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1 | # -*- coding: utf-8 -*- |
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1 | # -*- coding: utf-8 -*- | |
2 | """Tools for handling LaTeX.""" |
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2 | """Tools for handling LaTeX.""" | |
3 |
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3 | |||
4 | # Copyright (c) IPython Development Team. |
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4 | # Copyright (c) IPython Development Team. | |
5 | # Distributed under the terms of the Modified BSD License. |
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5 | # Distributed under the terms of the Modified BSD License. | |
6 |
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6 | |||
7 | from io import BytesIO, open |
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7 | from io import BytesIO, open | |
8 | from base64 import encodestring |
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|||
9 | import os |
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8 | import os | |
10 | import tempfile |
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9 | import tempfile | |
11 | import shutil |
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10 | import shutil | |
12 | import subprocess |
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11 | import subprocess | |
13 |
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12 | |||
14 | from IPython.utils.process import find_cmd, FindCmdError |
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13 | from IPython.utils.process import find_cmd, FindCmdError | |
15 | from traitlets.config import get_config |
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14 | from traitlets.config import get_config | |
16 | from traitlets.config.configurable import SingletonConfigurable |
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15 | from traitlets.config.configurable import SingletonConfigurable | |
17 | from traitlets import List, Bool, Unicode |
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16 | from traitlets import List, Bool, Unicode | |
18 | from IPython.utils.py3compat import cast_unicode, cast_unicode_py2 as u |
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17 | from IPython.utils.py3compat import cast_unicode, cast_unicode_py2 as u, PY3 | |
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18 | ||||
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19 | if PY3: | |||
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20 | from base64 import encodebytes | |||
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21 | else : | |||
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22 | from base64 import encodestring as encodebytes | |||
19 |
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23 | |||
20 |
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24 | |||
21 | class LaTeXTool(SingletonConfigurable): |
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25 | class LaTeXTool(SingletonConfigurable): | |
22 | """An object to store configuration of the LaTeX tool.""" |
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26 | """An object to store configuration of the LaTeX tool.""" | |
23 | def _config_default(self): |
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27 | def _config_default(self): | |
24 | return get_config() |
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28 | return get_config() | |
25 |
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29 | |||
26 | backends = List( |
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30 | backends = List( | |
27 | Unicode(), ["matplotlib", "dvipng"], |
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31 | Unicode(), ["matplotlib", "dvipng"], | |
28 | help="Preferred backend to draw LaTeX math equations. " |
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32 | help="Preferred backend to draw LaTeX math equations. " | |
29 | "Backends in the list are checked one by one and the first " |
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33 | "Backends in the list are checked one by one and the first " | |
30 | "usable one is used. Note that `matplotlib` backend " |
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34 | "usable one is used. Note that `matplotlib` backend " | |
31 | "is usable only for inline style equations. To draw " |
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35 | "is usable only for inline style equations. To draw " | |
32 | "display style equations, `dvipng` backend must be specified. ", |
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36 | "display style equations, `dvipng` backend must be specified. ", | |
33 | # It is a List instead of Enum, to make configuration more |
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37 | # It is a List instead of Enum, to make configuration more | |
34 | # flexible. For example, to use matplotlib mainly but dvipng |
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38 | # flexible. For example, to use matplotlib mainly but dvipng | |
35 | # for display style, the default ["matplotlib", "dvipng"] can |
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39 | # for display style, the default ["matplotlib", "dvipng"] can | |
36 | # be used. To NOT use dvipng so that other repr such as |
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40 | # be used. To NOT use dvipng so that other repr such as | |
37 | # unicode pretty printing is used, you can use ["matplotlib"]. |
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41 | # unicode pretty printing is used, you can use ["matplotlib"]. | |
38 | config=True) |
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42 | config=True) | |
39 |
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43 | |||
40 | use_breqn = Bool( |
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44 | use_breqn = Bool( | |
41 | True, |
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45 | True, | |
42 | help="Use breqn.sty to automatically break long equations. " |
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46 | help="Use breqn.sty to automatically break long equations. " | |
43 | "This configuration takes effect only for dvipng backend.", |
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47 | "This configuration takes effect only for dvipng backend.", | |
44 | config=True) |
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48 | config=True) | |
45 |
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49 | |||
46 | packages = List( |
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50 | packages = List( | |
47 | ['amsmath', 'amsthm', 'amssymb', 'bm'], |
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51 | ['amsmath', 'amsthm', 'amssymb', 'bm'], | |
48 | help="A list of packages to use for dvipng backend. " |
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52 | help="A list of packages to use for dvipng backend. " | |
49 | "'breqn' will be automatically appended when use_breqn=True.", |
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53 | "'breqn' will be automatically appended when use_breqn=True.", | |
50 | config=True) |
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54 | config=True) | |
51 |
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55 | |||
52 | preamble = Unicode( |
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56 | preamble = Unicode( | |
53 | help="Additional preamble to use when generating LaTeX source " |
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57 | help="Additional preamble to use when generating LaTeX source " | |
54 | "for dvipng backend.", |
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58 | "for dvipng backend.", | |
55 | config=True) |
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59 | config=True) | |
56 |
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60 | |||
57 |
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61 | |||
58 | def latex_to_png(s, encode=False, backend=None, wrap=False): |
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62 | def latex_to_png(s, encode=False, backend=None, wrap=False): | |
59 | """Render a LaTeX string to PNG. |
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63 | """Render a LaTeX string to PNG. | |
60 |
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64 | |||
61 | Parameters |
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65 | Parameters | |
62 | ---------- |
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66 | ---------- | |
63 | s : text |
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67 | s : text | |
64 | The raw string containing valid inline LaTeX. |
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68 | The raw string containing valid inline LaTeX. | |
65 | encode : bool, optional |
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69 | encode : bool, optional | |
66 | Should the PNG data base64 encoded to make it JSON'able. |
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70 | Should the PNG data base64 encoded to make it JSON'able. | |
67 | backend : {matplotlib, dvipng} |
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71 | backend : {matplotlib, dvipng} | |
68 | Backend for producing PNG data. |
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72 | Backend for producing PNG data. | |
69 | wrap : bool |
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73 | wrap : bool | |
70 | If true, Automatically wrap `s` as a LaTeX equation. |
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74 | If true, Automatically wrap `s` as a LaTeX equation. | |
71 |
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75 | |||
72 | None is returned when the backend cannot be used. |
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76 | None is returned when the backend cannot be used. | |
73 |
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77 | |||
74 | """ |
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78 | """ | |
75 | s = cast_unicode(s) |
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79 | s = cast_unicode(s) | |
76 | allowed_backends = LaTeXTool.instance().backends |
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80 | allowed_backends = LaTeXTool.instance().backends | |
77 | if backend is None: |
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81 | if backend is None: | |
78 | backend = allowed_backends[0] |
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82 | backend = allowed_backends[0] | |
79 | if backend not in allowed_backends: |
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83 | if backend not in allowed_backends: | |
80 | return None |
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84 | return None | |
81 | if backend == 'matplotlib': |
|
85 | if backend == 'matplotlib': | |
82 | f = latex_to_png_mpl |
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86 | f = latex_to_png_mpl | |
83 | elif backend == 'dvipng': |
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87 | elif backend == 'dvipng': | |
84 | f = latex_to_png_dvipng |
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88 | f = latex_to_png_dvipng | |
85 | else: |
|
89 | else: | |
86 | raise ValueError('No such backend {0}'.format(backend)) |
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90 | raise ValueError('No such backend {0}'.format(backend)) | |
87 | bin_data = f(s, wrap) |
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91 | bin_data = f(s, wrap) | |
88 | if encode and bin_data: |
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92 | if encode and bin_data: | |
89 |
bin_data = encodes |
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93 | bin_data = encodebytes(bin_data) | |
90 | return bin_data |
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94 | return bin_data | |
91 |
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95 | |||
92 |
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96 | |||
93 | def latex_to_png_mpl(s, wrap): |
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97 | def latex_to_png_mpl(s, wrap): | |
94 | try: |
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98 | try: | |
95 | from matplotlib import mathtext |
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99 | from matplotlib import mathtext | |
96 | except ImportError: |
|
100 | except ImportError: | |
97 | return None |
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101 | return None | |
98 |
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102 | |||
99 | # mpl mathtext doesn't support display math, force inline |
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103 | # mpl mathtext doesn't support display math, force inline | |
100 | s = s.replace('$$', '$') |
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104 | s = s.replace('$$', '$') | |
101 | if wrap: |
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105 | if wrap: | |
102 | s = u'${0}$'.format(s) |
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106 | s = u'${0}$'.format(s) | |
103 |
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107 | |||
104 | mt = mathtext.MathTextParser('bitmap') |
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108 | mt = mathtext.MathTextParser('bitmap') | |
105 | f = BytesIO() |
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109 | f = BytesIO() | |
106 | mt.to_png(f, s, fontsize=12) |
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110 | mt.to_png(f, s, fontsize=12) | |
107 | return f.getvalue() |
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111 | return f.getvalue() | |
108 |
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112 | |||
109 |
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113 | |||
110 | def latex_to_png_dvipng(s, wrap): |
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114 | def latex_to_png_dvipng(s, wrap): | |
111 | try: |
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115 | try: | |
112 | find_cmd('latex') |
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116 | find_cmd('latex') | |
113 | find_cmd('dvipng') |
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117 | find_cmd('dvipng') | |
114 | except FindCmdError: |
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118 | except FindCmdError: | |
115 | return None |
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119 | return None | |
116 | try: |
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120 | try: | |
117 | workdir = tempfile.mkdtemp() |
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121 | workdir = tempfile.mkdtemp() | |
118 | tmpfile = os.path.join(workdir, "tmp.tex") |
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122 | tmpfile = os.path.join(workdir, "tmp.tex") | |
119 | dvifile = os.path.join(workdir, "tmp.dvi") |
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123 | dvifile = os.path.join(workdir, "tmp.dvi") | |
120 | outfile = os.path.join(workdir, "tmp.png") |
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124 | outfile = os.path.join(workdir, "tmp.png") | |
121 |
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125 | |||
122 | with open(tmpfile, "w", encoding='utf8') as f: |
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126 | with open(tmpfile, "w", encoding='utf8') as f: | |
123 | f.writelines(genelatex(s, wrap)) |
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127 | f.writelines(genelatex(s, wrap)) | |
124 |
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128 | |||
125 | with open(os.devnull, 'wb') as devnull: |
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129 | with open(os.devnull, 'wb') as devnull: | |
126 | subprocess.check_call( |
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130 | subprocess.check_call( | |
127 | ["latex", "-halt-on-error", "-interaction", "batchmode", tmpfile], |
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131 | ["latex", "-halt-on-error", "-interaction", "batchmode", tmpfile], | |
128 | cwd=workdir, stdout=devnull, stderr=devnull) |
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132 | cwd=workdir, stdout=devnull, stderr=devnull) | |
129 |
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133 | |||
130 | subprocess.check_call( |
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134 | subprocess.check_call( | |
131 | ["dvipng", "-T", "tight", "-x", "1500", "-z", "9", |
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135 | ["dvipng", "-T", "tight", "-x", "1500", "-z", "9", | |
132 | "-bg", "transparent", "-o", outfile, dvifile], cwd=workdir, |
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136 | "-bg", "transparent", "-o", outfile, dvifile], cwd=workdir, | |
133 | stdout=devnull, stderr=devnull) |
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137 | stdout=devnull, stderr=devnull) | |
134 |
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138 | |||
135 | with open(outfile, "rb") as f: |
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139 | with open(outfile, "rb") as f: | |
136 | return f.read() |
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140 | return f.read() | |
137 | finally: |
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141 | finally: | |
138 | shutil.rmtree(workdir) |
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142 | shutil.rmtree(workdir) | |
139 |
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143 | |||
140 |
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144 | |||
141 | def kpsewhich(filename): |
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145 | def kpsewhich(filename): | |
142 | """Invoke kpsewhich command with an argument `filename`.""" |
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146 | """Invoke kpsewhich command with an argument `filename`.""" | |
143 | try: |
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147 | try: | |
144 | find_cmd("kpsewhich") |
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148 | find_cmd("kpsewhich") | |
145 | proc = subprocess.Popen( |
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149 | proc = subprocess.Popen( | |
146 | ["kpsewhich", filename], |
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150 | ["kpsewhich", filename], | |
147 | stdout=subprocess.PIPE, stderr=subprocess.PIPE) |
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151 | stdout=subprocess.PIPE, stderr=subprocess.PIPE) | |
148 | (stdout, stderr) = proc.communicate() |
|
152 | (stdout, stderr) = proc.communicate() | |
149 | return stdout.strip().decode('utf8', 'replace') |
|
153 | return stdout.strip().decode('utf8', 'replace') | |
150 | except FindCmdError: |
|
154 | except FindCmdError: | |
151 | pass |
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155 | pass | |
152 |
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156 | |||
153 |
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157 | |||
154 | def genelatex(body, wrap): |
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158 | def genelatex(body, wrap): | |
155 | """Generate LaTeX document for dvipng backend.""" |
|
159 | """Generate LaTeX document for dvipng backend.""" | |
156 | lt = LaTeXTool.instance() |
|
160 | lt = LaTeXTool.instance() | |
157 | breqn = wrap and lt.use_breqn and kpsewhich("breqn.sty") |
|
161 | breqn = wrap and lt.use_breqn and kpsewhich("breqn.sty") | |
158 | yield u(r'\documentclass{article}') |
|
162 | yield u(r'\documentclass{article}') | |
159 | packages = lt.packages |
|
163 | packages = lt.packages | |
160 | if breqn: |
|
164 | if breqn: | |
161 | packages = packages + ['breqn'] |
|
165 | packages = packages + ['breqn'] | |
162 | for pack in packages: |
|
166 | for pack in packages: | |
163 | yield u(r'\usepackage{{{0}}}'.format(pack)) |
|
167 | yield u(r'\usepackage{{{0}}}'.format(pack)) | |
164 | yield u(r'\pagestyle{empty}') |
|
168 | yield u(r'\pagestyle{empty}') | |
165 | if lt.preamble: |
|
169 | if lt.preamble: | |
166 | yield lt.preamble |
|
170 | yield lt.preamble | |
167 | yield u(r'\begin{document}') |
|
171 | yield u(r'\begin{document}') | |
168 | if breqn: |
|
172 | if breqn: | |
169 | yield u(r'\begin{dmath*}') |
|
173 | yield u(r'\begin{dmath*}') | |
170 | yield body |
|
174 | yield body | |
171 | yield u(r'\end{dmath*}') |
|
175 | yield u(r'\end{dmath*}') | |
172 | elif wrap: |
|
176 | elif wrap: | |
173 | yield u'$${0}$$'.format(body) |
|
177 | yield u'$${0}$$'.format(body) | |
174 | else: |
|
178 | else: | |
175 | yield body |
|
179 | yield body | |
176 | yield u'\end{document}' |
|
180 | yield u'\end{document}' | |
177 |
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181 | |||
178 |
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182 | |||
179 | _data_uri_template_png = u"""<img src="data:image/png;base64,%s" alt=%s />""" |
|
183 | _data_uri_template_png = u"""<img src="data:image/png;base64,%s" alt=%s />""" | |
180 |
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184 | |||
181 | def latex_to_html(s, alt='image'): |
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185 | def latex_to_html(s, alt='image'): | |
182 | """Render LaTeX to HTML with embedded PNG data using data URIs. |
|
186 | """Render LaTeX to HTML with embedded PNG data using data URIs. | |
183 |
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187 | |||
184 | Parameters |
|
188 | Parameters | |
185 | ---------- |
|
189 | ---------- | |
186 | s : str |
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190 | s : str | |
187 | The raw string containing valid inline LateX. |
|
191 | The raw string containing valid inline LateX. | |
188 | alt : str |
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192 | alt : str | |
189 | The alt text to use for the HTML. |
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193 | The alt text to use for the HTML. | |
190 | """ |
|
194 | """ | |
191 | base64_data = latex_to_png(s, encode=True).decode('ascii') |
|
195 | base64_data = latex_to_png(s, encode=True).decode('ascii') | |
192 | if base64_data: |
|
196 | if base64_data: | |
193 | return _data_uri_template_png % (base64_data, alt) |
|
197 | return _data_uri_template_png % (base64_data, alt) | |
194 |
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198 | |||
195 |
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199 |
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