bundles/org.simantics.databoard/src/org/simantics/databoard/accessor/impl/EventCollection.java

   1 /*******************************************************************************
   2  *  Copyright (c) 2010 Association for Decentralized Information Management in
   3  *  Industry THTH ry.
   4  *  All rights reserved. This program and the accompanying materials
   5  *  are made available under the terms of the Eclipse Public License v1.0
   6  *  which accompanies this distribution, and is available at
   7  *  http://www.eclipse.org/legal/epl-v10.html
   8  *
   9  *  Contributors:
  10  *      VTT Technical Research Centre of Finland - initial API and implementation
  11  *******************************************************************************/
  12 package org.simantics.databoard.accessor.impl;
  13
  14 import java.util.ArrayList;
  15 import java.util.Collection;
  16 import java.util.List;
  17
  18 import org.simantics.databoard.accessor.Accessor.Listener;
  19 import org.simantics.databoard.accessor.event.Event;
  20 import org.simantics.databoard.accessor.event.ModificationEvent;
  21
  22 /**
  23  * Event Collection is a {@link Listener} implementation that collects events.
  24  *
  25  * @see ModificationEvent
  26  * @author Toni Kalajainen <toni.kalajainen@vtt.fi>
  27  */
  28 public class EventCollection implements Listener {
  29
  30         public List<Event> events = new ArrayList<Event>();
  31
  32         public synchronized void addEvent(Event event) {
  33                 this.events.add(event);
  34         }
  35
  36         public synchronized void addEvents(Collection<Event> events) {
  37                 this.events.addAll(events);
  38         }
  39
  40         /**
  41          * Returns events and clears change set.
  42          *
  43          * @return the list of events
  44          */
  45         public synchronized List<Event> getAndClearEvents() {
  46                 List<Event> result = events;
  47                 events = new ArrayList<Event>();
  48                 return result;
  49         }
  50
  51         public synchronized boolean isEmpty() {
  52                 return events.isEmpty();
  53         }
  54
  55         /**
  56          * Get a snapshot of events.
  57          *
  58          * @return a copy of events
  59          */
  60         public synchronized List<Event> getEvents() {
  61                 return new ArrayList<Event>( events );
  62         }
  63
  64         @Override
  65         public void onEvents(Collection<Event> events) {
  66                 addEvents(events);
  67         }
  68
  69         @Override
  70         public synchronized String toString() {
  71                 StringBuilder sb = new StringBuilder();
  72                 sb.append('[');
  73                 int len = events.size();
  74                 if (len>1) sb.append("\n ");
  75                 for (int i=0; i<len; i++) {
  76                         Event e = events.get(i);
  77                         if (i>0) sb.append("\n ");
  78                         sb.append(e.toString());
  79                 }
  80                 if (len>1) sb.append('\n');
  81                 sb.append(']');
  82                 return sb.toString();
  83         }
  84
  85         public synchronized void clear() {
  86                 events.clear();
  87         }
  88
  89 }
  90