awesome/lib/awful/button.lua

---------------------------------------------------------------------------
--- Create easily new buttons objects ignoring certain modifiers.
--
-- @author Julien Danjou <julien@danjou.info>
-- @copyright 2009 Julien Danjou
-- @classmod awful.button
---------------------------------------------------------------------------

-- Grab environment we need
local setmetatable = setmetatable
local ipairs = ipairs
local capi = { button = button }
local gmath = require("gears.math")
local gtable = require("gears.table")

local button = { mt = {} }

--- Modifiers to ignore.
--
-- By default this is initialized as `{ "Lock", "Mod2" }`
-- so the `Caps Lock` or `Num Lock` modifier are not taking into account by awesome
-- when pressing keys.
--
-- @table ignore_modifiers
local ignore_modifiers = { "Lock", "Mod2" }

--- Create a new button to use as binding.
--
-- This function is useful to create several buttons from one, because it will use
-- the ignore_modifier variable to create more button with or without the ignored
-- modifiers activated.
--
-- For example if you want to ignore CapsLock in your buttonbinding (which is
-- ignored by default by this function), creating button binding with this function
-- will return 2 button objects: one with CapsLock on, and the other one with
-- CapsLock off.
--
-- @treturn table A table with one or several button objects.
function button.new(mod, _button, press, release)
    local ret = {}
    local subsets = gmath.subsets(ignore_modifiers)
    for _, set in ipairs(subsets) do
        ret[#ret + 1] = capi.button({ modifiers = gtable.join(mod, set),
                                      button = _button })
        if press then
            ret[#ret]:connect_signal("press", function(_, ...) press(...) end)
        end
        if release then
            ret[#ret]:connect_signal("release", function (_, ...) release(...) end)
        end
    end
    return ret
end

function button.mt:__call(...)
    return button.new(...)
end

return setmetatable(button, button.mt)

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