Slightly refactor controller code in HID

Now uses ranges where possible and a function to get the number of connected controllers has been added.

app/src/main/cpp/skyline/input/npad.cpp

@@ -69,14 +69,7 @@ namespace skyline::input {
 
         // We do this to prevent triggering the event unless there's a real change in a device's style, which would be caused if we disconnected all controllers then reconnected them
         for (auto &device : npads) {
-            bool connected{};
+            if (!ranges::any_of(controllers, [&](auto &controller) { return controller.device == &device; }))
-            for (const auto &controller : controllers) {
-                if (controller.device == &device) {
-                    connected = true;
-                    break;
-                }
-            }
-            if (!connected)
                 device.Disconnect();
         }
     }

app/src/main/cpp/skyline/input/npad.h

@@ -3,6 +3,7 @@
 
 #pragma once
 
+#include <range/v3/algorithm.hpp>
 #include "npad_device.h"
 
 namespace skyline::input {
@@ -69,6 +70,16 @@ namespace skyline::input {
             return npads.operator[](Translate(id));
         }
 
+        /**
+         * @brief Counts the number of currently connected controllers
+         */
+        size_t GetConnectedControllerCount() {
+             std::scoped_lock lock{mutex};
+             return static_cast<size_t>(ranges::count_if(controllers, [](const auto &controller) {
+                 return controller.device != nullptr && controller.device->connectionState.connected;
+             }));
+         }
+
         /**
          * @brief Deduces all the mappings from guest controllers -> players based on the configuration supplied by HID services and available controllers
          * @note If any class members were edited, the mutex shouldn't be released till this is called