001/*
002    Licensed to the Apache Software Foundation (ASF) under one
003    or more contributor license agreements.  See the NOTICE file
004    distributed with this work for additional information
005    regarding copyright ownership.  The ASF licenses this file
006    to you under the Apache License, Version 2.0 (the
007    "License"); you may not use this file except in compliance
008    with the License.  You may obtain a copy of the License at
009
010       http://www.apache.org/licenses/LICENSE-2.0
011
012    Unless required by applicable law or agreed to in writing,
013    software distributed under the License is distributed on an
014    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015    KIND, either express or implied.  See the License for the
016    specific language governing permissions and limitations
017    under the License.  
018 */
019package org.apache.wiki.ui.progress;
020
021/**
022 *  Manages progressing items.  In general this class is used whenever JSPWiki is doing something which may require a long time.
023 *  In addition, this manager provides a JSON interface for finding remotely what the progress is.  The JSON object name is
024 *  JSON_PROGRESSTRACKER = "{@value #JSON_PROGRESSTRACKER}".
025 *
026 *  @since  2.6
027 */
028public interface ProgressManager {
029
030    String JSON_PROGRESSTRACKER = "progressTracker";
031
032    /**
033     *  You can use this to get an unique process identifier.
034     *
035     *  @return A new random value
036     */
037    String getNewProgressIdentifier();
038
039    /**
040     *  Call this method to get your ProgressItem into the ProgressManager queue. The ProgressItem will be moved to state STARTED.
041     *
042     *  @param pi ProgressItem to start
043     *  @param id The progress identifier
044     */
045    void startProgress( ProgressItem pi, String id );
046
047    /**
048     *  Call this method to remove your ProgressItem from the queue (after which getProgress() will no longer find it.
049     *  The ProgressItem will be moved to state STOPPED.
050     *
051     *  @param id The progress identifier
052     */
053    void stopProgress( String id );
054
055    /**
056     *  Get the progress in percents.
057     *
058     *  @param id The progress identifier.
059     *  @return a value between 0 to 100 indicating the progress
060     *  @throws IllegalArgumentException If no such progress item exists.
061     */
062    int getProgress( String id ) throws IllegalArgumentException;
063
064}