awesome/lib/gears/object.lua.in

96 lines
2.7 KiB
Lua

---------------------------------------------------------------------------
-- @author Uli Schlachter
-- @copyright 2010 Uli Schlachter
-- @release @AWESOME_VERSION@
---------------------------------------------------------------------------
local setmetatable = setmetatable
local pairs = pairs
local type = type
local error = error
-- gears.object
local object = { mt = {} }
-- Verify that obj is indeed a valid object as returned by new()
local function check(obj)
if type(obj) ~= "table" or type(obj._signals) ~= "table" then
error("add_signal() called on non-object")
end
end
--- Find a given signal
-- @param obj The object to search in
-- @param name The signal to find
-- @param error_msg Error message for if the signal is not found
-- @return The signal table
local function find_signal(obj, name, error_msg)
check(obj)
if not obj._signals[name] then
error("Trying to " .. error_msg .. " non-existent signal '" .. name .. "'")
end
return obj._signals[name]
end
--- Add a signal to an object. All signals must be added before they can be used.
-- @param name The name of the new signal.
function object:add_signal(name)
check(self)
if not self._signals[name] then
self._signals[name] = {}
end
end
--- Connect to a signal
-- @param name The name of the signal
-- @param func The callback to call when the signal is emitted
function object:connect_signal(name, func)
local sig = find_signal(self, name, "connect to")
sig[func] = func
end
--- Disonnect to a signal
-- @param name The name of the signal
-- @param func The callback that should be disconnected
function object:disconnect_signal(name, func)
local sig = find_signal(self, name, "disconnect from")
sig[func] = nil
end
--- Emit a signal
-- @param name The name of the signal
-- @param ... Extra arguments for the callback functions. Each connected
-- function receives the object as first argument and then any extra
-- arguments that are given to emit_signal()
function object:emit_signal(name, ...)
local sig = find_signal(self, name, "emit")
for func in pairs(sig) do
func(self, ...)
end
end
-- Returns a new object. You can call :emit_signal(), :disconnect_signal,
-- :connect_signal() and :add_signal() on the resulting object.
local function new()
local ret = {}
-- Copy all our global functions to our new object
for k, v in pairs(object) do
if type(v) == "function" then
ret[k] = v
end
end
ret._signals = {}
return ret
end
function object.mt:__call(...)
return new(...)
end
return setmetatable(object, object.mt)
-- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80