lib/scripts/lyxpreview2bitmap.py

   1 #! /usr/bin/env python
   2 # -*- coding: utf-8 -*-
   3
   4 # file lyxpreview2bitmap.py
   5 # This file is part of LyX, the document processor.
   6 # Licence details can be found in the file COPYING.
   7
   8 # author Angus Leeming
   9 # with much advice from members of the preview-latex project:
  10 # David Kastrup, dak@gnu.org and
  11 # Jan-Åke Larsson, jalar@mai.liu.se.
  12
  13 # Full author contact details are available in file CREDITS
  14
  15 # This script takes a LaTeX file and generates a collection of
  16 # png or ppm image files, one per previewed snippet.
  17
  18 # Pre-requisites:
  19 # * A latex executable;
  20 # * preview.sty;
  21 # * dvipng;
  22 # * pngtoppm (if outputing ppm format images).
  23
  24 # preview.sty and dvipng are part of the preview-latex project
  25 # http://preview-latex.sourceforge.net/
  26
  27 # preview.sty can alternatively be obtained from
  28 # CTAN/support/preview-latex/
  29
  30 # Example usage:
  31 # lyxpreview2bitmap.py png 0lyxpreview.tex 128 000000 faf0e6
  32
  33 # This script takes five arguments:
  34 # FORMAT:   The desired output format. Either 'png' or 'ppm'.
  35 # TEXFILE:  the name of the .tex file to be converted.
  36 # DPI:      a scale factor, used to ascertain the resolution of the
  37 #           generated image which is then passed to gs.
  38 # FG_COLOR: the foreground color as a hexadecimal string, eg '000000'.
  39 # BG_COLOR: the background color as a hexadecimal string, eg 'faf0e6'.
  40
  41 # Decomposing TEXFILE's name as DIR/BASE.tex, this script will,
  42 # if executed successfully, leave in DIR:
  43 # * a (possibly large) number of image files with names
  44 #   like BASE[0-9]+.png
  45 # * a file BASE.metrics, containing info needed by LyX to position
  46 #   the images correctly on the screen.
  47
  48 import glob, os, re, string, sys
  49
  50 from legacy_lyxpreview2ppm import legacy_conversion, \
  51      legacy_conversion_step2
  52
  53 from lyxpreview_tools import copyfileobj, error, find_exe, \
  54      find_exe_or_terminate, make_texcolor, mkstemp, run_command, warning
  55
  56
  57 # Pre-compiled regular expressions.
  58 latex_file_re = re.compile("\.tex$")
  59
  60
  61 def usage(prog_name):
  62     return "Usage: %s <format> <latex file> <dpi> <fg color> <bg color>\n"\
  63            "\twhere the colors are hexadecimal strings, eg 'faf0e6'"\
  64            % prog_name
  65
  66
  67 def extract_metrics_info(dvipng_stdout, metrics_file):
  68     metrics = open(metrics_file, 'w')
  69 # "\[[0-9]+" can match two kinds of numbers: page numbers from dvipng
  70 # and glyph numbers from mktexpk. The glyph numbers always match
  71 # "\[[0-9]+\]" while the page number never is followed by "\]". Thus:
  72     page_re = re.compile("\[([0-9]+)[^]]");
  73     metrics_re = re.compile("depth=(-?[0-9]+) height=(-?[0-9]+)")
  74
  75     success = 0
  76     page = ""
  77     pos = 0
  78     while 1:
  79         match = page_re.search(dvipng_stdout, pos)
  80         if match == None:
  81             break
  82         page = match.group(1)
  83         pos = match.end()
  84         match = metrics_re.search(dvipng_stdout, pos)
  85         if match == None:
  86             break
  87         success = 1
  88
  89         # Calculate the 'ascent fraction'.
  90         descent = string.atof(match.group(1))
  91         ascent  = string.atof(match.group(2))
  92
  93         frac = 0.5
  94         if ascent >= 0 or descent >= 0:
  95             if abs(ascent + descent) > 0.1:
  96                 frac = ascent / (ascent + descent)
  97
  98             # Sanity check
  99             if frac < 0:
 100                 frac = 0.5
 101
 102         metrics.write("Snippet %s %f\n" % (page, frac))
 103         pos = match.end() + 2
 104
 105     return success
 106
 107
 108 def color_pdf(latex_file, bg_color):
 109     use_preview_pdf_re = re.compile("(\s*\\\\usepackage\[[^]]+)(pdftex\]{preview})")
 110
 111     tmp = mkstemp()
 112
 113     success = 0
 114     try:
 115         for line in open(latex_file, 'r').readlines():
 116             match = use_preview_pdf_re.match(line)
 117             if match == None:
 118                 tmp.write(line)
 119                 continue
 120             success = 1
 121             tmp.write("  \\usepackage{color}\n" \
 122                   "  \\pagecolor[rgb]{%s}\n" \
 123                   "%s\n" \
 124                   % (bg_color, match.group()))
 125             continue
 126
 127     except:
 128         # Unable to open the file, but do nothing here because
 129         # the calling function will act on the value of 'success'.
 130         warning('Warning in color_pdf! Unable to open "%s"' % latex_file)
 131         warning(`sys.exc_type` + ',' + `sys.exc_value`)
 132
 133     if success:
 134         copyfileobj(tmp, open(latex_file,"wb"), 1)
 135
 136     return success
 137
 138
 139 def convert_to_ppm_format(pngtopnm, basename):
 140     png_file_re = re.compile("\.png$")
 141
 142     for png_file in glob.glob("%s*.png" % basename):
 143         ppm_file = png_file_re.sub(".ppm", png_file)
 144
 145         p2p_cmd = '%s "%s"' % (pngtopnm, png_file)
 146         p2p_status, p2p_stdout = run_command(p2p_cmd)
 147         if p2p_status != None:
 148             error("Unable to convert %s to ppm format" % png_file)
 149
 150         ppm = open(ppm_file, 'w')
 151         ppm.write(p2p_stdout)
 152         os.remove(png_file)
 153
 154
 155 def main(argv):
 156     # Parse and manipulate the command line arguments.
 157     if len(argv) != 6:
 158         error(usage(argv[0]))
 159
 160     output_format = string.lower(argv[1])
 161
 162     dir, latex_file = os.path.split(argv[2])
 163     if len(dir) != 0:
 164         os.chdir(dir)
 165
 166     dpi = string.atoi(argv[3])
 167     fg_color = make_texcolor(argv[4], False)
 168     bg_color = make_texcolor(argv[5], False)
 169
 170     bg_color_gr = make_texcolor(argv[5], True)
 171
 172     # External programs used by the script.
 173     path = string.split(os.environ["PATH"], os.pathsep)
 174     latex = find_exe_or_terminate(["latex", "pplatex", "platex", "latex2e"], path)
 175
 176     # This can go once dvipng becomes widespread.
 177     dvipng = find_exe(["dvipng"], path)
 178     if dvipng == None:
 179         # The data is input to legacy_conversion in as similar
 180         # as possible a manner to that input to the code used in
 181         # LyX 1.3.x.
 182         vec = [ argv[0], argv[2], argv[3], argv[1], argv[4], argv[5] ]
 183         return legacy_conversion(vec)
 184
 185     pngtopnm = ""
 186     if output_format == "ppm":
 187         pngtopnm = find_exe_or_terminate(["pngtopnm"], path)
 188
 189     # Move color information for PDF into the latex file.
 190     if not color_pdf(latex_file, bg_color_gr):
 191         error("Unable to move color info into the latex file")
 192
 193     # Compile the latex file.
 194     latex_call = '%s "%s"' % (latex, latex_file)
 195
 196     latex_status, latex_stdout = run_command(latex_call)
 197     if latex_status != None:
 198         warning("%s failed to compile %s" \
 199               % (os.path.basename(latex), latex_file))
 200
 201     # Run the dvi file through dvipng.
 202     dvi_file = latex_file_re.sub(".dvi", latex_file)
 203     dvipng_call = '%s -Ttight -depth -height -D %d -fg "%s" -bg "%s" "%s"' \
 204                   % (dvipng, dpi, fg_color, bg_color, dvi_file)
 205
 206     dvipng_status, dvipng_stdout = run_command(dvipng_call)
 207     if dvipng_status != None:
 208         warning("%s failed to generate images from %s ... looking for PDF" \
 209               % (os.path.basename(dvipng), dvi_file))
 210         return legacy_conversion_step2(latex_file, dpi, output_format)
 211
 212     # Extract metrics info from dvipng_stdout.
 213     metrics_file = latex_file_re.sub(".metrics", latex_file)
 214     if not extract_metrics_info(dvipng_stdout, metrics_file):
 215         error("Failed to extract metrics info from dvipng")
 216
 217     # Convert images to ppm format if necessary.
 218     if output_format == "ppm":
 219         convert_to_ppm_format(pngtopnm, latex_file_re.sub("", latex_file))
 220
 221     return 0
 222
 223
 224 if __name__ == "__main__":
 225     main(sys.argv)