1 files changed, 46 insertions, 32 deletions

diff --git a/common/utility-rawinput.hpp b/common/utility-rawinput.hpp
index 3c44068..c43084b 100644
--- a/common/utility-rawinput.hpp
+++ b/common/utility-rawinput.hpp
@@ -2,7 +2,6 @@
 
 #pragma comment(lib, "cfgmgr32.lib")
 
-#include <iostream>
 #include <string>
 #include <system_error>
 #include <vector>
@@ -12,9 +11,40 @@
 #include <initguid.h> // needed for devpkey.h to parse properly
 #include <devpkey.h>
 
-// returns device handles corresponding to a "device id"
-// https://docs.microsoft.com/en-us/windows-hardware/drivers/install/device-ids
-std::vector<HANDLE> rawinput_handles_from_dev_id(const std::wstring& dev_id, DWORD input_type = RIM_TYPEMOUSE) {
+std::wstring dev_prop_wstr_from_interface(const WCHAR* interface_name, const DEVPROPKEY* key) {
+    ULONG size = 0;
+    DEVPROPTYPE type;
+    CONFIGRET cm_res;
+
+    cm_res = CM_Get_Device_Interface_PropertyW(interface_name, key,
+        &type, NULL, &size, 0);
+
+    if (cm_res != CR_BUFFER_SMALL && cm_res != CR_SUCCESS) {
+        throw std::runtime_error("CM_Get_Device_Interface_PropertyW failed (" +
+            std::to_string(cm_res) + ')');
+    }
+
+    std::wstring prop((size + 1) / 2, L'\0');
+
+    cm_res = CM_Get_Device_Interface_PropertyW(interface_name, key,
+        &type, reinterpret_cast<PBYTE>(&prop[0]), &size, 0);
+
+    if (cm_res != CR_SUCCESS) {
+        throw std::runtime_error("CM_Get_Device_Interface_PropertyW failed (" +
+            std::to_string(cm_res) + ')');
+    }
+
+    return prop;
+}
+
+std::wstring dev_id_from_interface(const WCHAR* interface_name) {
+    auto id = dev_prop_wstr_from_interface(interface_name, &DEVPKEY_Device_InstanceId);
+    id.resize(id.find_last_of('\\'));
+    return id;
+}
+
+template <typename Func>
+void rawinput_foreach_with_interface(Func fn, DWORD input_type = RIM_TYPEMOUSE) {
     const UINT RI_ERROR = -1;
 
     UINT num_devs = 0;
@@ -28,8 +58,6 @@ std::vector<HANDLE> rawinput_handles_from_dev_id(const std::wstring& dev_id, DWO
     if (GetRawInputDeviceList(&devs[0], &num_devs, sizeof(RAWINPUTDEVICELIST)) == RI_ERROR) {
         throw std::system_error(GetLastError(), std::system_category(), "GetRawInputDeviceList failed");
     }
-    
-    std::vector<HANDLE> handles;
 
     for (auto&& dev : devs) {
         if (dev.dwType != input_type) continue;
@@ -41,34 +69,20 @@ std::vector<HANDLE> rawinput_handles_from_dev_id(const std::wstring& dev_id, DWO
             throw std::system_error(GetLastError(), std::system_category(), "GetRawInputDeviceInfoW failed");
         }
 
-        ULONG id_size = 0;
-        DEVPROPTYPE type;
-        CONFIGRET cm_res;
-
-        cm_res = CM_Get_Device_Interface_PropertyW(name, &DEVPKEY_Device_InstanceId,
-            &type, NULL, &id_size, 0);
-
-        if (cm_res != CR_BUFFER_SMALL && cm_res != CR_SUCCESS) {
-            throw std::runtime_error("CM_Get_Device_Interface_PropertyW failed (" +
-                std::to_string(cm_res) + ')');
-        }
-
-        std::wstring id((static_cast<size_t>(id_size) + 1) / 2, '\0');
-
-        cm_res = CM_Get_Device_Interface_PropertyW(name, &DEVPKEY_Device_InstanceId,
-            &type, reinterpret_cast<PBYTE>(&id[0]), &id_size, 0);
-
-        if (cm_res != CR_SUCCESS) {
-            throw std::runtime_error("CM_Get_Device_Interface_PropertyW failed (" +
-                std::to_string(cm_res) + ')');
-        }
+        fn(dev, name);
+    }
+}
 
-        // remove instance id
-        id.resize(id.find_last_of('\\'));
+// returns device handles corresponding to a "device id"
+// https://docs.microsoft.com/en-us/windows-hardware/drivers/install/device-ids
+std::vector<HANDLE> rawinput_handles_from_dev_id(const std::wstring& device_id, DWORD input_type = RIM_TYPEMOUSE) {
+    std::vector<HANDLE> handles;
 
-        if (id == dev_id) handles.push_back(dev.hDevice);
-    }
+    rawinput_foreach_with_interface([&](const auto& dev, const WCHAR* name) {
+        if (device_id == dev_id_from_interface(name)) {
+            handles.push_back(dev.hDevice);
+        } 
+    }, input_type);
 
     return handles;
 }
-