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 import jexer.bits.StringUtils;
  33
  34 /**
  35  * A Word represents text that was entered by the user.  It can be either
  36  * whitespace or non-whitespace.
  37  *
  38  * Very dumb highlighting is supported, it has no sense of parsing (not even
  39  * comments).  For now this only highlights some Java keywords and
  40  * puctuation.
  41  */
  42 public class Word {
  43
  44     // ------------------------------------------------------------------------
  45     // Variables --------------------------------------------------------------
  46     // ------------------------------------------------------------------------
  47
  48     /**
  49      * The color to render this word as on screen.
  50      */
  51     private CellAttributes color = new CellAttributes();
  52
  53     /**
  54      * The default color for the TEditor class.
  55      */
  56     private CellAttributes defaultColor = null;
  57
  58     /**
  59      * The text highlighter to use.
  60      */
  61     private Highlighter highlighter = null;
  62
  63     /**
  64      * The actual text of this word.  Average word length is 6 characters,
  65      * with a lot of shorter ones, so start with 3.
  66      */
  67     private StringBuilder text = new StringBuilder(3);
  68
  69     // ------------------------------------------------------------------------
  70     // Constructors -----------------------------------------------------------
  71     // ------------------------------------------------------------------------
  72
  73     /**
  74      * Construct a word with one character.
  75      *
  76      * @param ch the first character of the word
  77      * @param defaultColor the color for unhighlighted text
  78      * @param highlighter the highlighter to use
  79      */
  80     public Word(final int ch, final CellAttributes defaultColor,
  81         final Highlighter highlighter) {
  82
  83         this.defaultColor = defaultColor;
  84         this.highlighter = highlighter;
  85         text.append(Character.toChars(ch));
  86     }
  87
  88     /**
  89      * Construct a word with an empty string.
  90      *
  91      * @param defaultColor the color for unhighlighted text
  92      * @param highlighter the highlighter to use
  93      */
  94     public Word(final CellAttributes defaultColor,
  95         final Highlighter highlighter) {
  96
  97         this.defaultColor = defaultColor;
  98         this.highlighter = highlighter;
  99     }
 100
 101     // ------------------------------------------------------------------------
 102     // Word -------------------------------------------------------------------
 103     // ------------------------------------------------------------------------
 104
 105     /**
 106      * Get the color used to display this word on screen.
 107      *
 108      * @return the color
 109      */
 110     public CellAttributes getColor() {
 111         return new CellAttributes(color);
 112     }
 113
 114     /**
 115      * Set the color used to display this word on screen.
 116      *
 117      * @param color the color
 118      */
 119     public void setColor(final CellAttributes color) {
 120         color.setTo(color);
 121     }
 122
 123     /**
 124      * Get the text to display.
 125      *
 126      * @return the text
 127      */
 128     public String getText() {
 129         return text.toString();
 130     }
 131
 132     /**
 133      * Get the on-screen display length.
 134      *
 135      * @return the number of cells needed to display this word
 136      */
 137     public int getDisplayLength() {
 138         // For now, just use the text length.  In the future, this will be a
 139         // grapheme count.
 140
 141         // TODO: figure out how to handle the tab character.  Do we have a
 142         // global tab stops list and current word position?
 143         return StringUtils.width(text.toString());
 144     }
 145
 146     /**
 147      * See if this is a whitespace word.  Note that empty string is
 148      * considered whitespace.
 149      *
 150      * @return true if this word is whitespace
 151      */
 152     public boolean isWhitespace() {
 153         if (text.length() == 0) {
 154             return true;
 155         }
 156         if (Character.isWhitespace(text.charAt(0))) {
 157             return true;
 158         }
 159         return false;
 160     }
 161
 162     /**
 163      * Perform highlighting.
 164      */
 165     public void applyHighlight() {
 166         color.setTo(defaultColor);
 167         if (highlighter == null) {
 168             return;
 169         }
 170         String key = text.toString();
 171         CellAttributes newColor = highlighter.getColor(key);
 172         if (newColor != null) {
 173             color.setTo(newColor);
 174         }
 175     }
 176
 177     /**
 178      * Add a character to this word.  If this is a whitespace character
 179      * adding to a non-whitespace word, create a new word and return that;
 180      * similarly if this a non-whitespace character adding to a whitespace
 181      * word, create a new word and return that.  Note package private access:
 182      * this is only called by Line to figure out highlighting boundaries.
 183      *
 184      * @param ch the new character to add
 185      * @return either this word (if it was added), or a new word that
 186      * contains ch
 187      */
 188     public Word addChar(final int ch) {
 189         if (text.length() == 0) {
 190             text.append(Character.toChars(ch));
 191             return this;
 192         }
 193
 194         // Give the highlighter the option to split here.
 195         if (highlighter != null) {
 196             if (highlighter.shouldSplit(ch)
 197                 || highlighter.shouldSplit(text.charAt(0))
 198             ) {
 199                 Word newWord = new Word(ch, defaultColor, highlighter);
 200                 return newWord;
 201             }
 202         }
 203
 204         // Highlighter didn't care, so split at whitespace.
 205         if (Character.isWhitespace(text.charAt(0))
 206             && Character.isWhitespace(ch)
 207         ) {
 208             // Adding to a whitespace word, keep at it.
 209             text.append(Character.toChars(ch));
 210             return this;
 211         }
 212         if (!Character.isWhitespace(text.charAt(0))
 213             && !Character.isWhitespace(ch)
 214         ) {
 215             // Adding to a non-whitespace word, keep at it.
 216             text.append(Character.toChars(ch));
 217             return this;
 218         }
 219
 220         // Switching from whitespace to non-whitespace or vice versa, so
 221         // split here.
 222         Word newWord = new Word(ch, defaultColor, highlighter);
 223         return newWord;
 224     }
 225
 226 }