/*
* Copyright 2004-2014 SmartBear Software
*
* Licensed under the EUPL, Version 1.1 or - as soon as they will be approved by the European Commission - subsequent
* versions of the EUPL (the "Licence");
* You may not use this work except in compliance with the Licence.
* You may obtain a copy of the Licence at:
*
* http://ec.europa.eu/idabc/eupl
*
* Unless required by applicable law or agreed to in writing, software distributed under the Licence is
* distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the Licence for the specific language governing permissions and limitations
* under the Licence.
*/
package org.syntax.jedit;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
/**
* Class with several utility functions used by the text area component.
*
* @author Slava Pestov
* @version $Id$
*/
public class TextUtilities {
/**
* Returns the offset of the bracket matching the one at the specified offset
* of the document, or -1 if the bracket is unmatched (or if the character is
* not a bracket).
*
* @param doc The document
* @param offset The offset
* @throws BadLocationException If an out-of-bounds access was attempted on the document
* text
*/
public static int findMatchingBracket(Document doc, int offset) throws BadLocationException {
if (doc.getLength() == 0) {
return -1;
}
char c = doc.getText(offset, 1).charAt(0);
char cprime; // c` - corresponding character
boolean direction; // true = back, false = forward
switch (c) {
case '(':
cprime = ')';
direction = false;
break;
case ')':
cprime = '(';
direction = true;
break;
case '[':
cprime = ']';
direction = false;
break;
case ']':
cprime = '[';
direction = true;
break;
case '{':
cprime = '}';
direction = false;
break;
case '}':
cprime = '{';
direction = true;
break;
default:
return -1;
}
int count;
// How to merge these two cases is left as an exercise
// for the reader.
// Go back or forward
if (direction) {
// Count is 1 initially because we have already
// `found' one closing bracket
count = 1;
// Get text[0,offset-1];
String text = doc.getText(0, offset);
// Scan backwards
for (int i = offset - 1; i >= 0; i--) {
// If text[i] == c, we have found another
// closing bracket, therefore we will need
// two opening brackets to complete the
// match.
char x = text.charAt(i);
if (x == c) {
count++;
}
// If text[i] == cprime, we have found a
// opening bracket, so we return i if
// --count == 0
else if (x == cprime) {
if (--count == 0) {
return i;
}
}
}
} else {
// Count is 1 initially because we have already
// `found' one opening bracket
count = 1;
// So we don't have to + 1 in every loop
offset++;
// Number of characters to check
int len = doc.getLength() - offset;
// Get text[offset+1,len];
String text = doc.getText(offset, len);
// Scan forwards
for (int i = 0; i < len; i++) {
// If text[i] == c, we have found another
// opening bracket, therefore we will need
// two closing brackets to complete the
// match.
char x = text.charAt(i);
if (x == c) {
count++;
}
// If text[i] == cprime, we have found an
// closing bracket, so we return i if
// --count == 0
else if (x == cprime) {
if (--count == 0) {
return i + offset;
}
}
}
}
// Nothing found
return -1;
}
/**
* Locates the start of the word at the specified position.
*
* @param line The text
* @param pos The position
*/
public static int findWordStart(String line, int pos, String noWordSep) {
char ch = line.charAt(pos - 1);
if (noWordSep == null) {
noWordSep = "";
}
boolean selectNoLetter = (!Character.isLetterOrDigit(ch) && noWordSep.indexOf(ch) == -1);
int wordStart = 0;
for (int i = pos - 1; i >= 0; i--) {
ch = line.charAt(i);
if (selectNoLetter ^ (!Character.isLetterOrDigit(ch) && noWordSep.indexOf(ch) == -1)) {
wordStart = i + 1;
break;
}
}
return wordStart;
}
/**
* Locates the end of the word at the specified position.
*
* @param line The text
* @param pos The position
*/
public static int findWordEnd(String line, int pos, String noWordSep) {
char ch = line.charAt(pos);
if (noWordSep == null) {
noWordSep = "";
}
boolean selectNoLetter = (!Character.isLetterOrDigit(ch) && noWordSep.indexOf(ch) == -1);
int wordEnd = line.length();
for (int i = pos; i < line.length(); i++) {
ch = line.charAt(i);
if (selectNoLetter ^ (!Character.isLetterOrDigit(ch) && noWordSep.indexOf(ch) == -1)) {
wordEnd = i;
break;
}
}
return wordEnd;
}
}