/*
* This file is part of lanterna (http://code.google.com/p/lanterna/).
*
* lanterna is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* Copyright (C) 2010-2017 Martin Berglund
*/
package com.googlecode.lanterna;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedList;
import java.util.List;
import com.googlecode.lanterna.graphics.StyleSet;
/**
* This class contains a number of utility methods for analyzing characters and strings in a terminal context. The main
* purpose is to make it easier to work with text that may or may not contain double-width text characters, such as CJK
* (Chinese, Japanese, Korean) and other special symbols. This class assumes those are all double-width and in case the
* terminal (-emulator) chooses to draw them (somehow) as single-column then all the calculations in this class will be
* wrong. It seems safe to assume what this class considers double-width really is taking up two columns though.
*
* @author Martin
*/
public class TerminalTextUtils {
private TerminalTextUtils() {
}
/**
* Given a string and an index in that string, returns the ANSI control sequence beginning on this index. If there
* is no control sequence starting there, the method will return null. The returned value is the complete escape
* sequence including the ESC prefix.
* @param string String to scan for control sequences
* @param index Index in the string where the control sequence begins
* @return {@code null} if there was no control sequence starting at the specified index, otherwise the entire
* control sequence
*/
public static String getANSIControlSequenceAt(String string, int index) {
int len = getANSIControlSequenceLength(string, index);
return len == 0 ? null : string.substring(index,index+len);
}
/**
* Given a string and an index in that string, returns the number of characters starting at index that make up
* a complete ANSI control sequence. If there is no control sequence starting there, the method will return 0.
* @param string String to scan for control sequences
* @param index Index in the string where the control sequence begins
* @return {@code 0} if there was no control sequence starting at the specified index, otherwise the length
* of the entire control sequence
*/
public static int getANSIControlSequenceLength(String string, int index) {
int len = 0, restlen = string.length() - index;
if (restlen >= 3) { // Control sequences require a minimum of three characters
char esc = string.charAt(index),
bracket = string.charAt(index+1);
if (esc == 0x1B && bracket == '[') { // escape & open bracket
len = 3; // esc,bracket and (later)terminator.
// digits or semicolons can still precede the terminator:
for (int i = 2; i < restlen; i++) {
char ch = string.charAt(i + index);
// only ascii-digits or semicolons allowed here:
if ( (ch >= '0' && ch <= '9') || ch == ';') {
len++;
} else {
break;
}
}
// if string ends in digits/semicolons, then it's not a sequence.
if (len > restlen) {
len = 0;
}
}
}
return len;
}
/**
* Given a character, is this character considered to be a CJK character?
* Shamelessly stolen from
* <a href="http://stackoverflow.com/questions/1499804/how-can-i-detect-japanese-text-in-a-java-string">StackOverflow</a>
* where it was contributed by user Rakesh N
* @param c Character to test
* @return {@code true} if the character is a CJK character
*
*/
public static boolean isCharCJK(final char c) {
Character.UnicodeBlock unicodeBlock = Character.UnicodeBlock.of(c);
return (unicodeBlock == Character.UnicodeBlock.HIRAGANA)
|| (unicodeBlock == Character.UnicodeBlock.KATAKANA)
|| (unicodeBlock == Character.UnicodeBlock.KATAKANA_PHONETIC_EXTENSIONS)
|| (unicodeBlock == Character.UnicodeBlock.HANGUL_COMPATIBILITY_JAMO)
|| (unicodeBlock == Character.UnicodeBlock.HANGUL_JAMO)
|| (unicodeBlock == Character.UnicodeBlock.HANGUL_SYLLABLES)
|| (unicodeBlock == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS)
|| (unicodeBlock == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_A)
|| (unicodeBlock == Character.UnicodeBlock.CJK_UNIFIED_IDEOGRAPHS_EXTENSION_B)
|| (unicodeBlock == Character.UnicodeBlock.CJK_COMPATIBILITY_FORMS)
|| (unicodeBlock == Character.UnicodeBlock.CJK_COMPATIBILITY_IDEOGRAPHS)
|| (unicodeBlock == Character.UnicodeBlock.CJK_RADICALS_SUPPLEMENT)
|| (unicodeBlock == Character.UnicodeBlock.CJK_SYMBOLS_AND_PUNCTUATION)
|| (unicodeBlock == Character.UnicodeBlock.ENCLOSED_CJK_LETTERS_AND_MONTHS)
|| (unicodeBlock == Character.UnicodeBlock.HALFWIDTH_AND_FULLWIDTH_FORMS && c < 0xFF61); //The magic number here is the separating index between full-width and half-width
}
/**
* Checks if a character is expected to be taking up two columns if printed to a terminal. This will generally be
* {@code true} for CJK (Chinese, Japanese and Korean) characters.
* @param c Character to test if it's double-width when printed to a terminal
* @return {@code true} if this character is expected to be taking up two columns when printed to the terminal,
* otherwise {@code false}
*/
public static boolean isCharDoubleWidth(final char c) {
return isCharCJK(c);
}
/**
* Checks if a particular character is a control character, in Lanterna this currently means it's 0-31 or 127 in the
* ascii table.
* @param c character to test
* @return {@code true} if the character is a control character, {@code false} otherwise
*/
public static boolean isControlCharacter(char c) {
return c < 32 || c == 127;
}
/**
* Checks if a particular character is printable. This generally means that the code is not a control character that
* isn't able to be printed to the terminal properly. For example, NULL, ENQ, BELL and ESC and all control codes
* that has no proper character associated with it so the behaviour is undefined and depends completely on the
* terminal what happens if you try to print them. However, certain control characters have a particular meaning to
* the terminal and are as such considered printable. In Lanterna, we consider these control characters printable:
* <ul>
* <li>Backspace</li>
* <li>Horizontal Tab</li>
* <li>Line feed</li>
* </ul>
*
* @param c character to test
* @return {@code true} if the character is considered printable, {@code false} otherwise
*/
public static boolean isPrintableCharacter(char c) {
return !isControlCharacter(c) || c == '\t' || c == '\n' || c == '\b';
}
/**
* @param s String to measure
* @return Returns the width (in columns) the string will take up when printed on the screen
* @deprecated Call {@code getColumnWidth(s)} instead
*/
@Deprecated
public static int getTrueWidth(String s) {
return getColumnWidth(s);
}
/**
* Given a string, returns how many columns this string would need to occupy in a terminal, taking into account that
* CJK characters takes up two columns.
* @param s String to check length
* @return Number of actual terminal columns the string would occupy
*/
public static int getColumnWidth(String s) {
return getColumnIndex(s, s.length());
}
/**
* Given a string and a character index inside that string, find out what the column index of that character would
* be if printed in a terminal. If the string only contains non-CJK characters then the returned value will be same
* as {@code stringCharacterIndex}, but if there are CJK characters the value will be different due to CJK
* characters taking up two columns in width. If the character at the index in the string is a CJK character itself,
* the returned value will be the index of the left-side of character.
* @param s String to translate the index from
* @param stringCharacterIndex Index within the string to get the terminal column index of
* @return Index of the character inside the String at {@code stringCharacterIndex} when it has been writted to a
* terminal
* @throws StringIndexOutOfBoundsException if the index given is outside the String length or negative
*/
public static int getColumnIndex(String s, int stringCharacterIndex) throws StringIndexOutOfBoundsException {
int index = 0;
for(int i = 0; i < stringCharacterIndex; i++) {
if(isCharCJK(s.charAt(i))) {
index++;
}
index++;
}
return index;
}
/**
* This method does the reverse of getColumnIndex, given a String and imagining it has been printed out to the
* top-left corner of a terminal, in the column specified by {@code columnIndex}, what is the index of that
* character in the string. If the string contains no CJK characters, this will always be the same as
* {@code columnIndex}. If the index specified is the right column of a CJK character, the index is the same as if
* the column was the left column. So calling {@code getStringCharacterIndex("英", 0)} and
* {@code getStringCharacterIndex("英", 1)} will both return 0.
* @param s String to translate the index to
* @param columnIndex Column index of the string written to a terminal
* @return The index in the string of the character in terminal column {@code columnIndex}
*/
public static int getStringCharacterIndex(String s, int columnIndex) {
int index = 0;
int counter = 0;
while(counter < columnIndex) {
if(isCharCJK(s.charAt(index++))) {
counter++;
if(counter == columnIndex) {
return index - 1;
}
}
counter++;
}
return index;
}
/**
* Given a string that may or may not contain CJK characters, returns the substring which will fit inside
* <code>availableColumnSpace</code> columns. This method does not handle special cases like tab or new-line.
* <p>
* Calling this method is the same as calling {@code fitString(string, 0, availableColumnSpace)}.
* @param string The string to fit inside the availableColumnSpace
* @param availableColumnSpace Number of columns to fit the string inside
* @return The whole or part of the input string which will fit inside the supplied availableColumnSpace
*/
public static String fitString(String string, int availableColumnSpace) {
return fitString(string, 0, availableColumnSpace);
}
/**
* Given a string that may or may not contain CJK characters, returns the substring which will fit inside
* <code>availableColumnSpace</code> columns. This method does not handle special cases like tab or new-line.
* <p>
* This overload has a {@code fromColumn} parameter that specified where inside the string to start fitting. Please
* notice that {@code fromColumn} is not a character index inside the string, but a column index as if the string
* has been printed from the left-most side of the terminal. So if the string is "日本語", fromColumn set to 1 will
* not starting counting from the second character ("本") in the string but from the CJK filler character belonging
* to "日". If you want to count from a particular character index inside the string, please pass in a substring
* and use fromColumn set to 0.
* @param string The string to fit inside the availableColumnSpace
* @param fromColumn From what column of the input string to start fitting (see description above!)
* @param availableColumnSpace Number of columns to fit the string inside
* @return The whole or part of the input string which will fit inside the supplied availableColumnSpace
*/
public static String fitString(String string, int fromColumn, int availableColumnSpace) {
if(availableColumnSpace <= 0) {
return "";
}
StringBuilder bob = new StringBuilder();
int column = 0;
int index = 0;
while(index < string.length() && column < fromColumn) {
char c = string.charAt(index++);
column += TerminalTextUtils.isCharCJK(c) ? 2 : 1;
}
if(column > fromColumn) {
bob.append(" ");
availableColumnSpace--;
}
while(availableColumnSpace > 0 && index < string.length()) {
char c = string.charAt(index++);
availableColumnSpace -= TerminalTextUtils.isCharCJK(c) ? 2 : 1;
if(availableColumnSpace < 0) {
bob.append(' ');
}
else {
bob.append(c);
}
}
return bob.toString();
}
/**
* This method will calculate word wrappings given a number of lines of text and how wide the text can be printed.
* The result is a list of new rows where word-wrapping was applied.
* @param maxWidth Maximum number of columns that can be used before word-wrapping is applied, if <= 0 then the
* lines will be returned unchanged
* @param lines Input text
* @return The input text word-wrapped at {@code maxWidth}; this may contain more rows than the input text
*/
public static List<String> getWordWrappedText(int maxWidth, String... lines) {
//Bounds checking
if(maxWidth <= 0) {
return Arrays.asList(lines);
}
List<String> result = new ArrayList<String>();
LinkedList<String> linesToBeWrapped = new LinkedList<String>(Arrays.asList(lines));
while(!linesToBeWrapped.isEmpty()) {
String row = linesToBeWrapped.removeFirst();
int rowWidth = getColumnWidth(row);
if(rowWidth <= maxWidth) {
result.add(row);
}
else {
//Now search in reverse and find the first possible line-break
final int characterIndexMax = getStringCharacterIndex(row, maxWidth);
int characterIndex = characterIndexMax;
while(characterIndex >= 0 &&
!Character.isSpaceChar(row.charAt(characterIndex)) &&
!isCharCJK(row.charAt(characterIndex))) {
characterIndex--;
}
// right *after* a CJK is also a "nice" spot to break the line!
if (characterIndex >= 0 && characterIndex < characterIndexMax &&
isCharCJK(row.charAt(characterIndex))) {
characterIndex++; // with these conditions it fits!
}
if(characterIndex < 0) {
//Failed! There was no 'nice' place to cut so just cut it at maxWidth
characterIndex = Math.max(characterIndexMax, 1); // at least 1 char
result.add(row.substring(0, characterIndex));
linesToBeWrapped.addFirst(row.substring(characterIndex));
}
else {
// characterIndex == 0 only happens, if either
// - first char is CJK and maxWidth==1 or
// - first char is whitespace
// either way: put it in row before break to prevent infinite loop.
characterIndex = Math.max( characterIndex, 1); // at least 1 char
//Ok, split the row, add it to the result and continue processing the second half on a new line
result.add(row.substring(0, characterIndex));
while(characterIndex < row.length() &&
Character.isSpaceChar(row.charAt(characterIndex))) {
characterIndex++;
}
if (characterIndex < row.length()) { // only if rest contains non-whitespace
linesToBeWrapped.addFirst(row.substring(characterIndex));
}
}
}
}
return result;
}
public static void updateModifiersFromCSICode(
String controlSequence,
StyleSet<?> target,
StyleSet<?> original) {
char controlCodeType = controlSequence.charAt(controlSequence.length() - 1);
controlSequence = controlSequence.substring(2, controlSequence.length() - 1);
String[] codes = controlSequence.split(";");
TextColor[] palette = TextColor.ANSI.values();
if(controlCodeType == 'm') { // SGRs
for (String s : codes) {
// An empty string is equivalent to 0.
// Warning: too large values could throw an Exception!
int code = s.isEmpty() ? 0 : Integer.parseInt(s);
switch (code) {
case 0:
target.setStyleFrom(original);
break;
case 1:
target.enableModifiers(SGR.BOLD);
break;
case 3:
target.enableModifiers(SGR.ITALIC);
break;
case 4:
target.enableModifiers(SGR.UNDERLINE);
break;
case 5:
target.enableModifiers(SGR.BLINK);
break;
case 7:
target.enableModifiers(SGR.REVERSE);
break;
case 21: // both do. 21 seems more straightforward.
case 22:
target.disableModifiers(SGR.BOLD);
break;
case 23:
target.disableModifiers(SGR.ITALIC);
break;
case 24:
target.disableModifiers(SGR.UNDERLINE);
break;
case 25:
target.disableModifiers(SGR.BLINK);
break;
case 27:
target.disableModifiers(SGR.REVERSE);
break;
case 39:
target.setForegroundColor(original.getForegroundColor());
break;
case 49:
target.setBackgroundColor(original.getBackgroundColor());
break;
default:
if (code >= 30 && code <= 37) {
target.setForegroundColor( palette[code - 30] );
}
else if (code >= 40 && code <= 47) {
target.setBackgroundColor( palette[code - 40] );
}
}
}
}
}
}