gears.debug: Use the API level as the source of truth.

Rather than the version.

lib/gears/debug.lua

@@ -82,7 +82,8 @@ local displayed_deprecations = {}
 --- Display a deprecation notice, but only once per traceback.
 --
 -- This function also emits the `debug::deprecation` signal on the `awesome`
--- global object.
+-- global object. If the deprecated API has been deprecated for more than one
+-- API level, it will also send a non-fatal error.
 --
 -- @param[opt] see The message to a new method / function to use.
 -- @tparam table args Extra arguments
@@ -90,17 +91,18 @@ local displayed_deprecations = {}
 -- @tparam integer args.deprecated_in Print the message only when Awesome's
 --   version is equal to or greater than deprecated_in.
 -- @staticfct gears.debug.deprecate
--- @emits debug::deprecation
--- @emitstparam @emitstparam string msg The full formatted message.
--- @emitstparam @emitstparam string see A message provided by the caller.
--- @emitstparam @emitstparam table args Some extra context.
+-- @emits debug::deprecation This is usually routed to stdout when the API is
+--  newly deprecated.
+-- @emitstparam debug::deprecation string msg The full formatted message.
+-- @emitstparam debug::deprecation string see A message provided by the caller.
+-- @emitstparam debug::deprecation table args Some extra context.
+-- @emits debug::error When the API has been deprecated for more than
+--  one API level.
+-- @emitstparam debug::error string msg The full formatted message.
 function debug.deprecate(see, args)
     args = args or {}
-    if args.deprecated_in then
-        local dep_ver = "v" .. tostring(args.deprecated_in)
-        if awesome.version < dep_ver then
-            return
-        end
+    if args.deprecated_in and awesome.api_level < args.deprecated_in then
+        return
     end
     local tb = _G.debug.traceback()
     if displayed_deprecations[tb] then
@@ -123,9 +125,15 @@ function debug.deprecate(see, args)
     end
     debug.print_warning(msg .. ".\n" .. tb)
 
-    if awesome then
+    if awesome and awesome.api_level == args.deprecated_in then
         awesome.emit_signal("debug::deprecation", msg, see, args)
     end
+
+    if args.deprecated_in and awesome.api_level > args.deprecated_in then
+        awesome.emit_signal(
+            "debug::error", msg, false
+        )
+    end
 end
 
 --- Create a class proxy with deprecation messages.
@@ -140,11 +148,8 @@ end
 -- @staticfct gears.debug.deprecate_class
 function debug.deprecate_class(fallback, old_name, new_name, args)
     args = args or {}
-    if args.deprecated_in then
-        local dep_ver = "v" .. tostring(args.deprecated_in)
-        if awesome.version < dep_ver then
-            return fallback
-        end
+    if args.deprecated_in and awesome.api_level < args.deprecated_in then
+        return fallback
     end
 
     local message = old_name.." has been renamed to "..new_name