Add and use gears.timer.delayed_call

This function calls a callback at the end of the current main loop iteration.

Signed-off-by: Uli Schlachter <psychon@znc.in>

lib/gears/timer.lua.in

@@ -4,10 +4,14 @@
 -- @release @AWESOME_VERSION@
 ---------------------------------------------------------------------------
 
-local setmetatable = setmetatable
+local capi = { awesome = awesome }
+local ipairs = ipairs
 local pairs = pairs
+local setmetatable = setmetatable
+local table = table
 local tonumber = tonumber
 local traceback = debug.traceback
+local unpack = unpack or table.unpack -- v5.1: unpack, v5.2: table.unpack
 local glib = require("lgi").GLib
 local object = require("gears.object")
 
@@ -93,6 +97,25 @@ local function new(args)
     return ret
 end
 
+local delayed_calls = {}
+capi.awesome.connect_signal("refresh", function()
+    for _, callback in ipairs(delayed_calls) do
+        local success, message = pcall(unpack(callback))
+        if not success then
+            print(message)
+        end
+    end
+    delayed_calls = {}
+end)
+
+--- Call the given function at the end of the current main loop iteration
+-- @param callback The function that should be called
+-- @param ... Arguments to the callback function
+function timer.delayed_call(callback, ...)
+    assert(type(callback) == "function", "callback must be a function, got: " .. type(callback))
+    table.insert(delayed_calls, { callback, ... })
+end
+
 function timer.mt:__call(...)
     return new(...)
 end

lib/wibox/drawable.lua.in

@@ -16,6 +16,7 @@ local debug = require("gears.debug")
 local object = require("gears.object")
 local sort = require("gears.sort")
 local surface = require("gears.surface")
+local timer = require("gears.timer")
 
 local drawables = setmetatable({}, { __mode = 'k' })
 local wallpaper = nil
@@ -241,14 +242,13 @@ function drawable.new(d, widget_arg)
     ret._redraw_pending = false
     ret._do_redraw = function()
         ret._redraw_pending = false
-        capi.awesome.disconnect_signal("refresh", ret._do_redraw)
         do_redraw(ret)
     end
 
     -- Connect our signal when we need a redraw
     ret.draw = function()
         if not ret._redraw_pending then
-            capi.awesome.connect_signal("refresh", ret._do_redraw)
+            timer.delayed_call(ret._do_redraw)
             ret._redraw_pending = true
         end
     end