net.sourceforge.phpeclipse/src/net/sourceforge/phpdt/internal/corext/util/Strings.java

   1 /*******************************************************************************
   2  * Copyright (c) 2000, 2003 IBM Corporation and others.
   3  * All rights reserved. This program and the accompanying materials
   4  * are made available under the terms of the Common Public License v1.0
   5  * which accompanies this distribution, and is available at
   6  * http://www.eclipse.org/legal/cpl-v10.html
   7  *
   8  * Contributors:
   9  *     IBM Corporation - initial API and implementation
  10  *******************************************************************************/
  11 package net.sourceforge.phpdt.internal.corext.util;
  12
  13 import org.eclipse.jface.text.BadLocationException;
  14 import org.eclipse.jface.text.DefaultLineTracker;
  15 import org.eclipse.jface.text.ILineTracker;
  16 import org.eclipse.jface.text.IRegion;
  17
  18 /**
  19  * Helper class to provide String manipulation functions not available in standard JDK.
  20  */
  21 public class Strings {
  22
  23         /**
  24          * Indent char is a space char but not a line delimiters.
  25          * <code>== Character.isWhitespace(ch) && ch != '\n' && ch != '\r'</code>
  26          */
  27         public static boolean isIndentChar(char ch) {
  28                 return Character.isWhitespace(ch) && !isLineDelimiterChar(ch);
  29         }
  30
  31         /**
  32          * tests if a char is lower case. Fix for 26529
  33          */
  34         public static boolean isLowerCase(char ch) {
  35                 return Character.toLowerCase(ch) == ch;
  36         }
  37
  38         /**
  39          * Line delimiter chars are  '\n' and '\r'.
  40          */
  41         public static boolean isLineDelimiterChar(char ch) {
  42                 return ch == '\n' || ch == '\r';
  43         }
  44
  45         public static String removeNewLine(String message) {
  46                 StringBuffer result= new StringBuffer();
  47                 int current= 0;
  48                 int index= message.indexOf('\n', 0);
  49                 while (index != -1) {
  50                         result.append(message.substring(current, index));
  51                         if (current < index && index != 0)
  52                                 result.append(' ');
  53                         current= index + 1;
  54                         index= message.indexOf('\n', current);
  55                 }
  56                 result.append(message.substring(current));
  57                 return result.toString();
  58         }
  59
  60         /**
  61          * Converts the given string into an array of lines. The lines
  62          * don't contain any line delimiter characters.
  63          *
  64          * @return the string converted into an array of strings. Returns <code>
  65          *      null</code> if the input string can't be converted in an array of lines.
  66          */
  67         public static String[] convertIntoLines(String input) {
  68                 try {
  69                         ILineTracker tracker= new DefaultLineTracker();
  70                         tracker.set(input);
  71                         int size= tracker.getNumberOfLines();
  72                         String result[]= new String[size];
  73                         for (int i= 0; i < size; i++) {
  74                                 IRegion region= tracker.getLineInformation(i);
  75                                 int offset= region.getOffset();
  76                                 result[i]= input.substring(offset, offset + region.getLength());
  77                         }
  78                         return result;
  79                 } catch (BadLocationException e) {
  80                         return null;
  81                 }
  82         }
  83
  84         /**
  85          * Returns <code>true</code> if the given string only consists of
  86          * white spaces according to Java. If the string is empty, <code>true
  87          * </code> is returned.
  88          *
  89          * @return <code>true</code> if the string only consists of white
  90          *      spaces; otherwise <code>false</code> is returned
  91          *
  92          * @see java.lang.Character#isWhitespace(char)
  93          */
  94         public static boolean containsOnlyWhitespaces(String s) {
  95                 int size= s.length();
  96                 for (int i= 0; i < size; i++) {
  97                         if (!Character.isWhitespace(s.charAt(i)))
  98                                 return false;
  99                 }
 100                 return true;
 101         }
 102
 103         /**
 104          * Removes leading tabs and spaces from the given string. If the string
 105          * doesn't contain any leading tabs or spaces then the string itself is
 106          * returned.
 107          */
 108         public static String trimLeadingTabsAndSpaces(String line) {
 109                 int size= line.length();
 110                 int start= size;
 111                 for (int i= 0; i < size; i++) {
 112                         char c= line.charAt(i);
 113                         if (!isIndentChar(c)) {
 114                                 start= i;
 115                                 break;
 116                         }
 117                 }
 118                 if (start == 0)
 119                         return line;
 120                 else if (start == size)
 121                         return ""; //$NON-NLS-1$
 122                 else
 123                         return line.substring(start);
 124         }
 125
 126         public static String trimTrailingTabsAndSpaces(String line) {
 127                 int size= line.length();
 128                 int end= size;
 129                 for (int i= size - 1; i >= 0; i--) {
 130                         char c= line.charAt(i);
 131                         if (isIndentChar(c)) {
 132                                 end= i;
 133                         } else {
 134                                 break;
 135                         }
 136                 }
 137                 if (end == size)
 138                         return line;
 139                 else if (end == 0)
 140                         return ""; //$NON-NLS-1$
 141                 else
 142                         return line.substring(0, end);
 143         }
 144
 145         /**
 146          * Returns the indent of the given string.
 147          *
 148          * @param line the text line
 149          * @param tabWidth the width of the '\t' character.
 150          */
 151         public static int computeIndent(String line, int tabWidth) {
 152                 int result= 0;
 153                 int blanks= 0;
 154                 int size= line.length();
 155                 for (int i= 0; i < size; i++) {
 156                         char c= line.charAt(i);
 157                         if (c == '\t') {
 158                                 result++;
 159                                 blanks= 0;
 160                         } else if (isIndentChar(c)) {
 161                                 blanks++;
 162                                 if (blanks == tabWidth) {
 163                                         result++;
 164                                         blanks= 0;
 165                                 }
 166                         } else {
 167                                 return result;
 168                         }
 169                 }
 170                 return result;
 171         }
 172
 173         /**
 174          * Removes the given number of idents from the line. Asserts that the given line
 175          * has the requested number of indents. If <code>indentsToRemove <= 0</code>
 176          * the line is returned.
 177          */
 178         public static String trimIndent(String line, int indentsToRemove, int tabWidth) {
 179                 if (line == null || indentsToRemove <= 0)
 180                         return line;
 181
 182                 int start= 0;
 183                 int indents= 0;
 184                 int blanks= 0;
 185                 int size= line.length();
 186                 for (int i= 0; i < size; i++) {
 187                         char c= line.charAt(i);
 188                         if (c == '\t') {
 189                                 indents++;
 190                                 blanks= 0;
 191                         } else if (isIndentChar(c)) {
 192                                         blanks++;
 193                                         if (blanks == tabWidth) {
 194                                                 indents++;
 195                                                 blanks= 0;
 196                                         }
 197                         } else {
 198                                 // Assert.isTrue(false, "Line does not have requested number of indents"); //$NON-NLS-1$
 199                                 start= i + 1;
 200                                 break;
 201                         }
 202                         if (indents == indentsToRemove) {
 203                                 start= i + 1;
 204                                 break;
 205                         }
 206                 }
 207                 if (start == size)
 208                         return ""; //$NON-NLS-1$
 209                 else
 210                         return line.substring(start);
 211         }
 212
 213         /**
 214          * Removes all leading indents from the given line. If the line doesn't contain
 215          * any indents the line itself is returned.
 216          */
 217         public static String trimIndents(String s, int tabWidth) {
 218                 int indent= computeIndent(s, tabWidth);
 219                 if (indent == 0)
 220                         return s;
 221                 return trimIndent(s, indent, tabWidth);
 222         }
 223
 224         /**
 225          * Removes the common number of indents from all lines. If a line
 226          * only consists out of white space it is ignored.
 227          */
 228         public static void trimIndentation(String[] lines, int tabWidth) {
 229                 trimIndentation(lines, tabWidth, true);
 230         }
 231
 232         /**
 233          * Removes the common number of indents from all lines. If a line
 234          * only consists out of white space it is ignored. If <code>
 235          * considerFirstLine</code> is false the first line will be ignored.
 236          */
 237         public static void trimIndentation(String[] lines, int tabWidth, boolean considerFirstLine) {
 238                 String[] toDo= new String[lines.length];
 239                 // find indentation common to all lines
 240                 int minIndent= Integer.MAX_VALUE; // very large
 241                 for (int i= considerFirstLine ? 0 : 1; i < lines.length; i++) {
 242                         String line= lines[i];
 243                         if (containsOnlyWhitespaces(line))
 244                                 continue;
 245                         toDo[i]= line;
 246                         int indent= computeIndent(line, tabWidth);
 247                         if (indent < minIndent) {
 248                                 minIndent= indent;
 249                         }
 250                 }
 251
 252                 if (minIndent > 0) {
 253                         // remove this indent from all lines
 254                         for (int i= considerFirstLine ? 0 : 1; i < toDo.length; i++) {
 255                                 String s= toDo[i];
 256                                 if (s != null)
 257                                         lines[i]= trimIndent(s, minIndent, tabWidth);
 258                                 else {
 259                                         String line= lines[i];
 260                                         int indent= computeIndent(line, tabWidth);
 261                                         if (indent > minIndent)
 262                                                 lines[i]= trimIndent(line, minIndent, tabWidth);
 263                                         else
 264                                                 lines[i]= trimLeadingTabsAndSpaces(line);
 265                                 }
 266                         }
 267                 }
 268         }
 269
 270         public static String getIndentString(String line, int tabWidth) {
 271                 int size= line.length();
 272                 int end= 0;
 273                 int blanks= 0;
 274                 for (int i= 0; i < size; i++) {
 275                         char c= line.charAt(i);
 276                         if (c == '\t') {
 277                                 end= i + 1;
 278                                 blanks= 0;
 279                         } else if (isIndentChar(c)) {
 280                                 blanks++;
 281                                 if (blanks == tabWidth) {
 282                                         end= i + 1;
 283                                         blanks= 0;
 284                                 }
 285                         } else {
 286                                 break;
 287                         }
 288                 }
 289                 if (end == 0)
 290                         return ""; //$NON-NLS-1$
 291                 else if (end == size)
 292                         return line;
 293                 else
 294                         return line.substring(0, end);
 295         }
 296
 297         public static String[] removeTrailingEmptyLines(String[] sourceLines) {
 298                 int lastNonEmpty= findLastNonEmptyLineIndex(sourceLines);
 299                 String[] result= new String[lastNonEmpty + 1];
 300                 for (int i= 0; i < result.length; i++) {
 301                         result[i]= sourceLines[i];
 302                 }
 303                 return result;
 304         }
 305
 306         private static int findLastNonEmptyLineIndex(String[] sourceLines) {
 307                 for (int i= sourceLines.length - 1; i >= 0; i--) {
 308                         if (! sourceLines[i].trim().equals(""))//$NON-NLS-1$
 309                                 return i;
 310                 }
 311                 return -1;
 312         }
 313
 314         /**
 315          * Change the indent of, possible muti-line, code range. The current indent is removed, a new indent added.
 316          * The first line of the code will not be changed. (It is considered to have no indent as it might start in
 317          * the middle of a line)
 318          */
 319         public static String changeIndent(String code, int codeIndentLevel, int tabWidth, String newIndent, String lineDelim) {
 320                 try {
 321                         ILineTracker tracker= new DefaultLineTracker();
 322                         tracker.set(code);
 323                         int nLines= tracker.getNumberOfLines();
 324                         if (nLines == 1) {
 325                                 return code;
 326                         }
 327
 328                         StringBuffer buf= new StringBuffer();
 329
 330                         for (int i= 0; i < nLines; i++) {
 331                                 IRegion region= tracker.getLineInformation(i);
 332                                 int start= region.getOffset();
 333                                 int end= start + region.getLength();
 334                                 String line= code.substring(start, end);
 335
 336                                 if (i == 0) {  // no indent for first line (contained in the formatted string)
 337                                         buf.append(line);
 338                                 } else { // no new line after last line
 339                                         buf.append(lineDelim);
 340                                         buf.append(newIndent);
 341                                         buf.append(trimIndent(line, codeIndentLevel, tabWidth));
 342                                 }
 343                         }
 344                         return buf.toString();
 345                 } catch (BadLocationException e) {
 346                         // can not happen
 347                         return code;
 348                 }
 349         }
 350
 351         /**
 352          * Concatenate the given strings into one strings using the passed line delimiter as a
 353          * delimiter. No delimiter is added to the last line.
 354          */
 355         public static String concatenate(String[] lines, String delimiter) {
 356                 StringBuffer buffer= new StringBuffer();
 357                 for (int i= 0; i < lines.length; i++) {
 358                         if (i > 0)
 359                                 buffer.append(delimiter);
 360                         buffer.append(lines[i]);
 361                 }
 362                 return buffer.toString();
 363         }
 364
 365         public static boolean equals(String s, char[] c) {
 366                 if (s.length() != c.length)
 367                         return false;
 368
 369                 for (int i = c.length; --i >= 0;)
 370                         if (s.charAt(i) != c[i])
 371                                 return false;
 372                 return true;
 373         }
 374 }
 375