src/xml/repr-util.cpp

	repr-util.cpp revision b7e61b7ae335cccd83b22cce8840848c2c7d80ef
#define __SP_REPR_UTIL_C__

/** \file
 * Miscellaneous helpers for reprs.
 */

/*
 * Authors:
 *   Lauris Kaplinski <lauris@ximian.com>
 *
 * Copyright (C) 1999-2000 Lauris Kaplinski
 * Copyright (C) 2000-2001 Ximian, Inc.
 * g++ port Copyright (C) 2003 Nathan Hurst
 *
 * Licensed under GNU GPL
 */

#include "config.h"

#include <math.h>

#if HAVE_STRING_H
# include <cstring>
#endif

#if HAVE_STDLIB_H
# include <cstdlib>
#endif


#include <glib.h>

#include "svg/stringstream.h"
#include "svg/css-ostringstream.h"

#include "xml/repr.h"
#include "xml/repr-sorting.h"

struct SPXMLNs {
    SPXMLNs *next;
    unsigned int uri, prefix;
};

/*#####################
# DEFINITIONS
#####################*/

#ifndef FALSE
# define FALSE 0
#endif

#ifndef TRUE
# define TRUE (!FALSE)
#endif

#ifndef MAX
# define MAX(a,b) (((a) < (b)) ? (b) : (a))
#endif

/*#####################
# FORWARD DECLARATIONS
#####################*/

static void sp_xml_ns_register_defaults();
static char *sp_xml_ns_auto_prefix(char const *uri);

/*#####################
# UTILITY
#####################*/

/**
 * Locale-independent double to string conversion
 */
unsigned int
sp_xml_dtoa(gchar *buf, double val, unsigned int tprec, unsigned int fprec, unsigned int padf)
{
    double dival, fval, epsilon;
    int idigits, ival, i;
    i = 0;
    if (val < 0.0) {
        buf[i++] = '-';
        val = -val;
    }
    /* Determine number of integral digits */
    if (val >= 1.0) {
        idigits = (int) floor(log10(val));
    } else {
        idigits = 0;
    }
    /* Determine the actual number of fractional digits */
    fprec = MAX(fprec, tprec - idigits);
    /* Find epsilon */
    epsilon = 0.5 * pow(10.0, - (double) fprec);
    /* Round value */
    val += epsilon;
    /* Extract integral and fractional parts */
    dival = floor(val);
    ival = (int) dival;
    fval = val - dival;
    /* Write integra */
    if (ival > 0) {
        char c[32];
        int j;
        j = 0;
        while (ival > 0) {
            c[32 - (++j)] = '0' + (ival % 10);
            ival /= 10;
        }
        memcpy(buf + i, &c[32 - j], j);
        i += j;
        tprec -= j;
    } else {
        buf[i++] = '0';
        tprec -= 1;
    }
    if ((fprec > 0) && (padf || (fval > epsilon))) {
        buf[i++] = '.';
        while ((fprec > 0) && (padf || (fval > epsilon))) {
            fval *= 10.0;
            dival = floor(fval);
            fval -= dival;
            buf[i++] = '0' + (int) dival;
            fprec -= 1;
        }

    }
    buf[i] = 0;
    return i;
}


/*#####################
# MAIN
#####################*/

/**
 * SPXMLNs
 */

static SPXMLNs *namespaces=NULL;

/*
 * There are the prefixes to use for the XML namespaces defined
 * in repr.h
 */
static void
sp_xml_ns_register_defaults()
{
    static SPXMLNs defaults[10];

    defaults[0].uri = g_quark_from_static_string(SP_SODIPODI_NS_URI);
    defaults[0].prefix = g_quark_from_static_string("sodipodi");
    defaults[0].next = &defaults[1];

    defaults[1].uri = g_quark_from_static_string(SP_XLINK_NS_URI);
    defaults[1].prefix = g_quark_from_static_string("xlink");
    defaults[1].next = &defaults[2];

    defaults[2].uri = g_quark_from_static_string(SP_SVG_NS_URI);
    defaults[2].prefix = g_quark_from_static_string("svg");
    defaults[2].next = &defaults[3];

    defaults[3].uri = g_quark_from_static_string(SP_INKSCAPE_NS_URI);
    defaults[3].prefix = g_quark_from_static_string("inkscape");
    defaults[3].next = &defaults[4];

    defaults[4].uri = g_quark_from_static_string(SP_RDF_NS_URI);
    defaults[4].prefix = g_quark_from_static_string("rdf");
    defaults[4].next = &defaults[5];

    defaults[5].uri = g_quark_from_static_string(SP_CC_NS_URI);
    defaults[5].prefix = g_quark_from_static_string("cc");
    defaults[5].next = &defaults[6];

    defaults[6].uri = g_quark_from_static_string(SP_DC_NS_URI);
    defaults[6].prefix = g_quark_from_static_string("dc");
    defaults[6].next = &defaults[7];

    // Inkscape versions prior to 0.44 would write this namespace
    // URI instead of the correct sodipodi namespace; by adding this
    // entry to the table last (where it gets used for URI -> prefix
    // lookups, but not prefix -> URI lookups), we effectively transfer
    // elements in this namespace to the correct sodipodi namespace:

    defaults[7].uri = g_quark_from_static_string(SP_BROKEN_SODIPODI_NS_URI);
    defaults[7].prefix = g_quark_from_static_string("sodipodi");
    defaults[7].next = &defaults[8];

    // "Duck prion"
    // This URL became widespread due to a bug in versions <= 0.43

    defaults[8].uri = g_quark_from_static_string("http://inkscape.sourceforge.net/DTD/s odipodi-0.dtd");
    defaults[8].prefix = g_quark_from_static_string("sodipodi");
    defaults[8].next = &defaults[9];

    // This namespace URI is being phased out by Creative Commons

    defaults[9].uri = g_quark_from_static_string(SP_OLD_CC_NS_URI);
    defaults[9].prefix = g_quark_from_static_string("cc");
    defaults[9].next = NULL;

    namespaces = &defaults[0];
}

char *
sp_xml_ns_auto_prefix(char const *uri)
{
    char const *start, *end;
    char *new_prefix;
    start = uri;
    while ((end = strpbrk(start, ":/"))) {
        start = end + 1;
    }
    end = start + strspn(start, "abcdefghijklmnopqrstuvwxyz");
    if (end == start) {
        start = "ns";
        end = start + 2;
    }
    new_prefix = g_strndup(start, end - start);
    if (sp_xml_ns_prefix_uri(new_prefix)) {
        char *temp;
        int counter=0;
        do {
            temp = g_strdup_printf("%s%d", new_prefix, counter++);
        } while (sp_xml_ns_prefix_uri(temp));
        g_free(new_prefix);
        new_prefix = temp;
    }
    return new_prefix;
}

gchar const *
sp_xml_ns_uri_prefix(gchar const *uri, gchar const *suggested)
{
    char const *prefix;

    if (!uri) return NULL;

    if (!namespaces) {
        sp_xml_ns_register_defaults();
    }

    GQuark const key = g_quark_from_string(uri);
    prefix = NULL;
    for ( SPXMLNs *iter=namespaces ; iter ; iter = iter->next ) {
        if ( iter->uri == key ) {
            prefix = g_quark_to_string(iter->prefix);
            break;
        }
    }

    if (!prefix) {
        char *new_prefix;
        SPXMLNs *ns;
        if (suggested) {
            GQuark const prefix_key=g_quark_from_string(suggested);

            SPXMLNs *found=namespaces;
            while ( found && found->prefix != prefix_key ) {
                found = found->next;
            }

            if (found) { // prefix already used?
                new_prefix = sp_xml_ns_auto_prefix(uri);
            } else { // safe to use suggested
                new_prefix = g_strdup(suggested);
            }
        } else {
            new_prefix = sp_xml_ns_auto_prefix(uri);
        }

        ns = g_new(SPXMLNs, 1);
        g_assert( ns != NULL );
        ns->uri = g_quark_from_string(uri);
        ns->prefix = g_quark_from_string(new_prefix);

        g_free(new_prefix);

        ns->next = namespaces;
        namespaces = ns;

        prefix = g_quark_to_string(ns->prefix);
    }

    return prefix;
}

gchar const *
sp_xml_ns_prefix_uri(gchar const *prefix)
{
    SPXMLNs *iter;
    char const *uri;

    if (!prefix) return NULL;

    if (!namespaces) {
        sp_xml_ns_register_defaults();
    }

    GQuark const key = g_quark_from_string(prefix);
    uri = NULL;
    for ( iter = namespaces ; iter ; iter = iter->next ) {
        if ( iter->prefix == key ) {
            uri = g_quark_to_string(iter->uri);
            break;
        }
    }
    return uri;
}

double sp_repr_get_double_attribute(Inkscape::XML::Node *repr, char const *key, double def)
{
    char *result;

    g_return_val_if_fail(repr != NULL, def);
    g_return_val_if_fail(key != NULL, def);

    result = (char *) repr->attribute(key);

    if (result == NULL) return def;

    return g_ascii_strtod(result, NULL);
}

long long int sp_repr_get_int_attribute(Inkscape::XML::Node *repr, char const *key, long long int def)
{
    char *result;

    g_return_val_if_fail(repr != NULL, def);
    g_return_val_if_fail(key != NULL, def);

    result = (char *) repr->attribute(key);

    if (result == NULL) return def;

    return atoll(result);
}

/**
 *  Works for different-parent objects, so long as they have a common ancestor. Return value:
 *    0    positions are equivalent
 *    1    first object's position is greater than the second
 *   -1    first object's position is less than the second
 */
int
sp_repr_compare_position(Inkscape::XML::Node *first, Inkscape::XML::Node *second)
{
    int p1, p2;
    if (sp_repr_parent(first) == sp_repr_parent(second)) {
        /* Basic case - first and second have same parent */
        p1 = first->position();
        p2 = second->position();
    } else {
        /* Special case - the two objects have different parents.  They
           could be in different groups or on different layers for
           instance. */

        // Find the lowest common ancestor(LCA)
        Inkscape::XML::Node *ancestor = LCA(first, second);
        g_assert(ancestor != NULL);

        if (ancestor == first) {
            return 1;
        } else if (ancestor == second) {
            return -1;
        } else {
            Inkscape::XML::Node const *to_first = AncetreFils(first, ancestor);
            Inkscape::XML::Node const *to_second = AncetreFils(second, ancestor);
            g_assert(sp_repr_parent(to_second) == sp_repr_parent(to_first));
            p1 = to_first->position();
            p2 = to_second->position();
        }
    }

    if (p1 > p2) return 1;
    if (p1 < p2) return -1;
    return 0;

    /* effic: Assuming that the parent--child relationship is consistent
       (i.e. that the parent really does contain first and second among
       its list of children), it should be equivalent to walk along the
       children and see which we encounter first (returning 0 iff first
       == second).

       Given that this function is used solely for sorting, we can use a
       similar approach to do the sort: gather the things to be sorted,
       into an STL vector (to allow random access and faster
       traversals).  Do a single pass of the parent's children; for each
       child, do a pass on whatever items in the vector we haven't yet
       encountered.  If the child is found, then swap it to the
       beginning of the yet-unencountered elements of the vector.
       Continue until no more than one remains unencountered.  --
       pjrm */
}

/**
 * lookup child by \a key, \a value.
 */
Inkscape::XML::Node *
sp_repr_lookup_child(Inkscape::XML::Node *repr,
                     gchar const *key,
                     gchar const *value)
{
    g_return_val_if_fail(repr != NULL, NULL);
    for ( Inkscape::XML::Node *child = repr->firstChild() ; child ; child = child->next() ) {
        gchar const *child_value = child->attribute(key);
        if ( child_value == value ||
             value && child_value && !strcmp(child_value, value) )
        {
            return child;
        }
    }
    return NULL;
}

/**
 *  \brief   Recursively find the Inkscape::XML::Node matching the given XML name.
 *  \return  A pointer to the matching Inkscape::XML::Node
 *  \param   repr    The Inkscape::XML::Node to start from
 *  \param   name    The desired XML name
 *
 */
Inkscape::XML::Node *
sp_repr_lookup_name( Inkscape::XML::Node *repr, gchar const *name, gint maxdepth )
{
    g_return_val_if_fail(repr != NULL, NULL);
    g_return_val_if_fail(name != NULL, NULL);

    GQuark const quark = g_quark_from_string(name);

    if ( (GQuark)repr->code() == quark ) return repr;
    if ( maxdepth == 0 ) return NULL;

    // maxdepth == -1 means unlimited
    if ( maxdepth == -1 ) maxdepth = 0;

    Inkscape::XML::Node *found = NULL;
    for (Inkscape::XML::Node *child = repr->firstChild() ; child && !found; child = child->next() ) {
        found = sp_repr_lookup_name( child, name, maxdepth-1 );
    }

    return found;
}

/**
 * Determine if the node is a 'title', 'desc' or 'metadata' element.
 */
bool
sp_repr_is_meta_element(const Inkscape::XML::Node *node)
{
    if (node == NULL) return false;
    if (node->type() != Inkscape::XML::ELEMENT_NODE) return false;
    gchar const *name = node->name();
    if (name == NULL) return false;
    if (!std::strcmp(name, "svg:title")) return true;
    if (!std::strcmp(name, "svg:desc")) return true;
    if (!std::strcmp(name, "svg:metadata")) return true;
    return false;
}

/**
 * Parses the boolean value of an attribute "key" in repr and sets val accordingly, or to FALSE if
 * the attr is not set.
 *
 * \return TRUE if the attr was set, FALSE otherwise.
 */
unsigned int
sp_repr_get_boolean(Inkscape::XML::Node *repr, gchar const *key, unsigned int *val)
{
    gchar const *v;

    g_return_val_if_fail(repr != NULL, FALSE);
    g_return_val_if_fail(key != NULL, FALSE);
    g_return_val_if_fail(val != NULL, FALSE);

    v = repr->attribute(key);

    if (v != NULL) {
        if (!g_strcasecmp(v, "true") ||
            !g_strcasecmp(v, "yes" ) ||
            !g_strcasecmp(v, "y"   ) ||
            (atoi(v) != 0)) {
            *val = TRUE;
        } else {
            *val = FALSE;
        }
        return TRUE;
    } else {
        *val = FALSE;
        return FALSE;
    }
}

unsigned int
sp_repr_get_int(Inkscape::XML::Node *repr, gchar const *key, int *val)
{
    gchar const *v;

    g_return_val_if_fail(repr != NULL, FALSE);
    g_return_val_if_fail(key != NULL, FALSE);
    g_return_val_if_fail(val != NULL, FALSE);

    v = repr->attribute(key);

    if (v != NULL) {
        *val = atoi(v);
        return TRUE;
    }

    return FALSE;
}

unsigned int
sp_repr_get_double(Inkscape::XML::Node *repr, gchar const *key, double *val)
{
    gchar const *v;

    g_return_val_if_fail(repr != NULL, FALSE);
    g_return_val_if_fail(key != NULL, FALSE);
    g_return_val_if_fail(val != NULL, FALSE);

    v = repr->attribute(key);

    if (v != NULL) {
        *val = g_ascii_strtod(v, NULL);
        return TRUE;
    }

    return FALSE;
}

unsigned int
sp_repr_set_boolean(Inkscape::XML::Node *repr, gchar const *key, unsigned int val)
{
    g_return_val_if_fail(repr != NULL, FALSE);
    g_return_val_if_fail(key != NULL, FALSE);

    repr->setAttribute(key, (val) ? "true" : "false");
    return true;
}

unsigned int
sp_repr_set_int(Inkscape::XML::Node *repr, gchar const *key, int val)
{
    gchar c[32];

    g_return_val_if_fail(repr != NULL, FALSE);
    g_return_val_if_fail(key != NULL, FALSE);

    g_snprintf(c, 32, "%d", val);

    repr->setAttribute(key, c);
    return true;
}

/**
 * Set a property attribute to \a val [slightly rounded], in the format
 * required for CSS properties: in particular, it never uses exponent
 * notation.
 */
unsigned int
sp_repr_set_css_double(Inkscape::XML::Node *repr, gchar const *key, double val)
{
    g_return_val_if_fail(repr != NULL, FALSE);
    g_return_val_if_fail(key != NULL, FALSE);

    Inkscape::CSSOStringStream os;
    os << val;

    repr->setAttribute(key, os.str().c_str());
    return true;
}

/**
 * For attributes where an exponent is allowed.
 *
 * Not suitable for property attributes (fill-opacity, font-size etc.).
 */
unsigned int
sp_repr_set_svg_double(Inkscape::XML::Node *repr, gchar const *key, double val)
{
    g_return_val_if_fail(repr != NULL, FALSE);
    g_return_val_if_fail(key != NULL, FALSE);

    Inkscape::SVGOStringStream os;
    os << val;

    repr->setAttribute(key, os.str().c_str());
    return true;
}

unsigned sp_repr_set_point(Inkscape::XML::Node *repr, gchar const *key, Geom::Point val)
{
    g_return_val_if_fail(repr != NULL, FALSE);
    g_return_val_if_fail(key != NULL, FALSE);

    Inkscape::SVGOStringStream os;
    os << val[Geom::X] << "," << val[Geom::Y];

    repr->setAttribute(key, os.str().c_str());
    return true;
}

unsigned int
sp_repr_get_point(Inkscape::XML::Node *repr, gchar const *key, Geom::Point *val)
{
    g_return_val_if_fail(repr != NULL, FALSE);
    g_return_val_if_fail(key != NULL, FALSE);
    g_return_val_if_fail(val != NULL, FALSE);

    gchar const *v = repr->attribute(key);

    gchar ** strarray = g_strsplit(v, ",", 2);

    if (strarray && strarray[0] && strarray[1]) {
        double newx, newy;
        newx = g_ascii_strtod(strarray[0], NULL);
        newy = g_ascii_strtod(strarray[1], NULL);
        g_strfreev (strarray);
        *val = Geom::Point(newx, newy);
        return TRUE;
    }

    g_strfreev (strarray);
    return FALSE;
}

/*
  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:encoding=utf-8:textwidth=99 :