RouteInstructionAgent.h

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#ifndef LIBOSMSCOUT_ROUTEINSTRUCTIONAGENT_H
#define LIBOSMSCOUT_ROUTEINSTRUCTIONAGENT_H
 
/*
 This source is part of the libosmscout library
 Copyright (C) 2019  Lukas Karas
 
 This library is free software; you can redistribute it and/or
 modify it under the terms of the GNU Lesser General Public
 License as published by the Free Software Foundation; either
 version 2.1 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
 Lesser General Public License for more details.
 
 You should have received a copy of the GNU Lesser General Public
 License along with this library; if not, write to the Free Software
 Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
 */
 
#include <osmscout/navigation/Engine.h>
#include <osmscout/navigation/Agents.h>
#include <osmscout/navigation/DataAgent.h>
 
namespace osmscout {
 
template <typename RouteInstruction>
struct RouteInstructionsMessage CLASS_FINAL : public NavigationMessage
{
public:
  std::list<RouteInstruction> instructions;
 
  inline RouteInstructionsMessage(const Timestamp& timestamp, const std::list<RouteInstruction> &instructions):
    NavigationMessage(timestamp), instructions(instructions)
  {}
};
 
template <typename RouteInstruction>
struct NextRouteInstructionsMessage CLASS_FINAL : public NavigationMessage
{
public:
  RouteInstruction nextRouteInstruction;
 
  inline NextRouteInstructionsMessage(const Timestamp& timestamp, const RouteInstruction &nextRouteInstruction):
      NavigationMessage(timestamp), nextRouteInstruction(nextRouteInstruction)
  {}
};
 
template <typename RouteInstruction, typename RouteInstructionBuilder>
class RouteInstructionAgent CLASS_FINAL : public NavigationAgent
{
private:
  RouteDescriptionRef prevRoute;
  std::list<RouteInstruction> instructions;
 
public:
  RouteInstructionAgent();
 
  std::list<NavigationMessageRef> Process(const NavigationMessageRef& message) override;
 
};
 
template <typename RouteInstruction, typename RouteInstructionBuilder>
RouteInstructionAgent<RouteInstruction, RouteInstructionBuilder>::RouteInstructionAgent() = default;
 
template <typename RouteInstruction, typename RouteInstructionBuilder>
std::list<NavigationMessageRef> RouteInstructionAgent<RouteInstruction, RouteInstructionBuilder>
    ::Process(const NavigationMessageRef& message)
{
  std::list<NavigationMessageRef> result;
 
  auto* positionMessage = dynamic_cast<PositionAgent::PositionMessage*>(message.get());
  if (positionMessage==nullptr) {
    return result;
  }
 
  if (!positionMessage->route){
    // we don't have route description yet
    return result;
  }
  if (positionMessage->position.state != PositionAgent::PositionState::OnRoute &&
      positionMessage->position.state != PositionAgent::PositionState::EstimateInTunnel) {
    // what route instruction we should show?
    return result;
  }
 
  RouteInstructionBuilder builder;
 
  Timestamp now = positionMessage->timestamp;
  if (prevRoute != positionMessage->route){
    instructions=builder.GenerateRouteInstructions(positionMessage->position.routeNode,
                                                   positionMessage->route->Nodes().end());
    result.push_back(std::make_shared<RouteInstructionsMessage<RouteInstruction>>(now,instructions));
  }
 
  // remove instructions behind our back (pop from the front of the list)
  bool updated=false;
  while (!instructions.empty() &&
         positionMessage->position.routeNode != positionMessage->route->Nodes().end() &&
         instructions.front().GetDistance() <= positionMessage->position.routeNode->GetDistance()){
 
    instructions.pop_front();
    updated=true;
  }
  if (updated){
    result.push_back(std::make_shared<RouteInstructionsMessage<RouteInstruction>>(now,instructions));
  }
 
  // next route instruction
  RouteInstruction nextInstruction = builder.GenerateNextRouteInstruction(positionMessage->position.routeNode,
                                                                          positionMessage->route->Nodes().end(),
                                                                          positionMessage->position.coord);
  result.push_back(std::make_shared<NextRouteInstructionsMessage<RouteInstruction>>(now,nextInstruction));
 
  prevRoute=positionMessage->route;
 
  return result;
}
 
}
 
#endif //LIBOSMSCOUT_ROUTEINSTRUCTIONAGENT_H