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Pick one slide from a beamer presentation provided a line number. It helps a lot when editing tikz figures for a beamer presentation with a dozen of tikz figures.
#!/usr/bin/python
#
# Given a line number, leave only the frame that covers the line number
# and invoke pdflatex. It is a nice way to preview one beamer slide,
# when the whole presentation is compiling for a couple of minutes.
#
# The preprocessor is very simple, if something breaks, let me know.
# To work properly with included files, we are using latexexpand.pl
# by Matthieu Moy.
#
# MULTIPLE FILES
#
# If you keep the frames in multiple files, specify the main file
# in the first line of each sub-file as follows:
#
# % main: my-main-file.tex
#
# USING WITH VIM
#
# This is how you can bind the preview on Ctrl-p in ~/.vimrc:
#
# nmap <C-p> :execute "!beamer-preview " . expand("%") . " " . line(".")<CR>
#
# USING WITH EMACS
#
# Define the following mapping ~/.emacs (thanks, Josef Widder):
#
# (defun beamerpreview ()
# (interactive "*")
# (shell-command (format "beamer-preview %s %d"
# (buffer-file-name)
# (1 + (count-lines 1 (point))))))
# (global-set-key "\C-c\C-n" 'beamerpreview)
#
# You will find the preview slide in preview.pdf
#
# Igor Konnov <konnov at forsyte.at>, 2013-2015
import re
import os
import shutil
import subprocess
import sys
import tempfile
from StringIO import StringIO
STATE_OUT_FRAME = 0
STATE_IN_FRAME = 1
AGAIN_FRAME_RE = re.compile(r'^(.*?)\\againframe[^{]*{[^}]*}(.*)$')
MAIN_RE = re.compile(r'^\s*%\s*main:\s*(.*)$')
# this regex is copied from latexexpand by Matthieu Moy
INPUT_RE = re.compile(r'^[^%\\]*\\input[{\s]+(.*?)[\s}].*$')
class InputError(Exception):
def __init__(self, msg):
self.msg = msg
def __str__(self):
return self.msg
# similar to that in latexexpand
def find_file(parent, name):
if os.path.isabs(name) and os.path.isfile(name):
return name
(parent_dir, _) = os.path.split(parent)
full_name = os.path.join(parent_dir, name)
if os.path.isfile(full_name):
return full_name
else:
return None
def find_tex_file(parent, name):
full = find_file(parent, name)
if full:
return full
else:
full = find_file(parent, name + '.tex')
if full:
return full
else:
(parent_dir, _) = os.path.split(parent)
raise InputError("Input file %s not found in %s" % (name, parent_dir))
def exclude_slides(out, filename, keep_filename, keep_line_no):
keep = (os.path.realpath(filename) == os.path.realpath(keep_filename))
state = STATE_OUT_FRAME
lineno, start_lineno, end_lineno = 1, -1, -1
f = open(filename, "r")
for line in f:
line = line.rstrip('\n')
line = line.rstrip('\r')
m = INPUT_RE.match(line)
if m:
if state == STATE_IN_FRAME:
fo = frame # write to the frame buffer
else:
fo = out # write to out directly
included_name = find_tex_file(filename, m.group(1))
fo.write('\makeatletter{}\n%% input %s:%d\n' % (included_name, lineno))
exclude_slides(fo, included_name, keep_filename, keep_line_no)
fo.write('%% end of %s:%d\n' % (included_name, lineno))
fo.write(' \n') # following the wisdom of latexexpand
elif line.find('\\begin{document}') >= 0:
# change the title to preview
out.write(' \\title{preview %s:%d}\n' % (keep_filename, keep_line_no))
out.write(line)
elif line.find('\\begin{frame}') >= 0:
state = STATE_IN_FRAME
start_lineno = lineno
frame = StringIO('')
frame.write(line)
elif line.find('\\end{frame}') >= 0:
state = STATE_OUT_FRAME
end_lineno = lineno
if keep and start_lineno <= keep_line_no and keep_line_no <= end_lineno:
# flush the selected frame
out.write(frame.getvalue())
out.write(line)
else:
out.write('%% forwarded to line %s:%d\n' % (filename, lineno))
frame.close()
elif state == STATE_OUT_FRAME:
# remove \againframe{...}
m = AGAIN_FRAME_RE.match(line)
if m:
out.write(m.group(1))
out.write(m.group(2))
out.write('\n')
else:
out.write(line)
out.write('\n')
elif state == STATE_IN_FRAME:
frame.write(line)
frame.write('\n')
else:
assert(False) # should not reach here
lineno += 1
f.close()
def find_main(filename):
"""Read the first line and if it looks like '% main: ...',
return the file specified there. Otherwise, return the
argument."""
with open(filename, 'r') as f:
line = f.readline()
m = MAIN_RE.match(line)
if m:
main = m.group(1).strip()
if os.path.isabs(main):
return main
else:
dirname, _ = os.path.split(filename)
return os.path.join(dirname, main)
else:
return filename
if __name__ == "__main__":
try:
filename = sys.argv[1]
user_lineno = int(sys.argv[2])
except IndexError:
print "Use: %s file.tex lineno" % sys.argv[0]
sys.exit(1)
main = find_main(filename)
print "Starting with main: %s" % main
tmpdir = tempfile.mkdtemp(prefix = '_preview.')
out = open(os.path.join(tmpdir, 'preview.tex'), 'w')
exclude_slides(out, main, filename, user_lineno)
out.write('%% end of main %s\n' % filename)
out.close()
subprocess.call(["pdflatex", "-output-directory", tmpdir,
"-halt-on-error", "-file-line-error", "preview.tex"])
shutil.copy(os.path.join(tmpdir, "preview.pdf"), "preview.pdf")
shutil.rmtree(tmpdir)
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