Handout

kernel/object/key.h

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+/*! \file
+ *  \brief \ref Key, an abstraction for handling pressed keys and their
+ * modifiers
+ */
+
+#pragma once
+#include "../types.h"
+
+/*! \brief Class that abstracts a key, made up of the scan code and the modifier
+ * bits.
+ */
+struct Key {
+	/*! \brief The keys' scan codes (code 1)
+	 */
+	enum class Scancode : uint8_t {
+		// Invalid scan code
+		KEY_INVALID = 0,
+
+		// "real" valid scan codes
+		KEY_ESCAPE,
+		KEY_1,
+		KEY_2,
+		KEY_3,
+		KEY_4,
+		KEY_5,
+		KEY_6,
+		KEY_7,
+		KEY_8,
+		KEY_9,
+		KEY_0,
+		KEY_DASH,
+		KEY_EQUAL,
+		KEY_BACKSPACE,
+		KEY_TAB,
+		KEY_Q,
+		KEY_W,
+		KEY_E,
+		KEY_R,
+		KEY_T,
+		KEY_Y,
+		KEY_U,
+		KEY_I,
+		KEY_O,
+		KEY_P,
+		KEY_OPEN_BRACKET,
+		KEY_CLOSE_BRACKET,
+		KEY_ENTER,
+		KEY_LEFT_CTRL,
+		KEY_A,
+		KEY_S,
+		KEY_D,
+		KEY_F,
+		KEY_G,
+		KEY_H,
+		KEY_J,
+		KEY_K,
+		KEY_L,
+		KEY_SEMICOLON,
+		KEY_APOSTROPH,
+		KEY_GRAVE_ACCENT,
+		KEY_LEFT_SHIFT,
+		KEY_BACKSLASH,
+		KEY_Z,
+		KEY_X,
+		KEY_C,
+		KEY_V,
+		KEY_B,
+		KEY_N,
+		KEY_M,
+		KEY_COMMA,
+		KEY_PERIOD,
+		KEY_SLASH,
+		KEY_RIGHT_SHIFT,
+		KEY_KP_STAR,
+		KEY_LEFT_ALT,
+		KEY_SPACEBAR,
+		KEY_CAPS_LOCK,
+		KEY_F1,
+		KEY_F2,
+		KEY_F3,
+		KEY_F4,
+		KEY_F5,
+		KEY_F6,
+		KEY_F7,
+		KEY_F8,
+		KEY_F9,
+		KEY_F10,
+		KEY_NUM_LOCK,
+		KEY_SCROLL_LOCK,
+		KEY_KP_7,
+		KEY_KP_8,
+		KEY_KP_9,
+		KEY_KP_DASH,
+		KEY_KP_4,
+		KEY_KP_5,
+		KEY_KP_6,
+		KEY_KP_PLUS,
+		KEY_KP_1,
+		KEY_KP_2,
+		KEY_KP_3,
+		KEY_KP_0,
+		KEY_KP_PERIOD,
+		KEY_SYSREQ,
+		KEY_EUROPE_2,
+		KEY_F11,
+		KEY_F12,
+		KEY_KP_EQUAL,
+
+		// Number of keys (excluding aliases below)
+		KEYS,
+
+		// aliases
+		KEY_DIV = KEY_KP_7,
+		KEY_DEL = KEY_KP_PERIOD,
+		KEY_UP = KEY_KP_8,
+		KEY_DOWN = KEY_KP_2,
+		KEY_LEFT = KEY_KP_4,
+		KEY_RIGHT = KEY_KP_6,
+	};
+
+	Scancode scancode = Scancode::KEY_INVALID;
+
+	// bit masks for the modifier keys
+	bool shift : 1 = false;
+	bool alt_left : 1 = false;
+	bool alt_right : 1 = false;
+	bool ctrl_left : 1 = false;
+	bool ctrl_right : 1 = false;
+	bool caps_lock : 1 = false;
+	bool num_lock : 1 = false;
+	bool scroll_lock : 1 = false;
+
+	/*! \brief Default constructor: Instantiates an invalid key by setting
+	 * ASCII, scan code, and modifier bits to 0
+	 */
+	Key() {}
+
+	/*! \brief Invalid keys have a scancode = 0
+	 *  \return Checks whether a key is valid.
+	 */
+	bool valid() const {
+		return scancode != Scancode::KEY_INVALID && scancode < Scancode::KEYS;
+	}
+
+	/*! \brief Marks the key as invalid by setting the scan code to 0.
+	 */
+	void invalidate() { scancode = Scancode::KEY_INVALID; }
+
+	/*! \brief Get the key's ASCII value
+	 *  \return the key's ASCII value
+	 */
+	unsigned char ascii() const;
+
+	/*! \brief Indicates whether the ALT modifier is set
+	 *  \return `true` if ALT key was pressed during key press
+	 */
+	bool alt() const { return alt_left || alt_right; }
+
+	/*! \brief Indicates whether the CTRL modifier is set
+	 *  \return `true` if CTRL key was pressed during key press
+	 */
+	bool ctrl() const { return ctrl_left || ctrl_right; }
+};