Acts/Navigation/MultiNavigationPolicy.hpp

0001 // This file is part of the ACTS project.
0002 //
0003 // Copyright (C) 2016 CERN for the benefit of the ACTS project
0004 //
0005 // This Source Code Form is subject to the terms of the Mozilla Public
0006 // License, v. 2.0. If a copy of the MPL was not distributed with this
0007 // file, You can obtain one at https://mozilla.org/MPL/2.0/.
0008
0009 #pragma once
0010
0011 #include "Acts/Navigation/INavigationPolicy.hpp"
0012
0013 namespace Acts {
0014
0015 /// Combined navigation policy that calls all contained other navigation
0016 /// policies. This class manages multiple navigation policies and executes
0017 /// them sequentially to populate the navigation stream with candidates.
0018 class MultiNavigationPolicy final : public INavigationPolicy {
0019  public:
0020   /// Constructor from multiple unique_ptr policies
0021   /// @tparam Policies The types of the navigation policies
0022   /// @param policies Unique pointers to navigation policies
0023   template <typename... Policies>
0024   explicit MultiNavigationPolicy(std::unique_ptr<Policies>... policies)
0025       : MultiNavigationPolicy{[](auto... args) {
0026           std::vector<std::unique_ptr<INavigationPolicy>> policyPtrs;
0027
0028           if constexpr (sizeof...(args) > 0) {
0029             auto fill = [&policyPtrs](auto& policy) {
0030               policyPtrs.push_back(std::move(policy));
0031             };
0032
0033             (fill(args), ...);
0034           }
0035
0036           return policyPtrs;
0037         }(std::move(policies)...)} {}
0038
0039   /// Constructor from a vector of navigation policies
0040   /// @param policies Vector of unique pointers to navigation policies
0041   explicit MultiNavigationPolicy(
0042       std::vector<std::unique_ptr<INavigationPolicy>>&& policies);
0043
0044   /// Connect this policy to a navigation delegate
0045   /// @param delegate The navigation delegate to connect to
0046   void connect(NavigationDelegate& delegate) const override;
0047
0048   /// Access the contained navigation policies
0049   /// @return Span of const unique pointers to the navigation policies
0050   std::span<const std::unique_ptr<INavigationPolicy>> policies() const;
0051
0052   /// Visit this policy first, and then all child policies one by one.
0053   /// @param visitor The function to call for each policy
0054   void visit(const std::function<void(const INavigationPolicy&)>& visitor)
0055       const override;
0056
0057  private:
0058   /// Initialize navigation candidates by calling all contained policies
0059   /// @param args The navigation arguments
0060   /// @param stream The navigation stream to populate
0061   /// @param logger Logger for debug output
0062   void initializeCandidates(const NavigationArguments& args,
0063                             AppendOnlyNavigationStream& stream,
0064                             const Logger& logger) const;
0065
0066   /// Vector of unique pointers to the contained navigation policies
0067   std::vector<std::unique_ptr<INavigationPolicy>> m_policyPtrs;
0068
0069   /// Vector of navigation delegates, one for each policy
0070   std::vector<NavigationDelegate> m_delegates;
0071 };
0072 }  // namespace Acts