src/jexer/backend/Backend.java

   1 /**
   2  * Jexer - Java Text User Interface
   3  *
   4  * Version: $Id$
   5  *
   6  * Author: Kevin Lamonte, <a href="mailto:kevin.lamonte@gmail.com">kevin.lamonte@gmail.com</a>
   7  *
   8  * License: LGPLv3 or later
   9  *
  10  * Copyright: This module is licensed under the GNU Lesser General
  11  * Public License Version 3.  Please see the file "COPYING" in this
  12  * directory for more information about the GNU Lesser General Public
  13  * License Version 3.
  14  *
  15  *     Copyright (C) 2015  Kevin Lamonte
  16  *
  17  * This program is free software; you can redistribute it and/or
  18  * modify it under the terms of the GNU Lesser General Public License
  19  * as published by the Free Software Foundation; either version 3 of
  20  * the License, or (at your option) any later version.
  21  *
  22  * This program is distributed in the hope that it will be useful, but
  23  * WITHOUT ANY WARRANTY; without even the implied warranty of
  24  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  25  * General Public License for more details.
  26  *
  27  * You should have received a copy of the GNU Lesser General Public
  28  * License along with this program; if not, see
  29  * http://www.gnu.org/licenses/, or write to the Free Software
  30  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
  31  * 02110-1301 USA
  32  */
  33 package jexer.backend;
  34
  35 import jexer.event.TInputEvent;
  36 import jexer.io.Screen;
  37 import jexer.session.SessionInfo;
  38
  39 /**
  40  * This abstract class provides a screen, keyboard, and mouse to
  41  * TApplication.  It also exposes session information as gleaned from lower
  42  * levels of the communication stack.
  43  */
  44 public abstract class Backend {
  45
  46     /**
  47      * The session information
  48      */
  49     public SessionInfo session;
  50
  51     /**
  52      * The screen to draw on
  53      */
  54     public Screen screen;
  55
  56     /**
  57      * Subclasses must provide an implementation that syncs the logical
  58      * screen to the physical device.
  59      */
  60     abstract public void flushScreen();
  61
  62     /**
  63      * Subclasses must provide an implementation to get keyboard, mouse, and
  64      * screen resize events.
  65      *
  66      * @param timeout maximum amount of time to wait for an event
  67      * @return events received, or an empty list if the timeout was reached
  68      */
  69     abstract public TInputEvent [] getEvents(int timeout);
  70
  71     /**
  72      * Subclasses must provide an implementation that closes sockets,
  73      * restores console, etc.
  74      */
  75     abstract public void shutdown();
  76
  77 }
  78