| 1 | /* |
| 2 | * This file is part of lanterna (http://code.google.com/p/lanterna/). |
| 3 | * |
| 4 | * lanterna is free software: you can redistribute it and/or modify |
| 5 | * it under the terms of the GNU Lesser General Public License as published by |
| 6 | * the Free Software Foundation, either version 3 of the License, or |
| 7 | * (at your option) any later version. |
| 8 | * |
| 9 | * This program is distributed in the hope that it will be useful, |
| 10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 12 | * GNU Lesser General Public License for more details. |
| 13 | * |
| 14 | * You should have received a copy of the GNU Lesser General Public License |
| 15 | * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 16 | * |
| 17 | * Copyright (C) 2010-2015 Martin |
| 18 | */ |
| 19 | package com.googlecode.lanterna.gui2; |
| 20 | |
| 21 | import java.io.EOFException; |
| 22 | import java.io.IOException; |
| 23 | import java.util.concurrent.CountDownLatch; |
| 24 | |
| 25 | /** |
| 26 | * Default implementation of TextGUIThread, this class runs the GUI event processing on a dedicated thread. The GUI |
| 27 | * needs to be explicitly started in order for the event processing loop to begin, so you must call {@code start()} |
| 28 | * for this. The GUI thread will stop if {@code stop()} is called, the input stream returns EOF or an exception is |
| 29 | * thrown from inside the event handling loop. |
| 30 | * <p> |
| 31 | * Here is an example of how to use this {@code TextGUIThread}: |
| 32 | * <pre> |
| 33 | * {@code |
| 34 | * MultiWindowTextGUI textGUI = new MultiWindowTextGUI(new SeparateTextGUIThread.Factory(), screen); |
| 35 | * // ... add components ... |
| 36 | * ((AsynchronousTextGUIThread)textGUI.getGUIThread()).start(); |
| 37 | * // ... this thread will continue while the GUI runs on a separate thread ... |
| 38 | * } |
| 39 | * </pre> |
| 40 | * @see TextGUIThread |
| 41 | * @see SameTextGUIThread |
| 42 | * @author Martin |
| 43 | */ |
| 44 | public class SeparateTextGUIThread extends AbstractTextGUIThread implements AsynchronousTextGUIThread { |
| 45 | private volatile State state; |
| 46 | private final Thread textGUIThread; |
| 47 | private final CountDownLatch waitLatch; |
| 48 | |
| 49 | private SeparateTextGUIThread(TextGUI textGUI) { |
| 50 | super(textGUI); |
| 51 | this.waitLatch = new CountDownLatch(1); |
| 52 | this.textGUIThread = new Thread("LanternaGUI") { |
| 53 | @Override |
| 54 | public void run() { |
| 55 | mainGUILoop(); |
| 56 | } |
| 57 | }; |
| 58 | state = State.CREATED; |
| 59 | } |
| 60 | |
| 61 | @Override |
| 62 | public void start() { |
| 63 | textGUIThread.start(); |
| 64 | state = State.STARTED; |
| 65 | } |
| 66 | |
| 67 | @Override |
| 68 | public void stop() { |
| 69 | if(state != State.STARTED) { |
| 70 | return; |
| 71 | } |
| 72 | |
| 73 | state = State.STOPPING; |
| 74 | } |
| 75 | |
| 76 | @Override |
| 77 | public void waitForStop() throws InterruptedException { |
| 78 | waitLatch.await(); |
| 79 | } |
| 80 | |
| 81 | @Override |
| 82 | public State getState() { |
| 83 | return state; |
| 84 | } |
| 85 | |
| 86 | @Override |
| 87 | public Thread getThread() { |
| 88 | return textGUIThread; |
| 89 | } |
| 90 | |
| 91 | @Override |
| 92 | public void invokeLater(Runnable runnable) throws IllegalStateException { |
| 93 | if(state != State.STARTED) { |
| 94 | throw new IllegalStateException("Cannot schedule " + runnable + " for execution on the TextGUIThread " + |
| 95 | "because the thread is in " + state + " state"); |
| 96 | } |
| 97 | super.invokeLater(runnable); |
| 98 | } |
| 99 | |
| 100 | private void mainGUILoop() { |
| 101 | try { |
| 102 | //Draw initial screen, after this only draw when the GUI is marked as invalid |
| 103 | try { |
| 104 | textGUI.updateScreen(); |
| 105 | } |
| 106 | catch(IOException e) { |
| 107 | exceptionHandler.onIOException(e); |
| 108 | } |
| 109 | catch(RuntimeException e) { |
| 110 | exceptionHandler.onRuntimeException(e); |
| 111 | } |
| 112 | while(state == State.STARTED) { |
| 113 | try { |
| 114 | if (!processEventsAndUpdate()) { |
| 115 | try { |
| 116 | Thread.sleep(1); |
| 117 | } |
| 118 | catch(InterruptedException ignored) {} |
| 119 | } |
| 120 | } |
| 121 | catch(EOFException e) { |
| 122 | stop(); |
| 123 | break; //Break out quickly from the main loop |
| 124 | } |
| 125 | catch(IOException e) { |
| 126 | if(exceptionHandler.onIOException(e)) { |
| 127 | stop(); |
| 128 | break; |
| 129 | } |
| 130 | } |
| 131 | catch(RuntimeException e) { |
| 132 | if(exceptionHandler.onRuntimeException(e)) { |
| 133 | stop(); |
| 134 | break; |
| 135 | } |
| 136 | } |
| 137 | } |
| 138 | } |
| 139 | finally { |
| 140 | state = State.STOPPED; |
| 141 | waitLatch.countDown(); |
| 142 | } |
| 143 | } |
| 144 | |
| 145 | |
| 146 | /** |
| 147 | * Factory class for creating SeparateTextGUIThread objects |
| 148 | */ |
| 149 | public static class Factory implements TextGUIThreadFactory { |
| 150 | @Override |
| 151 | public TextGUIThread createTextGUIThread(TextGUI textGUI) { |
| 152 | return new SeparateTextGUIThread(textGUI); |
| 153 | } |
| 154 | } |
| 155 | } |