revelation.lua

---------------------------------------------------------------------------
-- @author Espen Wiborg <espenhw@grumblesmurf.org>
-- @author Julien Danjou <julien@danjou.info>
-- @copyright 2008 Espen Wiborg, Julien Danjou
-- @release v3.1-rc3-14-gc7ee83f
-- 
-- note: rewritten by Perry Hargrave perry)dot(hargrave)at(gmail.com
-- note: this is a version of revelation.lua modified for awesome 3.1.223+
--
---------------------------------------------------------------------------
local math = math
local table = table
local pairs = pairs
local button = button
local awful = require("awful")
local capi =
{
    tag = tag,
    client = client,
    keygrabber = keygrabber,
    mouse = mouse,
    screen = screen
}
--- Exposé implementation
module("revelation")

function clients(class, s)
    local clients
    if class then
        clients = {}
        for k, c in pairs(capi.client.get(s)) do
            if c.class == class then
                table.insert(clients, c)
            end
        end
    else
        clients = capi.client.get(s)
    end
    return clients
end

function selectfn(restore)
    return function(c)
        restore()
        -- Pop to client tag
        awful.tag.viewonly(c:tags()[1])
        -- Focus and raise
        capi.client.focus = c
        c:raise()
    end
end

--- Returns keyboardhandler.
-- Arrow keys move focus, Return selects, Escape cancels.
-- Ignores modifiers.
function keyboardhandler (restore)
    return function (mod, key, event)
        if event ~= "press" then return true end
        -- translate vim-style home keys to directions
        translate = {
            j = "Down",
            k = "Up",
            h = "Left",
            l = "Right"
        }
        key = translate[key] or key

        if key == "Escape" then
            restore()
            -- awful.tag.history.restore()
            return false
        elseif key == "Return" then
            selectfn(restore)(capi.client.focus)
            return false
        elseif key == "Left" or key == "Right" or
            key == "Up" or key == "Down" then
            awful.client.focus.bydirection(key:lower())
        end
        return true
    end
end

--- Implement Exposé (from Mac OS X).
-- @param class The class of clients to expose, or nil for all clients.
-- @param fn A binary function f(t, n) to set the layout for tag t for n clients, or nil for the default layout.
-- @param s The screen to consider clients of, or nil for "current screen".
function revelation(class, fn, s)
    local screen = s or capi.mouse.screen
    local t = awful.tag.selected()
    local data = {}

    local clients = clients(class, screen)
    local oset = {}
    oset.mwfact = awful.tag.getmwfact(t)
    oset.ncol = awful.tag.getncol(t)
    oset.nmaster = awful.tag.getnmaster(t)
    oset.layout = awful.tag.getproperty(t,"layout")

    oset.clients = t.clients(t)

    local allc = capi.client.get(screen)
    if #allc == 0 then
        return
    end

    awful.tag.setproperty(t,"layout",awful.layout.suit.fair )

    t:clients(allc)

    local function restore()
        local t = awful.tag.selected()
        for i,c in pairs(allc) do
            -- Restore client mouse bindings
            c:buttons(data[c])
            data[c] = nil
            if not oset.clients[c] then
                awful.client.toggletag(t,c)
            end
        end
        awful.tag.setproperty(t,"layout",oset.layout)
        awful.tag.setnmaster(oset.nmaster,t)
        awful.tag.setmwfact(oset.mwfact, t)
        awful.tag.setncol(oset.ncol, t)
        awful.tag.viewonly(t)

        capi.keygrabber.stop()
    end

    for k, c in pairs(clients) do
        data[c] = c:buttons()
        c:buttons(awful.util.table.join(awful.button({}, 1, selectfn(restore)) ))
    end
    awful.tag.viewonly(t)
    capi.keygrabber.run(keyboardhandler(restore))
end