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"
23 using namespace lyx::support;
28 // I am not sure if "mu" should be possible to select (Lgb)
31 char const * const unit_name[] = {
32 "bp", "cc", "cm", "dd", "em", "ex", "in", "mm", "mu",
34 "text%", "col%", "page%", "line%",
35 "theight%", "pheight%", "" };
37 int const num_units = int(sizeof(unit_name) / sizeof(unit_name[0]) - 1);
40 char const * const unit_name_gui[] = {
41 N_("bp"), N_("cc[[unit of measure]]"), N_("cm"), N_("dd"), N_("em"),
42 N_("ex"), N_("in[[unit of measure]]"), N_("mm"), N_("mu[[unit of measure]]"), N_("pc"),
43 N_("pt"), N_("sp"), N_("Text Width %"),
44 N_("Column Width %"), N_("Page Width %"), N_("Line Width %"),
45 N_("Text Height %"), N_("Page Height %"), "" };
48 Length::UNIT unitFromString(string const & data)
51 while (i < num_units && data != unit_name[i])
53 return static_cast<Length::UNIT>(i);
59 /// skip n characters of input
60 inline void lyx_advance(string & data, size_t n)
66 /// return true when the input is at the end
67 inline bool isEndOfData(string const & data)
69 return ltrim(data).empty();
74 * nextToken - return the next token in the input
75 * @param data input string
76 * @param number_index the current position in the number array
77 * @param unit_index the current position in the unit array
78 * @return a char representing the type of token returned
80 * The possible return values are :
81 * + stretch indicator for glue length
82 * - shrink indicator for glue length
83 * n a numeric value (stored in number array)
84 * u a unit type (stored in unit array)
87 char nextToken(string & data, double * number, int & number_index,
88 Length::UNIT * unit, int & unit_index)
100 if (prefixIs(data, "plus")) {
101 lyx_advance(data, 4);
105 if (data[0] == '-') {
106 lyx_advance(data, 1);
110 if (prefixIs(data, "minus")) {
111 lyx_advance(data, 5);
115 size_t i = data.find_first_not_of("0123456789.");
118 if (number_index > 3)
123 // we have found some number
124 if (i == string::npos) {
128 buffer = data.substr(0, i);
131 lyx_advance(data, i);
133 if (isStrDbl(buffer)) {
134 number[number_index] = convert<double>(buffer);
141 i = data.find_first_not_of("abcdefghijklmnopqrstuvwxyz%");
148 // we have found some alphabetical string
149 if (i == string::npos) {
153 buffer = data.substr(0, i);
156 // possibly we have "mmplus" string or similar
157 if (buffer.size() > 5 &&
158 (buffer.substr(2, 4) == string("plus") ||
159 buffer.substr(2, 5) == string("minus")))
161 lyx_advance(data, 2);
162 unit[unit_index] = unitFromString(buffer.substr(0, 2));
164 lyx_advance(data, i);
165 unit[unit_index] = unitFromString(buffer);
168 if (unit[unit_index] != Length::UNIT_NONE) {
178 /// latex representation of a vspace
180 char const * pattern;
188 /// the possible formats for a vspace string
189 LaTeXLength table[] = {
190 { "nu", 0, 0, 0, 0 },
191 { "nu+nu", 2, 0, 2, 0 },
192 { "nu+nu-nu", 2, 3, 2, 3 },
193 { "nu+-nu", 2, 2, 2, 2 },
194 { "nu-nu", 0, 2, 0, 2 },
195 { "nu-nu+nu", 3, 2, 3, 2 },
196 { "nu-+nu", 2, 2, 2, 2 },
197 { "n+nu", 2, 0, 1, 0 },
198 { "n+n-nu", 2, 3, 1, 1 },
199 { "n+-nu", 2, 2, 1, 1 },
200 { "n-nu", 0, 2, 0, 1 },
201 { "n-n+nu", 3, 2, 1, 1 },
202 { "n-+nu", 2, 2, 1, 1 },
203 { "", 0, 0, 0, 0 } // sentinel, must be empty
210 const char * stringFromUnit(int unit)
212 if (unit < 0 || unit > num_units)
214 return unit_name[unit];
218 bool isValidGlueLength(string const & data, GlueLength * result)
220 // This parser is table-driven. First, it constructs a "pattern"
221 // that describes the sequence of tokens in "data". For example,
222 // "n-nu" means: number, minus sign, number, unit. As we go along,
223 // numbers and units are stored into static arrays. Then, "pattern"
224 // is searched in the "table". If it is found, the associated
225 // table entries tell us which number and unit should go where
226 // in the Length structure. Example: if "data" has the "pattern"
227 // "nu+nu-nu", the associated table entries are "2, 3, 2, 3".
228 // That means, "plus_val" is the second number that was seen
229 // in the input, "minus_val" is the third number, and "plus_uni"
230 // and "minus_uni" are the second and third units, respectively.
231 // ("val" and "uni" are always the first items seen in "data".)
232 // This is the most elegant solution I could find -- a straight-
233 // forward approach leads to very long, tedious code that would be
234 // much harder to understand and maintain. (AS)
238 *result = GlueLength();
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.
315 string buffer = data;
317 // To make isValidLength recognize negative values
318 // this little hack is needed:
319 int val_sign = 1; // positive as default
322 lyx_advance(buffer, 1);
326 lyx_advance(buffer, 1);
334 // used to return numeric values in parsing vspace
335 double number[4] = { 0, 0, 0, 0 };
336 // used to return unit types in parsing vspace
337 Length::UNIT unit[4] = {Length::UNIT_NONE, Length::UNIT_NONE,
338 Length::UNIT_NONE, Length::UNIT_NONE};
339 int number_index = 1; // entries at index 0 are sentinels
340 int unit_index = 1; // entries at index 0 are sentinels
342 // construct "pattern" from "data"
344 while (!isEndOfData(buffer)) {
345 if (pattern.size() > 2)
347 char const token = nextToken(buffer, number,
348 number_index, unit, unit_index);
354 // only the most basic pattern is accepted here
358 // It _was_ a correct length string.
359 // Store away the values we found.
361 result->val_ = number[1] * val_sign;
362 result->unit_ = unit[1];