/*
* Copyright (c) 2012, the Dart project authors.
*
* Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.eclipse.org/legal/epl-v10.html
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.dart.tools.ui.internal.text.dart;
import com.google.dart.tools.ui.internal.text.functions.DartHeuristicScanner;
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.swt.SWT;
import org.eclipse.swt.custom.StyleRange;
import java.util.ArrayList;
import java.util.List;
public class DartParameterListValidator implements IContextInformationValidator,
IContextInformationPresenter {
private int fPosition;
private ITextViewer fViewer;
private IContextInformation fInformation;
private int fCurrentParameter;
public DartParameterListValidator() {
}
/**
* @see IContextInformationValidator#install(IContextInformation, ITextViewer, int)
* @see IContextInformationPresenter#install(IContextInformation, ITextViewer, int)
*/
@Override
public void install(IContextInformation info, ITextViewer viewer, int documentPosition) {
fPosition = documentPosition;
fViewer = viewer;
fInformation = info;
fCurrentParameter = -1;
}
/**
* @see IContextInformationValidator#isContextInformationValid(int)
*/
@Override
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)
*/
@Override
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 boolean checkGenericsHeuristic(IDocument document, int end, int bound)
throws BadLocationException {
DartHeuristicScanner scanner = new DartHeuristicScanner(document);
return scanner.looksLikeClassInstanceCreationBackward(end, bound);
}
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;
}
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
offset = end;
}
}
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;
}
case ']':
if (considerNesting) {
if (nestingMode == BRACKET) {
if (--nestingLevel == 0) {
nestingMode = NONE;
}
}
break;
}
case '(':
if (considerNesting) {
if (nestingMode == ANGLE) {
// generics heuristic failed
nestingMode = PAREN;
nestingLevel = 1;
}
if (nestingMode == PAREN || nestingMode == NONE) {
nestingMode = PAREN;
nestingLevel++;
}
break;
}
case ')':
if (considerNesting) {
if (nestingMode == PAREN) {
if (--nestingLevel == 0) {
nestingMode = NONE;
}
}
break;
}
case '{':
if (considerNesting) {
if (nestingMode == ANGLE) {
// generics heuristic failed
nestingMode = BRACE;
nestingLevel = 1;
}
if (nestingMode == BRACE || nestingMode == NONE) {
nestingMode = BRACE;
nestingLevel++;
}
break;
}
case '}':
if (considerNesting) {
if (nestingMode == BRACE) {
if (--nestingLevel == 0) {
nestingMode = NONE;
}
}
break;
}
case '<':
if (considerNesting) {
if (nestingMode == ANGLE || nestingMode == NONE
&& checkGenericsHeuristic(document, offset - 1, start - 1)) {
nestingMode = ANGLE;
nestingLevel++;
}
break;
}
case '>':
if (considerNesting) {
if (nestingMode == ANGLE) {
if (--nestingLevel == 0) {
nestingMode = NONE;
}
}
break;
}
default:
if (nestingLevel != 0) {
continue;
}
if (increments.indexOf(curr) >= 0) {
++charCount;
}
if (decrements.indexOf(curr) >= 0) {
--charCount;
}
}
}
return charCount;
}
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;
}
}