Emoji support

The Unicode consortium has defined a set of emoji with the corresponding Unicode sequences. Doxygen supports the subset of emoji characters as used by GitHub (based on the list https://api.github.com/emojis). An emoji is created using the \emoji command. For example `\emoji smile` or `\emoji :smile:` both produce 😄.

# Representation

For the different doxygen output types there is an output defined:

- Unicode code sequence, the actual representation is depending on the possibilities of the fonts loaded:
  - HTML
  - DocBook
  - RTF, converted to UTF-16 representation.
- Image
  - , in case the image can be found (see Emoji image retrieval) otherwise the plain emoji text (i.e. `:<text>:`) is displayed
- plain emoji text (i.e. `:<text>:`)
  - man
  - perl
- For XML there is a dedicated `<emoji>` tag with `name` and `unicode` attributes.

# Emoji image retrieval

In the list of images can be downloaded via the following Python script:

# script to download the emoticons from GitHub and to produce a table for
# inclusion in doxygen. Works with python 2.7+ and python 3.x
import json
import os
import argparse
import re
try:
import urllib.request as urlrequest
except ImportError:
import urllib as urlrequest
unicode_re = re.compile(r'.*?/unicode/(.*?).png\?.*')
def get_emojis():
response = urlrequest.urlopen('https://api.github.com/emojis')
raw_data = response.read()
return json.loads(raw_data)
def download_images(dir_name):
if not os.path.exists(dir_name):
os.makedirs(dir_name)
json_data = get_emojis()
num_items = len(json_data)
cur_item=0
for image,url in sorted(json_data.items()):
image_name = image+'.png'
cur_item=cur_item+1
if url.find('/unicode/')==-1 or not os.path.isfile(dir_name+'/'+image_name):
with open(dir_name+'/'+image_name,'wb') as file:
print('%s/%s: fetching %s' % (cur_item,num_items,image_name))
file.write(urlrequest.urlopen(url).read())
else:
print('%s/%s: skipping %s' % (cur_item,num_items,image_name))
def produce_table():
json_data = get_emojis()
lines = []
for image,url in sorted(json_data.items()):
match = unicode_re.match(url)
if match:
unicodes = match.group(1).split('-')
unicodes_html = ''.join(["&#x"+x+";" for x in unicodes])
image_str = "\":"+image+":\","
unicode_str = "\""+unicodes_html+"\""
lines.append(' { %-42s %-38s }' % (image_str,unicode_str))
out_str = ',\n'.join(lines)
print("{")
print(out_str)
print("};")
if __name__=="__main__":
parser = argparse.ArgumentParser()
group = parser.add_mutually_exclusive_group()
group.add_argument('-d','--dir',help='directory to place images in')
group.add_argument('-t','--table',help='generate code fragment',action='store_true')
args = parser.parse_args()
if args.table:
produce_table()
else:
download_images(args.dir)

When invoking it with the `-d image_dir` option the images will by downloaded in the `image_dir` directory. By means of the doxygen configuration parameter LATEX_EMOJI_DIRECTORY the requested directory can be selected.

For convenience a zip with the result of running the script can also be downloaded from https://www.doxygen.nl/dl/github_emojis.zip

For an overview of the supported emoji one can issue the command:
`doxygen -f emoji <outputFileName>`

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