src/com/googlecode/lanterna/terminal/AbstractTerminal.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 import com.googlecode.lanterna.graphics.TextGraphics;
  23
  24 import java.io.IOException;
  25 import java.util.ArrayList;
  26 import java.util.List;
  27
  28 /**
  29  * Containing a some very fundamental functionality that should be common (and usable) to all terminal implementations.
  30  * All the Terminal implementers within Lanterna extends from this class.
  31  *
  32  * @author Martin
  33  */
  34 public abstract class AbstractTerminal implements Terminal {
  35
  36     private final List<ResizeListener> resizeListeners;
  37     private TerminalSize lastKnownSize;
  38
  39     protected AbstractTerminal() {
  40         this.resizeListeners = new ArrayList<ResizeListener>();
  41         this.lastKnownSize = null;
  42     }
  43
  44     @Override
  45     public void addResizeListener(ResizeListener listener) {
  46         if (listener != null) {
  47             resizeListeners.add(listener);
  48         }
  49     }
  50
  51     @Override
  52     public void removeResizeListener(ResizeListener listener) {
  53         if (listener != null) {
  54             resizeListeners.remove(listener);
  55         }
  56     }
  57
  58     /**
  59      * Call this method when the terminal has been resized or the initial size of the terminal has been discovered. It
  60      * will trigger all resize listeners, but only if the size has changed from before.
  61      *
  62      * @param columns Number of columns in the new size
  63      * @param rows Number of rows in the new size
  64      */
  65     protected synchronized void onResized(int columns, int rows) {
  66         TerminalSize newSize = new TerminalSize(columns, rows);
  67         if (lastKnownSize == null || !lastKnownSize.equals(newSize)) {
  68             lastKnownSize = newSize;
  69             for (ResizeListener resizeListener : resizeListeners) {
  70                 resizeListener.onResized(this, lastKnownSize);
  71             }
  72         }
  73     }
  74
  75     @Override
  76     public TextGraphics newTextGraphics() throws IOException {
  77         return new TerminalTextGraphics(this);
  78     }
  79 }