From 7f5d87dcd54481c7fe190a340a1d0850fdf1adf7 Mon Sep 17 00:00:00 2001
From: Chris Thrasher <chrisjthrasher@gmail.com>
Date: Sun, 26 Nov 2023 13:36:19 -0700
Subject: [PATCH] Add move semantics to `sf::Context`

---
 include/SFML/Window/Context.hpp | 12 +++++++
 src/SFML/Window/Context.cpp     | 30 ++++++++++++----
 test/Window/Context.test.cpp    | 63 +++++++++++++++++++++++++++++++--
 3 files changed, 96 insertions(+), 9 deletions(-)

diff --git a/include/SFML/Window/Context.hpp b/include/SFML/Window/Context.hpp
index 6c3499f7d..377337610 100644
--- a/include/SFML/Window/Context.hpp
+++ b/include/SFML/Window/Context.hpp
@@ -84,6 +84,18 @@ public:
     ////////////////////////////////////////////////////////////
     Context& operator=(const Context&) = delete;
 
+    ////////////////////////////////////////////////////////////
+    /// \brief Move constructor
+    ///
+    ////////////////////////////////////////////////////////////
+    Context(Context&& context) noexcept;
+
+    ////////////////////////////////////////////////////////////
+    /// \brief Move assignment
+    ///
+    ////////////////////////////////////////////////////////////
+    Context& operator=(Context&& context) noexcept;
+
     ////////////////////////////////////////////////////////////
     /// \brief Activate or deactivate explicitly the context
     ///
diff --git a/src/SFML/Window/Context.cpp b/src/SFML/Window/Context.cpp
index 6ee6f5b3e..3db168380 100644
--- a/src/SFML/Window/Context.cpp
+++ b/src/SFML/Window/Context.cpp
@@ -49,19 +49,37 @@ namespace sf
 Context::Context() : m_context(priv::GlContext::create())
 {
     if (!setActive(true))
-    {
         err() << "Failed to set context as active during construction" << std::endl;
-    }
 }
 
 
 ////////////////////////////////////////////////////////////
 Context::~Context()
 {
-    if (!setActive(false))
-    {
+    if (m_context && !setActive(false))
         err() << "Failed to set context as inactive during destruction" << std::endl;
-    }
+}
+
+
+////////////////////////////////////////////////////////////
+Context::Context(Context&& context) noexcept : m_context(std::move(context.m_context))
+{
+    if (&context == ContextImpl::currentContext)
+        ContextImpl::currentContext = this;
+}
+
+
+////////////////////////////////////////////////////////////
+Context& Context::operator=(Context&& context) noexcept
+{
+    if (this == &context)
+        return *this;
+
+    m_context = std::move(context.m_context);
+    if (&context == ContextImpl::currentContext)
+        ContextImpl::currentContext = this;
+
+    return *this;
 }
 
 
@@ -125,9 +143,7 @@ Context::Context(const ContextSettings& settings, const Vector2u& size) :
 m_context(priv::GlContext::create(settings, size))
 {
     if (!setActive(true))
-    {
         err() << "Failed to set context as active during construction" << std::endl;
-    }
 }
 
 } // namespace sf
diff --git a/test/Window/Context.test.cpp b/test/Window/Context.test.cpp
index 4c9067775..8ab84a667 100644
--- a/test/Window/Context.test.cpp
+++ b/test/Window/Context.test.cpp
@@ -21,8 +21,8 @@ TEST_CASE("[Window] sf::Context", runDisplayTests())
     {
         STATIC_CHECK(!std::is_copy_constructible_v<sf::Context>);
         STATIC_CHECK(!std::is_copy_assignable_v<sf::Context>);
-        STATIC_CHECK(!std::is_nothrow_move_constructible_v<sf::Context>);
-        STATIC_CHECK(!std::is_nothrow_move_assignable_v<sf::Context>);
+        STATIC_CHECK(std::is_nothrow_move_constructible_v<sf::Context>);
+        STATIC_CHECK(std::is_nothrow_move_assignable_v<sf::Context>);
     }
 
     SECTION("Construction")
@@ -33,6 +33,65 @@ TEST_CASE("[Window] sf::Context", runDisplayTests())
         CHECK(sf::Context::getActiveContextId() != 0);
     }
 
+    SECTION("Move semantics")
+    {
+        SECTION("Construction")
+        {
+            SECTION("From active context")
+            {
+                sf::Context       movedContext;
+                const sf::Context context(std::move(movedContext));
+                CHECK(context.getSettings().majorVersion > 0);
+                CHECK(sf::Context::getActiveContext() == &context);
+                CHECK(sf::Context::getActiveContextId() != 0);
+            }
+
+            SECTION("From inactive context")
+            {
+                sf::Context movedContext;
+                CHECK(movedContext.setActive(false));
+                CHECK(sf::Context::getActiveContext() == nullptr);
+                CHECK(sf::Context::getActiveContextId() == 0);
+
+                const sf::Context context(std::move(movedContext));
+                CHECK(context.getSettings().majorVersion > 0);
+                CHECK(sf::Context::getActiveContext() == nullptr);
+                CHECK(sf::Context::getActiveContextId() == 0);
+            }
+        }
+
+        SECTION("Assignment")
+        {
+            SECTION("From active context")
+            {
+                sf::Context movedContext;
+                sf::Context context;
+                CHECK(movedContext.setActive(true));
+                CHECK(sf::Context::getActiveContext() == &movedContext);
+                CHECK(sf::Context::getActiveContextId() != 0);
+
+                context = std::move(movedContext);
+                CHECK(context.getSettings().majorVersion > 0);
+                CHECK(sf::Context::getActiveContext() == &context);
+                CHECK(sf::Context::getActiveContextId() != 0);
+            }
+
+            SECTION("From inactive context")
+            {
+                sf::Context movedContext;
+                CHECK(movedContext.setActive(false));
+                CHECK(sf::Context::getActiveContext() == nullptr);
+                CHECK(sf::Context::getActiveContextId() == 0);
+
+                sf::Context context;
+                context = std::move(movedContext);
+                CHECK(context.getSettings().majorVersion > 0);
+                CHECK(sf::Context::getActiveContext() == nullptr);
+                CHECK(sf::Context::getActiveContextId() == 0);
+            }
+        }
+    }
+
     SECTION("setActive()")
     {
         sf::Context context;