protocol: disambiguate key codes in wl_keyboard.key

Explain that wl_keyboard.key yields platform-specific key codes.
Some compositors use Linux key codes (defined in the
linux/input-event-codes.h header file, e.g. KEY_ESC), however
clients should not assume that this is always the case. The only
reliable way for clients to interpret key codes is to feed them
into a keyboard mapping.

Signed-off-by: Simon Ser <contact@emersion.fr>

diff --git a/protocol/wayland.xml b/protocol/wayland.xml
index 9784680..d087e25 100644 (file)
--- a/protocol/wayland.xml
+++ b/protocol/wayland.xml
@@ -2240,6 +2240,9 @@
        The time argument is a timestamp with millisecond
        granularity, with an undefined base.
 
+       The key is a platform-specific key code that can be interpreted
+       by feeding it to the keyboard mapping (see the keymap event).
+
        If this event produces a change in modifiers, then the resulting
        wl_keyboard.modifiers event must be sent after this event.
       </description>