diff options
Diffstat (limited to 'xkbcommon/xkbcommon.h')
| -rw-r--r-- | xkbcommon/xkbcommon.h | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/xkbcommon/xkbcommon.h b/xkbcommon/xkbcommon.h index ddc715c..6387f92 100644 --- a/xkbcommon/xkbcommon.h +++ b/xkbcommon/xkbcommon.h @@ -147,7 +147,17 @@ struct xkb_state; * keymap would assign each of them a keycode, by which the user should * refer to the key throughout the library. * + * Historically, the X11 protocol, and consequentially the XKB protocol, + * assign only 8 bits for keycodes. This limits the number of different + * keys that can be used simultaneously in a single keymap to 256 + * (disregarding other limitations). This library does not share this limit; + * keycodes beyond 255 ('extended keycodes') are not treated specially. + * Keymaps and applications which are compatible with X11 should not use + * these keycodes. + * * @todo Explain how keycodes are mapped to scancodes. + * + * @sa xkb_keycode_is_legal_ext() xkb_keycode_is_legal_x11() */ typedef uint32_t xkb_keycode_t; @@ -260,7 +270,17 @@ typedef uint32_t xkb_led_mask_t; #define XKB_LED_INVALID (0xffffffff) #define XKB_KEYCODE_MAX (0xffffffff - 1) + +/** + * Test whether a value is a valid extended keycode. + * @sa xkb_keycode_t + **/ #define xkb_keycode_is_legal_ext(key) (key <= XKB_KEYCODE_MAX) + +/** + * Test whether a value is a valid X11 keycode. + * @sa xkb_keycode_t + */ #define xkb_keycode_is_legal_x11(key) (key >= 8 && key <= 255) /** |