Added some structor concepts

expcore/gui/concepts/flow.lua

@@ -0,0 +1,32 @@
+--[[-- Core Module - Gui
+    @module Gui
+    @alias Gui
+]]
+
+local Gui = require 'expcore.gui.core'
+
+--[[-- Invisible containers that lay out children either horizontally or vertically. The root GUI elements (top, left and center; see LuaGui) are flows.
+@element flow
+@tparam string direction the direction that children will be added
+@usage-- Making a basic flow, contains a label with hello world
+local basic_flow =
+Gui.clone_concept('flow','basic_flow')
+:define_draw(function(properties,parent,element)
+    element.add{
+        type = 'label',
+        caption = 'Hello, World!'
+    }
+end)
+]]
+Gui.new_concept('flow')
+:new_property('direction')
+:define_draw(function(properties,parent,element)
+    element = parent.add{
+        name = properties.name,
+        type = 'flow',
+        caption = properties.title,
+        direction = properties.direction
+    }
+
+    return element
+end)