From ae2e41983275f7008a70d7d38861b56117651f7f Mon Sep 17 00:00:00 2001
From: Zoe Roux <zoe.roux@sdg.moe>
Date: Wed, 2 Jun 2021 23:30:39 +0200
Subject: [PATCH] Creating a templated view class

---
 lib/wal/CMakeLists.txt          |  2 +-
 lib/wal/sources/Scene/Scene.hpp |  3 +++
 lib/wal/sources/View/View.hpp   | 35 +++++++++++++++++++++++++++++++++
 3 files changed, 39 insertions(+), 1 deletion(-)
 create mode 100644 lib/wal/sources/View/View.hpp

diff --git a/lib/wal/CMakeLists.txt b/lib/wal/CMakeLists.txt
index e8cd8655..ba2a60a0 100644
--- a/lib/wal/CMakeLists.txt
+++ b/lib/wal/CMakeLists.txt
@@ -17,6 +17,6 @@ add_library(wal
 	sources/Component/Component.cpp
 	sources/System/System.cpp
 	sources/Models/Callback.hpp
-)
+	sources/View/View.hpp)
 
 target_include_directories(wal PUBLIC sources)
\ No newline at end of file
diff --git a/lib/wal/sources/Scene/Scene.hpp b/lib/wal/sources/Scene/Scene.hpp
index bddf1e5c..840d2ec5 100644
--- a/lib/wal/sources/Scene/Scene.hpp
+++ b/lib/wal/sources/Scene/Scene.hpp
@@ -7,6 +7,7 @@
 
 #include <vector>
 #include <functional>
+#include "View/View.hpp"
 #include "Entity/Entity.hpp"
 
 namespace WAL
@@ -17,6 +18,8 @@ namespace WAL
 	private:
 		//! @brief The list of registered entities
 		std::vector<Entity> _entities = {};
+		//! @brief A list of cached views.
+//		std::vector<View> _views = {};
 	public:
 		//! @brief Get the list of entities.
 		std::vector<Entity> &getEntities();
diff --git a/lib/wal/sources/View/View.hpp b/lib/wal/sources/View/View.hpp
new file mode 100644
index 00000000..9f004188
--- /dev/null
+++ b/lib/wal/sources/View/View.hpp
@@ -0,0 +1,35 @@
+//
+// Created by Zoe Roux on 2021-06-02.
+//
+
+
+#pragma once
+
+#include <vector>
+#include <Entity/Entity.hpp>
+
+namespace WAL
+{
+	//! @brief A view caching entities containing requested components
+	template<typename ...Components>
+	class View
+	{
+		//! @brief A list of reference to entities that contains the
+		std::vector<std::reference_wrapper<Entity>> entities;
+
+		explicit View(std::vector<Entity> &entities)
+			: entities()
+		{
+			std::copy_if(entities.begin(), entities.end(), std::back_inserter(this->entities), [](Entity &entity) {
+				return (entity.hasComponent<Components>() && ...);
+			});
+		}
+
+		//! @brief A default copy constructor.
+		View(const View &) = default;
+		//! @brief A default destructor.
+		~View() = default;
+		//! @brief A View is assignable.
+		View &operator=(const View &) = default;
+	};
+}
\ No newline at end of file