CJKUtils.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;
  20
  21 /**
  22  * Utilities class for analyzing and working with CJK (Chinese, Japanese, Korean) characters. The main purpose of this
  23  * class is to assist in figuring out how many terminal columns a character (and in extension, a String) takes up. The
  24  * main issue is that while most latin (and latin-related) character can be trusted to consume one column in the
  25  * terminal, CJK characters tends to take two, partly due to the square nature of the characters but mostly due to the
  26  * fact that they require most space to distinguish.
  27  *
  28  * @author Martin
  29  * @see TerminalTextUtils
  30  * @deprecated Use {@code TerminalTextUtils} instead
  31  */
  32 public class CJKUtils {
  33     private CJKUtils() {
  34     }
  35
  36     /**
  37      * Given a character, is this character considered to be a CJK character?
  38      * Shamelessly stolen from
  39      * <a href="http://stackoverflow.com/questions/1499804/how-can-i-detect-japanese-text-in-a-java-string">StackOverflow</a>
  40      * where it was contributed by user Rakesh N
  41      * @param c Character to test
  42      * @return {@code true} if the character is a CJK character
  43      * @deprecated Use {@code TerminalTextUtils.isCharJCK(c)} instead
  44      * @see TerminalTextUtils#isCharCJK(char)
  45      */
  46     @Deprecated
  47     public static boolean isCharCJK(final char c) {
  48         return TerminalTextUtils.isCharCJK(c);
  49     }
  50
  51     /**
  52      * @deprecated Call {@code getColumnWidth(s)} instead
  53      */
  54     @Deprecated
  55     public static int getTrueWidth(String s) {
  56         return TerminalTextUtils.getColumnWidth(s);
  57     }
  58
  59     /**
  60      * Given a string, returns how many columns this string would need to occupy in a terminal, taking into account that
  61      * CJK characters takes up two columns.
  62      * @param s String to check length
  63      * @return Number of actual terminal columns the string would occupy
  64      * @deprecated Use {@code TerminalTextUtils.getColumnWidth(s)} instead
  65      * @see TerminalTextUtils#getColumnWidth(String)
  66      */
  67     @Deprecated
  68     public static int getColumnWidth(String s) {
  69         return TerminalTextUtils.getColumnIndex(s, s.length());
  70     }
  71
  72     /**
  73      * Given a string and a character index inside that string, find out what the column index of that character would
  74      * be if printed in a terminal. If the string only contains non-CJK characters then the returned value will be same
  75      * as {@code stringCharacterIndex}, but if there are CJK characters the value will be different due to CJK
  76      * characters taking up two columns in width. If the character at the index in the string is a CJK character itself,
  77      * the returned value will be the index of the left-side of character.
  78      * @param s String to translate the index from
  79      * @param stringCharacterIndex Index within the string to get the terminal column index of
  80      * @return Index of the character inside the String at {@code stringCharacterIndex} when it has been writted to a
  81      * terminal
  82      * @throws StringIndexOutOfBoundsException if the index given is outside the String length or negative
  83      * @deprecated Use {@code TerminalTextUtils.getColumnIndex(s, stringCharacterIndex)} instead
  84      * @see TerminalTextUtils#getColumnIndex(String, int)
  85      */
  86     @Deprecated
  87     public static int getColumnIndex(String s, int stringCharacterIndex) throws StringIndexOutOfBoundsException {
  88         return TerminalTextUtils.getColumnIndex(s, stringCharacterIndex);
  89     }
  90
  91     /**
  92      * This method does the reverse of getColumnIndex, given a String and imagining it has been printed out to the
  93      * top-left corner of a terminal, in the column specified by {@code columnIndex}, what is the index of that
  94      * character in the string. If the string contains no CJK characters, this will always be the same as
  95      * {@code columnIndex}. If the index specified is the right column of a CJK character, the index is the same as if
  96      * the column was the left column. So calling {@code getStringCharacterIndex("英", 0)} and
  97      * {@code getStringCharacterIndex("英", 1)} will both return 0.
  98      * @param s String to translate the index to
  99      * @param columnIndex Column index of the string written to a terminal
 100      * @return The index in the string of the character in terminal column {@code columnIndex}
 101      * @deprecated Use {@code TerminalTextUtils.getStringCharacterIndex(s, columnIndex} instead
 102      * @see TerminalTextUtils#getStringCharacterIndex(String, int)
 103      */
 104     @Deprecated
 105     public static int getStringCharacterIndex(String s, int columnIndex) {
 106         return TerminalTextUtils.getStringCharacterIndex(s, columnIndex);
 107     }
 108
 109     /**
 110      * Given a string that may or may not contain CJK characters, returns the substring which will fit inside
 111      * <code>availableColumnSpace</code> columns. This method does not handle special cases like tab or new-line.
 112      * <p>
 113      * Calling this method is the same as calling {@code fitString(string, 0, availableColumnSpace)}.
 114      * @param string The string to fit inside the availableColumnSpace
 115      * @param availableColumnSpace Number of columns to fit the string inside
 116      * @return The whole or part of the input string which will fit inside the supplied availableColumnSpace
 117      * @deprecated Use {@code TerminalTextUtils.fitString(string, availableColumnSpace)} instead
 118      * @see TerminalTextUtils#fitString(String, int)
 119      */
 120     @Deprecated
 121     public static String fitString(String string, int availableColumnSpace) {
 122         return TerminalTextUtils.fitString(string, availableColumnSpace);
 123     }
 124
 125     /**
 126      * Given a string that may or may not contain CJK characters, returns the substring which will fit inside
 127      * <code>availableColumnSpace</code> columns. This method does not handle special cases like tab or new-line.
 128      * <p>
 129      * This overload has a {@code fromColumn} parameter that specified where inside the string to start fitting. Please
 130      * notice that {@code fromColumn} is not a character index inside the string, but a column index as if the string
 131      * has been printed from the left-most side of the terminal. So if the string is "日本語", fromColumn set to 1 will
 132      * not starting counting from the second character ("本") in the string but from the CJK filler character belonging
 133      * to "日". If you want to count from a particular character index inside the string, please pass in a substring
 134      * and use fromColumn set to 0.
 135      * @param string The string to fit inside the availableColumnSpace
 136      * @param fromColumn From what column of the input string to start fitting (see description above!)
 137      * @param availableColumnSpace Number of columns to fit the string inside
 138      * @return The whole or part of the input string which will fit inside the supplied availableColumnSpace
 139      * @deprecated Use {@code TerminalTextUtils.fitString(string, fromColumn, availableColumnSpace)} instead
 140      * @see TerminalTextUtils#fitString(String, int, int)
 141      */
 142     @Deprecated
 143     public static String fitString(String string, int fromColumn, int availableColumnSpace) {
 144         return TerminalTextUtils.fitString(string, fromColumn, availableColumnSpace);
 145     }
 146 }