| /******************************************************************************* |
| * Copyright (c) 2011, 2012 Ericsson AB and others. |
| * |
| * All rights reserved. This program and the accompanying materials are |
| * made available under the terms of the Eclipse Public License v1.0 which |
| * accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/epl-v10.html |
| * |
| * Description: |
| * |
| * This class is adapted from org.eclipse.compare.internal.DocLineComparator |
| * and is used to compare lines in two or three-way compares |
| * |
| * Contributors: |
| * Sebastien Dubois - Created for Mylyn Review R4E project |
| * |
| ******************************************************************************/ |
| |
| package org.eclipse.mylyn.reviews.r4e.ui.internal.utils; |
| |
| import org.eclipse.compare.contentmergeviewer.ITokenComparator; |
| import org.eclipse.compare.rangedifferencer.IRangeComparator; |
| import org.eclipse.jface.text.BadLocationException; |
| import org.eclipse.jface.text.IDocument; |
| import org.eclipse.jface.text.IRegion; |
| |
| /** |
| * Implements the <code>IRangeComparator</code> interface for lines in a document. A <code>DocLineComparator</code> is |
| * used as the input for the <code>RangeDifferencer</code> engine to perform a line oriented compare on documents. |
| * <p> |
| * A <code>DocLineComparator</code> doesn't know anything about line separators because its notion of lines is solely |
| * defined in the underlying <code>IDocument</code>. |
| * |
| * @author Sebastien Dubois |
| * @version $Revision: 1.0 $ |
| */ |
| public class DocLineComparator implements ITokenComparator { |
| |
| /** |
| * Field fDocument. |
| */ |
| private final IDocument fDocument; |
| |
| /** |
| * Field fLineOffset. |
| */ |
| private int fLineOffset; |
| |
| /** |
| * Field fLineCount. |
| */ |
| private int fLineCount; |
| |
| /** |
| * Field fLength. |
| */ |
| private int fLength; |
| |
| /** |
| * Field fIgnoreWhiteSpace. |
| */ |
| private final boolean fIgnoreWhiteSpace; |
| |
| /** |
| * Creates a <code>DocLineComparator</code> for the given document range. ignoreWhiteSpace controls whether |
| * comparing lines (in method <code>rangesEqual<code>) should ignore whitespace. |
| * |
| * @param document |
| * the document from which the lines are taken |
| * @param region |
| * if non-<code>null</code> only lines within this range are taken |
| * @param ignoreWhiteSpace |
| * if <code>true</code> white space is ignored when comparing lines |
| */ |
| public DocLineComparator(IDocument document, IRegion region, boolean ignoreWhiteSpace) { |
| fDocument = document; |
| fIgnoreWhiteSpace = ignoreWhiteSpace; |
| |
| fLineOffset = 0; |
| if (null != region) { |
| fLength = region.getLength(); |
| final int start = region.getOffset(); |
| try { |
| fLineOffset = fDocument.getLineOfOffset(start); |
| } catch (BadLocationException ex) { |
| // silently ignored |
| } |
| |
| if (0 == fLength) { |
| // optimization, empty documents have one line |
| fLineCount = 1; |
| } else { |
| int endLine = fDocument.getNumberOfLines(); |
| try { |
| endLine = fDocument.getLineOfOffset(start + fLength); |
| } catch (BadLocationException ex) { |
| // silently ignored |
| } |
| fLineCount = endLine - fLineOffset + 1; |
| } |
| } else { |
| fLength = document.getLength(); |
| fLineCount = fDocument.getNumberOfLines(); |
| } |
| } |
| |
| /** |
| * Returns the number of lines in the document. |
| * |
| * @return number of lines * @see org.eclipse.compare.rangedifferencer.IRangeComparator#getRangeCount() |
| */ |
| public int getRangeCount() { |
| return fLineCount; |
| } |
| |
| /* (non Javadoc) |
| * see ITokenComparator.getTokenStart |
| */ |
| /** |
| * Method getTokenStart. |
| * |
| * @param line |
| * int |
| * @return int |
| * @see org.eclipse.compare.contentmergeviewer.ITokenComparator#getTokenStart(int) |
| */ |
| public int getTokenStart(int line) { |
| try { |
| final IRegion r = fDocument.getLineInformation(fLineOffset + line); |
| return r.getOffset(); |
| } catch (BadLocationException ex) { |
| return fDocument.getLength(); |
| } |
| } |
| |
| /* (non Javadoc) |
| * Returns the length of the given line. |
| * see ITokenComparator.getTokenLength |
| */ |
| /** |
| * Method getTokenLength. |
| * |
| * @param line |
| * int |
| * @return int |
| * @see org.eclipse.compare.contentmergeviewer.ITokenComparator#getTokenLength(int) |
| */ |
| public int getTokenLength(int line) { |
| return getTokenStart(line + 1) - getTokenStart(line); |
| } |
| |
| /** |
| * Returns <code>true</code> if a line given by the first index matches a line specified by the other |
| * <code>IRangeComparator</code> and index. |
| * |
| * @param thisIndex |
| * the number of the line within this range comparator |
| * @param otherComparator |
| * the range comparator to compare this with |
| * @param otherIndex |
| * the number of the line within the other comparator |
| * @return <code>true</code> if the lines are equal * @see |
| * org.eclipse.compare.rangedifferencer.IRangeComparator#rangesEqual(int, IRangeComparator, int) |
| */ |
| public boolean rangesEqual(int thisIndex, IRangeComparator otherComparator, int otherIndex) { |
| |
| if (null != otherComparator && otherComparator.getClass().equals(getClass())) { |
| final DocLineComparator other = (DocLineComparator) otherComparator; |
| |
| if (fIgnoreWhiteSpace) { |
| final String s1 = extract(thisIndex); |
| final String s2 = other.extract(otherIndex); |
| //return s1.trim().equals(s2.trim()); |
| return compare(s1, s2); |
| } |
| |
| final int tlen = getTokenLength(thisIndex); |
| final int olen = other.getTokenLength(otherIndex); |
| if (tlen == olen) { |
| final String s1 = extract(thisIndex); |
| final String s2 = other.extract(otherIndex); |
| return s1.equals(s2); |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * Aborts the comparison if the number of tokens is too large. |
| * |
| * @param length |
| * a number on which to base the decision whether to return <code>true</code> or <code>false</code> |
| * @param maxLength |
| * another number on which to base the decision whether to return <code>true</code> or <code>false</code> |
| * @param other |
| * the other <code>IRangeComparator</code> to compare with |
| * @return <code>true</code> to avoid a too lengthy range comparison * @see |
| * org.eclipse.compare.rangedifferencer.IRangeComparator#skipRangeComparison(int, int, IRangeComparator) |
| */ |
| public boolean skipRangeComparison(int length, int maxLength, IRangeComparator other) { |
| return false; |
| } |
| |
| //---- private methods |
| |
| /** |
| * Extract a single line from the underlying document without the line separator. |
| * |
| * @param line |
| * the number of the line to extract |
| * @return the contents of the line as a String |
| */ |
| private String extract(int line) { |
| if (line < fLineCount) { |
| try { |
| final IRegion r = fDocument.getLineInformation(fLineOffset + line); |
| return fDocument.get(r.getOffset(), r.getLength()); |
| } catch (BadLocationException e) { |
| // silently ignored |
| } |
| } |
| return ""; //$NON-NLS-1$ |
| } |
| |
| /** |
| * Method compare. |
| * |
| * @param s1 |
| * String |
| * @param s2 |
| * String |
| * @return boolean |
| */ |
| private boolean compare(String s1, String s2) { |
| final int l1 = s1.length(); |
| final int l2 = s2.length(); |
| int c1 = 0, c2 = 0; |
| int i1 = 0, i2 = 0; |
| |
| while (c1 != -1) { |
| |
| c1 = -1; |
| while (i1 < l1) { |
| char c = s1.charAt(i1++); |
| if (!Character.isWhitespace(c)) { |
| c1 = c; |
| break; |
| } |
| } |
| |
| c2 = -1; |
| while (i2 < l2) { |
| char c = s2.charAt(i2++); |
| if (!Character.isWhitespace(c)) { |
| c2 = c; |
| break; |
| } |
| } |
| |
| if (c1 != c2) { |
| return false; |
| } |
| } |
| return true; |
| } |
| } |