backend/Backend.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * The MIT License (MIT)
   5  *
   6  * Copyright (C) 2019 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
  35 /**
  36  * This interface provides a screen, keyboard, and mouse to TApplication.  It
  37  * also exposes session information as gleaned from lower levels of the
  38  * communication stack.
  39  */
  40 public interface Backend {
  41
  42     /**
  43      * Get a SessionInfo, which exposes text width/height, language,
  44      * username, and other information from the communication stack.
  45      *
  46      * @return the SessionInfo
  47      */
  48     public SessionInfo getSessionInfo();
  49
  50     /**
  51      * Get a Screen, which displays the text cells to the user.
  52      *
  53      * @return the Screen
  54      */
  55     public Screen getScreen();
  56
  57     /**
  58      * Classes must provide an implementation that syncs the logical screen
  59      * to the physical device.
  60      */
  61     public void flushScreen();
  62
  63     /**
  64      * Check if there are events in the queue.
  65      *
  66      * @return if true, getEvents() has something to return to the application
  67      */
  68     public boolean hasEvents();
  69
  70     /**
  71      * Classes must provide an implementation to get keyboard, mouse, and
  72      * screen resize events.
  73      *
  74      * @param queue list to append new events to
  75      */
  76     public void getEvents(List<TInputEvent> queue);
  77
  78     /**
  79      * Classes must provide an implementation that closes sockets, restores
  80      * console, etc.
  81      */
  82     public void shutdown();
  83
  84     /**
  85      * Classes must provide an implementation that sets the window title.
  86      *
  87      * @param title the new title
  88      */
  89     public void setTitle(final String title);
  90
  91     /**
  92      * Set listener to a different Object.
  93      *
  94      * @param listener the new listening object that run() wakes up on new
  95      * input
  96      */
  97     public void setListener(final Object listener);
  98
  99     /**
 100      * Reload backend options from System properties.
 101      */
 102     public void reloadOptions();
 103
 104 }