/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
using System;
using System.Text;
namespace Lucene.Net.Search.Highlight
{
///
/// Formats text with different color intensity depending on the score of the
/// term using the span tag. GradientFormatter uses a bgcolor argument to the font tag which
/// doesn't work in Mozilla, thus this class.
///
///
public class SpanGradientFormatter : GradientFormatter
{
// guess how much extra text we'll add to the text we're highlighting to try to avoid a StringBuilder resize
private static readonly String TEMPLATE = "...";
private static readonly int EXTRA = TEMPLATE.Length;
public SpanGradientFormatter(float maxScore, String minForegroundColor,
String maxForegroundColor, String minBackgroundColor,
String maxBackgroundColor)
: base(maxScore, minForegroundColor, maxForegroundColor, minBackgroundColor, maxBackgroundColor)
{ }
public override String HighlightTerm(String originalText, TokenGroup tokenGroup)
{
if (tokenGroup.TotalScore == 0)
return originalText;
float score = tokenGroup.TotalScore;
if (score == 0)
{
return originalText;
}
// try to size sb correctly
var sb = new StringBuilder(originalText.Length + EXTRA);
sb.Append("");
sb.Append(originalText);
sb.Append("");
return sb.ToString();
}
}
}