implemented keypad

Peripherals.hpp

@@ -8,11 +8,12 @@ namespace chocochip8 {
   constexpr size_t gcHeight = 64;
   using Scanline = std::bitset<gcWidth>;
 
-  enum class Key {
+  enum {
     KEY_0, KEY_1, KEY_2, KEY_3,
     KEY_4, KEY_5, KEY_6, KEY_7,
     KEY_8, KEY_9, KEY_A, KEY_B,
-    KEY_C, KEY_D, KEY_E, KEY_F
+    KEY_C, KEY_D, KEY_E, KEY_F,
+    KEY_COUNT
   };
 
   class Display {
@@ -32,7 +33,7 @@ namespace chocochip8 {
   class Keypad {
   public:
     virtual ~Keypad() = default;
-    virtual bool isKeyPressed(Key key) = 0;
+    virtual bool isKeyPressed(int key) const = 0;
   };
 
   class CountdownTimer {