svgpp-doc.h

Go to the documentation of this file.

#include <parser/svgpp-common.h>
#include <libxml/xpath.h>
#include <set>
 
#ifndef SVGPP_DOC_H
#define SVGPP_DOC_H
 
namespace Parser {
 
class SVGPPDoc {
public:
  class FollowRef;
 
  SVGPPDoc(xmlDocPtr xml_doc) : xml_(xml_doc) {
    xml_context_ = xmlXPathNewContext(xml_doc);
  }
 
  ~SVGPPDoc() {
    qDebug() << "[Memory] ~SVGPPDoc(" << this << ")";
    xmlFreeDoc(xml_);
    xmlXPathFreeContext(xml_context_);
  }
 
  xmlNodePtr root() { return xmlDocGetRootElement(xml_); }
 
  xmlNodePtr getElementById(std::string id) {
    std::string query = QString("//*[@id='" + QString::fromStdString(id) + "']").toStdString();
    xmlXPathObjectPtr result = xmlXPathEval(
         (const xmlChar *) query.c_str(),
         xml_context_);
    if (result == nullptr || result->nodesetval == nullptr) return nullptr;
 
    for (int i = 0; i < result->nodesetval->nodeNr; i++) {
      xmlNodePtr node = result->nodesetval->nodeTab[i];
      if (node->type == XML_ELEMENT_NODE) {
        xmlFree(result);
        return node;
      }
    }
    return nullptr;
  }
 
  xmlDocPtr xml_;
  xmlXPathContextPtr xml_context_;
  typedef std::set<xmlNodePtr> followed_refs_t;
  followed_refs_t followed_refs_;
};
 
class SVGPPDoc::FollowRef {
public:
  FollowRef(SVGPPDoc &svgpp_doc, xmlNodePtr el) : svgpp_doc_(svgpp_doc) {
    std::pair<SVGPPDoc::followed_refs_t::iterator, bool> ins = svgpp_doc.followed_refs_.insert(el);
    if (!ins.second)
      throw std::runtime_error("Cyclic reference found");
    lock_ = ins.first;
  }
 
  ~FollowRef() { svgpp_doc_.followed_refs_.erase(lock_); }
 
private:
  SVGPPDoc &svgpp_doc_;
  SVGPPDoc::followed_refs_t::iterator lock_;
};
 
}
 
#endif