protocol: Document how clients are supposed to get the xkb keycode

This encodes what everyone is doing and avoids other implementers
having to guess.

diff --git a/protocol/wayland.xml b/protocol/wayland.xml
index 3aa89af..db1b349 100644 (file)
--- a/protocol/wayland.xml
+++ b/protocol/wayland.xml
@@ -1503,7 +1503,8 @@
       </description>
       <entry name="no_keymap" value="0"
             summary="no keymap; client must understand how to interpret the raw keycode"/>
-      <entry name="xkb_v1" value="1" summary="libxkbcommon compatible"/>
+      <entry name="xkb_v1" value="1"
+             summary="libxkbcommon compatible; to determine the xkb keycode, clients must add 8 to the key event keycode"/>
     </enum>
 
     <event name="keymap">