Backends: Win32: minor tidying up. (#5819)

backends/imgui_impl_win32.cpp

@@ -88,10 +88,10 @@ struct ImGui_ImplWin32_Data
     INT64                       Time;
     INT64                       TicksPerSecond;
     ImGuiMouseCursor            LastMouseCursor;
-    bool                        HasGamepad;
-    bool                        WantUpdateHasGamepad;
 
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
+    bool                        HasGamepad;
+    bool                        WantUpdateHasGamepad;
     HMODULE                     XInputDLL;
     PFN_XInputGetCapabilities   XInputGetCapabilities;
     PFN_XInputGetState          XInputGetState;
@@ -129,7 +129,6 @@ bool    ImGui_ImplWin32_Init(void* hwnd)
     io.BackendFlags |= ImGuiBackendFlags_HasSetMousePos;          // We can honor io.WantSetMousePos requests (optional, rarely used)
 
     bd->hWnd = (HWND)hwnd;
-    bd->WantUpdateHasGamepad = true;
     bd->TicksPerSecond = perf_frequency;
     bd->Time = perf_counter;
     bd->LastMouseCursor = ImGuiMouseCursor_COUNT;
@@ -139,6 +138,7 @@ bool    ImGui_ImplWin32_Init(void* hwnd)
 
     // Dynamically load XInput library
 #ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
+    bd->WantUpdateHasGamepad = true;
     const char* xinput_dll_names[] =
     {
         "xinput1_4.dll",   // Windows 8+
@@ -634,8 +634,10 @@ IMGUI_IMPL_API LRESULT ImGui_ImplWin32_WndProcHandler(HWND hwnd, UINT msg, WPARA
             return 1;
         return 0;
     case WM_DEVICECHANGE:
+#ifndef IMGUI_IMPL_WIN32_DISABLE_GAMEPAD
         if ((UINT)wParam == DBT_DEVNODES_CHANGED)
             bd->WantUpdateHasGamepad = true;
+#endif
         return 0;
     }
     return 0;