/*
* (c) Copyright IBM Corp. 2000, 2001.
* All Rights Reserved.
*/
package org.epic.perleditor.templates.util;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.DefaultLineTracker;
import org.eclipse.jface.text.ILineTracker;
import org.eclipse.jface.text.IRegion;
//import org.eclipse.jdt.internal.corext.Assert;
/**
* Helper class to provide String manipulation functions not available in standard JDK.
*/
public class Strings {
public static String removeNewLine(String message) {
StringBuffer result= new StringBuffer();
int current= 0;
int index= message.indexOf('\n', 0);
while (index != -1) {
result.append(message.substring(current, index));
if (current < index && index != 0)
result.append(' ');
current= index + 1;
index= message.indexOf('\n', current);
}
result.append(message.substring(current));
return result.toString();
}
/**
* Converts the given string into an array of lines. The lines
* don't contain any line delimiter characters.
*
* @return the string converted into an array of strings. Returns <code>
* null</code> if the input string can't be converted in an array of lines.
*/
public static String[] convertIntoLines(String input) {
try {
ILineTracker tracker= new DefaultLineTracker();
tracker.set(input);
int size= tracker.getNumberOfLines();
String result[]= new String[size];
for (int i= 0; i < size; i++) {
IRegion region= tracker.getLineInformation(i);
int offset= region.getOffset();
result[i]= input.substring(offset, offset + region.getLength());
}
return result;
} catch (BadLocationException e) {
return null;
}
}
/**
* Returns <code>true</code> if the given string only consists of
* white spaces according to Java. If the string is empty, <code>true
* </code> is returned.
*
* @return <code>true</code> if the string only consists of white
* spaces; otherwise <code>false</code> is returned
*
* @see java.lang.Character#isWhitespace(char)
*/
public static boolean containsOnlyWhitespaces(String s) {
int size= s.length();
for (int i= 0; i < size; i++) {
if (!Character.isWhitespace(s.charAt(i)))
return false;
}
return true;
}
/**
* Removes leading tabs and spaces from the given string. If the string
* doesn't contain any leading tabs or spaces then the string itself is
* returned.
*/
public static String trimLeadingTabsAndSpaces(String line) {
int size= line.length();
int start= size;
for (int i= 0; i < size; i++) {
char c= line.charAt(i);
if (c != '\t' && !Character.isSpaceChar(c)) {
start= i;
break;
}
}
if (start == 0)
return line;
else if (start == size)
return ""; //$NON-NLS-1$
else
return line.substring(start);
}
public static String trimTrailingTabsAndSpaces(String line) {
int size= line.length();
int end= size;
for (int i= size - 1; i >= 0; i--) {
char c= line.charAt(i);
if (c == '\t' || Character.isSpaceChar(c)) {
end= i;
} else {
break;
}
}
if (end == size)
return line;
else if (end == 0)
return ""; //$NON-NLS-1$
else
return line.substring(0, end);
}
/**
* Returns the indent of the given string.
*
* @param line the text line
* @param tabWidth the width of the '\t' character.
*/
public static int computeIndent(String line, int tabWidth) {
int result= 0;
int blanks= 0;
int size= line.length();
for (int i= 0; i < size; i++) {
char c= line.charAt(i);
if (c == '\t') {
result++;
blanks= 0;
} else if (Character.isSpaceChar(c)) {
blanks++;
if (blanks == tabWidth) {
result++;
blanks= 0;
}
} else {
return result;
}
}
return result;
}
/**
* Removes the given number of idents from the line. Asserts that the given line
* has the requested number of indents. If <code>indentsToRemove <= 0</code>
* the line is returned.
*/
public static String trimIndent(String line, int indentsToRemove, int tabWidth) {
if (line == null || indentsToRemove <= 0)
return line;
int start= 0;
int indents= 0;
int blanks= 0;
int size= line.length();
for (int i= 0; i < size; i++) {
char c= line.charAt(i);
if (c == '\t') {
indents++;
blanks= 0;
} else if (Character.isSpaceChar(c)) {
blanks++;
if (blanks == tabWidth) {
indents++;
blanks= 0;
}
} else {
// Assert.isTrue(false, "Line does not have requested number of indents"); //$NON-NLS-1$
}
if (indents == indentsToRemove) {
start= i + 1;
break;
}
}
if (start == size)
return ""; //$NON-NLS-1$
else
return line.substring(start);
}
/**
* Removes all leading indents from the given line. If the line doesn't contain
* any indents the line itself is returned.
*/
public static String trimIndents(String s, int tabWidth) {
int indent= computeIndent(s, tabWidth);
if (indent == 0)
return s;
return trimIndent(s, indent, tabWidth);
}
/**
* Removes the common number of indents from all lines. If a line
* only consists out of white space it is ignored.
*/
public static void trimIndentation(String[] lines, int tabWidth) {
String[] toDo= new String[lines.length];
// find indentation common to all lines
int minIndent= Integer.MAX_VALUE; // very large
for (int i= 0; i < lines.length; i++) {
String line= lines[i];
if (containsOnlyWhitespaces(line))
continue;
toDo[i]= line;
int indent= computeIndent(line, tabWidth);
if (indent < minIndent) {
minIndent= indent;
}
}
if (minIndent > 0) {
// remove this indent from all lines
for (int i= 0; i < toDo.length; i++) {
String s= toDo[i];
if (s != null)
lines[i]= trimIndent(s, minIndent, tabWidth);
else {
String line= lines[i];
int indent= computeIndent(line, tabWidth);
if (indent > minIndent)
lines[i]= trimIndent(line, minIndent, tabWidth);
else
lines[i]= trimLeadingTabsAndSpaces(line);
}
}
}
}
public static String getIndentString(String line, int tabWidth) {
int size= line.length();
int end= 0;
int blanks= 0;
for (int i= 0; i < size; i++) {
char c= line.charAt(i);
if (c == '\t') {
end= i;
blanks= 0;
} else if (Character.isSpaceChar(c)) {
blanks++;
if (blanks == tabWidth) {
end= i;
blanks= 0;
}
} else {
break;
}
}
if (end == 0)
return ""; //$NON-NLS-1$
else if (end == size)
return line;
else
return line.substring(0, end + 1);
}
}