     [Inspectable(category="General")]
 
     /**
-     *  The measured size of this layout will be wide enough to display 
+     *  The measured size of this layout is wide enough to display 
      *  the first <code>requestedColumnCount</code> layout elements. 
-     * 
      *  If <code>requestedColumnCount</code> is -1, then the measured
      *  size will be big enough for all of the layout elements.
      * 
-     *  This property implies the layout target's <code>measuredWidth</code>.
-     * 
-     *  If the actual size of the <code>target</code> has been explicitly set,
-     *  then this property has no effect.
+     *  <p>If the actual size of the container using this layout has been explicitly set,
+     *  then this property has no effect.</p>
      * 
      *  @default -1
      *  

    
    /**
     *  Returns 1.0 if the specified index is completely in view, 0.0 if
     *  it's not, and a value in between if the index is partially 
     *  within the view.
     * 
     *  An index is "in view" if the corresponding non-null layout element is 
     *  within the horizontal limits of the layout target's scrollRect
     *  and included in the layout.
     *  
     *  If the specified index is partially within the view, the 
     *  returned value is the percentage of the corresponding
     *  layout element that's visible.
     * 
     *  Returns 0.0 if the specified index is invalid or if it corresponds to
     *  null element, or a ILayoutElement for which includeInLayout is false.
     * 
     *  @return the percentage of the specified element that's in view.
     *  @see firstIndexInView
     *  @see lastIndexInView
     *  
     *  @langversion 3.0
     *  @playerversion Flash 10

import spark.layouts.supportClasses.LinearLayoutVector;

/**
 *  The HorizontalLayout class arranges the layout elements in a horizontal sequence,
 *  left to right, with optional gaps between the elements and optional padding
 *  around the elements.
 *
 *  <p>The horizontal position of the elements is determined by arranging them
 *  in a horizontal sequence, left to right, taking into account the padding
 *  before the first element and the gaps between the elements.</p>
 *
 *  <p>The vertical position of the elements is determined by the layout's 
 *  <code>verticalAlign</code> property.</p>
 *
 *  <p>During the execution of the <code>measure()</code> method, 
 *  the default size of the container is calculated by
 *  accumulating the preferred sizes of the elements, including gaps and padding.
 *  When the <code>requestedColumnCount</code> property is set to a value other than -1, 
 *  only the space for that many elements
 *  is measured, starting from the first element.</p>
 *
 *  <p>During the execution of the <code>updateDisplayList()</code> method, 
 *  the width of each element is calculated
 *  according to the following rules, listed in their respective order of
 *  precedence (element's minimum width and maximum width are always respected):</p>
 *  <ul>
 *    <li>If <code>variableColumnWidth</code> is <code>false</code>, 
 *    then set the element's width to the
 *    value of the <code>columnWidth</code> property.</li>
 *
 *    <li>If the element's <code>percentWidth</code> is set, then calculate the element's
 *    width by distributing the available container width between all
 *    elements with <code>percentWidth</code> setting. 
 *    The available container width
 *    is equal to the container width minus the gaps, the padding and the
 *    space occupied by the rest of the elements. The element's <code>precentWidth</code>
 *    property is ignored when the layout is virtualized.</li>
 *
 *    <li>Set the element's width to its preferred width.</li>
 *  </ul>
 *
 *  <p>The height of each element is calculated according to the following rules,
 *  listed in their respective order of precedence (element's minimum height and
 *  maximum height are always respected):</p>
 *  <ul>
 *    <li>If the <code>verticalAlign</code> property is <code>"justify"</code>,
 *   then set the element's height to the container height.</li>
 *
 *    <li>If the <code>verticalAlign</code> property is <code>"contentJustify"</code>, 
 *    then set the element's height to the maximum between the container's height 
 *    and all elements' preferred height.</li>
 *
 *    <li>If the element's <code>percentHeight</code> property is set, 
 *    then calculate the element's height as a percentage of the container's height.</li>
 *
 *    <li>Set the element's height to its preferred height.</li>
 *  </ul>
 *
 *  @mxml 
 *  <p>The <code>&lt;HorizontalLayout&gt;</code> tag inherits all of the tag 
 *  attributes of its superclass and adds the following tag attributes:</p>
 *
 *  <pre>
 *  &lt;HorizontalLayout 
 *    <strong>Properties</strong>
 *    columnWidth="<i>calculated</i>"
 *    gap="6"
 *    paddingBottom="0"
 *    paddingLeft="0"
 *    paddingRight="0"
 *    paddingTop="0"
 *    requestedColumnCount="-1"
 *    variableColumnWidth="true"
 *    verticalAlign="top"
 *  /&gt;
 *  </pre>
 *
 *  @langversion 3.0
 *  @playerversion Flash 10
