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