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package flashx.textLayout.formats
{
    /**
     *  Defines values for setting the <code>leadingModel</code> property
     *  of the <code>TextLayoutFormat</code> class, composed of valid combinations of leading basis and leading direction.
     *  Leading basis describes which baselines determine the leading (or <code>lineHeight</code>) of lines in a paragraph.
     *  Leading direction specifies whether the <code>lineHeight</code> property refers to the distance of a line's 
     *  baseline from that of the line before it or the line after it. 
     *  <p>
     *  <img src="../../../images/textLayout_baselines.jpg" alt="baselines" border="0"/>
     *  <img src="../../../images/textLayout_LD1.jpg" alt="leadingDirection_1" border="0"/>
     *  <img src="../../../images/textLayout_LD2.jpg" alt="leadingDirection_2" border="0"/>
     *  <img src="../../../images/textLayout_LD3.jpg" alt="leadingDirection_3" border="0"/>
     *  </p>
     *  @playerversion Flash 10
     *  @playerversion AIR 1.5
     *  @langversion 3.0 
     * 
     *  @see TextLayoutFormat#leadingModel
     *  @see TextLayoutFormat#lineHeight
     *  @see flash.text.TextField
     *  @see flash.text.engine.TextLine 
     */
     
    public final class LeadingModel
    {
        /** Specifies that leading basis is ROMAN and leading direction is UP. 
         * In other words, <code>lineHeight</code> refers to the distance of a line's Roman baseline from the 
         * previous line's Roman baseline.
         *
         * @playerversion Flash 10
         * @playerversion AIR 1.5
         * @langversion 3.0 
         */
         
        public static const ROMAN_UP:String = "romanUp";
        
        /** Specifies that leading basis is IDEOGRAPHIC_TOP and leading direction is UP. 
         *  In other words, <code>lineHeight</code> refers to the distance of a line's ideographic top 
         *  baseline from the previous line's ideographic top baseline.
         *
         * @playerversion Flash 10
         * @playerversion AIR 1.5
         * @langversion 3.0 
         */
         
        public static const IDEOGRAPHIC_TOP_UP:String = "ideographicTopUp";
        
        /** Specifies that leading basis is IDEOGRAPHIC_CENTER and leading direction is UP. 
         * In other words, <code>lineHeight</code> refers to the distance of a line's ideographic center 
         * baseline from the previous line's ideographic center baseline.
         *
         * @playerversion Flash 10
         * @playerversion AIR 1.5
         * @langversion 3.0 
         */
         
        public static const IDEOGRAPHIC_CENTER_UP:String = "ideographicCenterUp";
        
        /** Specifies that leading basis is IDEOGRAPHIC_TOP and leading direction is DOWN.
         * In other words, <code>lineHeight</code> refers to the distance of a line's ideographic top baseline 
         * from the next line's ideographic top baseline.
         *
         * @playerversion Flash 10
         * @playerversion AIR 1.5
         * @langversion 3.0 
         */
         
        public static const IDEOGRAPHIC_TOP_DOWN:String = "ideographicTopDown";
        
        /** Specifies that leading basis is IDEOGRAPHIC_CENTER and leading direction is down.
         *  In other words, <code>lineHeight</code> refers to the distance of a line's ideographic center 
         *  baseline from the next line's ideographic center baseline.
         *
         * @playerversion Flash 10
         * @playerversion AIR 1.5
         * @langversion 3.0 
         */
         
        public static const IDEOGRAPHIC_CENTER_DOWN:String = "ideographicCenterDown";
        
        /** Specifies that leading basis is ASCENT/DESCENT and leading direction is UP. 
         *  In other words, <code>lineHeight</code> refers to the distance of a line's ascent baseline from the 
         *  previous line's descent baseline.
         *
         * @playerversion Flash 10
         * @playerversion AIR 1.5
         * @langversion 3.0 
         */
         
        public static const ASCENT_DESCENT_UP:String = "ascentDescentUp";
        
        /** Specifies that leading model is chosen automatically based on the paragraph's <code>locale</code> property.  
         * For Japanese and Chinese, it is IDEOGRAPHIC_TOP_DOWN and for all others it is ROMAN_UP.
         *
         * @playerversion Flash 10
         * @playerversion AIR 1.5
         * @langversion 3.0 
         * 
         * #IDEOGRAPHIC_TOP_DOWN
         * #ROMAN_UP
         */
         
        public static const AUTO:String = "auto";
        
        /** Specifies a leading model that approximates the line spacing behavior of <code>TextField</code>.
         * It is similar to <code>ASCENT_DESCENT_UP</code> in that <code>lineHeight</code> refers to the 
         * distance of a line's ascent baseline from the previous line's descent baseline. However, baseline 
         * positions approximate those determined by <code>TextField</code>, rather than using metrics 
         * offered by <code>TextLine</code>.  
         *
         * @playerversion Flash 10
         * @playerversion AIR 1.5
         * @langversion 3.0 
         */
        public static const APPROXIMATE_TEXT_FIELD:String = "approximateTextField";
        
        /**  Specifies a leading model based on the CSS inline formatting model, which involves stacking <i>line boxes</i> contiguously.
         * A <i>line box</i> is defined as the bounding box around <i>inline boxes</i> for all leaf elements on the text line, after they have been aligned
         * using <code>baselineShift</code>, <code>dominantBaseline</code>, <code>alignmentBaseline</code> etc. For a span, the <i>inline box</i> 
         * is obtained by applying leading equally above and below the text content such that its height equals <code>lineHeight</code>.
         * For an inline graphic, <code>lineHeight</code> is ignored; the <i>inline box</i> is derived from its specified dimensions and padding values.
         * Also, <code>firstBaselineOffset</code> is ignored with this leading model.
         * 
         * <p>For more information, see <a href='http://blogs.adobe.com/tlf/2010/11/box-leading-model.html'>Box leading model</a>.</p>
         * 
         * @playerversion Flash 10
         * @playerversion AIR 1.5
         * @langversion 3.0 
         */
        public static const BOX:String = "box";
        
    }
}