src/jexer/teditor/Word.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.teditor;
  30
  31 import jexer.bits.CellAttributes;
  32
  33 /**
  34  * A Word represents text that was entered by the user.  It can be either
  35  * whitespace or non-whitespace.
  36  *
  37  * Very dumb highlighting is supported, it has no sense of parsing (not even
  38  * comments).  For now this only highlights some Java keywords and
  39  * puctuation.
  40  */
  41 public class Word {
  42
  43     // ------------------------------------------------------------------------
  44     // Variables --------------------------------------------------------------
  45     // ------------------------------------------------------------------------
  46
  47     /**
  48      * The color to render this word as on screen.
  49      */
  50     private CellAttributes color = new CellAttributes();
  51
  52     /**
  53      * The default color for the TEditor class.
  54      */
  55     private CellAttributes defaultColor = null;
  56
  57     /**
  58      * The text highlighter to use.
  59      */
  60     private Highlighter highlighter = null;
  61
  62     /**
  63      * The actual text of this word.  Average word length is 6 characters,
  64      * with a lot of shorter ones, so start with 3.
  65      */
  66     private StringBuilder text = new StringBuilder(3);
  67
  68     // ------------------------------------------------------------------------
  69     // Constructors -----------------------------------------------------------
  70     // ------------------------------------------------------------------------
  71
  72     /**
  73      * Construct a word with one character.
  74      *
  75      * @param ch the first character of the word
  76      * @param defaultColor the color for unhighlighted text
  77      * @param highlighter the highlighter to use
  78      */
  79     public Word(final char ch, final CellAttributes defaultColor,
  80         final Highlighter highlighter) {
  81
  82         this.defaultColor = defaultColor;
  83         this.highlighter = highlighter;
  84         text.append(ch);
  85     }
  86
  87     /**
  88      * Construct a word with an empty string.
  89      *
  90      * @param defaultColor the color for unhighlighted text
  91      * @param highlighter the highlighter to use
  92      */
  93     public Word(final CellAttributes defaultColor,
  94         final Highlighter highlighter) {
  95
  96         this.defaultColor = defaultColor;
  97         this.highlighter = highlighter;
  98     }
  99
 100     // ------------------------------------------------------------------------
 101     // Word -------------------------------------------------------------------
 102     // ------------------------------------------------------------------------
 103
 104     /**
 105      * Get the color used to display this word on screen.
 106      *
 107      * @return the color
 108      */
 109     public CellAttributes getColor() {
 110         return new CellAttributes(color);
 111     }
 112
 113     /**
 114      * Set the color used to display this word on screen.
 115      *
 116      * @param color the color
 117      */
 118     public void setColor(final CellAttributes color) {
 119         color.setTo(color);
 120     }
 121
 122     /**
 123      * Get the text to display.
 124      *
 125      * @return the text
 126      */
 127     public String getText() {
 128         return text.toString();
 129     }
 130
 131     /**
 132      * Get the on-screen display length.
 133      *
 134      * @return the number of cells needed to display this word
 135      */
 136     public int getDisplayLength() {
 137         // For now, just use the text length.  In the future, this will be a
 138         // grapheme count.
 139
 140         // TODO: figure out how to handle the tab character.  Do we have a
 141         // global tab stops list and current word position?
 142         return text.length();
 143     }
 144
 145     /**
 146      * See if this is a whitespace word.  Note that empty string is
 147      * considered whitespace.
 148      *
 149      * @return true if this word is whitespace
 150      */
 151     public boolean isWhitespace() {
 152         if (text.length() == 0) {
 153             return true;
 154         }
 155         if (Character.isWhitespace(text.charAt(0))) {
 156             return true;
 157         }
 158         return false;
 159     }
 160
 161     /**
 162      * Perform highlighting.
 163      */
 164     public void applyHighlight() {
 165         color.setTo(defaultColor);
 166         if (highlighter == null) {
 167             return;
 168         }
 169         String key = text.toString();
 170         CellAttributes newColor = highlighter.getColor(key);
 171         if (newColor != null) {
 172             color.setTo(newColor);
 173         }
 174     }
 175
 176     /**
 177      * Add a character to this word.  If this is a whitespace character
 178      * adding to a non-whitespace word, create a new word and return that;
 179      * similarly if this a non-whitespace character adding to a whitespace
 180      * word, create a new word and return that.  Note package private access:
 181      * this is only called by Line to figure out highlighting boundaries.
 182      *
 183      * @param ch the new character to add
 184      * @return either this word (if it was added), or a new word that
 185      * contains ch
 186      */
 187     public Word addChar(final char ch) {
 188         if (text.length() == 0) {
 189             text.append(ch);
 190             return this;
 191         }
 192
 193         // Give the highlighter the option to split here.
 194         if (highlighter != null) {
 195             if (highlighter.shouldSplit(ch)
 196                 || highlighter.shouldSplit(text.charAt(0))
 197             ) {
 198                 Word newWord = new Word(ch, defaultColor, highlighter);
 199                 return newWord;
 200             }
 201         }
 202
 203         // Highlighter didn't care, so split at whitespace.
 204         if (Character.isWhitespace(text.charAt(0))
 205             && Character.isWhitespace(ch)
 206         ) {
 207             // Adding to a whitespace word, keep at it.
 208             text.append(ch);
 209             return this;
 210         }
 211         if (!Character.isWhitespace(text.charAt(0))
 212             && !Character.isWhitespace(ch)
 213         ) {
 214             // Adding to a non-whitespace word, keep at it.
 215             text.append(ch);
 216             return this;
 217         }
 218
 219         // Switching from whitespace to non-whitespace or vice versa, so
 220         // split here.
 221         Word newWord = new Word(ch, defaultColor, highlighter);
 222         return newWord;
 223     }
 224
 225 }