2 * \file lengthcommon.cpp
3 * This file is part of LyX, the document processor.
4 * Licence details can be found in the file COPYING.
6 * \author Lars Gullik Bjønnes
7 * \author Matthias Ettrich
10 * Full author contact details are available in file CREDITS.
17 #include "support/convert.h"
18 #include "support/gettext.h"
19 #include "support/lassert.h"
20 #include "support/lstrings.h"
26 using namespace lyx::support;
31 // I am not sure if "mu" should be possible to select (Lgb)
34 char const * const unit_name[] = {
35 "bp", "cc", "cm", "dd", "em", "ex", "in", "mm", "mu",
37 "text%", "col%", "page%", "line%",
38 "theight%", "pheight%", "" };
40 int const num_units = int(sizeof(unit_name) / sizeof(unit_name[0]) - 1);
43 char const * const unit_name_gui[] = {
44 N_("bp"), N_("cc[[unit of measure]]"), N_("cm"), N_("dd"), N_("em"),
45 N_("ex"), N_("in[[unit of measure]]"), N_("mm"), N_("mu[[unit of measure]]"), N_("pc"),
46 N_("pt"), N_("sp"), N_("Text Width %"),
47 N_("Column Width %"), N_("Page Width %"), N_("Line Width %"),
48 N_("Text Height %"), N_("Page Height %"), "" };
51 Length::UNIT unitFromString(string const & data)
54 while (i < num_units && data != unit_name[i])
56 return static_cast<Length::UNIT>(i);
62 /// skip n characters of input
63 inline void lyx_advance(string & data, size_t n)
69 /// return true when the input is at the end
70 inline bool isEndOfData(string const & data)
72 return ltrim(data).empty();
77 * nextToken - return the next token in the input
78 * @param data input string
79 * @param number_index the current position in the number array
80 * @param unit_index the current position in the unit array
81 * @return a char representing the type of token returned
83 * The possible return values are :
84 * + stretch indicator for glue length
85 * - shrink indicator for glue length
86 * n a numeric value (stored in number array)
87 * u a unit type (stored in unit array)
90 char nextToken(string & data, double * number, int & number_index,
91 Length::UNIT * unit, int & unit_index)
103 if (prefixIs(data, "plus")) {
104 lyx_advance(data, 4);
108 if (data[0] == '-') {
109 lyx_advance(data, 1);
113 if (prefixIs(data, "minus")) {
114 lyx_advance(data, 5);
118 size_t i = data.find_first_not_of("0123456789.");
121 if (number_index > 3)
126 // we have found some number
127 if (i == string::npos) {
131 buffer = data.substr(0, i);
134 lyx_advance(data, i);
136 if (isStrDbl(buffer)) {
137 number[number_index] = convert<double>(buffer);
144 i = data.find_first_not_of("abcdefghijklmnopqrstuvwxyz%");
151 // we have found some alphabetical string
152 if (i == string::npos) {
156 buffer = data.substr(0, i);
159 // possibly we have "mmplus" string or similar
160 if (buffer.size() > 5 &&
161 (buffer.substr(2, 4) == string("plus") ||
162 buffer.substr(2, 5) == string("minus")))
164 lyx_advance(data, 2);
165 unit[unit_index] = unitFromString(buffer.substr(0, 2));
167 lyx_advance(data, i);
168 unit[unit_index] = unitFromString(buffer);
171 if (unit[unit_index] != Length::UNIT_NONE) {
181 /// latex representation of a vspace
183 char const * pattern;
191 /// the possible formats for a vspace string
192 LaTeXLength table[] = {
193 { "nu", 0, 0, 0, 0 },
194 { "nu+nu", 2, 0, 2, 0 },
195 { "nu+nu-nu", 2, 3, 2, 3 },
196 { "nu+-nu", 2, 2, 2, 2 },
197 { "nu-nu", 0, 2, 0, 2 },
198 { "nu-nu+nu", 3, 2, 3, 2 },
199 { "nu-+nu", 2, 2, 2, 2 },
200 { "n+nu", 2, 0, 1, 0 },
201 { "n+n-nu", 2, 3, 1, 1 },
202 { "n+-nu", 2, 2, 1, 1 },
203 { "n-nu", 0, 2, 0, 1 },
204 { "n-n+nu", 3, 2, 1, 1 },
205 { "n-+nu", 2, 2, 1, 1 },
206 { "", 0, 0, 0, 0 } // sentinel, must be empty
213 const char * stringFromUnit(int unit)
215 if (unit < 0 || unit > num_units)
217 return unit_name[unit];
221 bool isValidGlueLength(string const & data, GlueLength * result)
223 // This parser is table-driven. First, it constructs a "pattern"
224 // that describes the sequence of tokens in "data". For example,
225 // "n-nu" means: number, minus sign, number, unit. As we go along,
226 // numbers and units are stored into static arrays. Then, "pattern"
227 // is searched in the "table". If it is found, the associated
228 // table entries tell us which number and unit should go where
229 // in the Length structure. Example: if "data" has the "pattern"
230 // "nu+nu-nu", the associated table entries are "2, 3, 2, 3".
231 // That means, "plus_val" is the second number that was seen
232 // in the input, "minus_val" is the third number, and "plus_uni"
233 // and "minus_uni" are the second and third units, respectively.
234 // ("val" and "uni" are always the first items seen in "data".)
235 // This is the most elegant solution I could find -- a straight-
236 // forward approach leads to very long, tedious code that would be
237 // much harder to understand and maintain. (AS)
241 string buffer = ltrim(data);
243 // To make isValidGlueLength recognize negative values as
244 // the first number this little hack is needed:
245 int val_sign = 1; // positive as default
248 lyx_advance(buffer, 1);
252 lyx_advance(buffer, 1);
259 // used to return numeric values in parsing vspace
260 double number[4] = { 0, 0, 0, 0 };
261 // used to return unit types in parsing vspace
262 Length::UNIT unit[4] = {Length::UNIT_NONE, Length::UNIT_NONE,
263 Length::UNIT_NONE, Length::UNIT_NONE};
264 int number_index = 1; // entries at index 0 are sentinels
265 int unit_index = 1; // entries at index 0 are sentinels
267 // construct "pattern" from "data"
268 size_t const pattern_max_size = 20;
270 while (!isEndOfData(buffer)) {
271 if (pattern.size() > pattern_max_size)
273 char const c = nextToken(buffer, number, number_index, unit,
277 pattern.push_back(c);
280 // search "pattern" in "table"
281 size_t table_index = 0;
282 while (pattern != table[table_index].pattern) {
284 if (!*table[table_index].pattern)
288 // Get the values from the appropriate places. If an index
289 // is zero, the corresponding array value is zero or UNIT_NONE,
290 // so we needn't check this.
292 result->len_.value (number[1] * val_sign);
293 result->len_.unit (unit[1]);
294 result->plus_.value (number[table[table_index].plus_val_index]);
295 result->plus_.unit (unit [table[table_index].plus_uni_index]);
296 result->minus_.value(number[table[table_index].minus_val_index]);
297 result->minus_.unit (unit [table[table_index].minus_uni_index]);
303 bool isValidLength(string const & data, Length * result)
305 // This is a trimmed down version of isValidGlueLength.
306 // The parser may seem overkill for lengths without
307 // glue, but since we already have it, using it is
308 // easier than writing something from scratch.
312 string buffer = data;
313 int pattern_index = 0;
316 // To make isValidLength recognize negative values
317 // this little hack is needed:
318 int val_sign = 1; // positive as default
321 lyx_advance(buffer, 1);
325 lyx_advance(buffer, 1);
333 // used to return numeric values in parsing vspace
334 double number[4] = { 0, 0, 0, 0 };
335 // used to return unit types in parsing vspace
336 Length::UNIT unit[4] = {Length::UNIT_NONE, Length::UNIT_NONE,
337 Length::UNIT_NONE, Length::UNIT_NONE};
338 int number_index = 1; // entries at index 0 are sentinels
339 int unit_index = 1; // entries at index 0 are sentinels
341 // construct "pattern" from "data"
342 while (!isEndOfData(buffer)) {
343 if (pattern_index > 2)
345 pattern[pattern_index] = nextToken(buffer, number,
346 number_index, unit, unit_index);
347 if (pattern[pattern_index] == 'E')
351 pattern[pattern_index] = '\0';
353 // only the most basic pattern is accepted here
354 if (strcmp(pattern, "nu") != 0)
357 // It _was_ a correct length string.
358 // Store away the values we found.
360 result->val_ = number[1] * val_sign;
361 result->unit_ = unit[1];