Add Windows Joystick hotplug support

A hidden window will listen for device attached and removed signals from Windows. In case such a event occurs, all devices are enumerated again.
ref T587

src/blackinput/win/joystickwindows.cpp

@@ -9,6 +9,7 @@
 #include "joystickwindows.h"
 #include "blackmisc/logmessage.h"
 #include "comdef.h"
+#include "Dbt.h"
 
 // Qt5 defines UNICODE, hence we can expect an wchar_t strings.
 // If it fails to compile, because of char/wchar_t errors, you are most likely
@@ -101,40 +102,24 @@ namespace BlackInput
 
     HRESULT CJoystickDevice::pollDeviceState()
     {
+        m_directInputDevice->Poll();
+
         DIJOYSTATE2 state;
-        HRESULT hr = S_OK;
+        HRESULT hr = m_directInputDevice->GetDeviceState(sizeof(DIJOYSTATE2), &state);
-
+        if (hr == DIERR_INPUTLOST || hr == DIERR_NOTACQUIRED)
-        if (FAILED(hr = m_directInputDevice->Poll()))
         {
-            if (hr == DIERR_INPUTLOST || hr == DIERR_NOTACQUIRED)
+            m_directInputDevice->Acquire();
-            {
+            m_directInputDevice->Poll();
-                m_directInputDevice->Acquire();
+            hr = m_directInputDevice->GetDeviceState(sizeof(DIJOYSTATE2), &state);
-                if (FAILED(hr = m_directInputDevice->Poll()))
-                {
-                    if (m_lastHRError == hr) { return hr; } // avoid flooding with messages
-                    m_lastHRError = hr;
-                    CLogMessage(this).warning(u"DirectInput error code (POLL input lost/notacquired): %1 %2") << hr << hrString(hr);
-                    return hr;
-                }
-            }
         }
 
-        if (FAILED(hr = m_directInputDevice->GetDeviceState(sizeof(DIJOYSTATE2), &state)))
-        {
-            if (hr == DIERR_INPUTLOST || hr == DIERR_NOTACQUIRED)
-            {
-                m_directInputDevice->Acquire();
-                if (FAILED(hr = m_directInputDevice->GetDeviceState(sizeof(DIJOYSTATE2), &state)))
-                {
-                    if (m_lastHRError == hr) { return hr; } // avoid flooding with messages
-                    m_lastHRError = hr;
-                    CLogMessage(this).warning(u"DirectInput error code (state input lost/notacquired): %1 %2") << hr << hrString(hr);
-                    return hr;
-                }
-            }
-        }
 
-        m_lastHRError = hr;
+        if (FAILED(hr))
+        {
+            CLogMessage(this).warning(u"Cannot acquire and poll joystick device %1. Removing it.") << m_deviceName;
+            emit connectionLost(m_guidDevice);
+            return hr;
+        }
 
         for (const CJoystickDeviceInput &input : as_const(m_joystickDeviceInputs))
         {
@@ -199,6 +184,7 @@ namespace BlackInput
             {
                 this->initDirectInput();
                 this->enumJoystickDevices();
+                this->requestDeviceNotification();
             }
         }
         else
@@ -218,6 +204,7 @@ namespace BlackInput
         m_joystickDevices.clear();
         m_directInput.reset();
         if (m_coInitializeSucceeded) { CoUninitialize(); }
+        if (hDevNotify) { UnregisterDeviceNotification(hDevNotify); }
         destroyHelperWindow();
     }
 
@@ -273,24 +260,22 @@ namespace BlackInput
 
     int CJoystickWindows::createHelperWindow()
     {
-        HINSTANCE hInstance = GetModuleHandle(nullptr);
-        WNDCLASS wce;
-
         // Make sure window isn't created twice
         if (helperWindow != nullptr)
         {
             return 0;
         }
 
-        // Create the class
+        HINSTANCE hInstance = GetModuleHandle(nullptr);
-        ZeroMemory(&wce, sizeof(WNDCLASS));
+        WNDCLASSEX wce;
-        wce.lpfnWndProc = DefWindowProc;
+        ZeroMemory(&wce, sizeof(wce));
+        wce.cbSize = sizeof(wce);
+        wce.lpfnWndProc = windowProc;
         wce.lpszClassName = (LPCWSTR) helperWindowClassName;
         wce.hInstance = hInstance;
 
         /* Register the class. */
-        helperWindowClass = RegisterClass(&wce);
+        if (! RegisterClassEx(&wce))
-        if (helperWindowClass == 0 && GetLastError() != ERROR_CLASS_ALREADY_EXISTS)
         {
             return -1;
         }
@@ -308,9 +293,20 @@ namespace BlackInput
             return -1;
         }
 
+        SetProp(helperWindow, L"CJoystickWindows", this);
+
         return 0;
     }
 
+    void CJoystickWindows::requestDeviceNotification()
+    {
+        DEV_BROADCAST_DEVICEINTERFACE notificationFilter;
+        ZeroMemory(&notificationFilter, sizeof(notificationFilter));
+        notificationFilter.dbcc_size = sizeof(DEV_BROADCAST_DEVICEINTERFACE);
+        notificationFilter.dbcc_devicetype = DBT_DEVTYP_DEVICEINTERFACE;
+        hDevNotify = RegisterDeviceNotification(helperWindow, &notificationFilter, DEVICE_NOTIFY_WINDOW_HANDLE | DEVICE_NOTIFY_ALL_INTERFACE_CLASSES);
+    }
+
     void CJoystickWindows::destroyHelperWindow()
     {
         HINSTANCE hInstance = GetModuleHandle(nullptr);
@@ -321,7 +317,6 @@ namespace BlackInput
         helperWindow = nullptr;
 
         UnregisterClass(helperWindowClassName, hInstance);
-        helperWindowClass = 0;
     }
 
     void CJoystickWindows::addJoystickDevice(const DIDEVICEINSTANCE *pdidInstance)
@@ -331,6 +326,7 @@ namespace BlackInput
         if (success)
         {
             connect(device, &CJoystickDevice::buttonChanged, this, &CJoystickWindows::joystickButtonChanged);
+            connect(device, &CJoystickDevice::connectionLost, this, &CJoystickWindows::removeJoystickDevice);
             m_joystickDevices.push_back(device);
         }
         else
@@ -339,6 +335,19 @@ namespace BlackInput
         }
     }
 
+    bool CJoystickWindows::isJoystickAlreadyAdded(const DIDEVICEINSTANCE *pdidInstance) const
+    {
+        for (const CJoystickDevice *device : m_joystickDevices)
+        {
+            if (IsEqualGUID(device->getDeviceGuid(), pdidInstance->guidInstance))
+            {
+                return true;
+            }
+        }
+
+        return false;
+    }
+
     void CJoystickWindows::joystickButtonChanged(const CJoystickButton &joystickButton, bool isPressed)
     {
         CHotkeyCombination oldCombination(m_buttonCombination);
@@ -351,6 +360,47 @@ namespace BlackInput
         }
     }
 
+    void CJoystickWindows::removeJoystickDevice(const GUID &guid)
+    {
+        for (auto it = m_joystickDevices.begin(); it != m_joystickDevices.end(); ++it)
+        {
+            CJoystickDevice *device = *it;
+            if (IsEqualGUID(guid, device->getDeviceGuid()))
+            {
+                device->deleteLater();
+                m_joystickDevices.erase(it);
+                break;
+            }
+        }
+    }
+
+    // Window callback function (handles window messages)
+    //
+    LRESULT CALLBACK CJoystickWindows::windowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam)
+    {
+        CJoystickWindows* joystickWindows = static_cast<CJoystickWindows*>(GetProp(hWnd, L"CJoystickWindows"));
+
+        if (joystickWindows)
+        {
+            switch (uMsg)
+            {
+            case WM_DEVICECHANGE:
+            {
+                if (wParam == DBT_DEVICEARRIVAL)
+                {
+                    DEV_BROADCAST_HDR* dbh = (DEV_BROADCAST_HDR*) lParam;
+                    if (dbh && dbh->dbch_devicetype == DBT_DEVTYP_DEVICEINTERFACE)
+                    {
+                        joystickWindows->enumJoystickDevices();
+                    }
+                }
+            }
+            }
+        }
+
+        return DefWindowProc(hWnd, uMsg, wParam, lParam);
+    }
+
     BOOL CALLBACK CJoystickWindows::enumJoysticksCallback(const DIDEVICEINSTANCE *pdidInstance, VOID *pContext)
     {
         CJoystickWindows *obj = static_cast<CJoystickWindows *>(pContext);
@@ -358,9 +408,12 @@ namespace BlackInput
         /* ignore XInput devices here, keep going. */
         //if (isXInputDevice( &pdidInstance->guidProduct )) return DIENUM_CONTINUE;
 
-        obj->addJoystickDevice(pdidInstance);
+        if (! obj->isJoystickAlreadyAdded(pdidInstance))
-        CLogMessage(static_cast<CJoystickWindows *>(nullptr)).debug() << "Found joystick device" << QString::fromWCharArray(pdidInstance->tszInstanceName);
+        {
-        return true;
+            obj->addJoystickDevice(pdidInstance);
+            CLogMessage(static_cast<CJoystickWindows *>(nullptr)).debug() << "Found joystick device" << QString::fromWCharArray(pdidInstance->tszInstanceName);
+        }
+        return DIENUM_CONTINUE;
     }
 
     bool operator == (const CJoystickDevice &lhs, const CJoystickDevice &rhs)

src/blackinput/win/joystickwindows.h

@@ -51,10 +51,16 @@ namespace BlackInput
         //! Get all available device buttons
         BlackMisc::Input::CJoystickButtonList getDeviceButtons() const;
 
+        //! Get device GUID
+        GUID getDeviceGuid() const { return m_guidDevice; }
+
     signals:
         //! Joystick button changed
         void buttonChanged(const BlackMisc::Input::CJoystickButton &joystickButton, bool isPressed);
 
+        //! Connection to joystick lost. Probably unplugged.
+        void connectionLost(const GUID &guid);
+
     protected:
         //! Timer based updates
         virtual void timerEvent(QTimerEvent *event) override;
@@ -85,7 +91,6 @@ namespace BlackInput
         //! Joystick button enumeration callback
         static BOOL CALLBACK enumObjectsCallback(const DIDEVICEOBJECTINSTANCE *dev, LPVOID pvRef);
 
-        HRESULT m_lastHRError = S_OK;
         GUID m_guidDevice;     //!< Device GUID
         GUID m_guidProduct;    //!< Product GUID
         QString m_deviceName;  //!< Device name
@@ -131,19 +136,31 @@ namespace BlackInput
         //! Creates a hidden DI helper window
         int createHelperWindow();
 
+        //! Request USB device notifications sent to our helper window.
+        //! This is required for joystick hotplug support
+        void requestDeviceNotification();
+
         //! Destroys a hidden DI helper window
         void destroyHelperWindow();
 
         //! Add new joystick device
         void addJoystickDevice(const DIDEVICEINSTANCE *pdidInstance);
 
+        //! Remove joystick device
+        void removeJoystickDevice(const GUID &guid);
+
+        //! Is joystick instance already added?
+        bool isJoystickAlreadyAdded(const DIDEVICEINSTANCE *pdidInstance) const;
+
         void joystickButtonChanged(const BlackMisc::Input::CJoystickButton &joystickButton, bool isPressed);
 
+        static LRESULT CALLBACK windowProc(HWND hWnd, UINT uMsg, WPARAM wParam, LPARAM lParam);
+
         //! Joystick enumeration callback
         static BOOL CALLBACK enumJoysticksCallback(const DIDEVICEINSTANCE *pdidInstance, VOID *pContext);
 
-        ATOM helperWindowClass = 0;
         HWND helperWindow = nullptr;
+        HDEVNOTIFY hDevNotify = nullptr;
 
         const TCHAR *helperWindowClassName = TEXT("HelperWindow");
         const TCHAR *helperWindowName = TEXT("JoystickCatcherWindow");