awesome/lib/gears/timer.lua

294 lines
8.9 KiB
Lua

---------------------------------------------------------------------------
--- Timer objects and functions.
--
-- @usage
-- -- Create a widget and update its content using the output of a shell
-- -- command every 10 seconds:
-- local mybatterybar = wibox.widget {
-- {
-- min_value = 0,
-- max_value = 100,
-- value = 0,
-- paddings = 1,
-- border_width = 1,
-- forced_width = 50,
-- border_color = "#0000ff",
-- id = "mypb",
-- widget = wibox.widget.progressbar,
-- },
-- {
-- id = "mytb",
-- text = "100%",
-- widget = wibox.widget.textbox,
-- },
-- layout = wibox.layout.stack,
-- set_battery = function(self, val)
-- self.mytb.text = tonumber(val).."%"
-- self.mypb.value = tonumber(val)
-- end,
-- }
--
-- gears.timer {
-- timeout = 10,
-- call_now = true,
-- autostart = true,
-- callback = function()
-- -- You should read it from `/sys/class/power_supply/` (on Linux)
-- -- instead of spawning a shell. This is only an example.
-- awful.spawn.easy_async(
-- {"sh", "-c", "acpi | sed -n 's/^.*, \([0-9]*\)%/\1/p'"},
-- function(out)
-- mybatterybar.battery = out
-- end
-- )
-- end
-- }
--
-- @author Uli Schlachter
-- @copyright 2014 Uli Schlachter
-- @coreclassmod gears.timer
---------------------------------------------------------------------------
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 -- luacheck: globals unpack (compatibility with Lua 5.1)
local glib = require("lgi").GLib
local object = require("gears.object")
local protected_call = require("gears.protected_call")
local gdebug = require("gears.debug")
local gmath = require("gears.math")
--- Timer objects. This type of object is useful when triggering events repeatedly.
--
-- The timer will emit the "timeout" signal every N seconds, N being the timeout
-- value. Note that a started timer will not be garbage collected. Call `:stop`
-- before dropping the last reference to prevent leaking the object.
--
-- @tfield number timeout Interval in seconds to emit the timeout signal.
-- Can be any value, including floating point ones (e.g. `1.5` seconds).
-- @tfield boolean started Read-only boolean field indicating if the timer has been
-- started.
-- @table timer
--- Emitted when the timer is started.
-- @signal start
--- Emitted when the timer is stopped.
-- @signal stop
--- Emitted when `timeout` seconds have elapsed.
--
-- This will be emitted repeatedly, unless `single_shot` has been set to `true`
-- for the timer.
-- @signal timeout
local timer = { mt = {} }
--- Start the timer.
-- @method start
-- @emits start
function timer:start()
if self.data.source_id ~= nil then
gdebug.print_error(traceback("timer already started"))
return
end
local timeout_ms = gmath.round(self.data.timeout * 1000)
self.data.source_id = glib.timeout_add(glib.PRIORITY_DEFAULT, timeout_ms, function()
protected_call(self.emit_signal, self, "timeout")
return true
end)
self:emit_signal("start")
end
--- Stop the timer.
--
-- Does nothing if the timer isn't running.
--
-- @method stop
-- @emits stop
function timer:stop()
if self.data.source_id == nil then
return
end
glib.source_remove(self.data.source_id)
self.data.source_id = nil
self:emit_signal("stop")
end
--- Restart the timer.
-- This is equivalent to stopping the timer if it is running and then starting
-- it.
-- @method again
-- @emits start
-- @emits stop
function timer:again()
if self.data.source_id ~= nil then
self:stop()
end
self:start()
end
--- The timer is started.
-- @property started
-- @param boolean
--- The timer timeout value.
-- **Signal:** property::timeout
-- @property timeout
-- @param number
-- @propemits true false
local timer_instance_mt = {
__index = function(self, property)
if property == "timeout" then
return self.data.timeout
elseif property == "started" then
return self.data.source_id ~= nil
end
return timer[property]
end,
__newindex = function(self, property, value)
if property == "timeout" then
self.data.timeout = tonumber(value)
self:emit_signal("property::timeout", value)
end
end
}
--- Create a new timer object.
--
-- `call_now` only takes effect when a `callback` is provided. `single_shot`,
-- on the other hand, also stops signals connected to the `timeout` signal.
--
-- Specifying a function `func` as `args.callback` is equivalent to calling
-- `:connect_signal(func)` on the timer object.
--
-- @tparam table args Arguments.
-- @tparam number args.timeout Timeout in seconds (e.g. `1.5`).
-- @tparam[opt=false] boolean args.autostart Automatically start the timer.
-- @tparam[opt=false] boolean args.call_now Call the callback at timer creation.
-- @tparam[opt] function args.callback Callback function to connect to the
-- "timeout" signal.
-- @tparam[opt=false] boolean args.single_shot Run only once then stop.
-- @treturn timer
-- @constructorfct gears.timer
function timer.new(args)
args = args or {}
local ret = object()
ret.data = { timeout = 0 } --TODO v5 rename to ._private
setmetatable(ret, timer_instance_mt)
for k, v in pairs(args) do
ret[k] = v
end
if args.autostart then
ret:start()
end
if args.callback then
if args.call_now then
args.callback()
end
ret:connect_signal("timeout", args.callback)
end
if args.single_shot then
ret:connect_signal("timeout", function() ret:stop() end)
end
return ret
end
--- Create a simple timer for calling the `callback` function continuously.
--
-- This is a small wrapper around `gears.timer`, that creates a timer based on
-- `callback`.
-- The timer will run continuously and call `callback` every `timeout` seconds.
-- It is stopped when `callback` returns `false`, when `callback` throws an
-- error or when the `:stop()` method is called on the return value.
--
-- @tparam number timeout Timeout in seconds (e.g. 1.5).
-- @tparam function callback Function to run.
-- @treturn timer The new timer object.
-- @staticfct gears.timer.start_new
-- @see gears.timer.weak_start_new
function timer.start_new(timeout, callback)
local t = timer.new({ timeout = timeout })
t:connect_signal("timeout", function()
local cont = protected_call(callback)
if not cont then
t:stop()
end
end)
t:start()
return t
end
--- Create a simple timer for calling the `callback` function continuously.
--
-- This function is almost identical to `gears.timer.start_new`. The only
-- difference is that this does not prevent the callback function from being
-- garbage collected.
-- In addition to the conditions in `gears.timer.start_new`,
-- this timer will also stop if `callback` was garbage collected since the
-- previous run.
--
-- @tparam number timeout Timeout in seconds (e.g. 1.5).
-- @tparam function callback Function to start.
-- @treturn timer The new timer object.
-- @staticfct gears.timer.weak_start_new
-- @see gears.timer.start_new
function timer.weak_start_new(timeout, callback)
local indirection = setmetatable({}, { __mode = "v" })
indirection.callback = callback
return timer.start_new(timeout, function()
local cb = indirection.callback
if cb then
return cb()
end
end)
end
local delayed_calls = {}
--- Run all pending delayed calls now. This function should best not be used at
-- all, because it means that less batching happens and the delayed calls run
-- prematurely.
-- @staticfct gears.timer.run_delayed_calls_now
function timer.run_delayed_calls_now()
for _, callback in ipairs(delayed_calls) do
protected_call(unpack(callback))
end
delayed_calls = {}
end
--- Call the given function at the end of the current GLib event loop iteration.
-- @tparam function callback The function that should be called
-- @param ... Arguments to the callback function
-- @staticfct gears.timer.delayed_call
function timer.delayed_call(callback, ...)
assert(type(callback) == "function", "callback must be a function, got: " .. type(callback))
table.insert(delayed_calls, { callback, ... })
end
capi.awesome.connect_signal("refresh", timer.run_delayed_calls_now)
function timer.mt.__call(_, ...)
return timer.new(...)
end
--@DOC_object_COMMON@
return setmetatable(timer, timer.mt)
-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80