001// Copyright 2011 The Apache Software Foundation
002//
003// Licensed under the Apache License, Version 2.0 (the "License");
004// you may not use this file except in compliance with the License.
005// You may obtain a copy of the License at
006//
007//     http://www.apache.org/licenses/LICENSE-2.0
008//
009// Unless required by applicable law or agreed to in writing, software
010// distributed under the License is distributed on an "AS IS" BASIS,
011// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
012// See the License for the specific language governing permissions and
013// limitations under the License.
014
015package org.apache.tapestry5.internal.services;
016
017import org.apache.tapestry5.services.StackTraceElementAnalyzer;
018
019import java.util.regex.Pattern;
020
021/**
022 * Uses a regular expression to identify which CSS class to apply to a frame. The frame's {@code toString()} is used. Uses
023 * {@link java.util.regex.Matcher#find()} to search for a subsequence of the frame's description.
024 *
025 * @since 5.3
026 */
027public class RegexpStackTraceElementAnalyzer implements StackTraceElementAnalyzer
028{
029    private final Pattern pattern;
030
031    private final String cssClass;
032
033    public RegexpStackTraceElementAnalyzer(Pattern pattern, String cssClass)
034    {
035        this.pattern = pattern;
036        this.cssClass = cssClass;
037    }
038
039    public String classForFrame(StackTraceElement frame)
040    {
041        if (pattern.matcher(frame.toString()).find())
042        {
043            return cssClass;
044        }
045
046        return null;
047    }
048}