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// -*- C++ -*-
/* svgparser.cc
*
* By Dan Dennedy <dan@dennedy.org>
*
* Copyright (C) 2003 The libxml++ development team
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <iostream>
#include <libxml/tree.h>
#include "svgparser.h"
#include "svgdocument.h"
#include "svgelement.h"
#include "svgpath.h"
#include "svggroup.h"
namespace SVG {
Parser::Parser(xmlpp::Document& document)
: xmlpp::SaxParser(true), m_doc(document)
{
set_substitute_entities(true);
}
Parser::~Parser()
{
}
void Parser::on_start_element(const Glib::ustring& name,
const AttributeList& attributes)
{
//This method replaces the normal libxml++ node
//with an instance of a derived node.
//This is not a recommended technique, and might not
//work with future versions of libxml++.
// Parse namespace prefix and save for later:
Glib::ustring elementPrefix;
Glib::ustring elementName = name;
Glib::ustring::size_type idx = name.find(':');
if (idx != Glib::ustring::npos) //If the separator was found
{
elementPrefix = name.substr(0, idx);
elementName = name.substr(idx + 1);
}
xmlpp::Element* element_normal = nullptr;
// Create a normal libxml++ node:
if (m_doc.get_root_node() == nullptr)
{
// Create the root node if necessary:
element_normal = m_doc.create_root_node(elementName);
}
else
{
// Create the other elements as child nodes of the last nodes:
element_normal = m_context.top()->add_child(elementName);
}
// TODO: The following is a hack because it leverages knowledge of libxml++
// implementation rather than interface - specifically that deleting the C++
// instance will leave the underlying C instance intact and part of the libxml DOM tree.
//
// Delete the xmlpp::Element created above so we can link the libxml2
// node with the derived Element object we create below.
auto node = element_normal->cobj(); //Save it for later.
delete element_normal;
element_normal = nullptr;
// TODO: Again, this requires knowledge of the libxml++ implemenation -
// specifically that the base xmlpp::Node() constructor will reassociate
// the underyling C instance with this new C++ instance, by seeting _private.
//
// Construct a custom Element based upon prefix and name.
// This will then be deleted by libxml++, just as libxml++ would normally have
// deleted its own node.
// TODO: Don't delete the original (above) if it isn't one of these node names.
xmlpp::Element* element_derived = nullptr;
if (elementName == "g")
element_derived = new SVG::Group(node);
else if (elementName == "path")
element_derived = new SVG::Path(node);
else
element_derived = new SVG::Element(node);
if(element_derived)
{
//Set the context, so that child nodes will be added to this node,
//until on_end_element():
m_context.push(element_derived);
// Copy the attributes form the old node to the new derived node:
// In theory, you could change the attributes here.
for(const auto& attr_pair : attributes)
{
const auto attr_name = attr_pair.name;
const auto attr_value = attr_pair.value;
const auto idx_colon = attr_name.find(':');
if (idx_colon == Glib::ustring::npos) // If the separator was not found.
{
if (attr_name == "xmlns") // This is a namespace declaration.
{
//There is no second part, so this is a default namespace declaration.
element_derived->set_namespace_declaration(attr_value);
}
else
{
//This is just an attribute value:
element_derived->set_attribute(attr_name, attr_value);
}
}
else
{
//The separator was found:
auto prefix = attr_name.substr(0, idx_colon);
auto suffix = attr_name.substr(idx_colon + 1);
if (prefix == "xmlns") // This is a namespace declaration.
element_derived->set_namespace_declaration(attr_value, suffix);
else
{
//This is a namespaced attribute value.
//(The namespace must have been declared already)
auto attr = element_derived->set_attribute(suffix, attr_value);
attr->set_namespace(prefix); //alternatively, we could have specified the whole name to set_attribute().
}
}
}
// We have to set the element namespace after the attributes because
// an attribute might declare the namespace used in the actual element's name.
if (!elementPrefix.empty())
element_derived->set_namespace(elementPrefix);
}
}
void Parser::on_end_element(const Glib::ustring& /* name */)
{
// This causes the next child elements to be added to the sibling, not this node.
m_context.pop();
}
void Parser::on_characters(const Glib::ustring& text)
{
if(!m_context.empty())
m_context.top()->add_child_text(text);
}
void Parser::on_comment(const Glib::ustring& text)
{
if(!m_context.empty())
m_context.top()->add_child_comment(text);
else
m_doc.add_comment(text);
}
void Parser::on_warning(const Glib::ustring& text)
{
std::cout << "on_warning(): " << text << std::endl;
}
void Parser::on_error(const Glib::ustring& text)
{
std::cout << "on_error(): " << text << std::endl;
}
void Parser::on_fatal_error(const Glib::ustring& text)
{
std::cout << "on_fatal_error(): " << text << std::endl;
}
void Parser::on_cdata_block(const Glib::ustring& text)
{
if(!m_context.empty())
m_context.top()->add_child_cdata(text);
}
}
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