Keyboard routines

These functions are declared in the main Allegro header file:

#include <allegro5/allegro.h>

ALLEGRO_KEYBOARD_STATE

typedef struct ALLEGRO_KEYBOARD_STATE ALLEGRO_KEYBOARD_STATE;

This is a structure that is used to hold a "snapshot" of a keyboard's state at a particular instant. It contains the following publically readable fields:

You cannot read the state of keys directly. Use the function al_key_down.

Key codes

The constant ALLEGRO_KEY_MAX is always one higher than the highest key code. So if you want to use the key code as array index you can do something like this:

bool pressed_keys[ALLEGRO_KEY_MAX];
...
pressed_keys[key_code] = true;

These are the list of key codes used by Allegro, which are returned in the event.keyboard.keycode field of the ALLEGRO_KEY_DOWN and ALLEGRO_KEY_UP events and which you can pass to al_key_down:

ALLEGRO_KEY_A ... ALLEGRO_KEY_Z,
ALLEGRO_KEY_0 ... ALLEGRO_KEY_9,
ALLEGRO_KEY_PAD_0 ... ALLEGRO_KEY_PAD_9,
ALLEGRO_KEY_F1 ... ALLEGRO_KEY_F12,
ALLEGRO_KEY_ESCAPE,
ALLEGRO_KEY_TILDE,
ALLEGRO_KEY_MINUS,
ALLEGRO_KEY_EQUALS,
ALLEGRO_KEY_BACKSPACE,
ALLEGRO_KEY_TAB,
ALLEGRO_KEY_OPENBRACE, ALLEGRO_KEY_CLOSEBRACE,
ALLEGRO_KEY_ENTER,
ALLEGRO_KEY_SEMICOLON,
ALLEGRO_KEY_QUOTE,
ALLEGRO_KEY_BACKSLASH, ALLEGRO_KEY_BACKSLASH2,
ALLEGRO_KEY_COMMA,
ALLEGRO_KEY_FULLSTOP,
ALLEGRO_KEY_SLASH,
ALLEGRO_KEY_SPACE,
ALLEGRO_KEY_INSERT, ALLEGRO_KEY_DELETE,
ALLEGRO_KEY_HOME, ALLEGRO_KEY_END,
ALLEGRO_KEY_PGUP, ALLEGRO_KEY_PGDN,
ALLEGRO_KEY_LEFT, ALLEGRO_KEY_RIGHT,
ALLEGRO_KEY_UP, ALLEGRO_KEY_DOWN,
ALLEGRO_KEY_PAD_SLASH, ALLEGRO_KEY_PAD_ASTERISK,
ALLEGRO_KEY_PAD_MINUS, ALLEGRO_KEY_PAD_PLUS,
ALLEGRO_KEY_PAD_DELETE, ALLEGRO_KEY_PAD_ENTER,
ALLEGRO_KEY_PRINTSCREEN, ALLEGRO_KEY_PAUSE,
ALLEGRO_KEY_ABNT_C1, ALLEGRO_KEY_YEN, ALLEGRO_KEY_KANA,
ALLEGRO_KEY_CONVERT, ALLEGRO_KEY_NOCONVERT,
ALLEGRO_KEY_AT, ALLEGRO_KEY_CIRCUMFLEX,
ALLEGRO_KEY_COLON2, ALLEGRO_KEY_KANJI,
ALLEGRO_KEY_LSHIFT, ALLEGRO_KEY_RSHIFT,
ALLEGRO_KEY_LCTRL, ALLEGRO_KEY_RCTRL,
ALLEGRO_KEY_ALT, ALLEGRO_KEY_ALTGR,
ALLEGRO_KEY_LWIN, ALLEGRO_KEY_RWIN,
ALLEGRO_KEY_MENU,
ALLEGRO_KEY_SCROLLLOCK,
ALLEGRO_KEY_NUMLOCK,
ALLEGRO_KEY_CAPSLOCK
ALLEGRO_KEY_PAD_EQUALS,
ALLEGRO_KEY_BACKQUOTE,
ALLEGRO_KEY_SEMICOLON2,
ALLEGRO_KEY_COMMAND

Keyboard modifier flags

ALLEGRO_KEYMOD_SHIFT
ALLEGRO_KEYMOD_CTRL
ALLEGRO_KEYMOD_ALT
ALLEGRO_KEYMOD_LWIN
ALLEGRO_KEYMOD_RWIN
ALLEGRO_KEYMOD_MENU
ALLEGRO_KEYMOD_ALTGR
ALLEGRO_KEYMOD_COMMAND
ALLEGRO_KEYMOD_SCROLLLOCK
ALLEGRO_KEYMOD_NUMLOCK
ALLEGRO_KEYMOD_CAPSLOCK
ALLEGRO_KEYMOD_INALTSEQ
ALLEGRO_KEYMOD_ACCENT1
ALLEGRO_KEYMOD_ACCENT2
ALLEGRO_KEYMOD_ACCENT3
ALLEGRO_KEYMOD_ACCENT4

The event field 'keyboard.modifiers' is a bitfield composed of these constants. These indicate the modifier keys which were pressed at the time a character was typed.

al_install_keyboard

bool al_install_keyboard(void)

Install a keyboard driver. Returns true if successful. If a driver was already installed, nothing happens and true is returned.

See also: al_uninstall_keyboard, al_is_keyboard_installed

al_is_keyboard_installed

bool al_is_keyboard_installed(void)

Returns true if al_install_keyboard was called successfully.

al_uninstall_keyboard

void al_uninstall_keyboard(void)

Uninstalls the active keyboard driver, if any. This will automatically unregister the keyboard event source with any event queues.

This function is automatically called when Allegro is shut down.

See also: al_install_keyboard

al_get_keyboard_state

void al_get_keyboard_state(ALLEGRO_KEYBOARD_STATE *ret_state)

Save the state of the keyboard specified at the time the function is called into the structure pointed to by ret_state.

See also: al_key_down, ALLEGRO_KEYBOARD_STATE

al_key_down

bool al_key_down(const ALLEGRO_KEYBOARD_STATE *state, int keycode)

Return true if the key specified was held down in the state specified.

See also: ALLEGRO_KEYBOARD_STATE

al_keycode_to_name

const char *al_keycode_to_name(int keycode)

Converts the given keycode to a description of the key.

al_set_keyboard_leds

bool al_set_keyboard_leds(int leds)

Overrides the state of the keyboard LED indicators. Set to -1 to return to default behavior. False is returned if the current keyboard driver cannot set LED indicators.

al_get_keyboard_event_source

ALLEGRO_EVENT_SOURCE *al_get_keyboard_event_source(void)

Retrieve the keyboard event source.

Returns NULL if the keyboard subsystem was not installed.

Allegro version 5.0.0 - Last updated: 2011-02-06 11:32:51 UTC