client: Move the `c:keys()` method to a property.

lib/awful/client.lua

@@ -1350,6 +1350,12 @@ object.properties._legacy_accessors(client, "buttons", "_buttons", true, functio
     ) or false
 end, true)
 
+object.properties._legacy_accessors(client, "keys", "_keys", true, function(new_btns)
+    return new_btns[1] and (
+        type(new_btns[1]) == "key" or new_btns[1]._is_capi_key
+    ) or false
+end, true)
+
 --- Set the client shape.
 -- @property shape
 -- @tparam gears.shape A gears.shape compatible function.

objects/client.c

@@ -3677,9 +3677,9 @@ luaA_client_set_shape_input(lua_State *L, client_t *c)
 
 /** Get or set keys bindings for a client.
  *
- * @param keys_table An array of key bindings objects, or nothing.
- * @return A table with all keys.
- * @method keys
+ * @property keys
+ * @param table
+ * @see awful.key
  */
 static int
 luaA_client_keys(lua_State *L)
@@ -3813,7 +3813,7 @@ client_class_setup(lua_State *L)
     {
         LUA_OBJECT_META(client)
         LUA_CLASS_META
-        { "keys", luaA_client_keys },
+        { "_keys", luaA_client_keys },
         { "isvisible", luaA_client_isvisible },
         { "geometry", luaA_client_geometry },
         { "apply_size_hints", luaA_client_apply_size_hints },

tests/examples/shims/key.lua

@@ -1,6 +1,6 @@
 local gobject = require("gears.object")
 local gtable  = require("gears.table")
 
-return setmetatable({}, {__call = function(_, args)
+return setmetatable({_is_capi_key = true}, {__call = function(_, args)
     return gtable.crush(gobject(), args)
 end})