src/com/googlecode/lanterna/terminal/SimpleTerminalResizeListener.java

   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.terminal;
  20
  21 import com.googlecode.lanterna.TerminalSize;
  22
  23 /**
  24  * This class is a simple implementation of Terminal.ResizeListener which will keep track of the size of the terminal
  25  * and let you know if the terminal has been resized since you last checked. This can be useful to avoid threading
  26  * problems with the resize callback when your application is using a main event loop.
  27  *
  28  * @author martin
  29  */
  30 @SuppressWarnings("WeakerAccess")
  31 public class SimpleTerminalResizeListener implements ResizeListener {
  32
  33     boolean wasResized;
  34     TerminalSize lastKnownSize;
  35
  36     /**
  37      * Creates a new SimpleTerminalResizeListener
  38      * @param initialSize Before any resize event, this listener doesn't know the size of the terminal. By supplying a
  39      * value here, you control what getLastKnownSize() will return if invoked before any resize events has reached us.
  40      */
  41     public SimpleTerminalResizeListener(TerminalSize initialSize) {
  42         this.wasResized = false;
  43         this.lastKnownSize = initialSize;
  44     }
  45
  46     /**
  47      * Checks if the terminal was resized since the last time this method was called. If this is the first time calling
  48      * this method, the result is going to be based on if the terminal has been resized since this listener was attached
  49      * to the Terminal.
  50      *
  51      * @return true if the terminal was resized, false otherwise
  52      */
  53     public synchronized boolean isTerminalResized() {
  54         if(wasResized) {
  55             wasResized = false;
  56             return true;
  57         }
  58         else {
  59             return false;
  60         }
  61     }
  62
  63     /**
  64      * Returns the last known size the Terminal is supposed to have.
  65      *
  66      * @return Size of the terminal, as of the last resize update
  67      */
  68     public TerminalSize getLastKnownSize() {
  69         return lastKnownSize;
  70     }
  71
  72     @Override
  73     public synchronized void onResized(Terminal terminal, TerminalSize newSize) {
  74         this.wasResized = true;
  75         this.lastKnownSize = newSize;
  76     }
  77
  78 }