doc: Add a wibox.container.rotate example

Also fix the documentation

lib/wibox/container/rotate.lua

@@ -1,4 +1,6 @@
 ---------------------------------------------------------------------------
+-- A container rotating the conained widget by 90 degrees.
+--
 -- @author Uli Schlachter
 -- @copyright 2010 Uli Schlachter
 -- @release @AWESOME_VERSION@
@@ -85,8 +87,16 @@ function rotate:reset()
     self:set_widget(nil)
 end
 
---- Set the direction of this rotating layout. Valid values are "north", "east",
+--- Set the direction of this rotating container.
--- "south" and "west". On an invalid value, this function will throw an error.
+-- Valid values are:
+--
+-- * *north*
+-- * *east*
+-- * *south*
+-- * *north*
+--
+--@DOC_wibox_container_rotate_angle_EXAMPLE@
+-- @tparam string dir The direction
 function rotate:set_direction(dir)
     local allowed = {
         north = true,

tests/examples/wibox/container/rotate/angle.lua

@@ -0,0 +1,66 @@
+local parent    = ... --DOC_HIDE
+local wibox     = require("wibox") --DOC_HIDE
+local gears     = {shape = require("gears.shape")} --DOC_HIDE
+local beautiful = require("beautiful") --DOC_HIDE
+
+local function create_arrow(text)                           --DOC_HIDE
+    return {                                                --DOC_HIDE
+        {                                                   --DOC_HIDE
+            {                                               --DOC_HIDE
+                text   = text,                              --DOC_HIDE
+                align  = "center",                          --DOC_HIDE
+                valign = "center",                          --DOC_HIDE
+                widget = wibox.widget.textbox,              --DOC_HIDE
+            },                                              --DOC_HIDE
+            shape              = gears.shape.arrow,         --DOC_HIDE
+            bg                 = beautiful.bg_normal,       --DOC_HIDE
+            shape_border_color = beautiful.border_color,    --DOC_HIDE
+            shape_border_width = beautiful.border_width,    --DOC_HIDE
+            widget             = wibox.container.background --DOC_HIDE
+        },                                                  --DOC_HIDE
+        strategy = 'exact',                                 --DOC_HIDE
+        width    = 70,                                      --DOC_HIDE
+        height   = 70,                                      --DOC_HIDE
+        widget   = wibox.container.constraint               --DOC_HIDE
+    }                                                       --DOC_HIDE
+end                                                         --DOC_HIDE
+
+local normal = create_arrow("Normal")
+ 
+local north  = wibox.container {
+    create_arrow("North"),
+ 
+    direction = "north",
+    widget    = wibox.container.rotate
+}
+ 
+local south  = wibox.container {
+    create_arrow("South"),
+ 
+    direction = "south",
+    widget    = wibox.container.rotate
+}
+ 
+local east  = wibox.container {
+    create_arrow("East"),
+ 
+    direction = "east",
+    widget    = wibox.container.rotate
+}
+ 
+local west  = wibox.container {
+    create_arrow("West"),
+ 
+    direction = "west",
+    widget    = wibox.container.rotate
+}
+
+parent : setup {                            --DOC_HIDE
+    normal,                                 --DOC_HIDE
+    north,                                  --DOC_HIDE
+    south,                                  --DOC_HIDE
+    east,                                   --DOC_HIDE
+    west,                                   --DOC_HIDE
+    spacing = 10,                           --DOC_HIDE
+    layout  = wibox.layout.fixed.horizontal --DOC_HIDE
+}                                           --DOC_HIDE