Add option to use custom message in warning

README.md

@@ -89,8 +89,12 @@ It **must** contain the following properties:
 - `preset`: a [naughty preset
   table](https://awesomewm.org/doc/api/libraries/naughty.html#config.presets)
 
-For example, one could ad a warning with a black foreground color and yellow
-background color once the battery discharges below 15% as follows:
+Optionally, it can also have the `message` property that should be a string
+with a custom warning message.
+
+For example, one could add a warning with a custom message, a black foreground
+color and yellow background color once the battery discharges below 15% as
+follows:
 
 ``` lua
 widget.warning_config = {
@@ -99,6 +103,7 @@ widget.warning_config = {
     bg = "#FFFF00",
     fg = "#000000",
   },
+  message = "The battery is getting low",
 }
 ```
 

power_widget.lua

@@ -69,12 +69,12 @@ local function update_icon(widget)
   end
 end
 
-local function maybe_warn(widget, warning_condition, notification_preset)
+local function maybe_warn(widget, warning_condition, notification_preset, message)
   local warning_level = device.warninglevel or "None"
   local percentage = get_percentage()
 
   if warning_condition then
-    local msg = (warning_level.name == "None" and "Low" or warning_level.name) .. " battery!"
+    local msg = message or (warning_level.name == "None" and "Low" or warning_level.name) .. " battery!"
 
     if notification then
       naughty.destroy(
@@ -158,7 +158,8 @@ local function update(widget)
     maybe_warn(
       widget,
       get_percentage() <= widget.warning_config.percentage,
-      widget.warning_config.preset
+      widget.warning_config.preset,
+      widget.warning_config.message
     )
   end