urdf_model.h

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/* Author: Wim Meeussen */

#ifndef URDF_INTERFACE_MODEL_H
#define URDF_INTERFACE_MODEL_H

#include <string>
#include <map>
#include "urdf_link.h"
#include "urdf_exception.h"

namespace urdf {

  class ModelInterface
  {
  public:

    std::shared_ptr<const Link> getRoot(void) const{
      return this->root_link_;
    };

    std::shared_ptr<const Link> getLink(const std::string& name) const {
      std::shared_ptr<const Link> ptr;
      if (this->links_.find(name) == this->links_.end())
        ptr.reset();
      else
        ptr = this->links_.find(name)->second;
      return ptr;
    };
    
    std::shared_ptr<const Joint> getJoint(const std::string& name) const {
      std::shared_ptr<const Joint> ptr;
      if (this->joints_.find(name) == this->joints_.end())
        ptr.reset();
      else
        ptr = this->joints_.find(name)->second;
      return ptr;
    };
    
    const std::string& getName() const {
      return name_;
    };
    
    void getLinks(std::vector<std::shared_ptr<Link> >& links) const {
      for (std::map<std::string,std::shared_ptr<Link> >::const_iterator link = this->links_.begin();
           link != this->links_.end(); link++)
        {
          links.push_back(link->second);
        }
    };
    
    void clear() {
      name_.clear();
      this->links_.clear();
      this->joints_.clear();
      this->materials_.clear();
      this->root_link_.reset();
    };
    
    void getLink(const std::string& name,std::shared_ptr<Link> &link) const {
      std::shared_ptr<Link> ptr;
      if (this->links_.find(name) == this->links_.end())
        ptr.reset();
      else
        ptr = this->links_.find(name)->second;
      link = ptr;
    };
    
    std::shared_ptr<Material> getMaterial(const std::string& name) const {
      std::shared_ptr<Material> ptr;
      if (this->materials_.find(name) == this->materials_.end())
        ptr.reset();
      else
        ptr = this->materials_.find(name)->second;
      return ptr;
    };
    
    void initTree(std::map<std::string, std::string> &parent_link_tree) {
      
      for (std::map<std::string,std::shared_ptr<Joint> >::iterator joint = this->joints_.begin();
           joint != this->joints_.end(); joint++) {
        std::string parent_link_name = joint->second->parent_link_name;
        std::string child_link_name = joint->second->child_link_name;
        
        if (parent_link_name.empty() || child_link_name.empty())
          {
            throw ParseError("Joint [" + joint->second->name + "] is missing a parent and/or child link specification.");
          }
        else
          {
            // find child and parent links
            std::shared_ptr<Link> child_link, parent_link;
            this->getLink(child_link_name, child_link);
            if (!child_link)
              {
                throw ParseError("child link [" + child_link_name + "] of joint [" + joint->first + "] not found");
              }
            this->getLink(parent_link_name, parent_link);
            if (!parent_link)
              {
                throw ParseError("parent link [" + parent_link_name + "] of joint [" + joint->first + "] not found.  This is not valid according to the URDF spec. Every link you refer to from a joint needs to be explicitly defined in the robot description. To fix this problem you can either remove this joint [" + joint->first + "] from your urdf file, or add \"<link name=\"" + parent_link_name + "\" />\" to your urdf file.");
              }
            
            //set parent link for child link
            child_link->setParent(parent_link);
            
            //set parent joint for child link        
            child_link->parent_joint = joint->second;
            
            //set child joint for parent link
            parent_link->child_joints.push_back(joint->second);
            
            //set child link for parent link
            parent_link->child_links.push_back(child_link);
              
            // fill in child/parent string map
            parent_link_tree[child_link->name] = parent_link_name;
          }
      }
    }
    
    void initRoot(const std::map<std::string, std::string> &parent_link_tree) { 
      this->root_link_.reset();
      
      // find the links that have no parent in the tree
      for (std::map<std::string, std::shared_ptr<Link> >::const_iterator l=this->links_.begin(); l!=this->links_.end(); l++)  
        {
          std::map<std::string, std::string >::const_iterator parent = parent_link_tree.find(l->first);
          if (parent == parent_link_tree.end())
            {
              // store root link
              if (!this->root_link_)
                {
                  getLink(l->first, this->root_link_);
                }
              // we already found a root link
              else
                {
                  throw ParseError("Two root links found: [" + this->root_link_->name + "] and [" + l->first + "]");
                }
            }
        }
      if (!this->root_link_)
        {
          throw ParseError("No root link found. The robot xml is not a valid tree.");
        }
    }
    
    
    std::map<std::string, std::shared_ptr<Link> > links_;
    std::map<std::string, std::shared_ptr<Joint> > joints_;
    std::map<std::string, std::shared_ptr<Material> > materials_;
    
    std::string name_;

    std::shared_ptr<Link> root_link_;
    
  };

}

#endif