| /******************************************************************************* |
| * Copyright (c) 2000, 2003 IBM Corporation and others. |
| * All rights reserved. This program and the accompanying materials |
| * are made available under the terms of the Common Public License v1.0 |
| * which accompanies this distribution, and is available at |
| * http://www.eclipse.org/legal/cpl-v10.html |
| * |
| * Contributors: |
| * IBM Corporation - initial API and implementation |
| *******************************************************************************/ |
| package org.eclipse.compare.internal; |
| |
| import org.eclipse.jface.text.*; |
| import org.eclipse.compare.contentmergeviewer.ITokenComparator; |
| import org.eclipse.compare.rangedifferencer.IRangeComparator; |
| |
| /** |
| * 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>. |
| */ |
| public class DocLineComparator implements ITokenComparator { |
| |
| private IDocument fDocument; |
| private int fLineOffset; |
| private int fLineCount; |
| private int fLength; |
| private 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 (region != null) { |
| fLength= region.getLength(); |
| int start= region.getOffset(); |
| try { |
| fLineOffset= fDocument.getLineOfOffset(start); |
| } catch (BadLocationException ex) { |
| // silently ignored |
| } |
| |
| if (fLength == 0) |
| fLineCount= 0; |
| 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 |
| */ |
| public int getRangeCount() { |
| return fLineCount; |
| } |
| |
| /* (non Javadoc) |
| * see ITokenComparator.getTokenStart |
| */ |
| public int getTokenStart(int line) { |
| try { |
| 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 |
| */ |
| 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 other 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 |
| */ |
| public boolean rangesEqual(int thisIndex, IRangeComparator other0, int otherIndex) { |
| |
| if (other0 != null && other0.getClass() == getClass()) { |
| DocLineComparator other= (DocLineComparator) other0; |
| |
| if (fIgnoreWhiteSpace) { |
| String s1= extract(thisIndex); |
| String s2= other.extract(otherIndex); |
| return compare(s1, s2); |
| } |
| |
| int tlen= getTokenLength(thisIndex); |
| int olen= other.getTokenLength(otherIndex); |
| if (tlen == olen) { |
| String s1= extract(thisIndex); |
| String s2= other.extract(otherIndex); |
| return s1.equals(s2); |
| } |
| } |
| return false; |
| } |
| |
| /** |
| * Aborts the comparison if the number of tokens is too large. |
| * |
| * @return <code>true</code> to abort a token comparison |
| */ |
| public boolean skipRangeComparison(int length, int max, 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 { |
| IRegion r= fDocument.getLineInformation(fLineOffset + line); |
| return fDocument.get(r.getOffset(), r.getLength()); |
| } catch(BadLocationException e) { |
| // silently ignored |
| } |
| } |
| return ""; //$NON-NLS-1$ |
| } |
| |
| private boolean compare(String s1, String s2) { |
| int l1= s1.length(); |
| 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; |
| } |
| |
| } |
| |