lib/wibox/layout/align.lua.in

   1 ---------------------------------------------------------------------------
   2 -- @author Uli Schlachter
   3 -- @copyright 2010 Uli Schlachter
   4 -- @release @AWESOME_VERSION@
   5 ---------------------------------------------------------------------------
   6
   7 local setmetatable = setmetatable
   8 local table = table
   9 local pairs = pairs
  10 local type = type
  11 local base = require("wibox.layout.base")
  12 local widget_base = require("wibox.widget.base")
  13
  14 -- wibox.layout.align
  15 local align = {}
  16
  17 --- Draw an align layout.
  18 -- @param wibox The wibox that this widget is drawn to.
  19 -- @param cr The cairo context to use.
  20 -- @param width The available width.
  21 -- @param height The available height.
  22 -- @return The total space needed by the layout.
  23 function align:draw(wibox, cr, width, height)
  24     local size_first = 0
  25     local size_third = 0
  26     local size_limit = self.dir == "y" and height or width
  27
  28     if self.first then
  29         local w, h, _ = width, height, nil
  30         if self.dir == "y" then
  31             _, h = self.first:fit(w, h)
  32             size_first = h
  33         else
  34             w, _ = self.first:fit(w, h)
  35             size_first = w
  36         end
  37         base.draw_widget(wibox, cr, self.first, 0, 0, w, h)
  38     end
  39
  40     if self.third and size_first < size_limit then
  41         local w, h, x, y, _
  42         if self.dir == "y" then
  43             w, h = width, height - size_first
  44             _, h = self.third:fit(w, h)
  45             x, y = 0, height - h
  46             size_third = h
  47         else
  48             w, h = width - size_first, height
  49             w, _ = self.third:fit(w, h)
  50             x, y = width - w, 0
  51             size_third = w
  52         end
  53         base.draw_widget(wibox, cr, self.third, x, y, w, h)
  54     end
  55
  56     if self.second and size_first + size_third < size_limit then
  57         local x, y, w, h
  58         if self.dir == "y" then
  59             w, h = width, size_limit - size_first - size_third
  60             local real_w, real_h = self.second:fit(w, h)
  61             x, y = 0, size_first + h / 2 - real_h / 2
  62             w, h = real_w, real_h
  63         else
  64             w, h = size_limit - size_first - size_third, height
  65             local real_w, real_h = self.second:fit(w, h)
  66             x, y = size_first + w / 2 - real_w / 2, 0
  67             w, h = real_w, real_h
  68         end
  69         base.draw_widget(wibox, cr, self.second, x, y, w, h)
  70     end
  71 end
  72
  73 local function widget_changed(layout, old_w, new_w)
  74     if old_w then
  75         old_w:disconnect_signal("widget::updated", layout._emit_updated)
  76     end
  77     if new_w then
  78         widget_base.check_widget(new_w)
  79         new_w:connect_signal("widget::updated", layout._emit_updated)
  80     end
  81     layout._emit_updated()
  82 end
  83
  84 --- Set the layout's first widget. This is the widget that is at the left/top
  85 function align:set_first(widget)
  86     widget_changed(self, self.first, widget)
  87     self.first = widget
  88 end
  89
  90 --- Set the layout's second widget. This is the centered one.
  91 function align:set_second(widget)
  92     widget_changed(self, self.second, widget)
  93     self.second = widget
  94 end
  95
  96 --- Set the layout's third widget. This is the widget that is at the right/bottom
  97 function align:set_third(widget)
  98     widget_changed(self, self.third, widget)
  99     self.third = widget
 100 end
 101
 102 --- Fit the align layout into the given space. The align layout will
 103 -- take all available space in its direction and the maximum size of
 104 -- it's all three inner widgets in the other axis.
 105 -- @param orig_width The available width.
 106 -- @param orig_height The available height.
 107 function align:fit(orig_width, orig_height)
 108     local used_max = 0
 109
 110     for k, v in pairs{self.first, self.second, self.third} do
 111         local w, h = v:fit(orig_width, orig_height)
 112
 113         local max = self.dir == "y" and w or h
 114
 115         if max > used_max then
 116             used_max = max
 117         end
 118     end
 119
 120     if self.dir == "y" then
 121         return used_max, orig_height
 122     end
 123     return orig_width, used_max
 124 end
 125
 126 function align:reset()
 127     for k, v in pairs({ "first", "second", "third" }) do
 128         self[v] = nil
 129     end
 130     self:emit_signal("widget::updated")
 131 end
 132
 133 local function get_layout(dir)
 134     local ret = widget_base.make_widget()
 135     ret.dir = dir
 136     ret._emit_updated = function()
 137         ret:emit_signal("widget::updated")
 138     end
 139
 140     for k, v in pairs(align) do
 141         if type(v) == "function" then
 142             ret[k] = v
 143         end
 144     end
 145
 146     return ret
 147 end
 148
 149 --- Returns a new horizontal align layout. An align layout can display up to
 150 -- three widgets. The widget set via :set_left() is left-aligned. :set_right()
 151 -- sets a widget which will be right-aligned. The remaining space between those
 152 -- two will be given to the widget set via :set_middle().
 153 function align.horizontal()
 154     local ret = get_layout("x")
 155
 156     ret.set_left = ret.set_first
 157     ret.set_middle = ret.set_second
 158     ret.set_right = ret.set_third
 159
 160     return ret
 161 end
 162
 163 --- Returns a new vertical align layout. An align layout can display up to
 164 -- three widgets. The widget set via :set_top() is top-aligned. :set_bottom()
 165 -- sets a widget which will be bottom-aligned. The remaining space between those
 166 -- two will be given to the widget set via :set_middle().
 167 function align.vertical()
 168     local ret = get_layout("y")
 169
 170     ret.set_top = ret.set_first
 171     ret.set_middle = ret.set_second
 172     ret.set_bottom = ret.set_third
 173
 174     return ret
 175 end
 176
 177 return align
 178
 179 -- vim: filetype=lua:expandtab:shiftwidth=4:tabstop=8:softtabstop=4:textwidth=80