The STACK container holds stack items defining
 a logical alignment of form items.
Important: This feature is experimental, the syntax/name and semantics/behavior may
   change in a future version.
 
Important: STACK layout was introduced for mobile application programming (GMA/GMI).
This type of layout is not supported by GWC-JS and GDC.
 
 
Syntax
  STACK
  { scalable-item
  | container-list
  }
END
            where 
container-list
                is:
grouping-item 
   leaf-item
   [...]
END
[...]
 
 
                - scalable-item is a leaf element of the stacked layout, for
                    widgets with a scalable width and height.
 
                - grouping-item is a stacked layout grouping element that holds
                    a list of leaf-items.
 
- leaf-item is a leaf element of the stacked layout, for widgets with a fixed
                    size (non-scalable).
 
  
        
Usage
            The STACK container is used to define a stack-based layout.
            
                Note: Unlike grid-based containers (GRID) where element definition
                    is splitted in the LAYOUT and ATTRIBUTES
                    sections, the items in a STACK container define both the
                    position and attributes.
             
            The 
STACK container typically defines a list of elements (such as
                
GROUP, 
FOLDER, 
TABLE), grouping
                leaf stack items (such as form fields) together:
LAYOUT
 STACK
  GROUP custinfo (TEXT="Customer info")
    EDIT customer.cust_num, TITLE="Num:", NOENTRY;
    EDIT customer.cust_name, TITLE="Name:", SCROLL;
    ...
  END
  TABLE cust_orders (STYLE="compact_list", DOUBLECLICK=select)
    LABEL orders.ord_num, TITLE="Num";
    LABEL orders.ord_ship, TITLE="Ship date";
    LABEL orders.ord_value, TITLE="Value";
    ...
  END
  ...
 END
END
 
            A stack container can also define a single scalable stack item, such as an
                IMAGE, TEXTEDIT or
                WEBCOMPONENT:
            STACK
  IMAGE FORMONLY.picture;
END