query.h

#pragma once
 
// This file contains implementation of helper methods and classes to perform query operations on a tinyxml2::XMLDocument.
 
#include <cgv/media/color.h>
#include <cgv/math/fvec.h>
#include <cgv/utils/scan.h>
 
#include "../tinyxml2/tinyxml2.h"
 
namespace cgv {
namespace xml {
 
class FindElementByNameVisitor : public tinyxml2::XMLVisitor {
private:
    std::string name = "";
    const tinyxml2::XMLElement* result = nullptr;
 
public:
    FindElementByNameVisitor() {}
 
    FindElementByNameVisitor(const std::string& name) : name(name) {}
 
    void SetQueryName(const std::string& name) {
 
        this->name = name;
    }
 
    const tinyxml2::XMLElement* Result() const {
 
        return result;
    }
 
    bool VisitEnter(const tinyxml2::XMLElement& element, const tinyxml2::XMLAttribute* attribute) override {
 
        if(strcmp(element.Name(), name.c_str()) == 0) {
            result = &element;
            return false;
        }
 
        return true;
    }
};
 
static tinyxml2::XMLError QueryStringAttribute(const tinyxml2::XMLElement& elem, const std::string& name, std::string& value) {
 
    const char* c = "";
    tinyxml2::XMLError result = elem.QueryStringAttribute(name.c_str(), &c);
    if (result == tinyxml2::XML_SUCCESS)
        value = std::string(c);
 
    return result;
};
 
static tinyxml2::XMLError QueryBoolAttribute(const tinyxml2::XMLElement& elem, const std::string& name, bool& value) {
 
    std::string str = "";
    tinyxml2::XMLError result = QueryStringAttribute(elem, name, str);
    if(result == tinyxml2::XML_SUCCESS) {
        if(str.length() > 0) {
            str = cgv::utils::to_lower(str);
 
            if(str[0] == '0' || str == "false") {
                value = false;
                return result;
            } else if(str[0] == '1' || str == "true") {
                value = true;
                return result;
            }
 
            return tinyxml2::XMLError::XML_WRONG_ATTRIBUTE_TYPE;
        } else {
            value = false;
            return result;
        }
    }
 
    return result;
};
 
template <typename T, cgv::type::uint32_type N>
static tinyxml2::XMLError QueryVecAttribute(const tinyxml2::XMLElement& elem, const std::string& name, cgv::math::fvec<T, N>& value) {
 
    std::string str = "";
    tinyxml2::XMLError result = QueryStringAttribute(elem, name, str);
    if(result == tinyxml2::XML_SUCCESS) {
        cgv::utils::remove(cgv::utils::trim(str, "()"), ',');
        
        if(!cgv::math::from_string(str, value))
            return tinyxml2::XMLError::XML_WRONG_ATTRIBUTE_TYPE;
    }
 
    return result;
};
 
static tinyxml2::XMLError QueryRGBAttribute(const tinyxml2::XMLElement& elem, const std::string& name, cgv::media::color<float, cgv::media::RGB>& value) {
    
    cgv::math::fvec<float, 3u> vec(0.0f);
    tinyxml2::XMLError result = QueryVecAttribute(elem, name, vec);
    if(result == tinyxml2::XML_SUCCESS)
        value = cgv::media::color<float, cgv::media::RGB>(vec[0], vec[1], vec[2]);
 
    return result;
};
 
}
}