J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2005-2006 Sun Microsystems, Inc. All Rights Reserved. |
| 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| 4 | * |
| 5 | * This code is free software; you can redistribute it and/or modify it |
| 6 | * under the terms of the GNU General Public License version 2 only, as |
| 7 | * published by the Free Software Foundation. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun in the LICENSE file that accompanied this code. |
| 10 | * |
| 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
| 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| 14 | * version 2 for more details (a copy is included in the LICENSE file that |
| 15 | * accompanied this code). |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License version |
| 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
| 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| 20 | * |
| 21 | * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | package sun.swing; |
| 26 | |
| 27 | import java.util.*; |
| 28 | import java.lang.reflect.Array; |
| 29 | import javax.swing.SwingUtilities; |
| 30 | |
| 31 | /** |
| 32 | * An abstract class to be used in the cases where we need {@code Runnable} |
| 33 | * to perform some actions on an appendable set of data. |
| 34 | * The set of data might be appended after the {@code Runnable} is |
| 35 | * sent for the execution. Usually such {@code Runnables} are sent to |
| 36 | * the EDT. |
| 37 | * |
| 38 | * <p> |
| 39 | * Usage example: |
| 40 | * |
| 41 | * <p> |
| 42 | * Say we want to implement JLabel.setText(String text) which sends |
| 43 | * {@code text} string to the JLabel.setTextImpl(String text) on the EDT. |
| 44 | * In the event JLabel.setText is called rapidly many times off the EDT |
| 45 | * we will get many updates on the EDT but only the last one is important. |
| 46 | * (Every next updates overrides the previous one.) |
| 47 | * We might want to implement this {@code setText} in a way that only |
| 48 | * the last update is delivered. |
| 49 | * <p> |
| 50 | * Here is how one can do this using {@code AccumulativeRunnable}: |
| 51 | * <pre> |
| 52 | * AccumulativeRunnable<String> doSetTextImpl = |
| 53 | * new AccumulativeRunnable<String>() { |
| 54 | * @Override |
| 55 | * protected void run(List<String> args) { |
| 56 | * //set to the last string being passed |
| 57 | * setTextImpl(args.get(args.size() - 1)); |
| 58 | * } |
| 59 | * } |
| 60 | * void setText(String text) { |
| 61 | * //add text and send for the execution if needed. |
| 62 | * doSetTextImpl.add(text); |
| 63 | * } |
| 64 | * </pre> |
| 65 | * |
| 66 | * <p> |
| 67 | * Say we want want to implement addDirtyRegion(Rectangle rect) |
| 68 | * which sends this region to the |
| 69 | * handleDirtyRegions(List<Rect> regiouns) on the EDT. |
| 70 | * addDirtyRegions better be accumulated before handling on the EDT. |
| 71 | * |
| 72 | * <p> |
| 73 | * Here is how it can be implemented using AccumulativeRunnable: |
| 74 | * <pre> |
| 75 | * AccumulativeRunnable<Rectangle> doHandleDirtyRegions = |
| 76 | * new AccumulativeRunnable<Rectangle>() { |
| 77 | * @Override |
| 78 | * protected void run(List<Rectangle> args) { |
| 79 | * handleDirtyRegions(args); |
| 80 | * } |
| 81 | * }; |
| 82 | * void addDirtyRegion(Rectangle rect) { |
| 83 | * doHandleDirtyRegions.add(rect); |
| 84 | * } |
| 85 | * </pre> |
| 86 | * |
| 87 | * @author Igor Kushnirskiy |
| 88 | * |
| 89 | * @param <T> the type this {@code Runnable} accumulates |
| 90 | * |
| 91 | * @since 1.6 |
| 92 | */ |
| 93 | public abstract class AccumulativeRunnable<T> implements Runnable { |
| 94 | private List<T> arguments = null; |
| 95 | |
| 96 | /** |
| 97 | * Equivalent to {@code Runnable.run} method with the |
| 98 | * accumulated arguments to process. |
| 99 | * |
| 100 | * @param args accumulated argumets to process. |
| 101 | */ |
| 102 | protected abstract void run(List<T> args); |
| 103 | |
| 104 | /** |
| 105 | * {@inheritDoc} |
| 106 | * |
| 107 | * <p> |
| 108 | * This implementation calls {@code run(List<T> args)} mehtod |
| 109 | * with the list of accumulated arguments. |
| 110 | */ |
| 111 | public final void run() { |
| 112 | run(flush()); |
| 113 | } |
| 114 | |
| 115 | /** |
| 116 | * appends arguments and sends this {@cod Runnable} for the |
| 117 | * execution if needed. |
| 118 | * <p> |
| 119 | * This implementation uses {@see #submit} to send this |
| 120 | * {@code Runnable} for execution. |
| 121 | * @param args the arguments to accumulate |
| 122 | */ |
| 123 | public final synchronized void add(T... args) { |
| 124 | boolean isSubmitted = true; |
| 125 | if (arguments == null) { |
| 126 | isSubmitted = false; |
| 127 | arguments = new ArrayList<T>(); |
| 128 | } |
| 129 | Collections.addAll(arguments, args); |
| 130 | if (!isSubmitted) { |
| 131 | submit(); |
| 132 | } |
| 133 | } |
| 134 | |
| 135 | /** |
| 136 | * Sends this {@code Runnable} for the execution |
| 137 | * |
| 138 | * <p> |
| 139 | * This method is to be executed only from {@code add} method. |
| 140 | * |
| 141 | * <p> |
| 142 | * This implementation uses {@code SwingWorker.invokeLater}. |
| 143 | */ |
| 144 | protected void submit() { |
| 145 | SwingUtilities.invokeLater(this); |
| 146 | } |
| 147 | |
| 148 | /** |
| 149 | * Returns accumulated arguments and flashes the arguments storage. |
| 150 | * |
| 151 | * @return accumulated arguments |
| 152 | */ |
| 153 | private final synchronized List<T> flush() { |
| 154 | List<T> list = arguments; |
| 155 | arguments = null; |
| 156 | return list; |
| 157 | } |
| 158 | } |