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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.IOException; | |
22 | ||
23 | /** | |
24 | * Class that represents the thread this is expected to run the event/input/update loop for the {@code TextGUI}. There | |
25 | * are mainly two implementations of this interface, one for having lanterna automatically spawn a new thread for doing | |
26 | * all the processing and leaving the creator thread free to do other things, and one that assumes the creator thread | |
27 | * will hand over control to lanterna for as long as the GUI is running. | |
28 | * @see SameTextGUIThread | |
29 | * @see SeparateTextGUIThread | |
30 | * @author Martin | |
31 | */ | |
32 | public interface TextGUIThread { | |
33 | /** | |
34 | * Invokes custom code on the GUI thread. If the caller is already on the GUI thread, the code is executed immediately | |
35 | * @param runnable Code to run | |
36 | * @throws java.lang.IllegalStateException If the GUI thread is not running | |
37 | */ | |
38 | void invokeLater(Runnable runnable) throws IllegalStateException; | |
39 | ||
40 | /** | |
41 | * Main method to call when you are managing the event/input/update loop yourself. This method will run one round | |
42 | * through the GUI's event/input queue and update the visuals if required. If the operation did nothing (returning | |
43 | * {@code false}) you could sleep for a millisecond and then try again. If you use {@code SameTextGUIThread} you | |
44 | * must either call this method directly to make the GUI update or use one of the methods on | |
45 | * {@code WindowBasedTextGUI} that blocks until a particular window has closed. | |
46 | * @return {@code true} if there was anything to process or the GUI was updated, otherwise {@code false} | |
47 | * @throws IOException | |
48 | */ | |
49 | @SuppressWarnings("BooleanMethodIsAlwaysInverted") | |
50 | boolean processEventsAndUpdate() throws IOException; | |
51 | ||
52 | /** | |
53 | * Schedules custom code to be executed on the GUI thread and waits until the code has been executed before | |
54 | * returning. | |
55 | * @param runnable Code to run | |
56 | * @throws IllegalStateException If the GUI thread is not running | |
57 | * @throws InterruptedException If the caller thread was interrupted while waiting for the task to be executed | |
58 | */ | |
59 | void invokeAndWait(Runnable runnable) throws IllegalStateException, InterruptedException; | |
60 | ||
61 | /** | |
62 | * Updates the exception handler used by this TextGUIThread. The exception handler will be invoked when an exception | |
63 | * occurs in the main event loop. You can then decide how to log this exception and if you want to terminate the | |
64 | * thread or not. | |
65 | * @param exceptionHandler Handler to inspect exceptions | |
66 | */ | |
67 | void setExceptionHandler(ExceptionHandler exceptionHandler); | |
68 | ||
69 | /** | |
70 | * Returns the Java thread which is processing GUI events and updating the screen | |
71 | * @return Thread which is processing events and updating the screen | |
72 | */ | |
73 | Thread getThread(); | |
74 | ||
75 | /** | |
76 | * This interface defines an exception handler, that is used for looking at exceptions that occurs during the main | |
77 | * event loop of the TextGUIThread. You can for example use this for logging, but also decide if you want the | |
78 | * exception to kill the thread. | |
79 | */ | |
80 | interface ExceptionHandler { | |
81 | /** | |
82 | * Will be called when an IOException has occurred in the main event thread | |
83 | * @param e IOException that occurred | |
84 | * @return If you return {@code true}, the event thread will be terminated | |
85 | */ | |
86 | boolean onIOException(IOException e); | |
87 | ||
88 | /** | |
89 | * Will be called when a RuntimeException has occurred in the main event thread | |
90 | * @param e RuntimeException that occurred | |
91 | * @return If you return {@code true}, the event thread will be terminated | |
92 | */ | |
93 | boolean onRuntimeException(RuntimeException e); | |
94 | } | |
95 | } |