src/jexer/teditor/Line.java

   1 /*
   2  * Jexer - Java Text User Interface
   3  *
   4  * The MIT License (MIT)
   5  *
   6  * Copyright (C) 2017 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 java.util.ArrayList;
  32 import java.util.List;
  33
  34 import jexer.bits.CellAttributes;
  35
  36 /**
  37  * A Line represents a single line of text on the screen, as a collection of
  38  * words.
  39  */
  40 public class Line {
  41
  42     /**
  43      * The list of words.
  44      */
  45     private ArrayList<Word> words = new ArrayList<Word>();
  46
  47     /**
  48      * The default color for the TEditor class.
  49      */
  50     private CellAttributes defaultColor = null;
  51
  52     /**
  53      * The text highlighter to use.
  54      */
  55     private Highlighter highlighter = null;
  56
  57     /**
  58      * The current cursor position on this line.
  59      */
  60     private int cursor = 0;
  61
  62     /**
  63      * The current word that the cursor position is in.
  64      */
  65     private Word currentWord;
  66
  67     /**
  68      * We use getDisplayLength() a lot, so cache the value.
  69      */
  70     private int displayLength = -1;
  71
  72     /**
  73      * Get the current cursor position.
  74      *
  75      * @return the cursor position
  76      */
  77     public int getCursor() {
  78         return cursor;
  79     }
  80
  81     /**
  82      * Set the current cursor position.
  83      *
  84      * @param cursor the new cursor position
  85      */
  86     public void setCursor(final int cursor) {
  87         if ((cursor < 0)
  88             || ((cursor >= getDisplayLength())
  89                 && (getDisplayLength() > 0))
  90         ) {
  91             throw new IndexOutOfBoundsException("Max length is " +
  92                 getDisplayLength() + ", requested position " + cursor);
  93         }
  94         this.cursor = cursor;
  95         // TODO: set word
  96     }
  97
  98     /**
  99      * Get a (shallow) copy of the list of words.
 100      *
 101      * @return the list of words
 102      */
 103     public List<Word> getWords() {
 104         return new ArrayList<Word>(words);
 105     }
 106
 107     /**
 108      * Get the on-screen display length.
 109      *
 110      * @return the number of cells needed to display this line
 111      */
 112     public int getDisplayLength() {
 113         if (displayLength != -1) {
 114             return displayLength;
 115         }
 116         int n = 0;
 117         for (Word word: words) {
 118             n += word.getDisplayLength();
 119         }
 120         displayLength = n;
 121
 122         // If we have any visible characters, add one to the display so that
 123         // the cursor is immediately after the data.
 124         if (displayLength > 0) {
 125             displayLength++;
 126         }
 127         return displayLength;
 128     }
 129
 130     /**
 131      * Construct a new Line from an existing text string, and highlight
 132      * certain strings.
 133      *
 134      * @param str the text string
 135      * @param defaultColor the color for unhighlighted text
 136      * @param highlighter the highlighter to use
 137      */
 138     public Line(final String str, final CellAttributes defaultColor,
 139         final Highlighter highlighter) {
 140
 141         this.defaultColor = defaultColor;
 142         this.highlighter = highlighter;
 143
 144         currentWord = new Word(this.defaultColor, this.highlighter);
 145         words.add(currentWord);
 146         for (int i = 0; i < str.length(); i++) {
 147             char ch = str.charAt(i);
 148             Word newWord = currentWord.addChar(ch);
 149             if (newWord != currentWord) {
 150                 words.add(newWord);
 151                 currentWord = newWord;
 152             }
 153         }
 154         for (Word word: words) {
 155             word.applyHighlight();
 156         }
 157     }
 158
 159     /**
 160      * Construct a new Line from an existing text string.
 161      *
 162      * @param str the text string
 163      * @param defaultColor the color for unhighlighted text
 164      */
 165     public Line(final String str, final CellAttributes defaultColor) {
 166         this(str, defaultColor, null);
 167     }
 168
 169     /**
 170      * Decrement the cursor by one.  If at the first column, do nothing.
 171      *
 172      * @return true if the cursor position changed
 173      */
 174     public boolean left() {
 175         if (cursor == 0) {
 176             return false;
 177         }
 178         // TODO: switch word
 179         cursor--;
 180         return true;
 181     }
 182
 183     /**
 184      * Increment the cursor by one.  If at the last column, do nothing.
 185      *
 186      * @return true if the cursor position changed
 187      */
 188     public boolean right() {
 189         if (getDisplayLength() == 0) {
 190             return false;
 191         }
 192         if (cursor == getDisplayLength() - 1) {
 193             return false;
 194         }
 195         // TODO: switch word
 196         cursor++;
 197         return true;
 198     }
 199
 200     /**
 201      * Go to the first column of this line.
 202      *
 203      * @return true if the cursor position changed
 204      */
 205     public boolean home() {
 206         if (cursor > 0) {
 207             cursor = 0;
 208             currentWord = words.get(0);
 209             return true;
 210         }
 211         return false;
 212     }
 213
 214     /**
 215      * Go to the last column of this line.
 216      *
 217      * @return true if the cursor position changed
 218      */
 219     public boolean end() {
 220         if (cursor != getDisplayLength() - 1) {
 221             cursor = getDisplayLength() - 1;
 222             if (cursor < 0) {
 223                 cursor = 0;
 224             }
 225             currentWord = words.get(words.size() - 1);
 226             return true;
 227         }
 228         return false;
 229     }
 230
 231     /**
 232      * Delete the character under the cursor.
 233      */
 234     public void del() {
 235         // TODO
 236     }
 237
 238     /**
 239      * Delete the character immediately preceeding the cursor.
 240      */
 241     public void backspace() {
 242         // TODO
 243     }
 244
 245     /**
 246      * Insert a character at the cursor.
 247      *
 248      * @param ch the character to insert
 249      */
 250     public void addChar(final char ch) {
 251         // TODO
 252     }
 253
 254     /**
 255      * Replace a character at the cursor.
 256      *
 257      * @param ch the character to replace
 258      */
 259     public void replaceChar(final char ch) {
 260         // TODO
 261     }
 262
 263 }