src/jexer/backend/Backend.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * The MIT License (MIT)
   5  *
   6  * Copyright (C) 2016 Kevin Lamonte
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a
   9  * copy of this software and associated documentation files (the "Software"),
  10  * to deal in the Software without restriction, including without limitation
  11  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
  12  * and/or sell copies of the Software, and to permit persons to whom the
  13  * Software is furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  23  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  24  * DEALINGS IN THE SOFTWARE.
  25  *
  26  * @author Kevin Lamonte [kevin.lamonte@gmail.com]
  27  * @version 1
  28  */
  29 package jexer.backend;
  30
  31 import java.util.List;
  32
  33 import jexer.event.TInputEvent;
  34 import jexer.io.Screen;
  35 import jexer.session.SessionInfo;
  36
  37 /**
  38  * This abstract class provides a screen, keyboard, and mouse to
  39  * TApplication.  It also exposes session information as gleaned from lower
  40  * levels of the communication stack.
  41  */
  42 public abstract class Backend {
  43
  44     /**
  45      * The session information.
  46      */
  47     protected SessionInfo sessionInfo;
  48
  49     /**
  50      * Getter for sessionInfo.
  51      *
  52      * @return the SessionInfo
  53      */
  54     public final SessionInfo getSessionInfo() {
  55         return sessionInfo;
  56     }
  57
  58     /**
  59      * The screen to draw on.
  60      */
  61     protected Screen screen;
  62
  63     /**
  64      * Getter for screen.
  65      *
  66      * @return the Screen
  67      */
  68     public final Screen getScreen() {
  69         return screen;
  70     }
  71
  72     /**
  73      * Subclasses must provide an implementation that syncs the logical
  74      * screen to the physical device.
  75      */
  76     public abstract void flushScreen();
  77
  78     /**
  79      * Subclasses must provide an implementation to get keyboard, mouse, and
  80      * screen resize events.
  81      *
  82      * @param queue list to append new events to
  83      */
  84     public abstract void getEvents(List<TInputEvent> queue);
  85
  86     /**
  87      * Subclasses must provide an implementation that closes sockets,
  88      * restores console, etc.
  89      */
  90     public abstract void shutdown();
  91
  92 }