8 files changed, 335 insertions, 674 deletions

diff --git a/domain/CMakeLists.txt b/domain/CMakeLists.txt
index 58a7900..ec9eb62 100644
--- a/domain/CMakeLists.txt
+++ b/domain/CMakeLists.txt
@@ -37,6 +37,8 @@ target_link_options("domain" PRIVATE
 # Tests
 
 add_executable("domain-tests"
+  "tests/register_types.cpp"
+
   "tests/disposition.cpp"
   "tests/participant.cpp"
   "tests/turn_order.cpp"
diff --git a/domain/include/turns/domain/participant.hpp b/domain/include/turns/domain/participant.hpp
index d845c77..b51425d 100644
--- a/domain/include/turns/domain/participant.hpp
+++ b/domain/include/turns/domain/participant.hpp
@@ -13,34 +13,44 @@
 
 namespace turns::domain
 {
-
   struct participant : Glib::Object
   {
     auto static create(Glib::ustring name, float priority, disposition disposition) -> Glib::RefPtr<participant>;
 
+    participant();
     participant(Glib::ustring name, float priority, disposition disposition);
 
     auto operator<=>(participant const & other) const noexcept -> std::partial_ordering;
 
-    auto property_disposition() -> Glib::PropertyProxy<disposition>;
-    auto property_disposition() const -> Glib::PropertyProxy_ReadOnly<disposition>;
-    auto get_disposition() const noexcept -> disposition;
-    auto set_disposition(disposition value) -> void;
-
-    auto property_name() -> Glib::PropertyProxy<Glib::ustring>;
-    auto property_name() const -> Glib::PropertyProxy_ReadOnly<Glib::ustring>;
-    auto get_name() const -> Glib::ustring;
-    auto set_name(Glib::ustring value) -> void;
-
-    auto property_priority() -> Glib::PropertyProxy<float>;
-    auto property_priority() const -> Glib::PropertyProxy_ReadOnly<float>;
-    auto get_priority() const noexcept -> float;
-    auto set_priority(float value) -> void;
+    template<typename Self>
+    auto disposition(this Self && self)
+    {
+      return self.m_disposition.get_proxy();
+    }
+
+    template<typename Self>
+    auto is_active(this Self && self)
+    {
+      return self.m_is_active.get_proxy();
+    }
+
+    template<typename Self>
+    auto name(this Self && self)
+    {
+      return self.m_name.get_proxy();
+    }
+
+    template<typename Self>
+    auto priority(this Self && self)
+    {
+      return self.m_priority.get_proxy();
+    }
 
   private:
-    Glib::Property<disposition> m_disposition;
-    Glib::Property<Glib::ustring> m_name;
-    Glib::Property<float> m_priority;
+    Glib::Property<domain::disposition> m_disposition{*this, "disposition", domain::disposition::neutral};
+    Glib::Property<bool> m_is_active{*this, "active", false};
+    Glib::Property<Glib::ustring> m_name{*this, "name", ""};
+    Glib::Property<float> m_priority{*this, "priority", 0.0f};
   };
 
 }  // namespace turns::domain
diff --git a/domain/include/turns/domain/turn_order.hpp b/domain/include/turns/domain/turn_order.hpp
index 3b42562..ca44b62 100644
--- a/domain/include/turns/domain/turn_order.hpp
+++ b/domain/include/turns/domain/turn_order.hpp
@@ -4,9 +4,12 @@
 #include "turns/domain/disposition.hpp"
 #include "turns/domain/participant.hpp"
 
+#include <initializer_list>
 #include <limits>
+#include <optional>
+#include <vector>
 
-#include <giomm/liststore.h>
+#include <giomm/listmodel.h>
 #include <glibmm/property.h>
 #include <glibmm/refptr.h>
 #include <glibmm/ustring.h>
@@ -14,91 +17,67 @@
 namespace turns::domain
 {
 
-  struct turn_order : Glib::Object
+  struct turn_order : Gio::ListModel,
+                      Glib::Object
   {
+    using value_type = Glib::RefPtr<participant>;
+    using container_type = std::vector<value_type>;
+    using iterator = container_type::iterator;
+    using const_iterator = container_type::const_iterator;
+
     using active_participant_type = unsigned int;
-    using empty_type = bool;
+    using is_empty_type = bool;
     using has_next_type = bool;
     using has_previous_type = bool;
-    using running_type = bool;
-    using round_type = unsigned int;
+    using is_running_type = bool;
+    using round_number_type = unsigned int;
 
     auto static constexpr invalid_participant_index = std::numeric_limits<active_participant_type>::max();
+    auto static constexpr invalid_round_number = std::numeric_limits<round_number_type>::max();
 
-    auto static create() -> Glib::RefPtr<turn_order>;
-
+    /** Life-time */
     turn_order();
 
-    /** Modifiers */
+    auto static create() -> Glib::RefPtr<turn_order>;
+
+    /** Properties */
+    auto is_empty() const -> Glib::PropertyProxy_ReadOnly<is_empty_type>;
+    auto has_next() const -> Glib::PropertyProxy_ReadOnly<has_next_type>;
+    auto has_previous() const -> Glib::PropertyProxy_ReadOnly<has_previous_type>;
+    auto is_running() const -> Glib::PropertyProxy_ReadOnly<is_running_type>;
+    auto round_number() const -> Glib::PropertyProxy_ReadOnly<round_number_type>;
 
+    /** Element Modifications */
     auto add(Glib::ustring const & name, float priority, disposition disposition) -> void;
     auto clear() -> void;
+    auto remove(unsigned index) -> void;
+
+    /** Turn Modification */
     auto next() -> void;
     auto previous() -> void;
-    auto remove(unsigned int index) -> void;
-    auto reset() -> void;
     auto start() -> void;
     auto stop() -> void;
 
-    /** Querries */
-
-    /**
-     * Get the index of the currently active participant of this turn order, if any.
-     *
-     * @returns an unsigned integer in the range [0, size()) if there is an active participant, or turn_order::invalid_participant_index otherwise.
-     */
-    auto active_participant() const noexcept -> active_participant_type;
-
-    /**
-     * Check if this turn order is empty.
-     */
-    auto empty() const noexcept -> empty_type;
-
-    /**
-     * Get the actor at the specified position in this turn order.
-     *
-     * @return a valid pointer to a participant object if the index was valid, nullptr otherwise.
-     */
-    auto get(unsigned int index) const noexcept -> Glib::RefPtr<participant>;
-
-    /**
-     * Get the underlying list model, to be used with list views.
-     */
-    auto list_model() -> Glib::RefPtr<Gio::ListModel>;
-
-    /**
-     * Get the current round.
-     */
-    auto round() const noexcept -> round_type;
-
-    /**
-     * Check if this turn order is currently running.
-     */
-    auto running() const noexcept -> running_type;
-
-    /**
-     * Get the size of this turn order
-     */
-    auto size() const noexcept -> unsigned int;
+  private:
+    auto get_item_type_vfunc() -> GType override;
+    auto get_n_items_vfunc() -> unsigned override;
+    auto get_item_vfunc(unsigned position) -> void * override;
 
-    /** Properties */
+    /** Signal handlers */
+    auto handle_priority_changed(value_type entry) -> void;
 
-    auto property_active_participant() const -> Glib::PropertyProxy_ReadOnly<active_participant_type>;
-    auto property_empty() const -> Glib::PropertyProxy_ReadOnly<empty_type>;
-    auto property_has_next() const -> Glib::PropertyProxy_ReadOnly<has_next_type>;
-    auto property_has_previous() const -> Glib::PropertyProxy_ReadOnly<has_previous_type>;
-    auto property_running() const -> Glib::PropertyProxy_ReadOnly<running_type>;
-    auto property_round() const -> Glib::PropertyProxy_ReadOnly<round_type>;
+    /** Data management */
+    auto find(value_type entry) const -> const_iterator;
+    auto insert(value_type entry) -> const_iterator;
 
-  private:
-    Glib::RefPtr<Gio::ListStore<participant>> m_model;
-
-    Glib::Property<active_participant_type> m_active_participant;
-    Glib::Property<empty_type> m_empty;
-    Glib::Property<has_next_type> m_has_next;
-    Glib::Property<has_previous_type> m_has_previous;
-    Glib::Property<running_type> m_running;
-    Glib::Property<round_type> m_round;
+    container_type m_data{};
+    std::optional<unsigned> m_active{};
+
+    Glib::Property<has_next_type> m_has_next{*this, "has-next", false};
+    Glib::Property<has_previous_type> m_has_previous{*this, "has-previous", false};
+    Glib::Property<is_empty_type> m_is_empty{*this, "is-empty", true};
+    Glib::Property<is_running_type> m_is_running{*this, "is-running", false};
+    Glib::Property<round_number_type> m_round_number{*this, "round-number", invalid_round_number};
   };
 
 }  // namespace turns::domain
diff --git a/domain/src/participant.cpp b/domain/src/participant.cpp
index 5265eb3..6f0efb1 100644
--- a/domain/src/participant.cpp
+++ b/domain/src/participant.cpp
@@ -3,87 +3,33 @@
 #include <typeinfo>
 #include <utility>
 
+#include <glibmm/class.h>
 #include <glibmm/refptr.h>
 
 namespace turns::domain
 {
-
-  auto participant::create(Glib::ustring name, float priority, disposition disposition) -> Glib::RefPtr<participant>
+  auto participant::create(Glib::ustring name, float priority, domain::disposition disposition) -> Glib::RefPtr<participant>
   {
     return Glib::make_refptr_for_instance(new participant{name, priority, disposition});
   }
 
-  participant::participant(Glib::ustring name, float priority, disposition disposition)
+  participant::participant()
       : Glib::ObjectBase{typeid(participant)}
-      , m_disposition{*this, "disposition", disposition}
-      , m_name{*this, "name", name}
-      , m_priority{*this, "priority", priority}
-  {
-  }
-
-  auto participant::operator<=>(participant const & other) const noexcept -> std::partial_ordering
-  {
-    return m_priority <=> other.m_priority;
-  }
-
-  auto participant::get_disposition() const noexcept -> disposition
-  {
-    return m_disposition;
-  }
-
-  auto participant::set_disposition(disposition value) -> void
-  {
-    m_disposition = value;
-  }
-
-  auto participant::get_name() const -> Glib::ustring
-  {
-    return m_name;
-  }
-
-  auto participant::set_name(Glib::ustring value) -> void
-  {
-    m_name = value;
-  }
-
-  auto participant::get_priority() const noexcept -> float
-  {
-    return m_priority;
-  }
-
-  auto participant::set_priority(float value) -> void
+      , Glib::Object{}
   {
-    m_priority = value;
   }
 
-  auto participant::property_disposition() -> Glib::PropertyProxy<disposition>
+  participant::participant(Glib::ustring name, float priority, domain::disposition disposition)
+      : participant()
   {
-    return m_disposition.get_proxy();
+    m_name = name;
+    m_priority = priority;
+    m_disposition = disposition;
   }
 
-  auto participant::property_disposition() const -> Glib::PropertyProxy_ReadOnly<disposition>
-  {
-    return m_disposition.get_proxy();
-  }
-
-  auto participant::property_name() -> Glib::PropertyProxy<Glib::ustring>
-  {
-    return m_name.get_proxy();
-  }
-
-  auto participant::property_name() const -> Glib::PropertyProxy_ReadOnly<Glib::ustring>
-  {
-    return m_name.get_proxy();
-  }
-
-  auto participant::property_priority() -> Glib::PropertyProxy<float>
-  {
-    return m_priority.get_proxy();
-  }
-
-  auto participant::property_priority() const -> Glib::PropertyProxy_ReadOnly<float>
+  auto participant::operator<=>(participant const & other) const noexcept -> std::partial_ordering
   {
-    return m_priority.get_proxy();
+    return m_priority <=> other.m_priority;
   }
 
 }  // namespace turns::domain
\ No newline at end of file
diff --git a/domain/src/turn_order.cpp b/domain/src/turn_order.cpp
index 61ccdca..0f8b6e8 100644
--- a/domain/src/turn_order.cpp
+++ b/domain/src/turn_order.cpp
@@ -2,11 +2,11 @@
 
 #include "turns/domain/participant.hpp"
 
+#include <algorithm>
 #include <compare>
 #include <limits>
 #include <typeinfo>
 
-#include <glibmm/binding.h>
 #include <glibmm/refptr.h>
 
 namespace turns::domain
@@ -32,194 +32,203 @@ namespace turns::domain
     };
   }  // namespace
 
+  /** Construction */
+
+  turn_order::turn_order()
+      : Glib::ObjectBase{typeid(turn_order)}
+      , Gio::ListModel{}
+  {
+  }
+
   auto turn_order::create() -> Glib::RefPtr<turn_order>
   {
     return Glib::make_refptr_for_instance(new turn_order{});
   }
 
-  turn_order::turn_order()
-      : Glib::ObjectBase{typeid(turn_order)}
-      , m_model{Gio::ListStore<participant>::create()}
-      , m_active_participant(*this, "active_participant", invalid_participant_index)
-      , m_empty{*this, "empty", true}
-      , m_has_next{*this, "has-next", false}
-      , m_has_previous{*this, "has-previous", false}
-      , m_running{*this, "running", false}
-      , m_round{*this, "round", 0}
+  /** Queries */
+
+  auto turn_order::is_empty() const -> Glib::PropertyProxy_ReadOnly<is_empty_type>
+  {
+    return m_is_empty.get_proxy();
+  }
+
+  auto turn_order::has_next() const -> Glib::PropertyProxy_ReadOnly<has_next_type>
+  {
+    return m_has_next.get_proxy();
+  }
+
+  auto turn_order::has_previous() const -> Glib::PropertyProxy_ReadOnly<has_previous_type>
+  {
+    return m_has_previous.get_proxy();
+  }
+
+  auto turn_order::is_running() const -> Glib::PropertyProxy_ReadOnly<is_running_type>
   {
-    Glib::Binding::bind_property(m_model->property_n_items(), m_empty.get_proxy(), Glib::Binding::Flags::DEFAULT, [](auto n) {
-      return n == 0;
-    });
+    return m_is_running.get_proxy();
+  }
+
+  auto turn_order::round_number() const -> Glib::PropertyProxy_ReadOnly<round_number_type>
+  {
+    return m_round_number.get_proxy();
   }
 
   /** Modifiers */
 
   auto turn_order::add(Glib::ustring const & name, float priority, disposition disposition) -> void
   {
-    auto participant = participant::create(name, priority, disposition);
-    if (auto [found, index] = m_model->find(participant, equal_comparator); !found)
-    {
-      auto position = m_model->insert_sorted(participant, comparator);
-      participant->property_priority().signal_changed().connect([this] { m_model->sort(comparator); });
+    auto entry = participant::create(name, priority, disposition);
+    entry->priority().signal_changed().connect(sigc::bind(sigc::mem_fun(*this, &turn_order::handle_priority_changed), entry));
+    auto position = std::distance(m_data.cbegin(), insert(entry));
+    items_changed(position, 0, 1);
 
-      if (m_active_participant != invalid_participant_index && position <= m_active_participant)
-      {
-        m_active_participant = m_active_participant + 1;
-      }
+    if (get_n_items() == 1)
+    {
+      m_is_empty = false;
+      m_has_next = true;
     }
   }
 
   auto turn_order::clear() -> void
   {
-    m_model->remove_all();
-    m_active_participant = invalid_participant_index;
+    m_is_running = false;
+    m_is_empty = true;
     m_has_next = false;
     m_has_previous = false;
-    m_running = false;
+    m_active.reset();
+    m_round_number = invalid_round_number;
+
+    auto old_size = get_n_items();
+    m_data.clear();
+    items_changed(0, old_size, 0);
   }
 
   auto turn_order::next() -> void
   {
-    m_active_participant = (m_active_participant + 1) % size();
-    if (!m_active_participant)
+    auto old_active = *m_active;
+    m_active = m_active.transform([this](auto index) { return (index + 1) % get_n_items(); });
+
+    m_has_previous = true;
+    m_data[old_active]->is_active() = false;
+    m_data[*m_active]->is_active() = true;
+
+    if (m_active == 0)
     {
-      m_round = round() + 1;
+      m_round_number = m_round_number + 1;
     }
-    m_has_previous = m_active_participant || m_round;
   }
 
   auto turn_order::previous() -> void
   {
-    if (!m_has_previous)
+    if (!(m_has_previous && m_is_running))
     {
       return;
     }
 
-    if (m_active_participant)
-    {
-      m_active_participant = m_active_participant - 1;
-    }
-    else if (m_round)
+    auto old_active = *m_active;
+    m_active = m_active.transform([this](auto index) { return index ? index - 1 : get_n_items() - 1; });
+
+    m_has_previous = m_round_number > 0 || m_active > 0;
+    m_data[old_active]->is_active() = false;
+    m_data[*m_active]->is_active() = true;
+
+    if (m_active == 0)
     {
-      m_round = round() - 1;
-      m_active_participant = size() - 1;
+      m_round_number = m_round_number - 1;
     }
-
-    m_has_previous = m_active_participant || m_round;
   }
 
-  auto turn_order::remove(unsigned int index) -> void
+  auto turn_order::remove(unsigned index) -> void
   {
-    m_model->remove(index);
-    if (empty())
+    if (index >= get_n_items())
     {
-      m_active_participant = invalid_participant_index;
-      m_has_next = false;
-      m_has_previous = false;
-      m_running = false;
+      return;
     }
-    else if (m_active_participant != invalid_participant_index)
+
+    auto position = m_data.begin() + index;
+    m_data.erase(position);
+    items_changed(index, 1, 0);
+    if (get_n_items() == 0)
     {
-      if (m_active_participant > size() - 1)
-      {
-        m_active_participant = size() - 1;
-      }
-      else if (index <= m_active_participant)
-      {
-        m_active_participant = m_active_participant - 1;
-      }
+      m_is_empty = true;
+      m_is_running = false;
+      m_has_next = false;
     }
   }
 
-  auto turn_order::reset() -> void
-  {
-    m_running = false;
-    m_active_participant = 0;
-  }
-
   auto turn_order::start() -> void
   {
-    if (m_active_participant == invalid_participant_index)
+    if (!m_active)
     {
-      m_active_participant = 0;
+      m_active = 0;
+      m_data[*m_active]->is_active() = true;
     }
-    m_running = true;
-    m_has_next = true;
+    if (m_round_number == invalid_round_number)
+    {
+      m_round_number = 0;
+    }
+    m_is_running = true;
   }
 
   auto turn_order::stop() -> void
   {
-    m_running = false;
-    m_has_next = false;
-  }
-
-  /** Querries */
-
-  auto turn_order::active_participant() const noexcept -> active_participant_type
-  {
-    return m_active_participant;
-  }
-
-  auto turn_order::empty() const noexcept -> bool
-  {
-    return m_empty;
-  }
-
-  auto turn_order::get(unsigned int index) const noexcept -> Glib::RefPtr<participant>
-  {
-    return m_model->get_item(index);
+    m_is_running = false;
   }
 
-  auto turn_order::list_model() -> Glib::RefPtr<Gio::ListModel>
-  {
-    return m_model;
-  }
+  /** ListModel implementation */
 
-  auto turn_order::round() const noexcept -> round_type
+  auto turn_order::get_item_type_vfunc() -> GType
   {
-    return m_round;
+    return participant::get_type();
   }
 
-  auto turn_order::running() const noexcept -> running_type
+  auto turn_order::get_n_items_vfunc() -> unsigned
   {
-    return m_running;
+    return m_data.size();
   }
 
-  auto turn_order::size() const noexcept -> unsigned int
+  auto turn_order::get_item_vfunc(unsigned position) -> void *
   {
-    return m_model->get_n_items();
+    if (position >= get_n_items())
+    {
+      return nullptr;
+    }
+    auto item = m_data[position];
+    item->reference();
+    return item->gobj();
   }
 
-  /** Properties */
+  /** Signal handlers */
 
-  auto turn_order::property_active_participant() const -> Glib::PropertyProxy_ReadOnly<active_participant_type>
+  auto turn_order::handle_priority_changed(value_type entry) -> void
   {
-    return m_active_participant.get_proxy();
-  }
-
-  auto turn_order::property_empty() const -> Glib::PropertyProxy_ReadOnly<bool>
-  {
-    return m_empty.get_proxy();
-  }
+    auto original_position = find(entry);
+    auto original_index = distance(m_data.cbegin(), original_position);
+    auto target_position = std::ranges::upper_bound(m_data, entry, comparator);
+    if (original_position == target_position)
+    {
+      return;
+    }
 
-  auto turn_order::property_has_next() const -> Glib::PropertyProxy_ReadOnly<has_next_type>
-  {
-    return m_has_next.get_proxy();
+    m_data.erase(original_position);
+    auto inserted_position = insert(entry);
+    items_changed(0, get_n_items(), get_n_items());
+    if (m_active == original_index)
+    {
+      m_active = distance(m_data.cbegin(), inserted_position);
+      m_has_previous = m_round_number > 0 || m_active > 0;
+    }
   }
 
-  auto turn_order::property_has_previous() const -> Glib::PropertyProxy_ReadOnly<has_previous_type>
-  {
-    return m_has_previous.get_proxy();
-  }
+  /** Data management */
 
-  auto turn_order::property_running() const -> Glib::PropertyProxy_ReadOnly<running_type>
+  auto turn_order::find(value_type entry) const -> const_iterator
   {
-    return m_running.get_proxy();
+    return std::ranges::find(m_data, entry);
   }
 
-  auto turn_order::property_round() const -> Glib::PropertyProxy_ReadOnly<round_type>
+  auto turn_order::insert(value_type entry) -> const_iterator
   {
-    return m_round.get_proxy();
+    return m_data.insert(std::ranges::upper_bound(m_data, entry, comparator), entry);
   }
 
 }  // namespace turns::domain
\ No newline at end of file
diff --git a/domain/tests/participant.cpp b/domain/tests/participant.cpp
index dd244f4..e4e185c 100644
--- a/domain/tests/participant.cpp
+++ b/domain/tests/participant.cpp
@@ -22,123 +22,63 @@ namespace turns::domain::tests
       REQUIRE(participant::create(constructed_name, constructed_priority, constructed_disposition));
     }
 
-    SECTION("allows access to its disposition via the associated accessors")
+    SECTION("allows access to its disposition")
     {
       SECTION("allowing to get it")
       {
-        REQUIRE(instance.get_disposition() == constructed_disposition);
+        REQUIRE(instance.disposition() == constructed_disposition);
       }
 
       SECTION("allowing to get it via a constant object")
       {
         auto const & cref = instance;
-        REQUIRE(cref.get_disposition() == constructed_disposition);
+        REQUIRE(cref.disposition() == constructed_disposition);
       }
 
       SECTION("allowing to set it")
       {
-        instance.set_disposition(disposition::hostile);
-        REQUIRE(instance.get_disposition() == disposition::hostile);
+        instance.disposition() = disposition::hostile;
+        REQUIRE(instance.disposition() == disposition::hostile);
       }
     }
 
-    SECTION("allows access to its disposition via the associated property")
+    SECTION("allows access to its name")
     {
       SECTION("allowing to get it")
       {
-        REQUIRE(instance.property_disposition() == constructed_disposition);
+        REQUIRE(instance.name() == constructed_name);
       }
 
       SECTION("allowing to get it via a constant object")
       {
         auto const & cref = instance;
-        REQUIRE(cref.property_disposition() == constructed_disposition);
+        REQUIRE(cref.name() == constructed_name);
       }
 
       SECTION("allowing to set it")
       {
-        instance.property_disposition() = disposition::hostile;
-        REQUIRE(instance.get_disposition() == disposition::hostile);
+        instance.name() = "replaced";
+        REQUIRE(instance.name() == "replaced");
       }
     }
 
-    SECTION("allows access to its name via the associated accessors")
+    SECTION("allows access to its priority")
     {
       SECTION("allowing to get it")
       {
-        REQUIRE(instance.get_name() == constructed_name);
+        REQUIRE(instance.priority() == constructed_priority);
       }
 
       SECTION("allowing to get it via a constant object")
       {
         auto const & cref = instance;
-        REQUIRE(cref.get_name() == constructed_name);
+        REQUIRE(cref.priority() == constructed_priority);
       }
 
       SECTION("allowing to set it")
       {
-        instance.set_name("replaced");
-        REQUIRE(instance.get_name() == "replaced");
-      }
-    }
-
-    SECTION("allows access to its name via the associated property")
-    {
-      SECTION("allowing to get it")
-      {
-        REQUIRE(instance.property_name() == constructed_name);
-      }
-
-      SECTION("allowing to get it via a constant object")
-      {
-        auto const & cref = instance;
-        REQUIRE(cref.property_name() == constructed_name);
-      }
-
-      SECTION("allowing to set it")
-      {
-        instance.property_name() = "replaced";
-        REQUIRE(instance.get_name() == "replaced");
-      }
-    }
-
-    SECTION("allows access to its priority via the associated accessors")
-    {
-      SECTION("allowing to get it")
-      {
-        REQUIRE(instance.get_priority() == constructed_priority);
-      }
-
-      SECTION("allowing to get it via a constant object")
-      {
-        auto const & cref = instance;
-        REQUIRE(cref.get_priority() == constructed_priority);
-      }
-
-      SECTION("allowing to set it")
-      {
-        instance.set_priority(3);
-        REQUIRE(instance.get_priority() == 3);
-      }
-    }
-
-    SECTION("allows access to its priority via the associated property")
-    {
-      SECTION("allowing to get it")
-      {
-        REQUIRE(instance.property_priority() == constructed_priority);
-      }
-
-      SECTION("allowing to get it via a constant object")
-      {
-        auto const & cref = instance;
-        REQUIRE(cref.property_priority() == constructed_priority);
-      }
-
-      SECTION("allowing to set it")
-      {
-        instance.property_priority() = 4;
-        REQUIRE(instance.get_priority() == 4);
+        instance.priority() = 4;
+        REQUIRE(instance.priority() == 4);
       }
     }
 
diff --git a/domain/tests/register_types.cpp b/domain/tests/register_types.cpp
new file mode 100644
index 0000000..de8bb52
--- /dev/null
+++ b/domain/tests/register_types.cpp
@@ -0,0 +1,13 @@
+#include "turns/domain/participant.hpp"
+#include "turns/domain/turn_order.hpp"
+
+namespace turns::tests
+{
+
+  auto register_types() -> void
+  {
+    static_cast<void>(domain::participant{});
+    static_cast<void>(domain::turn_order{});
+  }
+
+}  // namespace turns::tests
\ No newline at end of file
diff --git a/domain/tests/turn_order.cpp b/domain/tests/turn_order.cpp
index de1689c..eb05581 100644
--- a/domain/tests/turn_order.cpp
+++ b/domain/tests/turn_order.cpp
@@ -1,459 +1,221 @@
 #include "turns/domain/turn_order.hpp"
 
+#include "turns/domain/participant.hpp"
+
 #include <catch2/catch_test_macros.hpp>
 
-#include <glibmm/ustring.h>
+#include <giomm/liststore.h>
 
 namespace turns::domain::tests
 {
-
   SCENARIO("Queries on a fresh turn_order instance", "[turn_order]")
   {
     GIVEN("an empty turn_order")
     {
       auto instance = turn_order::create();
 
-      THEN("active_participant() is turn_order::invalid_participant_index")
+      THEN("get_n_items() returns 0")
       {
-        REQUIRE(instance->active_participant() == turn_order::invalid_participant_index);
+        auto str = Gio::ListStore<Glib::Object>::create();
+        REQUIRE(instance->get_n_items() == str->get_n_items());
       }
 
-      THEN("empty() is true")
+      THEN("get_type() returns participant::get_type()")
       {
-        REQUIRE(instance->empty());
+        REQUIRE(instance->get_item_type() == participant::get_type());
       }
 
-      THEN("get() returns a nullptr")
+      THEN("get_typed_object(0) returns nullptr")
       {
-        REQUIRE(instance->get(0) == nullptr);
+        REQUIRE(instance->get_typed_object<participant>(0) == nullptr);
       }
 
-      THEN("list_model() returns a non-null pointer")
+      THEN("has_next() returns false")
       {
-        REQUIRE(instance->list_model());
+        REQUIRE_FALSE(instance->has_next());
       }
 
-      THEN("round() returns 0")
+      THEN("has_previous() returns false")
       {
-        REQUIRE(instance->round() == 0);
+        REQUIRE_FALSE(instance->has_previous());
       }
 
-      THEN("running() returns false")
+      THEN("is_empty() returns true")
       {
-        REQUIRE_FALSE(instance->running());
+        REQUIRE(instance->is_empty());
       }
 
-      THEN("size() returns 0")
+      THEN("is_running() returns false")
       {
-        REQUIRE(instance->size() == 0);
+        REQUIRE_FALSE(instance->is_running());
       }
 
-      THEN("size() returns the same value as list_model()->get_n_item()")
+      THEN("round_number() returns invalid_round_number")
       {
-        REQUIRE(instance->size() == instance->list_model()->get_n_items());
+        REQUIRE(instance->round_number() == turn_order::invalid_round_number);
       }
+    }
+  }
 
-      WHEN("accessing turn_order:active-participant")
-      {
-        THEN("get() returns turn_order::invalid_participant_index")
-        {
-          REQUIRE(instance->property_active_participant().get_value() == turn_order::invalid_participant_index);
-        }
+  SCENARIO("Adding participants")
+  {
+    auto instance = turn_order::create();
 
-        THEN("get_object() returns a pointer to the instance")
-        {
-          REQUIRE(instance->property_active_participant().get_object() == instance.get());
-        }
+    GIVEN("a participant has been added to a turn_order")
+    {
+      instance->add("Participant #0", 0, disposition::neutral);
 
-        THEN("get_name() returns \"active-participant\"")
-        {
-          REQUIRE(instance->property_active_participant().get_name() == Glib::ustring{"active-participant"});
-        }
+      THEN("get_n_items() returns 1")
+      {
+        REQUIRE(instance->get_n_items() == 1);
       }
 
-      WHEN("accessing turn_order:empty")
+      THEN("get_typed_object(0) returns a non-null pointer")
       {
-        THEN("get() returns true")
-        {
-          REQUIRE(instance->property_empty().get_value());
-        }
-
-        THEN("get_object() returns a pointer to the instance")
-        {
-          REQUIRE(instance->property_empty().get_object() == instance.get());
-        }
-
-        THEN("get_name() returns \"empty\"")
-        {
-          REQUIRE(instance->property_empty().get_name() == Glib::ustring{"empty"});
-        }
+        REQUIRE(instance->get_typed_object<participant>(0) != nullptr);
       }
 
-      WHEN("accessing turn_order:has-next")
+      THEN("has_next() returns true")
       {
-        THEN("get() returns false")
-        {
-          REQUIRE_FALSE(instance->property_has_next().get_value());
-        }
-
-        THEN("get_object() returns a pointer to the instance")
-        {
-          REQUIRE(instance->property_has_next().get_object() == instance.get());
-        }
+        REQUIRE(instance->has_next());
+      }
 
-        THEN("get_name() returns \"has-next\"")
-        {
-          REQUIRE(instance->property_has_next().get_name() == Glib::ustring{"has-next"});
-        }
+      THEN("has_previous() returns false")
+      {
+        REQUIRE_FALSE(instance->has_previous());
       }
 
-      WHEN("accessing turn_order:has-previous")
+      THEN("is_empty() returns false")
       {
-        THEN("get() returns false")
-        {
-          REQUIRE_FALSE(instance->property_has_previous().get_value());
-        }
+        REQUIRE_FALSE(instance->is_empty());
+      }
 
-        THEN("get_object() returns a pointer to the instance")
-        {
-          REQUIRE(instance->property_has_previous().get_object() == instance.get());
-        }
+      THEN("is_running() returns false")
+      {
+        REQUIRE_FALSE(instance->is_running());
+      }
 
-        THEN("get_name() returns \"has-previous\"")
-        {
-          REQUIRE(instance->property_has_previous().get_name() == Glib::ustring{"has-previous"});
-        }
+      THEN("round_number() returns invalid_round_number")
+      {
+        REQUIRE(instance->round_number() == turn_order::invalid_round_number);
       }
 
-      WHEN("accessing turn_order:running")
+      WHEN("the turn_order is start()ed")
       {
-        THEN("get() returns false")
+        instance->start();
+
+        THEN("get_n_items() still returns 1")
         {
-          REQUIRE_FALSE(instance->property_running().get_value());
+          REQUIRE(instance->get_n_items() == 1);
         }
 
-        THEN("get_object() returns a pointer to the instance")
+        THEN("get_typed_object(0) still returns a non-null pointer")
         {
-          REQUIRE(instance->property_running().get_object() == instance.get());
+          REQUIRE(instance->get_typed_object<participant>(0) != nullptr);