com.googlecode.lanterna.TerminalTextUtils Maven / Gradle / Ivy
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/*
* 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
* - Backspace
* - Horizontal Tab
* - Line feed
*
*
* @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
* availableColumnSpace columns. This method does not handle special cases like tab or new-line.
*
* 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
* availableColumnSpace columns. This method does not handle special cases like tab or new-line.
*
* 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 getWordWrappedText(int maxWidth, String... lines) {
//Bounds checking
if(maxWidth <= 0) {
return Arrays.asList(lines);
}
List result = new ArrayList();
LinkedList linesToBeWrapped = new LinkedList(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] );
}
}
}
}
}
}