d, context, get_font_path):
  32     # todo: do this in a subimg
  33     newimg = Image.new(
  34         'RGBA',
  35         (
  36             img.size[0] - d.get('x', 0),
  37             d.get('max-height', img.size[1] - d.get('y', 0)),
  38         )
  39     )
  40
  41     draw = ImageDraw.Draw(newimg)
  42     cursor = 0
  43     for item in d['items']:
  44         if item.get('vskip'):
  45             cursor += item['vskip']
  46         text = item['text'].format(**context)
  47         if item.get('uppercase'):
  48             text = text.upper()
  49         font = ImageFont.truetype(get_font_path(item['font-family']), item['font-size'])
  50         max_width = item.get('max-width', newimg.size[0])
  51
  52         for line in split_to_lines(text, draw, font, max_width):
  53             realheight = draw.textsize(line, font=font)[1]
  54             if cursor + realheight > newimg.size[1]:
  55                 return False
  56             cursor += item['line-height']
  57
  58     img.paste(newimg, (d.get('x', 0), d.get('y', 0)), newimg)
  59     return True
  60
  61
  62 def create_thumbnail(background_path, defn, context, get_font_path):
  63     img = Image.open(background_path)
  64     d = yaml.load(defn)
  65     for boxdef in d['boxes']:
  66         drawbox(img, boxdef, context, get_font_path)
  67     return img