Merge pull request #7693 from jordan-woyak/hotplug-callback-fix

ControllerInterface: Hotplug callback fixes.

Source/Core/InputCommon/ControllerInterface/ControllerInterface.cpp

@@ -249,10 +249,20 @@ void ControllerInterface::UpdateInput()
 
 // Register a callback to be called when a device is added or removed (as from the input backends'
 // hotplug thread), or when devices are refreshed
-void ControllerInterface::RegisterDevicesChangedCallback(std::function<void()> callback)
+// Returns a handle for later removing the callback.
+ControllerInterface::HotplugCallbackHandle
+ControllerInterface::RegisterDevicesChangedCallback(std::function<void()> callback)
 {
   std::lock_guard<std::mutex> lk(m_callbacks_mutex);
   m_devices_changed_callbacks.emplace_back(std::move(callback));
+  return std::prev(m_devices_changed_callbacks.end());
+}
+
+// Unregister a device callback.
+void ControllerInterface::UnregisterDevicesChangedCallback(const HotplugCallbackHandle& handle)
+{
+  std::lock_guard<std::mutex> lk(m_callbacks_mutex);
+  m_devices_changed_callbacks.erase(handle);
 }
 
 // Invoke all callbacks that were registered

Source/Core/InputCommon/ControllerInterface/ControllerInterface.h

@@ -6,9 +6,9 @@
 
 #include <atomic>
 #include <functional>
+#include <list>
 #include <memory>
 #include <mutex>
-#include <vector>
 
 #include "Common/WindowSystemInfo.h"
 #include "InputCommon/ControllerInterface/Device.h"
@@ -40,6 +40,8 @@
 class ControllerInterface : public ciface::Core::DeviceContainer
 {
 public:
+  using HotplugCallbackHandle = std::list<std::function<void()>>::iterator;
+
   ControllerInterface() : m_is_init(false) {}
   void Initialize(const WindowSystemInfo& wsi);
   void ChangeWindow(void* hwnd);
@@ -50,11 +52,12 @@ public:
   bool IsInit() const { return m_is_init; }
   void UpdateInput();
 
-  void RegisterDevicesChangedCallback(std::function<void(void)> callback);
+  HotplugCallbackHandle RegisterDevicesChangedCallback(std::function<void(void)> callback);
+  void UnregisterDevicesChangedCallback(const HotplugCallbackHandle& handle);
   void InvokeDevicesChangedCallbacks() const;
 
 private:
-  std::vector<std::function<void()>> m_devices_changed_callbacks;
+  std::list<std::function<void()>> m_devices_changed_callbacks;
   mutable std::mutex m_callbacks_mutex;
   std::atomic<bool> m_is_init;
   std::atomic<bool> m_is_populating_devices{false};

Source/Core/InputCommon/InputConfig.cpp

@@ -147,6 +147,21 @@ std::size_t InputConfig::GetControllerCount() const
   return m_controllers.size();
 }
 
+void InputConfig::RegisterHotplugCallback()
+{
+  // Update control references on all controllers
+  // as configured devices may have been added or removed.
+  m_hotplug_callback_handle = g_controller_interface.RegisterDevicesChangedCallback([this] {
+    for (auto& controller : m_controllers)
+      controller->UpdateReferences(g_controller_interface);
+  });
+}
+
+void InputConfig::UnregisterHotplugCallback()
+{
+  g_controller_interface.UnregisterDevicesChangedCallback(m_hotplug_callback_handle);
+}
+
 bool InputConfig::IsControllerControlledByGamepadDevice(int index) const
 {
   if (static_cast<size_t>(index) >= m_controllers.size())

Source/Core/InputCommon/InputConfig.h

@@ -9,6 +9,8 @@
 #include <utility>
 #include <vector>
 
+#include "InputCommon/ControllerInterface/ControllerInterface.h"
+
 namespace ControllerEmu
 {
 class EmulatedController;
@@ -40,7 +42,12 @@ public:
   std::string GetProfileName() const { return m_profile_name; }
   std::size_t GetControllerCount() const;
 
+  // These should be used after creating all controllers and before clearing them, respectively.
+  void RegisterHotplugCallback();
+  void UnregisterHotplugCallback();
+
 private:
+  ControllerInterface::HotplugCallbackHandle m_hotplug_callback_handle;
   std::vector<std::unique_ptr<ControllerEmu::EmulatedController>> m_controllers;
   const std::string m_ini_name;
   const std::string m_gui_name;