feat: Add mouse grab state change event and related handling in input services

src/events/event_types.hpp

@@ -32,6 +32,7 @@ enum class EventType {
     MouseButtonPressed,
     MouseButtonReleased,
     MouseWheel,
+    MouseGrabChanged,
     TextInput,
 
     // Rendering events
@@ -147,6 +148,13 @@ struct MouseWheelEvent {
     bool flipped;
 };
 
+/**
+ * @brief Mouse grab state change event data.
+ */
+struct MouseGrabEvent {
+    bool grabbed;
+};
+
 /**
  * @brief Text input event data.
  */

src/services/impl/sdl_input_service.cpp

@@ -66,10 +66,31 @@ SdlInputService::SdlInputService(std::shared_ptr<events::IEventBus> eventBus,
         OnTextInput(e);
     });
 
+    eventBus_->Subscribe(events::EventType::WindowFocusGained, [this](const events::Event& e) {
+        OnWindowFocusGained(e);
+    });
+
+    eventBus_->Subscribe(events::EventType::WindowFocusLost, [this](const events::Event& e) {
+        OnWindowFocusLost(e);
+    });
+
+    eventBus_->Subscribe(events::EventType::MouseGrabChanged, [this](const events::Event& e) {
+        OnMouseGrabChanged(e);
+    });
+
     if (logger_) {
         logger_->Trace("SdlInputService", "SdlInputService",
                        "eventBus=" + std::string(eventBus_ ? "set" : "null"));
     }
+    if (configService_) {
+        const auto& mouseGrabConfig = configService_->GetMouseGrabConfig();
+        mouseGrabGatesLook_ = mouseGrabConfig.enabled &&
+                              (mouseGrabConfig.grabOnClick || mouseGrabConfig.startGrabbed);
+        if (logger_) {
+            logger_->Trace("SdlInputService", "SdlInputService",
+                           "mouseGrabGatesLook=" + std::string(mouseGrabGatesLook_ ? "true" : "false"));
+        }
+    }
     BuildActionKeyMapping();
     EnsureGamepadSubsystem();
 }
@@ -102,8 +123,10 @@ void SdlInputService::ProcessEvent(const SDL_Event& event) {
             // GUI input processing
             guiInputSnapshot_.mouseX = static_cast<float>(event.motion.x);
             guiInputSnapshot_.mouseY = static_cast<float>(event.motion.y);
-            guiInputSnapshot_.mouseDeltaX += static_cast<float>(event.motion.xrel);
-            guiInputSnapshot_.mouseDeltaY += static_cast<float>(event.motion.yrel);
+            if (ShouldCaptureMouseDelta()) {
+                guiInputSnapshot_.mouseDeltaX += static_cast<float>(event.motion.xrel);
+                guiInputSnapshot_.mouseDeltaY += static_cast<float>(event.motion.yrel);
+            }
             break;
 
         case SDL_EVENT_MOUSE_BUTTON_DOWN:
@@ -218,8 +241,10 @@ void SdlInputService::OnMouseMoved(const events::Event& event) {
     state_.mouseY = mouseEvent.y;
     guiInputSnapshot_.mouseX = mouseEvent.x;
     guiInputSnapshot_.mouseY = mouseEvent.y;
-    guiInputSnapshot_.mouseDeltaX += mouseEvent.deltaX;
-    guiInputSnapshot_.mouseDeltaY += mouseEvent.deltaY;
+    if (ShouldCaptureMouseDelta()) {
+        guiInputSnapshot_.mouseDeltaX += mouseEvent.deltaX;
+        guiInputSnapshot_.mouseDeltaY += mouseEvent.deltaY;
+    }
 }
 
 void SdlInputService::OnMouseButtonPressed(const events::Event& event) {
@@ -275,6 +300,37 @@ void SdlInputService::OnTextInput(const events::Event& event) {
     guiInputSnapshot_.textInput += textEvent.text;
 }
 
+void SdlInputService::OnWindowFocusGained(const events::Event& event) {
+    (void)event;
+    windowFocused_ = true;
+    if (logger_) {
+        logger_->Trace("SdlInputService", "OnWindowFocusGained", "windowFocused=true");
+    }
+}
+
+void SdlInputService::OnWindowFocusLost(const events::Event& event) {
+    (void)event;
+    windowFocused_ = false;
+    guiInputSnapshot_.mouseDeltaX = 0.0f;
+    guiInputSnapshot_.mouseDeltaY = 0.0f;
+    if (logger_) {
+        logger_->Trace("SdlInputService", "OnWindowFocusLost", "windowFocused=false");
+    }
+}
+
+void SdlInputService::OnMouseGrabChanged(const events::Event& event) {
+    const auto& grabEvent = event.GetData<events::MouseGrabEvent>();
+    mouseGrabbed_ = grabEvent.grabbed;
+    if (!mouseGrabbed_) {
+        guiInputSnapshot_.mouseDeltaX = 0.0f;
+        guiInputSnapshot_.mouseDeltaY = 0.0f;
+    }
+    if (logger_) {
+        logger_->Trace("SdlInputService", "OnMouseGrabChanged",
+                       "grabbed=" + std::string(mouseGrabbed_ ? "true" : "false"));
+    }
+}
+
 void SdlInputService::BuildActionKeyMapping() {
     actionKeyNames_.clear();
     gamepadButtonActions_.clear();
@@ -462,6 +518,16 @@ bool SdlInputService::IsActionKeyPressed(const std::string& action) const {
     return false;
 }
 
+bool SdlInputService::ShouldCaptureMouseDelta() const {
+    if (!windowFocused_) {
+        return false;
+    }
+    if (mouseGrabGatesLook_) {
+        return mouseGrabbed_;
+    }
+    return true;
+}
+
 void SdlInputService::EnsureGamepadSubsystem() {
     uint32_t initialized = SDL_WasInit(0);
     if ((initialized & SDL_INIT_GAMEPAD) != 0) {

src/services/impl/sdl_input_service.hpp

@@ -53,6 +53,9 @@ private:
     GuiInputSnapshot guiInputSnapshot_;
     IGuiScriptService* guiScriptService_ = nullptr;
     SDL_Gamepad* gamepad_ = nullptr;
+    bool windowFocused_ = true;
+    bool mouseGrabbed_ = false;
+    bool mouseGrabGatesLook_ = false;
     SDL_GamepadButton musicToggleButton_ = SDL_GAMEPAD_BUTTON_START;
     SDL_GamepadButton dpadUpButton_ = SDL_GAMEPAD_BUTTON_DPAD_UP;
     SDL_GamepadButton dpadDownButton_ = SDL_GAMEPAD_BUTTON_DPAD_DOWN;
@@ -75,6 +78,9 @@ private:
     void OnMouseButtonReleased(const events::Event& event);
     void OnMouseWheel(const events::Event& event);
     void OnTextInput(const events::Event& event);
+    void OnWindowFocusGained(const events::Event& event);
+    void OnWindowFocusLost(const events::Event& event);
+    void OnMouseGrabChanged(const events::Event& event);
     void EnsureGamepadSubsystem();
     void TryOpenGamepad();
     void CloseGamepad();
@@ -82,6 +88,7 @@ private:
     void BuildActionKeyMapping();
     void ApplyKeyMapping(SDL_Keycode key, bool isDown);
     bool IsActionKeyPressed(const std::string& action) const;
+    bool ShouldCaptureMouseDelta() const;
 
     // GUI key mapping (extracted from old Sdl3App)
     static const std::unordered_map<SDL_Keycode, std::string> kGuiKeyNames;

src/services/impl/sdl_window_service.cpp

@@ -378,6 +378,17 @@ void SdlWindowService::ApplyMouseGrab(bool grabbed) {
 
     if (success) {
         mouseGrabbed_ = grabbed;
+        if (eventBus_) {
+            eventBus_->Publish(events::Event{
+                events::EventType::MouseGrabChanged,
+                GetCurrentTime(),
+                events::MouseGrabEvent{grabbed}
+            });
+        }
+        if (logger_) {
+            logger_->Trace("SdlWindowService", "ApplyMouseGrab",
+                           "mouseGrabChanged=true, grabbed=" + std::string(grabbed ? "true" : "false"));
+        }
     } else if (logger_) {
         logger_->Trace("SdlWindowService", "ApplyMouseGrab", "grabChangeFailed=true");
     }