text: /*
   * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *
   * 1. Redistributions of source code must retain the above copyright notice, this
   *    list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright notice,
   *    this list of conditions and the following disclaimer in the documentation
   *    and/or other materials provided with the distribution.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
   * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
   * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
   * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
   * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
   * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
   * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
   * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  #pragma once
  
  #include <AK/Forward.h>
  #include <AK/IntrusiveList.h>
  #include <AK/Noncopyable.h>
  #include <AK/NonnullRefPtrVector.h>
  #include <AK/String.h>
  #include <AK/Weakable.h>
  #include <LibCore/Forward.h>
  
  namespace Core {
  
  enum class TimerShouldFireWhenNotVisible {
      No = 0,
      Yes
  };
  
  #define C_OBJECT(klass)                                                \
  public:                                                                \
      virtual const char* class_name() const override { return #klass; } \
      template<class... Args>                                            \
      static inline NonnullRefPtr<klass> construct(Args&&... args)       \
      {                                                                  \
          return adopt(*new klass(forward<Args>(args)...));              \
      }
  
  #define C_OBJECT_ABSTRACT(klass) \
  public:                          \
      virtual const char* class_name() const override { return #klass; }
  
  class Object
      : public RefCounted<Object>
      , public Weakable<Object> {
      // NOTE: No C_OBJECT macro for Core::Object itself.
  
      AK_MAKE_NONCOPYABLE(Object)
      AK_MAKE_NONMOVABLE(Object)
  public:
      IntrusiveListNode m_all_objects_list_node;
  
      virtual ~Object();
  
      virtual const char* class_name() const = 0;
      virtual void event(Core::Event&);
  
      const String& name() const { return m_name; }
      void set_name(const StringView& name) { m_name = name; }
  
      NonnullRefPtrVector<Object>& children() { return m_children; }
      const NonnullRefPtrVector<Object>& children() const { return m_children; }
  
      template<typename Callback>
      void for_each_child(Callback callback)
      {
          for (auto& child : m_children) {
              if (callback(child) == IterationDecision::Break)
                  return;
          }
      }
  
      template<typename T, typename Callback>
      void for_each_child_of_type(Callback callback);
  
      bool is_ancestor_of(const Object&) const;
  
      Object* parent() { return m_parent; }
      const Object* parent() const { return m_parent; }
  
      void start_timer(int ms, TimerShouldFireWhenNotVisible = TimerShouldFireWhenNotVisible::No);
      void stop_timer();
      bool has_timer() const { return m_timer_id; }
  
      void add_child(Object&);
      void insert_child_before(Object& new_child, Object& before_child);
      void remove_child(Object&);
  
      void dump_tree(int indent = 0);
  
      void deferred_invoke(Function<void(Object&)>);
  
      bool is_widget() const { return m_widget; }
      virtual bool is_action() const { return false; }
      virtual bool is_window() const { return false; }
  
      virtual void save_to(AK::JsonObject&);
  
      static IntrusiveList<Object, &Object::m_all_objects_list_node>& all_objects();
  
      void dispatch_event(Core::Event&, Object* stay_within = nullptr);
  
      void remove_from_parent()
      {
          if (m_parent)
              m_parent->remove_child(*this);
      }
  
      virtual bool is_visible_for_timer_purposes() const;
  
  protected:
      explicit Object(Object* parent = nullptr, bool is_widget = false);
  
      virtual void timer_event(TimerEvent&);
      virtual void custom_event(CustomEvent&);
  
      // NOTE: You may get child events for children that are not yet fully constructed!
      virtual void child_event(ChildEvent&);
  
  private:
      Object* m_parent { nullptr };
      String m_name;
      int m_timer_id { 0 };
      bool m_widget { false };
      NonnullRefPtrVector<Object> m_children;
  };
  
  template<typename T>
  inline bool is(const Object&) { return false; }
  
  template<typename T>
  inline T& to(Object& object)
  {
      ASSERT(is<typename RemoveConst<T>::Type>(object));
      return static_cast<T&>(object);
  }
  
  template<typename T>
  inline const T& to(const Object& object)
  {
      ASSERT(is<typename RemoveConst<T>::Type>(object));
      return static_cast<const T&>(object);
  }
  
  template<typename T, typename Callback>
  inline void Object::for_each_child_of_type(Callback callback)
  {
      for_each_child([&](auto& child) {
          if (is<T>(child))
              return callback(to<T>(child));
          return IterationDecision::Continue;
      });
  }
  
  const LogStream& operator<<(const LogStream&, const Object&);
  
  }
  