Initial commit

lib/lain/widget/contrib/redshift.lua

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+--[[
+
+     Licensed under GNU General Public License v2
+      * (c) 2017, Luca CPZ
+      * (c) 2014, blueluke <http://github.com/blueluke>
+
+--]]
+
+local async = require('lain.helpers').async
+local awful = require('awful')
+local execute = os.execute
+local type = type
+
+-- Redshift
+-- lain.widget.contrib.redshift
+local redshift = { active = false, pid = nil }
+
+function redshift.start()
+	execute('pkill redshift')
+	awful.spawn.with_shell('redshift -x') -- clear adjustments
+	redshift.pid = awful.spawn.with_shell('redshift')
+	redshift.active = true
+	if type(redshift.update_fun) == 'function' then
+		redshift.update_fun(redshift.active)
+	end
+end
+
+function redshift.toggle()
+	async({ awful.util.shell, '-c', string.format('ps -p %d -o pid=', redshift.pid) }, function(f)
+		if f and #f > 0 then -- redshift is running
+			-- Sending -USR1 toggles redshift (See project website)
+			execute('pkill -USR1 redshift')
+			redshift.active = not redshift.active
+		else -- not started or killed, (re)start it
+			redshift.start()
+		end
+		redshift.update_fun(redshift.active)
+	end)
+end
+
+-- Attach to a widget
+-- Provides a button which toggles redshift on/off on click
+-- @param widget:  Widget to attach to.
+-- @param fun:     Function to be run each time redshift is toggled (optional).
+--                 Use it to update widget text or icons on status change.
+function redshift.attach(widget, fun)
+	redshift.update_fun = fun or function() end
+	if not redshift.pid then
+		redshift.start()
+	end
+	if widget then
+		widget:buttons(awful.util.table.join(awful.button({}, 1, function()
+			redshift.toggle()
+		end)))
+	end
+end
+
+return redshift