bling/layout/centered.lua

local awful = require("awful")
local gears = require("gears")
local gcolor = require("gears.color")
local beautiful = require("beautiful")
local math = math

local mylayout = {}

mylayout.name = "centered"

function mylayout.arrange(p)
    local area = p.workarea
    local t = p.tag or screen[p.screen].selected_tag
    local mwfact = t.master_width_factor
    local nmaster = math.min(t.master_count, #p.clients)
    local nslaves = #p.clients - nmaster

    local master_area_width = area.width * mwfact
    local slave_area_width  = area.width - master_area_width
    local master_area_x = area.x + 0.5*slave_area_width

    local number_of_left_sided_slaves =math.floor(nslaves/2)
    local number_of_right_sided_slaves = nslaves - number_of_left_sided_slaves
    local left_iterator = 0
    local right_iterator = 0

    -- Special case: no maters -> rrelapse into awesomes fair layout
    if t.master_count == 0 then
        awful.layout.suit.fair.arrange(p)
        return
    end

    -- Special case: one slave -> relapse into awesomes masterstack tile layout 
    if nslaves == 1 then
        awful.layout.suit.tile.right.arrange(p)
        return
    end 

    -- Special case: no slaves -> fullscreen master area
    if nslaves < 1 then
        master_area_width = area.width 
        master_area_x = area.x
    end 
    
    -- iterate through masters
    for idx=1,nmaster do
       local c = p.clients[idx]
       local g
       g = {
         x = master_area_x, 
         y = area.y + (nmaster-idx)*(area.height/nmaster),
         width = master_area_width,
         height = area.height/nmaster,
       }
       p.geometries[c] = g
    end

    -- iterate through slaves
    for idx=1,nslaves do -- idx=nmaster+1,#p.clients do
      local c = p.clients[idx+nmaster]
      if idx % 2 == 0 then
        g = {
          x = area.x,
          y = area.y + left_iterator * (area.height/number_of_left_sided_slaves),
          width = slave_area_width/2,
          height = area.height/number_of_left_sided_slaves,
        }
        left_iterator = left_iterator + 1
      else
        g = {
          x = area.x + master_area_width + slave_area_width/2,
          y = area.y + right_iterator * (area.height/number_of_right_sided_slaves),
          width = slave_area_width/2,
          height = area.height/number_of_right_sided_slaves,
        }
        right_iterator = right_iterator + 1

      end
      p.geometries[c] = g
    end
end

local icon_raw = gears.filesystem.get_configuration_dir() .. tostring(...):match("^.*bling"):gsub("%.", "/") .. "/icons/layouts/centered.png"

local function get_icon()
   if icon_raw ~= nil then
      return gcolor.recolor_image(icon_raw, beautiful.fg_normal)
   else
      return nil
   end
end


return {
  layout = mylayout,
  icon_raw = icon_raw,
  get_icon = get_icon,
}