fix(windows): Add dynamic cursor fix (mousekeys) for KVM switches or when stream doesn't detect a mouse.

Author: tstokes22

src/main.cpp

@@ -22,6 +22,16 @@
 #include "upnp.h"
 #include "video.h"
 
+#ifdef _WIN32
+  #define WIN32_LEAN_AND_MEAN
+  #include "platform/windows/misc.h"
+
+// clang-format off
+  #include <Windows.h>  // must come before dbt.h
+  #include <Dbt.h>
+// clang-format on
+#endif
+
 extern "C" {
 #include "rswrapper.h"
 }
@@ -74,6 +84,17 @@ LRESULT CALLBACK SessionMonitorWindowProc(HWND hwnd, UINT uMsg, WPARAM wParam, L
         lifetime::exit_sunshine(0, false);
         return 0;
       }
+    case WM_DEVICECHANGE:
+      {
+        // Check if streaming
+        if (platf::is_streaming) {
+          // Check if devices change
+          if (wParam == DBT_DEVNODES_CHANGED) {
+            platf::check_and_force_cursor_visibility();
+          }
+        }
+        return 0;
+      }
     default:
       return DefWindowProc(hwnd, uMsg, wParam, lParam);
   }

src/platform/windows/misc.cpp

@@ -96,6 +96,9 @@ namespace bp = boost::process;
 using namespace std::literals;
 
 namespace platf {
+  void check_and_force_cursor_visibility();
+  bool is_streaming = false;
+
   using adapteraddrs_t = util::c_ptr<IP_ADAPTER_ADDRESSES>;
 
   bool enabled_mouse_keys = false;
@@ -1133,33 +1136,10 @@ namespace platf {
         }
       }
     }
-
-    // If there is no mouse connected, enable Mouse Keys to force the cursor to appear
-    if (!GetSystemMetrics(SM_MOUSEPRESENT)) {
-      BOOST_LOG(info) << "A mouse was not detected. Sunshine will enable Mouse Keys while streaming to force the mouse cursor to appear.";
-
-      // Get the current state of Mouse Keys so we can restore it when streaming is over
-      previous_mouse_keys_state.cbSize = sizeof(previous_mouse_keys_state);
-      if (SystemParametersInfoW(SPI_GETMOUSEKEYS, 0, &previous_mouse_keys_state, 0)) {
-        MOUSEKEYS new_mouse_keys_state = {};
-
-        // Enable Mouse Keys
-        new_mouse_keys_state.cbSize = sizeof(new_mouse_keys_state);
-        new_mouse_keys_state.dwFlags = MKF_MOUSEKEYSON | MKF_AVAILABLE;
-        new_mouse_keys_state.iMaxSpeed = 10;
-        new_mouse_keys_state.iTimeToMaxSpeed = 1000;
-        if (SystemParametersInfoW(SPI_SETMOUSEKEYS, 0, &new_mouse_keys_state, 0)) {
-          // Remember to restore the previous settings when we stop streaming
-          enabled_mouse_keys = true;
-        } else {
-          auto winerr = GetLastError();
-          BOOST_LOG(warning) << "Unable to enable Mouse Keys: "sv << winerr;
-        }
-      } else {
-        auto winerr = GetLastError();
-        BOOST_LOG(warning) << "Unable to get current state of Mouse Keys: "sv << winerr;
-      }
-    }
+    // Ensure the cursor is visible at stream startup
+    check_and_force_cursor_visibility();
+    // Started streaming
+    is_streaming = true;
   }
 
   void streaming_will_stop() {
@@ -1175,6 +1155,8 @@ namespace platf {
     } else {
       timeEndPeriod(1);
     }
+    // Update is_streaming to not run cursor visibility while not streaming
+    is_streaming = false;
 
     // Disable MMCSS scheduling for DWM
     DwmEnableMMCSS(false);
@@ -1798,4 +1780,33 @@ namespace platf {
   std::unique_ptr<high_precision_timer> create_high_precision_timer() {
     return std::make_unique<win32_high_precision_timer>();
   }
+
+  void check_and_force_cursor_visibility() {
+    if (!GetSystemMetrics(SM_MOUSEPRESENT)) {
+      BOOST_LOG(info) << "A mouse was not detected. Sunshine will enable Mouse Keys while streaming to force the mouse cursor to appear.";
+
+      // Get the current state of Mouse Keys so we can restore it when streaming is over
+      previous_mouse_keys_state.cbSize = sizeof(previous_mouse_keys_state);
+      if (SystemParametersInfoW(SPI_GETMOUSEKEYS, 0, &previous_mouse_keys_state, 0)) {
+        MOUSEKEYS new_mouse_keys_state = {};
+
+        // Enable Mouse Keys
+        new_mouse_keys_state.cbSize = sizeof(new_mouse_keys_state);
+        new_mouse_keys_state.dwFlags = MKF_MOUSEKEYSON | MKF_AVAILABLE;
+        new_mouse_keys_state.iMaxSpeed = 10;
+        new_mouse_keys_state.iTimeToMaxSpeed = 1000;
+        if (SystemParametersInfoW(SPI_SETMOUSEKEYS, 0, &new_mouse_keys_state, 0)) {
+          // Remember to restore the previous settings when we stop streaming
+          enabled_mouse_keys = true;
+        } else {
+          auto winerr = GetLastError();
+          BOOST_LOG(warning) << "Unable to enable Mouse Keys: "sv << winerr;
+        }
+      } else {
+        auto winerr = GetLastError();
+        BOOST_LOG(warning) << "Unable to get current state of Mouse Keys: "sv << winerr;
+      }
+    }
+  }
+
 }  // namespace platf

src/platform/windows/misc.h

@@ -33,4 +33,14 @@ namespace platf {
    * @return The converted UTF-8 string.
    */
   std::string to_utf8(const std::wstring &string);
+
+  /**
+   * @brief Checks if a mouse is physically present and, if not, toggles Mouse Keys
+   * to force the software cursor to become visible.
+   * @details This is used as a workaround for KVM switches that do not send
+   * standard device removal messages, which can cause the cursor to disappear.
+   */
+  void check_and_force_cursor_visibility();
+
+  extern bool is_streaming;
 }  // namespace platf