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;

Source Code

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:

display - points to the display that had keyboard focus at the time the state was saved. If no display was focused, this points to NULL.

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

Examples:

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_EVENT_KEY_DOWN and ALLEGRO_EVENT_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

/* Since: 5.1.1 */
/* Android only for now */
ALLEGRO_KEY_BACK

/* Since: 5.1.2 */
/* Android only for now */
ALLEGRO_KEY_VOLUME_UP
ALLEGRO_KEY_VOLUME_DOWN

/* Since: 5.1.6 */
/* Android only for now */
ALLEGRO_KEY_SEARCH
ALLEGRO_KEY_DPAD_CENTER
ALLEGRO_KEY_BUTTON_X
ALLEGRO_KEY_BUTTON_Y
ALLEGRO_KEY_DPAD_UP
ALLEGRO_KEY_DPAD_DOWN
ALLEGRO_KEY_DPAD_LEFT
ALLEGRO_KEY_DPAD_RIGHT
ALLEGRO_KEY_SELECT
ALLEGRO_KEY_START
ALLEGRO_KEY_L1
ALLEGRO_KEY_R1

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)

Source Code

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

Examples:

al_is_keyboard_installed

bool al_is_keyboard_installed(void)

Source Code

Returns true if al_install_keyboard was called successfully.

al_uninstall_keyboard

void al_uninstall_keyboard(void)

Source Code

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.

al_get_keyboard_state

void al_get_keyboard_state(ALLEGRO_KEYBOARD_STATE *ret_state)

Source Code

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

Examples:

al_clear_keyboard_state

void al_clear_keyboard_state(ALLEGRO_DISPLAY *display)

Source Code

Clear the state of the keyboard, emitting ALLEGRO_EVENT_KEY_UP for each currently pressed key. The given display is regarded as the one which had the keyboard focus when the event occurred. In case display is NULL no event is emitted. For most keyboard drivers Allegro maintains its own state of the keyboard, which might get out of sync with the real one. This function is intended to remedy such situation by resetting Allegro’s keyboard state to a known default (no key pressed). This is particularly useful in response to ALLEGRO_EVENT_DISPLAY_SWITCH_OUT events.

Since: 5.2.3

Unstable API: This is a new feature and the exact semantics are still being decided upon.

Examples:

ex_keyboard_events.c

al_key_down

bool al_key_down(const ALLEGRO_KEYBOARD_STATE *state, int keycode)

Source Code

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

al_keycode_to_name

const char *al_keycode_to_name(int keycode)

Source Code

Converts the given keycode to a description of the key.

Examples:

ex_keyboard_events.c

al_can_set_keyboard_leds

bool al_can_set_keyboard_leds(void)

Source Code

Returns true if setting the keyboard LED indicators is available.

Since: 5.2.9

al_set_keyboard_leds

bool al_set_keyboard_leds(int leds)

Source Code

Overrides the state of the keyboard LED indicators. Set leds to a combination of the keyboard modifier flags to enable the corresponding LED indicators (ALLEGRO_KEYMOD_NUMLOCK, ALLEGRO_KEYMOD_CAPSLOCK and ALLEGRO_KEYMOD_SCROLLLOCK are supported) or 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)

Source Code

Retrieve the keyboard event source. All keyboard events are generated by this event source.

Returns NULL if the keyboard subsystem was not installed.

Examples:

Allegro version 5.2.10 (20231119) - Last updated: 2024-11-21 07:18:28 UTC