/*******************************************************************************
* Copyright (c) 2000, 2011 IBM Corporation 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
*
* Contributors:
* IBM Corporation - initial API and implementation
*******************************************************************************/
package org.eclipse.jdt.internal.ui.text.java;
import java.util.ArrayList;
import java.util.List;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.StyleRange;
import org.eclipse.core.runtime.Assert;
import org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.ITextViewer;
import org.eclipse.jface.text.TextPresentation;
import org.eclipse.jface.text.contentassist.IContextInformation;
import org.eclipse.jface.text.contentassist.IContextInformationPresenter;
import org.eclipse.jface.text.contentassist.IContextInformationValidator;
import org.eclipse.jdt.internal.ui.text.JavaHeuristicScanner;
public class JavaParameterListValidator implements IContextInformationValidator, IContextInformationPresenter {
private int fPosition;
private ITextViewer fViewer;
private IContextInformation fInformation;
private int fCurrentParameter;
public JavaParameterListValidator() {
}
/**
* @see IContextInformationValidator#install(IContextInformation, ITextViewer, int)
* @see IContextInformationPresenter#install(IContextInformation, ITextViewer, int)
*/
public void install(IContextInformation info, ITextViewer viewer, int documentPosition) {
fPosition= documentPosition;
fViewer= viewer;
fInformation= info;
fCurrentParameter= -1;
}
private int getCommentEnd(IDocument d, int pos, int end) throws BadLocationException {
while (pos < end) {
char curr= d.getChar(pos);
pos++;
if (curr == '*') {
if (pos < end && d.getChar(pos) == '/') {
return pos + 1;
}
}
}
return end;
}
private int getStringEnd(IDocument d, int pos, int end, char ch) throws BadLocationException {
while (pos < end) {
char curr= d.getChar(pos);
pos++;
if (curr == '\\') {
// ignore escaped characters
pos++;
} else if (curr == ch) {
return pos;
}
}
return end;
}
private int getCharCount(IDocument document, final int start, final int end, String increments, String decrements, boolean considerNesting) throws BadLocationException {
Assert.isTrue((increments.length() != 0 || decrements.length() != 0) && !increments.equals(decrements));
final int NONE= 0;
final int BRACKET= 1;
final int BRACE= 2;
final int PAREN= 3;
final int ANGLE= 4;
int nestingMode= NONE;
int nestingLevel= 0;
int charCount= 0;
int offset= start;
while (offset < end) {
char curr= document.getChar(offset++);
switch (curr) {
case '/':
if (offset < end) {
char next= document.getChar(offset);
if (next == '*') {
// a comment starts, advance to the comment end
offset= getCommentEnd(document, offset + 1, end);
} else if (next == '/') {
// '//'-comment: nothing to do anymore on this line
int nextLine= document.getLineOfOffset(offset) + 1;
if (nextLine == document.getNumberOfLines())
offset= end;
else
offset= document.getLineOffset(nextLine);
}
}
break;
case '*':
if (offset < end) {
char next= document.getChar(offset);
if (next == '/') {
// we have been in a comment: forget what we read before
charCount= 0;
++ offset;
}
}
break;
case '"':
case '\'':
offset= getStringEnd(document, offset, end, curr);
break;
case '[':
if (considerNesting) {
if (nestingMode == BRACKET || nestingMode == NONE) {
nestingMode= BRACKET;
nestingLevel++;
}
break;
}
//$FALL-THROUGH$
case ']':
if (considerNesting) {
if (nestingMode == BRACKET)
if (--nestingLevel == 0)
nestingMode= NONE;
break;
}
//$FALL-THROUGH$
case '(':
if (considerNesting) {
if (nestingMode == ANGLE) {
// generics heuristic failed
nestingMode=PAREN;
nestingLevel= 1;
}
if (nestingMode == PAREN || nestingMode == NONE) {
nestingMode= PAREN;
nestingLevel++;
}
break;
}
//$FALL-THROUGH$
case ')':
if (considerNesting) {
if (nestingMode == PAREN)
if (--nestingLevel == 0)
nestingMode= NONE;
break;
}
//$FALL-THROUGH$
case '{':
if (considerNesting) {
if (nestingMode == ANGLE) {
// generics heuristic failed
nestingMode=BRACE;
nestingLevel= 1;
}
if (nestingMode == BRACE || nestingMode == NONE) {
nestingMode= BRACE;
nestingLevel++;
}
break;
}
//$FALL-THROUGH$
case '}':
if (considerNesting) {
if (nestingMode == BRACE)
if (--nestingLevel == 0)
nestingMode= NONE;
break;
}
//$FALL-THROUGH$
case '<':
if (considerNesting) {
if (nestingMode == ANGLE || nestingMode == NONE && checkGenericsHeuristic(document, offset - 1, start - 1)) {
nestingMode= ANGLE;
nestingLevel++;
}
break;
}
//$FALL-THROUGH$
case '>':
if (considerNesting) {
if (nestingMode == ANGLE)
if (--nestingLevel == 0)
nestingMode= NONE;
break;
}
//$FALL-THROUGH$
default:
if (nestingLevel != 0)
continue;
if (increments.indexOf(curr) >= 0) {
++ charCount;
}
if (decrements.indexOf(curr) >= 0) {
-- charCount;
}
}
}
return charCount;
}
private boolean checkGenericsHeuristic(IDocument document, int end, int bound) {
JavaHeuristicScanner scanner= new JavaHeuristicScanner(document);
return scanner.looksLikeClassInstanceCreationBackward(end, bound);
}
/**
* @see IContextInformationValidator#isContextInformationValid(int)
*/
public boolean isContextInformationValid(int position) {
try {
if (position < fPosition)
return false;
IDocument document= fViewer.getDocument();
IRegion line= document.getLineInformationOfOffset(fPosition);
if (position < line.getOffset() || position >= document.getLength())
return false;
return getCharCount(document, fPosition, position, "(<", ")>", false) >= 0; //$NON-NLS-1$ //$NON-NLS-2$
} catch (BadLocationException x) {
return false;
}
}
/**
* @see IContextInformationPresenter#updatePresentation(int, TextPresentation)
*/
public boolean updatePresentation(int position, TextPresentation presentation) {
int currentParameter= -1;
try {
currentParameter= getCharCount(fViewer.getDocument(), fPosition, position, ",", "", true); //$NON-NLS-1$//$NON-NLS-2$
} catch (BadLocationException x) {
return false;
}
if (fCurrentParameter != -1) {
if (currentParameter == fCurrentParameter)
return false;
}
presentation.clear();
fCurrentParameter= currentParameter;
String s= fInformation.getInformationDisplayString();
int[] commas= computeCommaPositions(s);
if (commas.length - 2 < fCurrentParameter) {
presentation.addStyleRange(new StyleRange(0, s.length(), null, null, SWT.NORMAL));
return true;
}
int start= commas[fCurrentParameter] + 1;
int end= commas[fCurrentParameter + 1];
if (start > 0)
presentation.addStyleRange(new StyleRange(0, start, null, null, SWT.NORMAL));
if (end > start)
presentation.addStyleRange(new StyleRange(start, end - start, null, null, SWT.BOLD));
if (end < s.length())
presentation.addStyleRange(new StyleRange(end, s.length() - end, null, null, SWT.NORMAL));
return true;
}
private int[] computeCommaPositions(String code) {
final int length= code.length();
int pos= 0;
List<Integer> positions= new ArrayList<Integer>();
positions.add(new Integer(-1));
while (pos < length && pos != -1) {
char ch= code.charAt(pos);
switch (ch) {
case ',':
positions.add(new Integer(pos));
break;
case '<':
pos= code.indexOf('>', pos);
break;
case '[':
pos= code.indexOf(']', pos);
break;
default:
break;
}
if (pos != -1)
pos++;
}
positions.add(new Integer(length));
int[] fields= new int[positions.size()];
for (int i= 0; i < fields.length; i++)
fields[i]= positions.get(i).intValue();
return fields;
}
}