net.sourceforge.phpeclipse/src/net/sourceforge/phpeclipse/phpeditor/php/PHPAutoIndentStrategy.java

   1 /**********************************************************************
   2 Copyright (c) 2000, 2002 IBM Corp. 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 implementation
  10     www.phpeclipse.de
  11 **********************************************************************/
  12 package net.sourceforge.phpeclipse.phpeditor.php;
  13
  14 import org.eclipse.jface.text.BadLocationException;
  15 import org.eclipse.jface.text.DefaultAutoIndentStrategy;
  16 import org.eclipse.jface.text.DocumentCommand;
  17 import org.eclipse.jface.text.IDocument;
  18
  19 /**
  20  * Auto indent strategy sensitive to brackets.
  21  */
  22 public class PHPAutoIndentStrategy extends DefaultAutoIndentStrategy {
  23
  24         public PHPAutoIndentStrategy() {
  25         }
  26
  27         /* (non-Javadoc)
  28          * Method declared on IAutoIndentStrategy
  29          */
  30         public void customizeDocumentCommand(IDocument d, DocumentCommand c) {
  31                 if (c.length == 0 && c.text != null && endsWithDelimiter(d, c.text))
  32                         smartIndentAfterNewLine(d, c);
  33                 else if ("}".equals(c.text)) {
  34                         smartInsertAfterBracket(d, c);
  35                 }
  36         }
  37
  38         /**
  39          * Returns whether or not the text ends with one of the given search strings.
  40          */
  41         private boolean endsWithDelimiter(IDocument d, String txt) {
  42
  43                 String[] delimiters= d.getLegalLineDelimiters();
  44
  45                 for (int i= 0; i < delimiters.length; i++) {
  46                         if (txt.endsWith(delimiters[i]))
  47                                 return true;
  48                 }
  49
  50                 return false;
  51         }
  52
  53         /**
  54          * Returns the line number of the next bracket after end.
  55          * @returns the line number of the next matching bracket after end
  56          * @param document - the document being parsed
  57          * @param line - the line to start searching back from
  58          * @param end - the end position to search back from
  59          * @param closingBracketIncrease - the number of brackets to skip
  60          */
  61          protected int findMatchingOpenBracket(IDocument document, int line, int end, int closingBracketIncrease) throws BadLocationException {
  62
  63                 int start= document.getLineOffset(line);
  64                 int brackcount= getBracketCount(document, start, end, false) - closingBracketIncrease;
  65
  66                 // sum up the brackets counts of each line (closing brackets count negative,
  67                 // opening positive) until we find a line the brings the count to zero
  68                 while (brackcount < 0) {
  69                         line--;
  70                         if (line < 0) {
  71                                 return -1;
  72                         }
  73                         start= document.getLineOffset(line);
  74                         end= start + document.getLineLength(line) - 1;
  75                         brackcount += getBracketCount(document, start, end, false);
  76                 }
  77                 return line;
  78         }
  79
  80         /**
  81          * Returns the bracket value of a section of text. Closing brackets have a value of -1 and
  82          * open brackets have a value of 1.
  83          * @returns the line number of the next matching bracket after end
  84          * @param document - the document being parsed
  85          * @param start - the start position for the search
  86          * @param end - the end position for the search
  87          * @param ignoreCloseBrackets - whether or not to ignore closing brackets in the count
  88          */
  89          private int getBracketCount(IDocument document, int start, int end, boolean ignoreCloseBrackets) throws BadLocationException {
  90
  91                 int begin = start;
  92                 int bracketcount= 0;
  93                 while (begin < end) {
  94                         char curr= document.getChar(begin);
  95                         begin++;
  96                         switch (curr) {
  97                                 case '/' :
  98                                         if (begin < end) {
  99                                                 char next= document.getChar(begin);
 100                                                 if (next == '*') {
 101                                                         // a comment starts, advance to the comment end
 102                                                         begin= getCommentEnd(document, begin + 1, end);
 103                                                 } else if (next == '/') {
 104                                                         // '//'-comment: nothing to do anymore on this line
 105                                                         begin= end;
 106                                                 }
 107                                         }
 108                                         break;
 109                                 case '*' :
 110                                         if (begin < end) {
 111                                                 char next= document.getChar(begin);
 112                                                 if (next == '/') {
 113                                                         // we have been in a comment: forget what we read before
 114                                                         bracketcount= 0;
 115                                                         begin++;
 116                                                 }
 117                                         }
 118                                         break;
 119                                 case '{' :
 120                                         bracketcount++;
 121                                         ignoreCloseBrackets= false;
 122                                         break;
 123                                 case '}' :
 124                                         if (!ignoreCloseBrackets) {
 125                                                 bracketcount--;
 126                                         }
 127                                         break;
 128                                 case '"' :
 129                                 case '\'' :
 130                                         begin= getStringEnd(document, begin, end, curr);
 131                                         break;
 132                                 default :
 133                                         }
 134                 }
 135                 return bracketcount;
 136         }
 137
 138         /**
 139          * Returns the end position a comment starting at pos.
 140          * @returns the end position a comment starting at pos
 141          * @param document - the document being parsed
 142          * @param position - the start position for the search
 143          * @param end - the end position for the search
 144          */
 145          private int getCommentEnd(IDocument document, int position, int end) throws BadLocationException {
 146                 int currentPosition = position;
 147                 while (currentPosition < end) {
 148                         char curr= document.getChar(currentPosition);
 149                         currentPosition++;
 150                         if (curr == '*') {
 151                                 if (currentPosition < end && document.getChar(currentPosition) == '/') {
 152                                         return currentPosition + 1;
 153                                 }
 154                         }
 155                 }
 156                 return end;
 157         }
 158
 159         /**
 160          * Returns the String at line with the leading whitespace removed.
 161          * @returns the String at line with the leading whitespace removed.
 162          * @param document - the document being parsed
 163          * @param line - the line being searched
 164          */
 165          protected String getIndentOfLine(IDocument document, int line) throws BadLocationException {
 166                 if (line > -1) {
 167                         int start= document.getLineOffset(line);
 168                         int end= start + document.getLineLength(line) - 1;
 169                         int whiteend= findEndOfWhiteSpace(document, start, end);
 170                         return document.get(start, whiteend - start);
 171                 } else {
 172                         return ""; //$NON-NLS-1$
 173                 }
 174         }
 175
 176         /**
 177          * Returns the position of the character in the document after position.
 178          * @returns the next location of character.
 179          * @param document - the document being parsed
 180          * @param position - the position to start searching from
 181          * @param end - the end of the document
 182          * @param character - the character you are trying to match
 183          */
 184          private int getStringEnd(IDocument document, int position, int end, char character) throws BadLocationException {
 185                 int currentPosition = position;
 186                 while (currentPosition < end) {
 187                         char currentCharacter= document.getChar(currentPosition);
 188                         currentPosition++;
 189                         if (currentCharacter == '\\') {
 190                                 // ignore escaped characters
 191                                 currentPosition++;
 192                         } else if (currentCharacter == character) {
 193                                 return currentPosition;
 194                         }
 195                 }
 196                 return end;
 197         }
 198
 199         /**
 200          * Set the indent of a new line based on the command provided in the supplied document.
 201          * @param document - the document being parsed
 202          * @param command - the command being performed
 203          */
 204          protected void smartIndentAfterNewLine(IDocument document, DocumentCommand command) {
 205
 206                 int docLength= document.getLength();
 207                 if (command.offset == -1 || docLength == 0)
 208                         return;
 209
 210                 try {
 211                         int p= (command.offset == docLength ? command.offset - 1 : command.offset);
 212                         int line= document.getLineOfOffset(p);
 213
 214                         StringBuffer buf= new StringBuffer(command.text);
 215                         if (command.offset < docLength && document.getChar(command.offset) == '}') {
 216                                 int indLine= findMatchingOpenBracket(document, line, command.offset, 0);
 217                                 if (indLine == -1) {
 218                                         indLine= line;
 219                                 }
 220                                 buf.append(getIndentOfLine(document, indLine));
 221                         } else {
 222                                 int start= document.getLineOffset(line);
 223                                 int whiteend= findEndOfWhiteSpace(document, start, command.offset);
 224                                 buf.append(document.get(start, whiteend - start));
 225                                 if (getBracketCount(document, start, command.offset, true) > 0) {
 226                                         buf.append('\t');
 227                                 }
 228                         }
 229                         command.text= buf.toString();
 230
 231                 } catch (BadLocationException excp) {
 232                         System.out.println(PHPEditorMessages.getString("AutoIndent.error.bad_location_1")); //$NON-NLS-1$
 233                 }
 234         }
 235
 236         /**
 237          * Set the indent of a bracket based on the command provided in the supplied document.
 238          * @param document - the document being parsed
 239          * @param command - the command being performed
 240          */
 241          protected void smartInsertAfterBracket(IDocument document, DocumentCommand command) {
 242                 if (command.offset == -1 || document.getLength() == 0)
 243                         return;
 244
 245                 try {
 246                         int p= (command.offset == document.getLength() ? command.offset - 1 : command.offset);
 247                         int line= document.getLineOfOffset(p);
 248                         int start= document.getLineOffset(line);
 249                         int whiteend= findEndOfWhiteSpace(document, start, command.offset);
 250
 251                         // shift only when line does not contain any text up to the closing bracket
 252                         if (whiteend == command.offset) {
 253                                 // evaluate the line with the opening bracket that matches out closing bracket
 254                                 int indLine= findMatchingOpenBracket(document, line, command.offset, 1);
 255                                 if (indLine != -1 && indLine != line) {
 256                                         // take the indent of the found line
 257                                         StringBuffer replaceText= new StringBuffer(getIndentOfLine(document, indLine));
 258                                         // add the rest of the current line including the just added close bracket
 259                                         replaceText.append(document.get(whiteend, command.offset - whiteend));
 260                                         replaceText.append(command.text);
 261                                         // modify document command
 262                                         command.length= command.offset - start;
 263                                         command.offset= start;
 264                                         command.text= replaceText.toString();
 265                                 }
 266                         }
 267                 } catch (BadLocationException excp) {
 268                         System.out.println(PHPEditorMessages.getString("AutoIndent.error.bad_location_2")); //$NON-NLS-1$
 269                 }
 270         }
 271 }