Package org.apache.lucene.search.highlight

Class GradientFormatter

  • All Implemented Interfaces:
    Formatter
    Direct Known Subclasses:
    SpanGradientFormatter
    public class GradientFormatter
extends java.lang.Object
implements Formatter
    Formats text with different color intensity depending on the score of the term.

    • Constructor Summary

      Constructors 
      Constructor Description
      GradientFormatter​(float maxScore, java.lang.String minForegroundColor, java.lang.String maxForegroundColor, java.lang.String minBackgroundColor, java.lang.String maxBackgroundColor)
      Sets the color range for the IDF scores

    • Method Summary

      All Methods Static Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      static int hexToInt​(java.lang.String hex)
      Converts a hex string into an int.
      java.lang.String highlightTerm​(java.lang.String originalText, TokenGroup tokenGroup)  

      • Methods inherited from class java.lang.Object

        equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • GradientFormatter

        public GradientFormatter​(float maxScore,
                         java.lang.String minForegroundColor,
                         java.lang.String maxForegroundColor,
                         java.lang.String minBackgroundColor,
                         java.lang.String maxBackgroundColor)
        Sets the color range for the IDF scores
        Parameters:
        maxScore - The score (and above) displayed as maxColor (See QueryScorer.getMaxWeight which can be used to calibrate scoring scale)
        minForegroundColor - The hex color used for representing IDF scores of zero eg #FFFFFF (white) or null if no foreground color required
        maxForegroundColor - The largest hex color used for representing IDF scores eg #000000 (black) or null if no foreground color required
        minBackgroundColor - The hex color used for representing IDF scores of zero eg #FFFFFF (white) or null if no background color required
        maxBackgroundColor - The largest hex color used for representing IDF scores eg #000000 (black) or null if no background color required

    • Method Detail

      • highlightTerm

        public java.lang.String highlightTerm​(java.lang.String originalText,
                                      TokenGroup tokenGroup)
        Specified by:
        highlightTerm in interface Formatter
        Parameters:
        originalText - The section of text being considered for markup
        tokenGroup - contains one or several overlapping Tokens along with their scores and positions.

      • hexToInt

        public static final int hexToInt​(java.lang.String hex)
        Converts a hex string into an int. Integer.parseInt(hex, 16) assumes the input is nonnegative unless there is a preceding minus sign. This method reads the input as twos complement instead, so if the input is 8 bytes long, it will correctly restore a negative int produced by Integer.toHexString() but not necessarily one produced by Integer.toString(x,16) since that method will produce a string like '-FF' for negative integer values.
        Parameters:
        hex - A string in capital or lower case hex, of no more then 16 characters.
        Throws:
        java.lang.NumberFormatException - if the string is more than 16 characters long, or if any character is not in the set [0-9a-fA-f]