units.cpp revision 73f5f519746323f02f682c9ed8ce51a5f67cbce9
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif
#include <cmath>
#include <cerrno>
#include <glib.h>
#include "io/simple-sax.h"
#include "util/units.h"
#include "path-prefix.h"
#include "streq.h"
namespace Inkscape {
namespace Util {
class UnitsSAXHandler : public Inkscape::IO::FlatSaxHandler
{
public:
UnitsSAXHandler(UnitTable *table);
virtual ~UnitsSAXHandler() {}
virtual void _startElement(xmlChar const *name, xmlChar const **attrs);
virtual void _endElement(xmlChar const *name);
UnitTable *tbl;
bool primary;
bool skip;
Unit unit;
};
UnitsSAXHandler::UnitsSAXHandler(UnitTable *table) :
FlatSaxHandler(),
tbl(table),
primary(0),
skip(0),
unit()
{
}
#define BUFSIZE (255)
/**
* Returns the suggested precision to use for displaying numbers
* of this unit.
*/
int Unit::defaultDigits() const {
int factor_digits = int(log10(factor));
if (factor_digits < 0) {
g_warning("factor = %f, factor_digits = %d", factor, factor_digits);
g_warning("factor_digits < 0 - returning 0");
return 0;
} else {
return factor_digits;
}
}
/** Checks if a unit is compatible with the specified unit. */
bool Unit::compatibleWith(const Unit *u) const {
// Percentages
if (type == UNIT_TYPE_DIMENSIONLESS || u->type == UNIT_TYPE_DIMENSIONLESS) {
return true;
}
// Other units with same type
if (type == u->type) {
return true;
}
// Different, incompatible types
return false;
}
/** Check if units are equal. */
bool operator== (const Unit &u1, const Unit &u2) {
return (u1.type == u2.type && u1.name.compare(u2.name) == 0);
}
/** Check if units are not equal. */
bool operator!= (const Unit &u1, const Unit &u2) {
return !(u1 == u2);
}
/** Temporary - get SVG unit. */
int Unit::svgUnit() const {
if (!abbr.compare("px"))
return 1;
if (!abbr.compare("pt"))
return 2;
if (!abbr.compare("pc"))
return 3;
if (!abbr.compare("mm"))
return 4;
if (!abbr.compare("cm"))
return 5;
if (!abbr.compare("in"))
return 6;
if (!abbr.compare("ft"))
return 7;
if (!abbr.compare("em"))
return 8;
if (!abbr.compare("ex"))
return 9;
if (!abbr.compare("%"))
return 10;
return 0;
}
/**
* Initializes the unit tables and identifies the primary unit types.
*
* The primary unit's conversion factor is required to be 1.00
*/
UnitTable::UnitTable()
{
// if we swich to the xml file, don't forget to force locale to 'C'
// load("share/ui/units.xml"); // <-- Buggy
gchar *filename = g_build_filename(INKSCAPE_UIDIR, "units.txt", NULL);
loadText(filename);
g_free(filename);
}
UnitTable::~UnitTable() {
UnitMap::iterator iter = _unit_map.begin();
while (iter != _unit_map.end()) {
delete (*iter).second;
++iter;
}
}
/** Add a new unit to the table */
void UnitTable::addUnit(Unit const &u, bool primary) {
_unit_map[u.abbr] = new Unit(u);
if (primary) {
_primary_unit[u.type] = u.abbr;
}
}
/** Retrieve a given unit based on its string identifier */
Unit UnitTable::getUnit(Glib::ustring const &unit_abbr) const {
UnitMap::const_iterator iter = _unit_map.find(unit_abbr);
if (iter != _unit_map.end()) {
return *((*iter).second);
} else {
return Unit();
}
}
/** Remove a unit definition from the given unit type table */
bool UnitTable::deleteUnit(Unit const &u) {
if (u.abbr == _primary_unit[u.type]) {
// Cannot delete the primary unit type since it's
// used for conversions
return false;
}
UnitMap::iterator iter = _unit_map.find(u.abbr);
if (iter != _unit_map.end()) {
delete (*iter).second;
_unit_map.erase(iter);
return true;
} else {
return false;
}
}
/** Returns true if the given string 'name' is a valid unit in the table */
bool UnitTable::hasUnit(Glib::ustring const &unit) const
{
UnitMap::const_iterator iter = _unit_map.find(unit);
return (iter != _unit_map.end());
}
/** Provides an iteratable list of items in the given unit table */
UnitTable::UnitMap UnitTable::units(UnitType type) const
{
UnitMap submap;
for (UnitMap::const_iterator iter = _unit_map.begin();
iter != _unit_map.end(); ++iter) {
if (((*iter).second)->type == type) {
submap.insert(UnitMap::value_type((*iter).first, new Unit(*((*iter).second))));
}
}
return submap;
}
/** Returns the default unit abbr for the given type */
Glib::ustring UnitTable::primary(UnitType type) const
{
return _primary_unit[type];
}
/** Loads units from a text file.
loadText loads and merges the contents of the given file into the UnitTable,
possibly overwriting existing unit definitions.
@param filename: file to be loaded*/
bool UnitTable::loadText(Glib::ustring const &filename)
{
char buf[BUFSIZE];
// Open file for reading
FILE * f = fopen(filename.c_str(), "r");
if (f == NULL) {
g_warning("Could not open units file '%s': %s\n",
filename.c_str(), strerror(errno));
g_warning("* INKSCAPE_DATADIR is: '%s'\n", INKSCAPE_DATADIR);
g_warning("* INKSCAPE_UIDIR is: '%s'\n", INKSCAPE_UIDIR);
return false;
}
// bypass current locale in order to make
// sscanf read floats with '.' as a separator
// set locale to 'C' and keep old locale
char *old_locale;
old_locale = g_strdup (setlocale (LC_NUMERIC, NULL));
setlocale (LC_NUMERIC, "C");
while (fgets(buf, BUFSIZE, f) != NULL) {
char name[BUFSIZE];
char plural[BUFSIZE];
char abbr[BUFSIZE];
char type[BUFSIZE];
double factor;
char primary[BUFSIZE];
int nchars = 0;
// locale is set to C, scanning %lf should work _everywhere_
if (sscanf(buf, "%15s %15s %15s %15s %8lf %1s %15n",
name, plural, abbr, type, &factor, primary, &nchars) != 6)
{
// Skip the line - doesn't appear to be valid
continue;
}
g_assert(nchars < BUFSIZE);
char *desc = buf;
desc += nchars; // buf is now only the description
// insert into _unit_map
Unit u;
u.name = name;
u.name_plural = plural;
u.abbr = abbr;
u.description = desc;
u.factor = factor;
if (streq(type, "DIMENSIONLESS")) {
u.type = UNIT_TYPE_DIMENSIONLESS;
} else if (streq(type, "LINEAR")) {
u.type = UNIT_TYPE_LINEAR;
} else if (streq(type, "RADIAL")) {
u.type = UNIT_TYPE_RADIAL;
} else if (streq(type, "FONT_HEIGHT")) {
u.type = UNIT_TYPE_FONT_HEIGHT;
} else {
g_warning("Skipping unknown unit type '%s' for %s.\n",
type, name);
continue;
}
// if primary is 'Y', list this unit as a primary
addUnit(u, (primary[0]=='Y' || primary[0]=='y'));
}
// set back the saved locale
setlocale (LC_NUMERIC, old_locale);
g_free (old_locale);
// close file
if (fclose(f) != 0) {
g_warning("Error closing units file '%s': %s\n",
filename.c_str(), strerror(errno));
return false;
}
return true;
}
bool UnitTable::load(Glib::ustring const &filename) {
UnitsSAXHandler handler(this);
int result = handler.parseFile( filename.c_str() );
if ( result != 0 ) {
// perhaps
g_warning("Problem loading units file '%s': %d\n",
filename.c_str(), result);
return false;
}
return true;
}
/** Saves the current UnitTable to the given file. */
bool UnitTable::save(Glib::ustring const &filename) {
// open file for writing
FILE *f = fopen(filename.c_str(), "w");
if (f == NULL) {
g_warning("Could not open units file '%s': %s\n",
filename.c_str(), strerror(errno));
return false;
}
// write out header
// foreach item in _unit_map, sorted alphabetically by type and then unit name
// sprintf a line
// name
// name_plural
// abbr
// type
// factor
// PRI - if listed in primary unit table, 'Y', else 'N'
// description
// write line to the file
// close file
if (fclose(f) != 0) {
g_warning("Error closing units file '%s': %s\n",
filename.c_str(), strerror(errno));
return false;
}
return true;
}
void UnitsSAXHandler::_startElement(xmlChar const *name, xmlChar const **attrs)
{
if (streq("unit", (char const *)name)) {
// reset for next use
unit.name.clear();
unit.name_plural.clear();
unit.abbr.clear();
unit.description.clear();
unit.type = UNIT_TYPE_DIMENSIONLESS;
unit.factor = 1.0;
primary = false;
skip = false;
for ( int i = 0; attrs[i]; i += 2 ) {
char const *const key = (char const *)attrs[i];
if (streq("type", key)) {
char const *type = (char const*)attrs[i+1];
if (streq(type, "DIMENSIONLESS")) {
unit.type = UNIT_TYPE_DIMENSIONLESS;
} else if (streq(type, "LINEAR")) {
unit.type = UNIT_TYPE_LINEAR;
} else if (streq(type, "RADIAL")) {
unit.type = UNIT_TYPE_RADIAL;
} else if (streq(type, "FONT_HEIGHT")) {
unit.type = UNIT_TYPE_FONT_HEIGHT;
} else {
g_warning("Skipping unknown unit type '%s' for %s.\n", type, name);
skip = true;
}
} else if (streq("pri", key)) {
primary = attrs[i+1][0] == 'y' || attrs[i+1][0] == 'Y';
}
}
}
}
void UnitsSAXHandler::_endElement(xmlChar const *xname)
{
char const *const name = (char const *) xname;
if (streq("name", name)) {
unit.name = data;
} else if (streq("plural", name)) {
unit.name_plural = data;
} else if (streq("abbr", name)) {
unit.abbr = data;
} else if (streq("factor", name)) {
// TODO make sure we use the right conversion
unit.factor = atol(data.c_str());
} else if (streq("description", name)) {
unit.description = data;
} else if (streq("unit", name)) {
if (!skip) {
tbl->addUnit(unit, primary);
}
}
}
/** Initialize a quantity. */
Quantity::Quantity(Unit *u, double q) {
unit = u;
quantity = q;
}
/** Checks if a quantity is compatible with the specified unit. */
bool Quantity::compatibleWith(const Unit *u) const {
return unit->compatibleWith(u);
}
/** Return the quantity's value in the specified unit. */
double Quantity::value(Unit *u) const {
return convert(quantity, unit, u);
}
/** Convert distances. */
double Quantity::convert(const double from_dist, const Unit *from, const Unit *to) {
// Incompatible units
if (from->type != to->type) {
return -1;
}
// Compatible units
return from_dist * from->factor / to->factor;
}
} // namespace Util
} // namespace Inkscape
/*
Local Variables:
mode:c++
c-file-style:"stroustrup"
c-file-offsets:((innamespace . 0)(inline-open . 0)(case-label . +))
indent-tabs-mode:nil
fill-column:99
End:
*/
// vim: filetype=cpp:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:fileencoding=utf-8:textwidth=99 :