lyx_mirror/src/VSpace.cpp

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/**
* \file VSpace.cpp
* This file is part of LyX, the document processor.
* Licence details can be found in the file COPYING.
*
* \author Matthias Ettrich
*
* Full author contact details are available in file CREDITS.
*/
#include <config.h>
#include "VSpace.h"
#include "Buffer.h"
#include "BufferParams.h"
#include "BufferView.h"
#include "gettext.h"
#include "lengthcommon.h"
#include "Text.h"
#include "support/convert.h"
#include "support/lstrings.h"
namespace lyx {
using support::compare;
using support::isStrDbl;
using support::ltrim;
using support::prefixIs;
using support::rtrim;
using std::string;
namespace {
/// used to return numeric values in parsing vspace
double number[4] = { 0, 0, 0, 0 };
/// used to return unit types in parsing vspace
Length::UNIT unit[4] = { Length::UNIT_NONE,
Length::UNIT_NONE,
Length::UNIT_NONE,
Length::UNIT_NONE };
/// the current position in the number array
int number_index;
/// the current position in the unit array
int unit_index;
/// skip n characters of input
inline
void lyx_advance(string & data, string::size_type n)
{
data.erase(0, n);
}
/// return true when the input is at the end
inline
bool isEndOfData(string const & data)
{
return ltrim(data).empty();
}
/**
* nextToken - return the next token in the input
* @param data input string
* @return a char representing the type of token returned
*
* The possible return values are :
* + stretch indicator for glue length
* - shrink indicator for glue length
* n a numeric value (stored in number array)
* u a unit type (stored in unit array)
* E parse error
*/
char nextToken(string & data)
{
data = ltrim(data);
if (data.empty())
return '\0';
if (data[0] == '+') {
lyx_advance(data, 1);
return '+';
}
if (prefixIs(data, "plus")) {
lyx_advance(data, 4);
return '+';
}
if (data[0] == '-') {
lyx_advance(data, 1);
return '-';
}
if (prefixIs(data, "minus")) {
lyx_advance(data, 5);
return '-';
}
string::size_type i = data.find_first_not_of("0123456789.");
if (i != 0) {
if (number_index > 3)
return 'E';
string buffer;
// we have found some number
if (i == string::npos) {
buffer = data;
i = data.size() + 1;
} else
buffer = data.substr(0, i);
lyx_advance(data, i);
if (isStrDbl(buffer)) {
number[number_index] = convert<double>(buffer);
++number_index;
return 'n';
}
return 'E';
}
i = data.find_first_not_of("abcdefghijklmnopqrstuvwxyz%");
if (i != 0) {
if (unit_index > 3)
return 'E';
string buffer;
// we have found some alphabetical string
if (i == string::npos) {
buffer = data;
i = data.size() + 1;
} else
buffer = data.substr(0, i);
// possibly we have "mmplus" string or similar
if (buffer.size() > 5 &&
(buffer.substr(2, 4) == string("plus") ||
buffer.substr(2, 5) == string("minus")))
{
lyx_advance(data, 2);
unit[unit_index] = unitFromString(buffer.substr(0, 2));
} else {
lyx_advance(data, i);
unit[unit_index] = unitFromString(buffer);
}
if (unit[unit_index] != Length::UNIT_NONE) {
++unit_index;
return 'u';
}
return 'E'; // Error
}
return 'E'; // Error
}
/// latex representation of a vspace
struct LaTeXLength {
char const * pattern;
int plus_val_index;
int minus_val_index;
int plus_uni_index;
int minus_uni_index;
};
/// the possible formats for a vspace string
LaTeXLength table[] = {
{ "nu", 0, 0, 0, 0 },
{ "nu+nu", 2, 0, 2, 0 },
{ "nu+nu-nu", 2, 3, 2, 3 },
{ "nu+-nu", 2, 2, 2, 2 },
{ "nu-nu", 0, 2, 0, 2 },
{ "nu-nu+nu", 3, 2, 3, 2 },
{ "nu-+nu", 2, 2, 2, 2 },
{ "n+nu", 2, 0, 1, 0 },
{ "n+n-nu", 2, 3, 1, 1 },
{ "n+-nu", 2, 2, 1, 1 },
{ "n-nu", 0, 2, 0, 1 },
{ "n-n+nu", 3, 2, 1, 1 },
{ "n-+nu", 2, 2, 1, 1 },
{ "", 0, 0, 0, 0 } // sentinel, must be empty
};
} // namespace anon
const char * stringFromUnit(int unit)
{
if (unit < 0 || unit > num_units)
return 0;
return unit_name[unit];
}
bool isValidGlueLength(string const & data, GlueLength * result)
{
// This parser is table-driven. First, it constructs a "pattern"
// that describes the sequence of tokens in "data". For example,
// "n-nu" means: number, minus sign, number, unit. As we go along,
// numbers and units are stored into static arrays. Then, "pattern"
// is searched in the "table". If it is found, the associated
// table entries tell us which number and unit should go where
// in the Length structure. Example: if "data" has the "pattern"
// "nu+nu-nu", the associated table entries are "2, 3, 2, 3".
// That means, "plus_val" is the second number that was seen
// in the input, "minus_val" is the third number, and "plus_uni"
// and "minus_uni" are the second and third units, respectively.
// ("val" and "uni" are always the first items seen in "data".)
// This is the most elegant solution I could find -- a straight-
// forward approach leads to very long, tedious code that would be
// much harder to understand and maintain. (AS)
if (data.empty())
return true;
string buffer = ltrim(data);
// To make isValidGlueLength recognize negative values as
// the first number this little hack is needed:
int val_sign = 1; // positive as default
switch (buffer[0]) {
case '-':
lyx_advance(buffer, 1);
val_sign = -1;
break;
case '+':
lyx_advance(buffer, 1);
break;
default:
break;
}
// end of hack
int pattern_index = 0;
int table_index = 0;
char pattern[20];
number_index = 1;
unit_index = 1; // entries at index 0 are sentinels
// construct "pattern" from "data"
while (!isEndOfData (buffer)) {
if (pattern_index > 20) return false;
pattern[pattern_index] = nextToken (buffer);
if (pattern[pattern_index] == 'E') return false;
++pattern_index;
}
pattern[pattern_index] = '\0';
// search "pattern" in "table"
table_index = 0;
while (compare(pattern, table[table_index].pattern)) {
++table_index;
if (!*table[table_index].pattern)
return false;
}
// Get the values from the appropriate places. If an index
// is zero, the corresponding array value is zero or UNIT_NONE,
// so we needn't check this.
if (result) {
result->len_.value (number[1] * val_sign);
result->len_.unit (unit[1]);
result->plus_.value (number[table[table_index].plus_val_index]);
result->plus_.unit (unit [table[table_index].plus_uni_index]);
result->minus_.value(number[table[table_index].minus_val_index]);
result->minus_.unit (unit [table[table_index].minus_uni_index]);
}
return true;
}
bool isValidLength(string const & data, Length * result)
{
// This is a trimmed down version of isValidGlueLength.
// The parser may seem overkill for lengths without
// glue, but since we already have it, using it is
// easier than writing something from scratch.
if (data.empty())
return true;
string buffer = data;
int pattern_index = 0;
char pattern[3];
// To make isValidLength recognize negative values
// this little hack is needed:
int val_sign = 1; // positive as default
switch (buffer[0]) {
case '-':
lyx_advance(buffer, 1);
val_sign = -1;
break;
case '+':
lyx_advance(buffer, 1);
// fall through
default:
// no action
break;
}
// end of hack
number_index = unit_index = 1; // entries at index 0 are sentinels
// construct "pattern" from "data"
while (!isEndOfData(buffer)) {
if (pattern_index > 2)
return false;
pattern[pattern_index] = nextToken(buffer);
if (pattern[pattern_index] == 'E')
return false;
++pattern_index;
}
pattern[pattern_index] = '\0';
// only the most basic pattern is accepted here
if (compare(pattern, "nu") != 0) return false;
// It _was_ a correct length string.
// Store away the values we found.
if (result) {
result->val_ = number[1] * val_sign;
result->unit_ = unit[1];
}
return true;
}
//
// VSpace class
//
VSpace::VSpace()
: kind_(DEFSKIP), len_(), keep_(false)
{}
VSpace::VSpace(vspace_kind k)
: kind_(k), len_(), keep_(false)
{}
VSpace::VSpace(Length const & l)
: kind_(LENGTH), len_(l), keep_(false)
{}
VSpace::VSpace(GlueLength const & l)
: kind_(LENGTH), len_(l), keep_(false)
{}
VSpace::VSpace(string const & data)
: kind_(DEFSKIP), len_(), keep_(false)
{
if (data.empty())
return;
string input = rtrim(data);
string::size_type const length = input.length();
if (length > 1 && input[length - 1] == '*') {
keep_ = true;
input.erase(length - 1);
}
if (prefixIs(input, "defskip"))
kind_ = DEFSKIP;
else if (prefixIs(input, "smallskip"))
kind_ = SMALLSKIP;
else if (prefixIs(input, "medskip"))
kind_ = MEDSKIP;
else if (prefixIs(input, "bigskip"))
kind_ = BIGSKIP;
else if (prefixIs(input, "vfill"))
kind_ = VFILL;
else if (isValidGlueLength(input, &len_))
kind_ = LENGTH;
else if (isStrDbl(input)) {
// This last one is for reading old .lyx files
// without units in added_space_top/bottom.
// Let unit default to centimeters here.
kind_ = LENGTH;
len_ = GlueLength(Length(convert<double>(input), Length::CM));
}
}
VSpace::vspace_kind VSpace::kind() const
{
return kind_;
}
GlueLength const & VSpace::length() const
{
return len_;
}
bool VSpace::keep() const
{
return keep_;
}
void VSpace::setKeep(bool val)
{
keep_ = val;
}
bool VSpace::operator==(VSpace const & other) const
{
if (kind_ != other.kind_)
return false;
if (kind_ != LENGTH)
return this->keep_ == other.keep_;
if (len_ != other.len_)
return false;
return keep_ == other.keep_;
}
string const VSpace::asLyXCommand() const
{
string result;
switch (kind_) {
case DEFSKIP: result = "defskip"; break;
case SMALLSKIP: result = "smallskip"; break;
case MEDSKIP: result = "medskip"; break;
case BIGSKIP: result = "bigskip"; break;
case VFILL: result = "vfill"; break;
case LENGTH: result = len_.asString(); break;
}
if (keep_)
result += '*';
return result;
}
string const VSpace::asLatexCommand(BufferParams const & params) const
{
switch (kind_) {
case DEFSKIP:
return params.getDefSkip().asLatexCommand(params);
case SMALLSKIP:
return keep_ ? "\\vspace*{\\smallskipamount}" : "\\smallskip{}";
case MEDSKIP:
return keep_ ? "\\vspace*{\\medskipamount}" : "\\medskip{}";
case BIGSKIP:
return keep_ ? "\\vspace*{\\bigskipamount}" : "\\bigskip{}";
case VFILL:
return keep_ ? "\\vspace*{\\fill}" : "\\vfill{}";
case LENGTH:
return keep_ ? "\\vspace*{" + len_.asLatexString() + '}'
: "\\vspace{" + len_.asLatexString() + '}';
default:
BOOST_ASSERT(false);
return string();
}
}
docstring const VSpace::asGUIName() const
{
docstring result;
switch (kind_) {
case DEFSKIP:
result = _("Default skip");
break;
case SMALLSKIP:
result = _("Small skip");
break;
case MEDSKIP:
result = _("Medium skip");
break;
case BIGSKIP:
result = _("Big skip");
break;
case VFILL:
result = _("Vertical fill");
break;
case LENGTH:
result = from_ascii(len_.asString());
break;
}
if (keep_)
result += ", " + _("protected");
return result;
}
int VSpace::inPixels(BufferView const & bv) const
{
// Height of a normal line in pixels (zoom factor considered)
int const default_height = defaultRowHeight();
switch (kind_) {
case DEFSKIP:
return bv.buffer().params().getDefSkip().inPixels(bv);
// This is how the skips are normally defined by LateX.
// But there should be some way to change this per document.
case SMALLSKIP:
return default_height / 4;
case MEDSKIP:
return default_height / 2;
case BIGSKIP:
return default_height;
case VFILL:
// leave space for the vfill symbol
return 3 * default_height;
case LENGTH:
return len_.len().inPixels(bv.workWidth());
default:
BOOST_ASSERT(false);
return 0;
}
}
} // namespace lyx