lib/wibox/layout/flex.lua.in

   1 ---------------------------------------------------------------------------
   2 -- @author Uli Schlachter
   3 -- @copyright 2010 Uli Schlachter
   4 -- @release @AWESOME_VERSION@
   5 ---------------------------------------------------------------------------
   6
   7 local base = require("wibox.layout.base")
   8 local fixed = require("wibox.layout.fixed")
   9 local widget_base = require("wibox.widget.base")
  10 local table = table
  11 local pairs = pairs
  12 local floor = math.floor
  13
  14 -- wibox.layout.flex
  15 local flex = {}
  16
  17 local function round(x)
  18     return floor(x + 0.5)
  19 end
  20
  21 --- Draw a flex layout. Each widget gets an equal share of the available space
  22 -- @param dir "x" for a horizontal layout and "y" for vertical.
  23 -- @param widgets The widgets to draw.
  24 -- @param wibox The wibox that this widget is drawn to.
  25 -- @param cr The cairo context to use.
  26 -- @param width The available width.
  27 -- @param height The available height.
  28 -- @return The total space needed by the layout.
  29 function flex.draw_flex(dir, widgets, wibox, cr, width, height)
  30     local pos = 0
  31
  32     local num = #widgets
  33     local space_per_item
  34     if dir == "y" then
  35         space_per_item = height / num
  36     else
  37         space_per_item = width / num
  38     end
  39
  40     for k, v in pairs(widgets) do
  41         local x, y, w, h
  42         if dir == "y" then
  43             x, y = 0, round(pos)
  44             w, h = width, floor(space_per_item)
  45         else
  46             x, y = round(pos), 0
  47             w, h = floor(space_per_item), height
  48         end
  49         base.draw_widget(wibox, cr, v, x, y, w, h)
  50
  51         pos = pos + space_per_item
  52
  53         if (dir == "y" and pos >= height) or
  54             (dir ~= "y" and pos >= width) then
  55             break
  56         end
  57     end
  58 end
  59
  60 local function add(layout, widget)
  61     widget_base.check_widget(widget)
  62     table.insert(layout.widgets, widget)
  63     widget:connect_signal("widget::updated", layout._emit_updated)
  64     layout._emit_updated()
  65 end
  66
  67 local function reset(layout)
  68     for k, v in pairs(layout.widgets) do
  69         v:disconnect_signal("widget::updated", layout._emit_updated)
  70     end
  71     layout.widgets = {}
  72     layout:emit_signal("widget::updated")
  73 end
  74
  75 local function get_layout(dir)
  76     local function draw(layout, wibox, cr, width, height)
  77         flex.draw_flex(dir, layout.widgets, wibox, cr, width, height)
  78     end
  79
  80     local function fit(layout, width, height)
  81         return fixed.fit_fixed(dir, layout.widgets, width, height)
  82     end
  83
  84     local ret = widget_base.make_widget()
  85     ret.draw = draw
  86     ret.fit = fit
  87     ret.add = add
  88     ret.reset = reset
  89     ret.widgets = {}
  90     ret.get_dir = function () return dir end
  91     ret._emit_updated = function()
  92         ret:emit_signal("widget::updated")
  93     end
  94
  95     return ret
  96 end
  97
  98 --- Returns a new horizontal flex layout. A flex layout shares the available space
  99 -- equally among all widgets. Widgets can be added via :add(widget).
 100 function flex.horizontal()
 101     return get_layout("x")
 102 end
 103
 104 --- Returns a new vertical flex layout. A flex layout shares the available space
 105 -- equally among all widgets. Widgets can be added via :add(widget).
 106 function flex.vertical()
 107     return get_layout("y")
 108 end
 109
 110 return flex
 111
 112 -- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80