awesome/lib/wibox/widget/template.lua

148 lines
4.3 KiB
Lua

---------------------------------------------------------------------------
-- An abstract widget that handles a preset of concrete widget.
--
-- The `wibox.widget.template` widget is an abstraction layer that contains a
-- concrete widget definition. The template widget can be used to build widgets
-- that the user can customize at their will, thanks to the template mechanism.
--
-- @author Aire-One
-- @copyright 2021 Aire-One <aireone@aireone.xyz>
--
-- @classmod wibox.widget.template
-- @supermodule wibox.widget.base
---------------------------------------------------------------------------
local wbase = require("wibox.widget.base")
local gtable = require("gears.table")
local gtimer = require("gears.timer")
local template = {
mt = {},
queued_updates = {},
}
-- Layout this layout
function template:layout(_, width, height)
if not self._private.widget then
return
end
return { wbase.place_widget_at(self._private.widget, 0, 0, width, height) }
end
-- Fit this layout into the given area.
function template:fit(context, width, height)
if not self._private.widget then
return 0, 0
end
return wbase.fit_widget(self, context, self._private.widget, width, height)
end
function template:draw(...)
return self._private.widget:draw(...)
end
function template:_do_update_now()
if type(self._private.update_callback) == "function" then
self._private.update_callback(self, self._private.update_args)
end
self._private.update_args = nil
template.queued_updates[self] = false
end
--- Update the widget.
-- This function will call the `update_callback` function at the end of the
-- current GLib event loop. Updates are batched by event loop, it means that the
-- widget can only be update once by event loop. If the `template:update` method
-- is called multiple times during the same GLib event loop, only the first call
-- will be run.
-- All arguments are passed to the queued `update_callback` call.
function template:update(args)
if type(args) == "table" then
self._private.update_args = gtable.crush(
gtable.clone(self._private.update_args or {}, false),
args
)
end
if not template.queued_updates[self] then
gtimer.delayed_call(function()
self:_do_update_now()
end)
template.queued_updates[self] = true
end
end
function template:set_template(widget_template)
local widget = type(widget_template) == "function" and widget_template()
or widget_template
or wbase.empty_widget()
self._private.template = widget
self._private.widget = wbase.make_widget_from_value(widget)
-- We need to connect to these signals to actually redraw the template
-- widget when its child needs to.
local signals = {
"widget::redraw_needed",
"widget::layout_changed",
}
for _, signal in pairs(signals) do
self._private.widget:connect_signal(signal, function(...)
self:emit_signal(signal, ...)
end)
end
self:emit_signal("widget::redraw_needed")
end
function template:get_widget()
return self._private.widget
end
function template:set_update_callback(update_callback)
assert(type(update_callback) == "function" or update_callback == nil)
self._private.update_callback = update_callback
end
-- @hidden
function template:set_update_now(update_now)
if update_now then
self:update()
end
end
--- Create a new `wibox.widget.template` instance.
-- @tparam[opt] table args
-- @tparam[opt] table|widget|function args.template The widget template to use.
-- @tparam[opt] function args.update_callback The callback function to update the widget.
-- @treturn wibox.widget.template The new instance.
function template.new(args)
args = args or {}
local ret = wbase.make_widget(nil, nil, { enable_properties = true })
gtable.crush(ret, template, true)
ret:set_template(args.template)
ret:set_update_callback(args.update_callback)
ret:set_update_now(args.update_now)
if args.buttons then
ret:set_buttons(args.buttons)
end
return ret
end
function template.mt:__call(...)
return template.new(...)
end
return setmetatable(template, template.mt)
-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80