nitind | b12994e | 2005-05-26 17:34:10 +0000 | [diff] [blame] | 1 | /******************************************************************************* |
| 2 | * Copyright (c) 2001, 2005 IBM Corporation and others. |
| 3 | * All rights reserved. This program and the accompanying materials |
| 4 | * are made available under the terms of the Eclipse Public License v1.0 |
| 5 | * which accompanies this distribution, and is available at |
| 6 | * http://www.eclipse.org/legal/epl-v10.html |
| 7 | * |
| 8 | * Contributors: |
| 9 | * IBM Corporation - initial API and implementation |
| 10 | * |
| 11 | *******************************************************************************/ |
| 12 | package org.eclipse.wst.html.ui.internal.text; |
| 13 | |
| 14 | // taken from package org.eclipse.jdt.ui.text; |
| 15 | |
| 16 | import java.io.IOException; |
| 17 | |
| 18 | import org.eclipse.jface.text.BadLocationException; |
| 19 | import org.eclipse.jface.text.IDocument; |
nitind | f8e7763 | 2005-09-07 23:49:25 +0000 | [diff] [blame] | 20 | import org.eclipse.wst.html.ui.internal.derived.SingleCharReader; |
nitind | b12994e | 2005-05-26 17:34:10 +0000 | [diff] [blame] | 21 | |
| 22 | /** |
| 23 | * Reads from a document either forwards or backwards. May be configured to |
| 24 | * skip comments and strings. |
| 25 | */ |
| 26 | class JavaCodeReader extends SingleCharReader { |
| 27 | |
| 28 | /** The EOF character */ |
| 29 | public static final int EOF = -1; |
| 30 | |
| 31 | private boolean fSkipComments = false; |
| 32 | private boolean fSkipStrings = false; |
| 33 | private boolean fForward = false; |
| 34 | |
| 35 | private IDocument fDocument; |
| 36 | private int fOffset; |
| 37 | |
| 38 | private int fEnd = -1; |
| 39 | private int fCachedLineNumber = -1; |
| 40 | private int fCachedLineOffset = -1; |
| 41 | |
| 42 | |
| 43 | public JavaCodeReader() { |
| 44 | } |
| 45 | |
| 46 | /** |
| 47 | * Returns the offset of the last read character. Should only be called |
| 48 | * after read has been called. |
| 49 | */ |
| 50 | public int getOffset() { |
| 51 | return fForward ? fOffset - 1 : fOffset; |
| 52 | } |
| 53 | |
| 54 | public void configureForwardReader(IDocument document, int offset, int length, boolean skipComments, boolean skipStrings) throws IOException { |
| 55 | fDocument = document; |
| 56 | fOffset = offset; |
| 57 | fSkipComments = skipComments; |
| 58 | fSkipStrings = skipStrings; |
| 59 | |
| 60 | fForward = true; |
| 61 | fEnd = Math.min(fDocument.getLength(), fOffset + length); |
| 62 | } |
| 63 | |
| 64 | public void configureBackwardReader(IDocument document, int offset, boolean skipComments, boolean skipStrings) throws IOException { |
| 65 | fDocument = document; |
| 66 | fOffset = offset; |
| 67 | fSkipComments = skipComments; |
| 68 | fSkipStrings = skipStrings; |
| 69 | |
| 70 | fForward = false; |
| 71 | try { |
| 72 | fCachedLineNumber = fDocument.getLineOfOffset(fOffset); |
| 73 | } |
| 74 | catch (BadLocationException x) { |
| 75 | throw new IOException(x.getMessage()); |
| 76 | } |
| 77 | } |
| 78 | |
| 79 | /* |
| 80 | * @see Reader#close() |
| 81 | */ |
| 82 | public void close() throws IOException { |
| 83 | fDocument = null; |
| 84 | } |
| 85 | |
| 86 | /* |
| 87 | * @see SingleCharReader#read() |
| 88 | */ |
| 89 | public int read() throws IOException { |
| 90 | try { |
| 91 | return fForward ? readForwards() : readBackwards(); |
| 92 | } |
| 93 | catch (BadLocationException x) { |
| 94 | throw new IOException(x.getMessage()); |
| 95 | } |
| 96 | } |
| 97 | |
| 98 | private void gotoCommentEnd() throws BadLocationException { |
| 99 | while (fOffset < fEnd) { |
| 100 | char current = fDocument.getChar(fOffset++); |
| 101 | if (current == '*') { |
| 102 | if (fOffset < fEnd && fDocument.getChar(fOffset) == '/') { |
| 103 | ++fOffset; |
| 104 | return; |
| 105 | } |
| 106 | } |
| 107 | } |
| 108 | } |
| 109 | |
| 110 | private void gotoStringEnd(char delimiter) throws BadLocationException { |
| 111 | while (fOffset < fEnd) { |
| 112 | char current = fDocument.getChar(fOffset++); |
| 113 | if (current == '\\') { |
| 114 | // ignore escaped characters |
| 115 | ++fOffset; |
| 116 | } |
| 117 | else if (current == delimiter) { |
| 118 | return; |
| 119 | } |
| 120 | } |
| 121 | } |
| 122 | |
| 123 | private void gotoLineEnd() throws BadLocationException { |
| 124 | int line = fDocument.getLineOfOffset(fOffset); |
| 125 | fOffset = fDocument.getLineOffset(line + 1); |
| 126 | } |
| 127 | |
| 128 | private int readForwards() throws BadLocationException { |
| 129 | while (fOffset < fEnd) { |
| 130 | char current = fDocument.getChar(fOffset++); |
| 131 | |
| 132 | switch (current) { |
| 133 | case '/' : |
| 134 | |
| 135 | if (fSkipComments && fOffset < fEnd) { |
| 136 | char next = fDocument.getChar(fOffset); |
| 137 | if (next == '*') { |
| 138 | // a comment starts, advance to the comment end |
| 139 | ++fOffset; |
| 140 | gotoCommentEnd(); |
| 141 | continue; |
| 142 | } |
| 143 | else if (next == '/') { |
| 144 | // '//'-comment starts, advance to the line end |
| 145 | gotoLineEnd(); |
| 146 | continue; |
| 147 | } |
| 148 | } |
| 149 | |
| 150 | return current; |
| 151 | |
| 152 | case '"' : |
| 153 | case '\'' : |
| 154 | |
| 155 | if (fSkipStrings) { |
| 156 | gotoStringEnd(current); |
| 157 | continue; |
| 158 | } |
| 159 | |
| 160 | return current; |
| 161 | } |
| 162 | |
| 163 | return current; |
| 164 | } |
| 165 | |
| 166 | return EOF; |
| 167 | } |
| 168 | |
| 169 | private void handleSingleLineComment() throws BadLocationException { |
| 170 | int line = fDocument.getLineOfOffset(fOffset); |
| 171 | if (line < fCachedLineNumber) { |
| 172 | fCachedLineNumber = line; |
| 173 | fCachedLineOffset = fDocument.getLineOffset(line); |
| 174 | int offset = fOffset; |
| 175 | while (fCachedLineOffset < offset) { |
| 176 | char current = fDocument.getChar(offset--); |
| 177 | if (current == '/' && fCachedLineOffset <= offset && fDocument.getChar(offset) == '/') { |
| 178 | fOffset = offset; |
| 179 | return; |
| 180 | } |
| 181 | } |
| 182 | } |
| 183 | } |
| 184 | |
| 185 | private void gotoCommentStart() throws BadLocationException { |
| 186 | while (0 < fOffset) { |
| 187 | char current = fDocument.getChar(fOffset--); |
| 188 | if (current == '*' && 0 <= fOffset && fDocument.getChar(fOffset) == '/') |
| 189 | return; |
| 190 | } |
| 191 | } |
| 192 | |
| 193 | private void gotoStringStart(char delimiter) throws BadLocationException { |
| 194 | while (0 < fOffset) { |
| 195 | char current = fDocument.getChar(fOffset); |
| 196 | if (current == delimiter) { |
| 197 | if (!(0 <= fOffset && fDocument.getChar(fOffset - 1) == '\\')) |
| 198 | return; |
| 199 | } |
| 200 | --fOffset; |
| 201 | } |
| 202 | } |
| 203 | |
| 204 | private int readBackwards() throws BadLocationException { |
| 205 | |
| 206 | while (0 < fOffset) { |
| 207 | --fOffset; |
| 208 | |
| 209 | handleSingleLineComment(); |
| 210 | |
| 211 | char current = fDocument.getChar(fOffset); |
| 212 | switch (current) { |
| 213 | case '/' : |
| 214 | |
| 215 | if (fSkipComments && fOffset > 1) { |
| 216 | char next = fDocument.getChar(fOffset - 1); |
| 217 | if (next == '*') { |
| 218 | // a comment ends, advance to the comment start |
| 219 | fOffset -= 2; |
| 220 | gotoCommentStart(); |
| 221 | continue; |
| 222 | } |
| 223 | } |
| 224 | |
| 225 | return current; |
| 226 | |
| 227 | case '"' : |
| 228 | case '\'' : |
| 229 | |
| 230 | if (fSkipStrings) { |
| 231 | --fOffset; |
| 232 | gotoStringStart(current); |
| 233 | continue; |
| 234 | } |
| 235 | |
| 236 | return current; |
| 237 | } |
| 238 | |
| 239 | return current; |
| 240 | } |
| 241 | |
| 242 | return EOF; |
| 243 | } |
| 244 | } |