Use <span> instead of <font> (as in GradientFormatter) to keep Mozilla happy.

git-svn-id: https://svn.apache.org/repos/asf/lucene/java/trunk@151029 13f79535-47bb-0310-9956-ffa450edef68

sandbox/contributions/highlighter/src/java/org/apache/lucene/search/highlight/SpanGradientFormatter.java

@@ -0,0 +1,78 @@
+package org.apache.lucene.search.highlight;
+/**
+ * Copyright 2002-2004 The Apache Software Foundation
+ *
+ * Licensed 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.
+ */
+
+/**
+ * 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.
+ *
+ * @see GradientFormatter
+ * @author David Spencer dave@searchmorph.com
+ */
+
+import org.apache.lucene.search.highlight.*;
+
+public class SpanGradientFormatter
+	extends GradientFormatter
+{
+	public SpanGradientFormatter(float maxScore, String minForegroundColor,
+            String maxForegroundColor, String minBackgroundColor,
+            String maxBackgroundColor)
+    {
+		super( maxScore, minForegroundColor,
+			   maxForegroundColor, minBackgroundColor,
+			   maxBackgroundColor);
+	}
+	
+
+	
+	public String highlightTerm(String originalText, TokenGroup tokenGroup)
+    {
+        if (tokenGroup.getTotalScore() == 0)
+            return originalText;
+        float score = tokenGroup.getTotalScore();
+        if (score == 0)
+        {
+            return originalText;
+        }
+
+		// try to size sb correctly
+        StringBuffer sb = new StringBuffer( originalText.length() + EXTRA);
+		
+		sb.append("<span style=\""); 
+		if (highlightForeground) 
+		{
+			sb.append("color: "); 
+			sb.append(getForegroundColorString(score)); 
+			sb.append("; "); 
+		}
+		if (highlightBackground)
+		{
+			sb.append("background: ");
+			sb.append(getBackgroundColorString(score));
+			sb.append("; ");
+		}
+		sb.append("\">");
+		sb.append(originalText);
+		sb.append("</span>");
+        return sb.toString();
+    }
+
+	// guess how much extra text we'll add to the text we're highlighting to try to avoid a  StringBuffer resize
+	private static final String TEMPLATE = "<span style=\"background: #EEEEEE; color: #000000;\">...</span>";
+	private static final int EXTRA = TEMPLATE.length();	
+}