Added some structor concepts

expcore/gui/concepts/scroll.lua

@@ -0,0 +1,37 @@
+--[[-- Core Module - Gui
+    @module Gui
+    @alias Gui
+]]
+
+local Gui = require 'expcore.gui.core'
+
+--[[-- Similar to a flow but includes the ability to show and use scroll bars.
+@element scroll
+@tparam string horizontal_scroll the horizontal scroll policy for this scroll pane
+@tparam string vertical_scroll the vertical scroll policy for this scroll pane
+@usage-- Making a basic flow, contains a label with hello world
+local basic_scroll =
+Gui.clone_concept('scroll','basic_scroll')
+:define_draw(function(properties,parent,element)
+    element.style.hieght = 50
+    for i = 1,10 do
+        element.add{
+            type = 'label',
+            caption = i
+        }
+    end
+end)
+]]
+Gui.new_concept('scroll')
+:new_property('horizontal_scroll')
+:new_property('vertical_scroll')
+:define_draw(function(properties,parent,element)
+    element = parent.add{
+        name = properties.name,
+        type = 'scroll-pane',
+        horizontal_scroll_policy = properties.horizontal_scroll,
+        vertical_scroll_policy = properties.vertical_scroll
+    }
+
+    return element
+end)