Return std::optional<Event> from sf::WindowBase::pollEvent

.github/ISSUE_TEMPLATE/bug_report.yml

@@ -57,8 +57,10 @@ body:
 
                   while (window.isOpen())
                   {
-                      for (sf::Event event; window.pollEvent(event);)
+                      while (const auto maybeEvent = window.pollEvent())
                       {
+                          const auto& event = *maybeEvent;
+
                           if (event.is<sf::Event::Closed>())
                               window.close();
                       }

.github/ISSUE_TEMPLATE/feature_request.yml

@@ -54,8 +54,10 @@ body:
 
                   while (window.isOpen())
                   {
-                      for (sf::Event event; window.pollEvent(event);)
+                      while (const auto maybeEvent = window.pollEvent())
                       {
+                          const auto& event = *maybeEvent;
+
                           if (event.is<sf::Event::Closed>())
                               window.close();
                       }

.github/pull_request_template.md

@@ -39,8 +39,10 @@ int main()
 
     while (window.isOpen())
     {
-        for (sf::Event event; window.pollEvent(event);)
+        while (const auto maybeEvent = window.pollEvent())
         {
+            const auto& event = *maybeEvent;
+
             if (event.is<sf::Event::Closed>())
                 window.close();
         }

doc/mainpage.hpp

@@ -44,8 +44,10 @@
 ///     while (window.isOpen())
 ///     {
 ///         // Process events
-///         for (sf::Event event; window.pollEvent(event);)
+///         while (const auto maybeEvent = window.pollEvent())
 ///         {
+///             const auto& event = *maybeEvent;
+///
 ///             // Close window: exit
 ///             if (event.is<sf::Event::Closed>())
 ///                 window.close();

examples/android/app/src/main/jni/main.cpp

@@ -113,8 +113,10 @@ int main(int argc, char* argv[])
 
     while (window.isOpen())
     {
-        for (sf::Event event; active ? window.pollEvent(event) : window.waitEvent(event);)
+        while (const auto maybeEvent = active ? window.pollEvent() : window.waitEvent())
         {
+            const auto& event = *maybeEvent;
+
             switch (event.getType())
             {
                 case sf::Event::Type::Closed:

examples/island/Island.cpp

@@ -179,8 +179,10 @@ int main()
     while (window.isOpen())
     {
         // Handle events
-        for (sf::Event event; window.pollEvent(event);)
+        while (const auto maybeEvent = window.pollEvent())
         {
+            const auto& event = *maybeEvent;
+
             // Window closed or escape key pressed: exit
             if (event.is<sf::Event::Closed>() ||
                 (event.is<sf::Event::KeyPressed>() && event.get<sf::Event::KeyPressed>().code == sf::Keyboard::Escape))

examples/joystick/Joystick.cpp

@@ -159,8 +159,10 @@ int main()
     while (window.isOpen())
     {
         // Handle events
-        for (sf::Event event; window.pollEvent(event);)
+        while (const auto maybeEvent = window.pollEvent())
         {
+            const auto& event = *maybeEvent;
+
             // Window closed or escape key pressed: exit
             if (event.is<sf::Event::Closed>() ||
                 (event.is<sf::Event::KeyPressed>() && event.get<sf::Event::KeyPressed>().code == sf::Keyboard::Escape))

examples/opengl/OpenGL.cpp

@@ -204,8 +204,10 @@ int main()
         while (window.isOpen())
         {
             // Process events
-            for (sf::Event event; window.pollEvent(event);)
+            while (const auto maybeEvent = window.pollEvent())
             {
+                const auto& event = *maybeEvent;
+
                 // Close window: exit
                 if (event.is<sf::Event::Closed>())
                 {

examples/shader/Shader.cpp

@@ -390,8 +390,10 @@ int main()
     while (window.isOpen())
     {
         // Process events
-        for (sf::Event event; window.pollEvent(event);)
+        while (const auto maybeEvent = window.pollEvent())
         {
+            const auto& event = *maybeEvent;
+
             // Close window: exit
             if (event.is<sf::Event::Closed>())
                 window.close();

examples/tennis/Tennis.cpp

@@ -111,8 +111,10 @@ int main()
     while (window.isOpen())
     {
         // Handle events
-        for (sf::Event event; window.pollEvent(event);)
+        while (const auto maybeEvent = window.pollEvent())
         {
+            const auto& event = *maybeEvent;
+
             // Window closed or escape key pressed: exit
             if (event.is<sf::Event::Closed>() ||
                 (event.is<sf::Event::KeyPressed>() && event.get<sf::Event::KeyPressed>().code == sf::Keyboard::Escape))

examples/vulkan/Vulkan.cpp

@@ -2541,8 +2541,10 @@ public:
         while (window.isOpen())
         {
             // Process events
-            for (sf::Event event; window.pollEvent(event);)
+            while (const auto maybeEvent = window.pollEvent())
             {
+                const auto& event = *maybeEvent;
+
                 // Close window: exit
                 if (event.is<sf::Event::Closed>())
                     window.close();

examples/window/Window.cpp

@@ -141,8 +141,10 @@ int main()
     while (window.isOpen())
     {
         // Process events
-        for (sf::Event event; window.pollEvent(event);)
+        while (const auto maybeEvent = window.pollEvent())
         {
+            const auto& event = *maybeEvent;
+
             // Close window: exit
             if (event.is<sf::Event::Closed>())
                 window.close();

include/SFML/Graphics/RenderWindow.hpp

@@ -214,9 +214,11 @@ private:
 /// // The main loop - ends as soon as the window is closed
 /// while (window.isOpen())
 /// {
-///    // Event processing
+///     // Event processing
-///    for (sf::Event event; window.pollEvent(event);)
+///     while (const auto maybeEvent = window.pollEvent())
-///    {
+///     {
+///        const auto& event = *maybeEvent;
+///
 ///        // Request for closing the window
 ///        if (event.is<sf::Event::Closed>())
 ///            window.close();

include/SFML/Window/Clipboard.hpp

@@ -91,8 +91,10 @@ SFML_WINDOW_API void setString(const String& text);
 /// sf::String string = sf::Clipboard::getString();
 ///
 /// // or use it in the event loop
-/// for (sf::Event event; window.pollEvent(event);)
+/// while (const auto maybeEvent = window.pollEvent())
 /// {
+///     const auto& event = *maybeEvent;
+///
 ///     if(event.is<sf::Event::Closed>())
 ///         window.close();
 ///     if(event.is<sf::Event::KeyPressed>())

include/SFML/Window/Event.hpp

@@ -441,8 +441,10 @@ const T* Event::getIf() const
 /// statement to process events.
 ///
 /// \code
-/// for (sf::Event event; window.pollEvent(event);)
+/// while (const auto maybeEvent = window.pollEvent())
 /// {
+///     const auto& event = *maybeEvent;
+///
 ///     switch (event.getType())
 ///     {
 ///         // Request for closing the window
@@ -475,8 +477,10 @@ const T* Event::getIf() const
 /// process events in a series of if/else if blocks.
 ///
 /// \code
-/// for (sf::Event event; window.pollEvent(event);)
+/// while (const auto maybeEvent = window.pollEvent())
 /// {
+///     const auto& event = *maybeEvent;
+///
 ///     // Request for closing the window
 ///     if (event.is<sf::Event::Closed>())
 ///         window.close();

include/SFML/Window/Window.hpp

@@ -321,8 +321,10 @@ private:
 /// while (window.isOpen())
 /// {
 ///    // Event processing
-///    for (sf::Event event; window.pollEvent(event);)
+///    while (const auto maybeEvent = window.pollEvent())
 ///    {
+///        const auto& event = *maybeEvent;
+///
 ///        // Request for closing the window
 ///        if (event.is<sf::Event::Closed>())
 ///            window.close();

include/SFML/Window/WindowBase.hpp

@@ -167,7 +167,7 @@ public:
     /// thus you should always call this function in a loop
     /// to make sure that you process every pending event.
     /// \code
-    /// for (sf::Event event; window.pollEvent(event);)
+    /// while (const auto maybeEvent = window.pollEvent())
     /// {
     ///    // process event...
     /// }
@@ -180,7 +180,7 @@ public:
     /// \see waitEvent
     ///
     ////////////////////////////////////////////////////////////
-    [[nodiscard]] bool pollEvent(Event& event);
+    [[nodiscard]] std::optional<Event> pollEvent();
 
     ////////////////////////////////////////////////////////////
     /// \brief Wait for an event and return it
@@ -193,8 +193,7 @@ public:
     /// is dedicated to events handling: you want to make this thread
     /// sleep as long as no new event is received.
     /// \code
-    /// sf::Event event;
+    /// if (window.waitEvent())
-    /// if (window.waitEvent(event))
     /// {
     ///    // process event...
     /// }
@@ -207,7 +206,7 @@ public:
     /// \see pollEvent
     ///
     ////////////////////////////////////////////////////////////
-    [[nodiscard]] bool waitEvent(Event& event);
+    [[nodiscard]] std::optional<Event> waitEvent();
 
     ////////////////////////////////////////////////////////////
     /// \brief Get the position of the window
@@ -532,8 +531,10 @@ private:
 /// while (window.isOpen())
 /// {
 ///    // Event processing
-///    for (sf::Event event; window.pollEvent(event);)
+///    while (const auto maybeEvent = window.pollEvent())
 ///    {
+///        const auto& event = *maybeEvent;
+///
 ///        // Request for closing the window
 ///        if (event.is<sf::Event::Closed>())
 ///            window.close();

src/SFML/Window/WindowBase.cpp

@@ -157,36 +157,30 @@ bool WindowBase::isOpen() const
 
 
 ////////////////////////////////////////////////////////////
-bool WindowBase::pollEvent(Event& event)
+std::optional<Event> WindowBase::pollEvent()
 {
     if (!m_impl)
-        return false;
+        return std::nullopt;
 
-    if (const auto maybeEvent = m_impl->popEvent(false))
+    const auto event = m_impl->popEvent(false);
-    {
+    if (event)
-        filterEvent(*maybeEvent);
+        filterEvent(*event);
-        event = *maybeEvent;
-        return true;
-    }
 
-    return false;
+    return event;
 }
 
 
 ////////////////////////////////////////////////////////////
-bool WindowBase::waitEvent(Event& event)
+std::optional<Event> WindowBase::waitEvent()
 {
     if (!m_impl)
-        return false;
+        return std::nullopt;
 
-    if (const auto maybeEvent = m_impl->popEvent(true))
+    const auto event = m_impl->popEvent(true);
-    {
+    if (event)
-        filterEvent(*maybeEvent);
+        filterEvent(*event);
-        event = *maybeEvent;
-        return true;
-    }
 
-    return false;
+    return event;
 }
 
 

test/Window/WindowBase.test.cpp

@@ -81,15 +81,13 @@ TEST_CASE("[Window] sf::WindowBase", runDisplayTests())
     SECTION("pollEvent()")
     {
         sf::WindowBase windowBase;
-        sf::Event      event;
+        CHECK(!windowBase.pollEvent());
-        CHECK(!windowBase.pollEvent(event));
     }
 
     SECTION("waitEvent()")
     {
         sf::WindowBase windowBase;
-        sf::Event      event;
+        CHECK(!windowBase.waitEvent());
-        CHECK(!windowBase.waitEvent(event));
     }
 
     SECTION("Set/get position")

tools/xcode/templates/SFML/SFML App.xctemplate/main.cpp

@@ -65,8 +65,10 @@ int main()
     while (window.isOpen())
     {
         // Process events
-        for (sf::Event event; window.pollEvent(event);)
+        while (const auto maybeEvent = window.pollEvent())
         {
+            const auto& event = *maybeEvent;
+
             // Close window: exit
             if (event.is<sf::Event::Closed>())
             {

tools/xcode/templates/SFML/SFML CLT.xctemplate/main.cpp

@@ -63,8 +63,10 @@ int main()
     while (window.isOpen())
     {
         // Process events
-        for (sf::Event event; window.pollEvent(event);)
+        while (const auto maybeEvent = window.pollEvent())
         {
+            const auto& event = *maybeEvent;
+
             // Close window: exit
             if (event.is<sf::Event::Closed>())
             {