change: releasing a key reorders the keycodes list instead

src/HID-APIs/DefaultKeyboardAPI.hpp

@@ -51,39 +51,57 @@ size_t DefaultKeyboardAPI::set(KeyboardKeycode k, bool s)
 			for (uint8_t i = 0; i < keycodesSize; i++)
 			{
 				auto key = _keyReport.keycodes[i];
-				// if target key is found
-				if (key == uint8_t(k)) {
-					// do nothing and exit
-					return 1;
-				}
-			}
-			// iterate through the keycodes again, this only happens if no existing
-			// keycodes matches k
-			for (uint8_t i = 0; i < keycodesSize; i++)
-			{
-				auto key = _keyReport.keycodes[i];
-				// if first instance of empty slot is found
-				if (key == KEY_RESERVED) {
-					// change empty slot to k and exit
+
+				// write to keycodes on first instance of k or null in keycodes
+				if (key == uint8_t(k) || key == KEY_RESERVED) {
 					_keyReport.keycodes[i] = k;
 					return 1;
 				}
 			}
 		} else { // we are removing k from keycodes
+			// this will replace the first instance of k with the last entry in the pseudo-linkedlist
+
+			uint8_t keyIndex = 255; // if keyIndex == 255 then k does not exist in keycodes
+
 			// iterate through the keycodes
 			for (uint8_t i = 0; i < keycodesSize; i++)
 			{
 				auto key = _keyReport.keycodes[i];
+
 				// if target key is found
-				if (key == k) {
-					// remove target and exit
-					_keyReport.keycodes[i] = KEY_RESERVED;
-					return 1;
+				if (key == uint8_t(k)) {
+					// record target key index to keyIndex;
+					keyIndex = i;
+					break;
 				}
 			}
+
+			// if the target key is found (AKA if there is a key to remove)
+			if (keyIndex != 255)
+			{
+				// iterate through the keycodes from the back
+				KeyboardKeycode lastElement;
+				for (uint8_t i = keycodesSize; i > 0; --i)
+				{
+					// slot is occupied
+					if (_keyReport.keycodes[i] != KEY_RESERVED)
+					{
+						_keyReport.keycodes[i] = KEY_RESERVED; // remove last element
+
+						// target key is the last non-null element in the pseudo-linkedlist
+						if (i == keyIndex)
+						{
+							return 1; // no further operations needed, exit now
+						}
+						lastElement = _keyReport.keycodes[i]; // copy current element to temp
+						break;
+					}
+				}
+				_keyReport.keycodes[keyIndex] = lastElement; // replace k with last element
+				return 1;
+			}
 		}
 	}
-
 	// No empty/pressed key was found
 	return 0;
 }