lyx_mirror/src/vspace.C
Jean-Marc Lasgouttes d5c4ecc548 tentative fix for #177; small things
git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@3624 a592a061-630c-0410-9148-cb99ea01b6c8
2002-03-01 12:39:22 +00:00

509 lines
11 KiB
C

/**
* \file vspace.C
* Copyright 1995-2002 the LyX Team
* Read the file COPYING
*
* \author Matthias Ettrich
*/
#include <config.h>
#ifdef __GNUG__
#pragma implementation
#endif
#include "vspace.h"
#include "lengthcommon.h"
#include "lyx_main.h"
#include "buffer.h"
#include "lyxrc.h"
#include "lyxtext.h"
#include "BufferView.h"
#include "support/LAssert.h"
#include "support/lstrings.h"
#include <cstdio>
namespace {
/// used to return numeric values in parsing vspace
double number[4] = { 0, 0, 0, 0 };
/// used to return unit types in parsing vspace
LyXLength::UNIT unit[4] = { LyXLength::UNIT_NONE,
LyXLength::UNIT_NONE,
LyXLength::UNIT_NONE,
LyXLength::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 frontStrip(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 = frontStrip(data);
if (data.empty())
return '\0';
else if (data[0] == '+') {
lyx_advance(data, 1);
return '+';
} else if (prefixIs(data, "plus")) {
lyx_advance(data, 4);
return '+';
} else if (data[0] == '-') {
lyx_advance(data, 1);
return '-';
} else if (prefixIs(data, "minus")) {
lyx_advance(data, 5);
return '-';
} else {
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] = strToDbl(buffer);
++number_index;
return 'n';
} else 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] != LyXLength::UNIT_NONE) {
++unit_index;
return 'u';
} else 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, LyXGlueLength * 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 LyXLength 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 = frontStrip(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);
// fall through
default:
// no action
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, LyXLength * 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_(NONE), len_(), keep_(false)
{}
VSpace::VSpace(vspace_kind k)
: kind_(k), len_(), keep_(false)
{}
VSpace::VSpace(LyXLength const & l)
: kind_(LENGTH), len_(l), keep_(false)
{}
VSpace::VSpace(LyXGlueLength const & l)
: kind_(LENGTH), len_(l), keep_(false)
{}
VSpace::VSpace(string const & data)
: kind_(NONE), len_(), keep_(false)
{
if (data.empty())
return;
double value;
string input = strip(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 (sscanf(input.c_str(), "%lf", &value) == 1) {
// 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_ = LyXGlueLength(LyXLength(value, LyXLength::CM));
}
}
VSpace::vspace_kind VSpace::kind() const
{
return kind_;
}
LyXGlueLength 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 NONE: break;
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_ && kind_ != NONE && kind_ != DEFSKIP)
result += '*';
return result;
}
string const VSpace::asLatexCommand(BufferParams const & params) const
{
string ret;
switch (kind_) {
case NONE:
break;
case DEFSKIP:
ret = params.getDefSkip().asLatexCommand(params);
break;
case SMALLSKIP:
ret = keep_ ? "\\vspace*{\\smallskipamount}"
: "\\smallskip{}";
break;
case MEDSKIP:
ret = keep_ ? "\\vspace*{\\medskipamount}"
: "\\medskip{}";
break;
case BIGSKIP:
ret = keep_ ? "\\vspace*{\\bigskipamount}"
: "\\bigskip{}";
break;
case VFILL:
ret = keep_ ? "\\vspace*{\\fill}"
: "\\vfill{}";
break;
case LENGTH:
ret = keep_ ? "\\vspace*{" + len_.asLatexString() + '}'
: "\\vspace{" + len_.asLatexString() + '}';
break;
}
return ret;
}
int VSpace::inPixels(BufferView * bv) const
{
// Height of a normal line in pixels (zoom factor considered)
int const default_height = bv->text->defaultHeight(); // [pixels]
int retval = 0;
switch (kind_) {
case NONE:
// Value for this is already set
break;
case DEFSKIP:
retval = bv->buffer()->params.getDefSkip().inPixels(bv);
break;
// This is how the skips are normally defined by
// LateX. But there should be some way to change
// this per document.
case SMALLSKIP:
retval = default_height / 4;
break;
case MEDSKIP:
retval = default_height / 2;
break;
case BIGSKIP:
retval = default_height;
break;
case VFILL:
// leave space for the vfill symbol
retval = 3 * default_height;
break;
case LENGTH: {
int const default_width = bv->workWidth();
retval = len_.len().inPixels(default_width, default_height);
break;
}
}
return retval;
}