src/main/java/org/apache/log4j/chainsaw/ThresholdSlider.java

/*
 * 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.
 */

package org.apache.log4j.chainsaw;

import java.util.Arrays;
import java.util.Hashtable;
import java.util.List;

import javax.swing.DefaultBoundedRangeModel;
import javax.swing.JLabel;
import javax.swing.JSlider;
import javax.swing.SwingConstants;

import org.apache.log4j.Level;


/**
 * A Slider implementation that allows a user to
 * choose a particular Threshold
 * .
 * @author Paul Smith <psmith@apache.org>
 *
 */
final class ThresholdSlider extends JSlider {
  final List priorityList;

  ThresholdSlider() {
    Level[] levels =
      new Level[] {
        Level.OFF, Level.FATAL, Level.ERROR, Level.WARN, Level.INFO,
        Level.DEBUG, Level.TRACE, Level.ALL
      };

    priorityList = Arrays.asList(levels);

    priorityList.sort((o1, o2) -> {
        Level p1 = (Level) o1;
        Level p2 = (Level) o2;

        if (p1.toInt() == p2.toInt()) {
            return 0;
        } else if (p1.toInt() < p2.toInt()) {
            return -1;
        }

        return 1;
    });

    setModel(
      new DefaultBoundedRangeModel(
        priorityList.indexOf(Level.TRACE), 0, 0, priorityList.size() - 1));

    Hashtable<Integer, JLabel> labelMap = new Hashtable<>();

      for (Object aPriorityList : priorityList) {
          Level item = (Level) aPriorityList;
          labelMap.put(
                  priorityList.indexOf(item), new JLabel(item.toString()));

          //      System.out.println("creating levels for :: " + item.toInt() + "," + item.toString());
      }

    setOrientation(SwingConstants.VERTICAL);
    setInverted(true);
    setLabelTable(labelMap);

    setPaintLabels(true);

    //    setPaintTicks(true);
    setSnapToTicks(true);

    //    setMajorTickSpacing(10000);
    //    setPaintTrack(true);
  }

  void setChosenLevel(Level level) {
    setValue(priorityList.indexOf(level));
  }

  /**
   * Returns the Log4j Level that is currently selected in this slider
   * @return
   */
  Level getSelectedLevel() {
    Level level = (Level) priorityList.get(getValue());

    if (level == null) {
      level = Level.TRACE;
    }

    return level;
  }
}