component.h

Go to the documentation of this file.

#pragma once
#include <cstddef>
#include <functional>
#include <memory>
#include <optional>
#include <string>
#include <typeinfo>
#include <vector>
 
class GameObject;
 
class Component {
 private:
  std::optional<std::reference_wrapper<GameObject>> parent_;
  bool active_{true};
  bool marked_for_deletion_{false};
 
  std::vector<std::function<void(Component&)>> on_detach_actions_;
  std::vector<std::function<void(Component&)>> on_attach_actions_;
 
 public:
  explicit Component();
  virtual ~Component() = default;
 
  [[nodiscard]] bool active() const noexcept;
  Component& active(bool value) noexcept;
 
  [[nodiscard]] bool marked_for_deletion() const noexcept;
  Component& mark_for_deletion() noexcept;
 
  virtual void update(float dt) = 0;
 
  virtual void on_attach();
  virtual void on_detach();
 
  virtual void on_serialize(std::vector<uint8_t>& /*out*/) const;
 
  virtual void on_deserialize(const std::vector<uint8_t>& /*data*/,
                              size_t& /*offset*/);
 
  virtual std::string type_name() const = 0;
 
  const std::optional<std::reference_wrapper<GameObject>>& parent()
      const noexcept;  // NOLINT
 
  std::optional<std::reference_wrapper<GameObject>>&
  parent() noexcept;  // NOLINT
 
  Component& parent(GameObject& parent);
  Component& parent(std::nullopt_t nullopt);
 
  size_t add_on_attach(const std::function<void(Component&)>& action);
  void remove_on_attach(size_t index);
 
  size_t add_on_detach(const std::function<void(Component&)>& action);
  void remove_on_detach(size_t index);
};
 
template <typename T>
concept IsComponent = std::is_base_of_v<Component, T>;