Handout

device/keydecoder.h

@@ -0,0 +1,40 @@
+/*! \file
+ *  \brief \ref KeyDecoder decodes a keystroke to the corresponding \ref Key
+ * object
+ */
+
+#pragma once
+#include "../object/key.h"
+#include "../types.h"
+
+/*! \brief Decoder for \ref ps2keyboardset1 "keyboard codes" received from the
+ * \ref PS2Controller
+ *  \ingroup io
+ *
+ *  Extracts the make and break codes, modifier and scan codes from the pressed
+ * key.
+ */
+class KeyDecoder {
+  unsigned char prefix;  ///< Prefix byte for keys
+  Key modifier;          ///< activated modifier keys (e.g., caps lock)
+
+ public:
+  /*! \brief Current state (pressed or released) of all keys.
+   */
+  bool status[Key::Scancode::KEYS];
+
+  /*! \brief Default constructor
+   */
+  KeyDecoder() {}
+
+  /*! \brief Interprets the  \ref ps2keyboardset1 "make and break codes"
+   * received from the keyboard and derives the corresponding scan code and
+   * further information about other pressed keys, such as \key{shift} and
+   * \key{ctrl}.
+   *
+   * \param code Byte from Keyboard to decode
+   * \return Pressed key (\ref Key::valid returns `false` if the key is not yet
+   * complete)
+   */
+  Key decode(unsigned char code);
+};