From 0d1e2cc1f3b63c908567b0aee0c53f760d7b0288 Mon Sep 17 00:00:00 2001
From: Jan Niklas Hasse <jhasse@bixense.com>
Date: Thu, 25 Jan 2024 17:04:50 +0100
Subject: [PATCH] Add WorkFactory which allows to delay creation of the next
 Work

---
 src/jngl.hpp             |  3 ++-
 src/jngl/WorkFactory.cpp | 27 +++++++++++++++++++++++++++
 src/jngl/WorkFactory.hpp | 23 +++++++++++++++++++++++
 3 files changed, 52 insertions(+), 1 deletion(-)
 create mode 100644 src/jngl/WorkFactory.cpp
 create mode 100644 src/jngl/WorkFactory.hpp

diff --git a/src/jngl.hpp b/src/jngl.hpp
index 5de7a4cde..f0901eee2 100644
--- a/src/jngl.hpp
+++ b/src/jngl.hpp
@@ -1,4 +1,4 @@
-// Copyright 2012-2023 Jan Niklas Hasse <jhasse@bixense.com>
+// Copyright 2012-2024 Jan Niklas Hasse <jhasse@bixense.com>
 // For conditions of distribution and use, see copyright notice in LICENSE.txt
 /// Includes all JNGL headers except for init.hpp
 /// @file
@@ -21,6 +21,7 @@
 #include "jngl/Vertex.hpp"
 #include "jngl/Video.hpp"
 #include "jngl/Widget.hpp"
+#include "jngl/WorkFactory.hpp"
 #include "jngl/debug.hpp"
 #include "jngl/effects.hpp"
 #include "jngl/font.hpp"
diff --git a/src/jngl/WorkFactory.cpp b/src/jngl/WorkFactory.cpp
new file mode 100644
index 000000000..2fbe893bc
--- /dev/null
+++ b/src/jngl/WorkFactory.cpp
@@ -0,0 +1,27 @@
+// Copyright 2024 Jan Niklas Hasse <jhasse@bixense.com>
+// For conditions of distribution and use, see copyright notice in LICENSE.txt
+#include "WorkFactory.hpp"
+#include <cassert>
+
+namespace jngl {
+
+WorkFactory::WorkFactory(std::function<std::shared_ptr<Work>()> factory)
+: factory(std::move(factory)) {
+}
+
+void WorkFactory::step() {
+	assert(factory); // we should only be stepped once
+	factory = nullptr;
+	work->step();
+}
+
+void WorkFactory::draw() const {
+	work->draw();
+}
+
+void WorkFactory::onLoad() {
+	work = factory();
+	jngl::setWork(work);
+}
+
+} // namespace jngl
diff --git a/src/jngl/WorkFactory.hpp b/src/jngl/WorkFactory.hpp
new file mode 100644
index 000000000..74d9aafd3
--- /dev/null
+++ b/src/jngl/WorkFactory.hpp
@@ -0,0 +1,23 @@
+// Copyright 2024 Jan Niklas Hasse <jhasse@bixense.com>
+// For conditions of distribution and use, see copyright notice in LICENSE.txt
+/// @file
+#pragma once
+
+#include "work.hpp"
+
+namespace jngl {
+
+class WorkFactory : public jngl::Work {
+public:
+    explicit WorkFactory(std::function<std::shared_ptr<Work>()>);
+
+private:
+    void step() override;
+    void draw() const override;
+    void onLoad() override;
+
+    std::shared_ptr<Work> work;
+    std::function<std::shared_ptr<Work>()> factory;
+};
+
+} // namespace jngl