util: Add a class deprecation function.

lib/awful/util.lua

@@ -60,6 +60,36 @@ function util.deprecate(see)
     gears_debug.print_warning(msg .. ".\n" .. tb)
 end
 
+--- Create a class proxy with deprecation messages.
+-- This is useful when a class has moved somewhere else.
+-- @tparam table fallback The new class
+-- @tparam string old_name The old class name
+-- @tparam string new_name The new class name
+-- @treturn table A proxy class.
+function util.deprecate_class(fallback, old_name, new_name)
+    local message = old_name.." has been renamed to "..new_name
+
+    local function call(_,...)
+        util.deprecate(message)
+
+        return fallback(...)
+    end
+
+    local function index(_, k)
+        util.deprecate(message)
+
+        return fallback[k]
+    end
+
+    local function newindex(_, k, v)
+        util.deprecate(message)
+
+        fallback[k] = v
+    end
+
+    return setmetatable({}, {__call = call, __index = index, __newindex  = newindex})
+end
+
 --- Get a valid color for Pango markup
 -- @param color The color.
 -- @tparam string fallback The color to return if the first is invalid. (default: black)

lib/awful/wibox.lua

@@ -7,26 +7,7 @@
 -- @module awful.wibox
 ---------------------------------------------------------------------------
 local util = require("awful.util")
-local wibar = require("awful.wibar")
 
-local function call(_,...)
-    util.deprecate("awful.wibox has been renamed to awful.wibar")
-
-    return wibar(...)
-end
-
-local function index(_, k)
-    util.deprecate("awful.wibox has been renamed to awful.wibar")
-
-    return wibar[k]
-end
-
-local function newindex(_, k, v)
-    util.deprecate("awful.wibox has been renamed to awful.wibar")
-
-    wibar[k] = v
-end
-
-return setmetatable({}, {__call = call, __index = index, __newindex  = newindex})
+return util.deprecate_class(require("awful.wibar"), "awful.wibox", "awful.wibar")
 
 -- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80