src/jexer/backend/GenericBackend.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 abstract class provides a screen, keyboard, and mouse to
  37  * TApplication.  It also exposes session information as gleaned from lower
  38  * levels of the communication stack.
  39  */
  40 public abstract class GenericBackend implements Backend {
  41
  42     // ------------------------------------------------------------------------
  43     // Variables --------------------------------------------------------------
  44     // ------------------------------------------------------------------------
  45
  46     /**
  47      * The session information.
  48      */
  49     protected SessionInfo sessionInfo;
  50
  51     /**
  52      * The screen to draw on.
  53      */
  54     protected Screen screen;
  55
  56     /**
  57      * Input events are processed by this Terminal.
  58      */
  59     protected TerminalReader terminal;
  60
  61     // ------------------------------------------------------------------------
  62     // Constructors -----------------------------------------------------------
  63     // ------------------------------------------------------------------------
  64
  65     // ------------------------------------------------------------------------
  66     // Backend ----------------------------------------------------------------
  67     // ------------------------------------------------------------------------
  68
  69     /**
  70      * Getter for sessionInfo.
  71      *
  72      * @return the SessionInfo
  73      */
  74     public final SessionInfo getSessionInfo() {
  75         return sessionInfo;
  76     }
  77
  78     /**
  79      * Getter for screen.
  80      *
  81      * @return the Screen
  82      */
  83     public final Screen getScreen() {
  84         return screen;
  85     }
  86
  87     /**
  88      * Sync the logical screen to the physical device.
  89      */
  90     public void flushScreen() {
  91         screen.flushPhysical();
  92     }
  93
  94     /**
  95      * Check if there are events in the queue.
  96      *
  97      * @return if true, getEvents() has something to return to the application
  98      */
  99     public boolean hasEvents() {
 100         return terminal.hasEvents();
 101     }
 102
 103     /**
 104      * Get keyboard, mouse, and screen resize events.
 105      *
 106      * @param queue list to append new events to
 107      */
 108     public void getEvents(final List<TInputEvent> queue) {
 109         if (terminal.hasEvents()) {
 110             terminal.getEvents(queue);
 111         }
 112     }
 113
 114     /**
 115      * Close the I/O, restore the console, etc.
 116      */
 117     public void shutdown() {
 118         terminal.closeTerminal();
 119     }
 120
 121     /**
 122      * Set the window title.
 123      *
 124      * @param title the new title
 125      */
 126     public void setTitle(final String title) {
 127         screen.setTitle(title);
 128     }
 129
 130     /**
 131      * Set listener to a different Object.
 132      *
 133      * @param listener the new listening object that run() wakes up on new
 134      * input
 135      */
 136     public void setListener(final Object listener) {
 137         terminal.setListener(listener);
 138     }
 139
 140     /**
 141      * Reload backend options from System properties.
 142      */
 143     public void reloadOptions() {
 144         terminal.reloadOptions();
 145     }
 146
 147 }