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 %"), "" };
50 Length::UNIT unitFromString(string const & data)
53 while (i < num_units && data != unit_name[i])
55 return static_cast<Length::UNIT>(i);
61 /// skip n characters of input
62 inline void lyx_advance(string & data, size_t n)
68 /// return true when the input is at the end
69 inline bool isEndOfData(string const & data)
71 return ltrim(data).empty();
76 * nextToken - return the next token in the input
77 * @param data input string
78 * @param number_index the current position in the number array
79 * @param unit_index the current position in the unit array
80 * @return a char representing the type of token returned
82 * The possible return values are :
83 * + stretch indicator for glue length
84 * - shrink indicator for glue length
85 * n a numeric value (stored in number array)
86 * u a unit type (stored in unit array)
89 char nextToken(string & data, double * number, int & number_index,
90 Length::UNIT * unit, int & unit_index)
102 if (prefixIs(data, "plus")) {
103 lyx_advance(data, 4);
107 if (data[0] == '-') {
108 lyx_advance(data, 1);
112 if (prefixIs(data, "minus")) {
113 lyx_advance(data, 5);
117 size_t i = data.find_first_not_of("0123456789.");
120 if (number_index > 3)
125 // we have found some number
126 if (i == string::npos) {
130 buffer = data.substr(0, i);
133 lyx_advance(data, i);
135 if (isStrDbl(buffer)) {
136 number[number_index] = convert<double>(buffer);
143 i = data.find_first_not_of("abcdefghijklmnopqrstuvwxyz%");
150 // we have found some alphabetical string
151 if (i == string::npos) {
155 buffer = data.substr(0, i);
158 // possibly we have "mmplus" string or similar
159 if (buffer.size() > 5 &&
160 (buffer.substr(2, 4) == string("plus") ||
161 buffer.substr(2, 5) == string("minus")))
163 lyx_advance(data, 2);
164 unit[unit_index] = unitFromString(buffer.substr(0, 2));
166 lyx_advance(data, i);
167 unit[unit_index] = unitFromString(buffer);
170 if (unit[unit_index] != Length::UNIT_NONE) {
180 /// latex representation of a vspace
182 char const * pattern;
190 /// the possible formats for a vspace string
191 LaTeXLength table[] = {
192 { "nu", 0, 0, 0, 0 },
193 { "nu+nu", 2, 0, 2, 0 },
194 { "nu+nu-nu", 2, 3, 2, 3 },
195 { "nu+-nu", 2, 2, 2, 2 },
196 { "nu-nu", 0, 2, 0, 2 },
197 { "nu-nu+nu", 3, 2, 3, 2 },
198 { "nu-+nu", 2, 2, 2, 2 },
199 { "n+nu", 2, 0, 1, 0 },
200 { "n+n-nu", 2, 3, 1, 1 },
201 { "n+-nu", 2, 2, 1, 1 },
202 { "n-nu", 0, 2, 0, 1 },
203 { "n-n+nu", 3, 2, 1, 1 },
204 { "n-+nu", 2, 2, 1, 1 },
205 { "", 0, 0, 0, 0 } // sentinel, must be empty
211 const char * stringFromUnit(int unit)
213 if (unit < 0 || unit > num_units)
215 return unit_name[unit];
219 bool isValidGlueLength(string const & data, GlueLength * result)
221 // This parser is table-driven. First, it constructs a "pattern"
222 // that describes the sequence of tokens in "data". For example,
223 // "n-nu" means: number, minus sign, number, unit. As we go along,
224 // numbers and units are stored into static arrays. Then, "pattern"
225 // is searched in the "table". If it is found, the associated
226 // table entries tell us which number and unit should go where
227 // in the Length structure. Example: if "data" has the "pattern"
228 // "nu+nu-nu", the associated table entries are "2, 3, 2, 3".
229 // That means, "plus_val" is the second number that was seen
230 // in the input, "minus_val" is the third number, and "plus_uni"
231 // and "minus_uni" are the second and third units, respectively.
232 // ("val" and "uni" are always the first items seen in "data".)
233 // This is the most elegant solution I could find -- a straight-
234 // forward approach leads to very long, tedious code that would be
235 // much harder to understand and maintain. (AS)
239 string buffer = ltrim(data);
241 // To make isValidGlueLength recognize negative values as
242 // the first number this little hack is needed:
243 int val_sign = 1; // positive as default
246 lyx_advance(buffer, 1);
250 lyx_advance(buffer, 1);
257 // used to return numeric values in parsing vspace
258 double number[4] = { 0, 0, 0, 0 };
259 // used to return unit types in parsing vspace
260 Length::UNIT unit[4] = {Length::UNIT_NONE, Length::UNIT_NONE,
261 Length::UNIT_NONE, Length::UNIT_NONE};
262 int number_index = 1; // entries at index 0 are sentinels
263 int unit_index = 1; // entries at index 0 are sentinels
265 // construct "pattern" from "data"
266 size_t const pattern_max_size = 20;
268 while (!isEndOfData(buffer)) {
269 if (pattern.size() > pattern_max_size)
271 char const c = nextToken(buffer, number, number_index, unit,
275 pattern.push_back(c);
278 // search "pattern" in "table"
279 size_t table_index = 0;
280 while (pattern != table[table_index].pattern) {
282 if (!*table[table_index].pattern)
286 // Get the values from the appropriate places. If an index
287 // is zero, the corresponding array value is zero or UNIT_NONE,
288 // so we needn't check this.
290 result->len_.value (number[1] * val_sign);
291 result->len_.unit (unit[1]);
292 result->plus_.value (number[table[table_index].plus_val_index]);
293 result->plus_.unit (unit [table[table_index].plus_uni_index]);
294 result->minus_.value(number[table[table_index].minus_val_index]);
295 result->minus_.unit (unit [table[table_index].minus_uni_index]);
301 bool isValidLength(string const & data, Length * result)
303 // This is a trimmed down version of isValidGlueLength.
304 // The parser may seem overkill for lengths without
305 // glue, but since we already have it, using it is
306 // easier than writing something from scratch.
310 string buffer = data;
311 int pattern_index = 0;
314 // To make isValidLength recognize negative values
315 // this little hack is needed:
316 int val_sign = 1; // positive as default
319 lyx_advance(buffer, 1);
323 lyx_advance(buffer, 1);
331 // used to return numeric values in parsing vspace
332 double number[4] = { 0, 0, 0, 0 };
333 // used to return unit types in parsing vspace
334 Length::UNIT unit[4] = {Length::UNIT_NONE, Length::UNIT_NONE,
335 Length::UNIT_NONE, Length::UNIT_NONE};
336 int number_index = 1; // entries at index 0 are sentinels
337 int unit_index = 1; // entries at index 0 are sentinels
339 // construct "pattern" from "data"
340 while (!isEndOfData(buffer)) {
341 if (pattern_index > 2)
343 pattern[pattern_index] = nextToken(buffer, number,
344 number_index, unit, unit_index);
345 if (pattern[pattern_index] == 'E')
349 pattern[pattern_index] = '\0';
351 // only the most basic pattern is accepted here
352 if (strcmp(pattern, "nu") != 0)
355 // It _was_ a correct length string.
356 // Store away the values we found.
358 result->val_ = number[1] * val_sign;
359 result->unit_ = unit[1];