core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/text/CParameterListValidator.java - cdt/org.eclipse.cdt - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2016 QNX Software Systems 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:
  *     QNX Software Systems - Initial API and implementation
  *     Anton Leherbauer (Wind River Systems)
  *     Sergey Prigogin (Google)
  *******************************************************************************/
 package org.eclipse.cdt.internal.ui.text;

 import java.util.ArrayList;
 import java.util.List;

 import org.eclipse.core.runtime.Assert;
 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.IDocument;
 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 org.eclipse.cdt.internal.ui.text.contentassist.CProposalContextInformation;

 /**
  * This class provides the function parameter parsing for the C/C++ Editor hover.
  * It is based heavily on the Java class JavaParameterListValidator.
  *
  * @author thomasf
  */
 public class CParameterListValidator implements IContextInformationValidator, IContextInformationPresenter {
 	private int fPosition;
 	private ITextViewer fViewer;
 	private IContextInformation fInformation;

 	private int fCurrentParameter;

 	public CParameterListValidator() {
 	}

 	/**
 	 * @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;
 	}

 	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, int start, int end, char increment, char decrement,
 			boolean considerNesting) throws BadLocationException {
 		Assert.isTrue((increment != 0 || decrement != 0) && increment != decrement);

 		int parenNestingLevel = 0;
 		int braceNestingLevel = 0;
 		int charCount = 0;
 		while (start < end) {
 			char curr = document.getChar(start++);
 			switch (curr) {
 			case '/':
 				if (start < end) {
 					char next= document.getChar(start);
 					if (next == '*') {
 						// A comment starts, advance to the comment end.
 						start= getCommentEnd(document, start + 1, end);
 					} else if (next == '/') {
 						// '//'-comment: nothing to do anymore on this line
 						start= end;
 					}
 				}
 				break;

 			case '*':
 				if (start < end) {
 					char next= document.getChar(start);
 					if (next == '/') {
 						// We have been in a comment: forget what we read before.
 						charCount= 0;
 						++ start;
 					}
 				}
 				break;

 			case '"':
 			case '\'':
 				start= getStringEnd(document, start, end, curr);
 				break;

 			default:
 				if (considerNesting) {
 					if ('(' == curr) {
 						++parenNestingLevel;
 					} else if (')' == curr) {
 						--parenNestingLevel;
 					}

 					if (parenNestingLevel != 0)
 						break;

 					if ('{' == curr) {
 						++braceNestingLevel;
 					} else if ('}' == curr) {
 						--braceNestingLevel;
 					}

 					if (braceNestingLevel != 0)
 						break;
 				}

 				if (increment != 0) {
 					if (curr == increment)
 						++charCount;
 				}

 				if (decrement != 0) {
 					if (curr == decrement)
 						--charCount;
 				}
 			}
 		}

 		return charCount;
 	}

 	/**
 	 * @see IContextInformationValidator#isContextInformationValid(int)
 	 */
 	@Override
 	public boolean isContextInformationValid(int position) {
 		try {
 			if (position < fPosition)
 				return false;

 			IDocument document= fViewer.getDocument();
 			return getCharCount(document, fPosition, position, '(', ')', false) >= 0;
 		} catch (BadLocationException x) {
 			return false;
 		}
 	}

 	@Override
 	public boolean updatePresentation(int position, TextPresentation presentation) {
 		int currentParameter= -1;

 		try {
 			currentParameter= getCharCount(fViewer.getDocument(), fPosition, position, ',', (char) 0, true);
 		} catch (BadLocationException x) {
 			return false;
 		}

 		if (fCurrentParameter != -1) {
 			if (currentParameter == fCurrentParameter)
 				return false;
 		}

 		presentation.clear();
 		fCurrentParameter= currentParameter;

 		// Don't presume what has been done to the string, rather use as is.
 		String s = fInformation.getInformationDisplayString();
 		String params = s;

 		// Context information objects of type CProposalContextInformation can have
 		// an optional prefix before and suffix after the parameter list.
 		// In such a case, query the indices that bound the parameter list part of
 		// the string, so we can parse the comma positions accurately.
 		int paramlistStartIndex = 0;
 		int paramlistEndIndex = s.length();
 		if (fInformation instanceof CProposalContextInformation) {
 			CProposalContextInformation info = (CProposalContextInformation) fInformation;
 			if (info.hasPrefixSuffix()) {
 				paramlistStartIndex = info.getArglistStartIndex();
 				paramlistEndIndex = info.getArglistEndIndex();
 				params = s.substring(paramlistStartIndex, paramlistEndIndex);
 			}
 		}

 		int[] commas= computeCommaPositions(params);
 		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(paramlistStartIndex, start, null, null, SWT.NORMAL));

 		if (end > start)
 			presentation.addStyleRange(new StyleRange(paramlistStartIndex + start, end - start, null, null, SWT.BOLD));

 		if (end < s.length())
 			presentation.addStyleRange(new StyleRange(paramlistStartIndex + end, params.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<>();
 		positions.add(Integer.valueOf(-1));
 		while (pos < length && pos != -1) {
 			char ch= code.charAt(pos);
 			switch (ch) {
 	            case ',':
 		            positions.add(Integer.valueOf(pos));
 		            break;
 	            case '(':
 	            	pos= indexOfClosingPeer(code, '(', ')', pos);
 	            	break;
 	            case '<':
 	            	pos= indexOfClosingPeer(code, '<', '>', pos);
 	            	break;
 	            case '[':
 	            	pos= indexOfClosingPeer(code, '[', ']', pos);
 	            	break;
 	            case '{':
 	            	pos= indexOfClosingPeer(code, '{', '}', pos);
 	            	break;
 	            default:
 	            	break;
             }
 			if (pos != -1)
 				pos++;
 		}
 		positions.add(Integer.valueOf(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 indexOfClosingPeer(String code, char left, char right, int pos) {
 		int level= 0;
 		final int length= code.length();
 		while (pos < length) {
 			char ch= code.charAt(pos);
 			if (ch == left) {
 				++level;
 			} else if (ch == right) {
 				if (--level == 0) {
 					return pos;
 				}
 			}
 			++pos;
 		}
 		return -1;
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2016 QNX Software Systems 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:
	* QNX Software Systems - Initial API and implementation
	* Anton Leherbauer (Wind River Systems)
	* Sergey Prigogin (Google)
	*******************************************************************************/
	package org.eclipse.cdt.internal.ui.text;

	import java.util.ArrayList;
	import java.util.List;

	import org.eclipse.core.runtime.Assert;
	import org.eclipse.jface.text.BadLocationException;
	import org.eclipse.jface.text.IDocument;
	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 org.eclipse.cdt.internal.ui.text.contentassist.CProposalContextInformation;

	/**
	* This class provides the function parameter parsing for the C/C++ Editor hover.
	* It is based heavily on the Java class JavaParameterListValidator.
	*
	* @author thomasf
	*/
	public class CParameterListValidator implements IContextInformationValidator, IContextInformationPresenter {
	private int fPosition;
	private ITextViewer fViewer;
	private IContextInformation fInformation;

	private int fCurrentParameter;

	public CParameterListValidator() {
	}

	/**
	* @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;
	}

	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, int start, int end, char increment, char decrement,
	boolean considerNesting) throws BadLocationException {
	Assert.isTrue((increment != 0 \|\| decrement != 0) && increment != decrement);

	int parenNestingLevel = 0;
	int braceNestingLevel = 0;
	int charCount = 0;
	while (start < end) {
	char curr = document.getChar(start++);
	switch (curr) {
	case '/':
	if (start < end) {
	char next= document.getChar(start);
	if (next == '*') {
	// A comment starts, advance to the comment end.
	start= getCommentEnd(document, start + 1, end);
	} else if (next == '/') {
	// '//'-comment: nothing to do anymore on this line
	start= end;
	}
	}
	break;

	case '*':
	if (start < end) {
	char next= document.getChar(start);
	if (next == '/') {
	// We have been in a comment: forget what we read before.
	charCount= 0;
	++ start;
	}
	}
	break;

	case '"':
	case '\'':
	start= getStringEnd(document, start, end, curr);
	break;

	default:
	if (considerNesting) {
	if ('(' == curr) {
	++parenNestingLevel;
	} else if (')' == curr) {
	--parenNestingLevel;
	}

	if (parenNestingLevel != 0)
	break;

	if ('{' == curr) {
	++braceNestingLevel;
	} else if ('}' == curr) {
	--braceNestingLevel;
	}

	if (braceNestingLevel != 0)
	break;
	}

	if (increment != 0) {
	if (curr == increment)
	++charCount;
	}

	if (decrement != 0) {
	if (curr == decrement)
	--charCount;
	}
	}
	}

	return charCount;
	}

	/**
	* @see IContextInformationValidator#isContextInformationValid(int)
	*/
	@Override
	public boolean isContextInformationValid(int position) {
	try {
	if (position < fPosition)
	return false;

	IDocument document= fViewer.getDocument();
	return getCharCount(document, fPosition, position, '(', ')', false) >= 0;
	} catch (BadLocationException x) {
	return false;
	}
	}

	@Override
	public boolean updatePresentation(int position, TextPresentation presentation) {
	int currentParameter= -1;

	try {
	currentParameter= getCharCount(fViewer.getDocument(), fPosition, position, ',', (char) 0, true);
	} catch (BadLocationException x) {
	return false;
	}

	if (fCurrentParameter != -1) {
	if (currentParameter == fCurrentParameter)
	return false;
	}

	presentation.clear();
	fCurrentParameter= currentParameter;

	// Don't presume what has been done to the string, rather use as is.
	String s = fInformation.getInformationDisplayString();
	String params = s;

	// Context information objects of type CProposalContextInformation can have
	// an optional prefix before and suffix after the parameter list.
	// In such a case, query the indices that bound the parameter list part of
	// the string, so we can parse the comma positions accurately.
	int paramlistStartIndex = 0;
	int paramlistEndIndex = s.length();
	if (fInformation instanceof CProposalContextInformation) {
	CProposalContextInformation info = (CProposalContextInformation) fInformation;
	if (info.hasPrefixSuffix()) {
	paramlistStartIndex = info.getArglistStartIndex();
	paramlistEndIndex = info.getArglistEndIndex();
	params = s.substring(paramlistStartIndex, paramlistEndIndex);
	}
	}

	int[] commas= computeCommaPositions(params);
	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(paramlistStartIndex, start, null, null, SWT.NORMAL));

	if (end > start)
	presentation.addStyleRange(new StyleRange(paramlistStartIndex + start, end - start, null, null, SWT.BOLD));

	if (end < s.length())
	presentation.addStyleRange(new StyleRange(paramlistStartIndex + end, params.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<>();
	positions.add(Integer.valueOf(-1));
	while (pos < length && pos != -1) {
	char ch= code.charAt(pos);
	switch (ch) {
	case ',':
	positions.add(Integer.valueOf(pos));
	break;
	case '(':
	pos= indexOfClosingPeer(code, '(', ')', pos);
	break;
	case '<':
	pos= indexOfClosingPeer(code, '<', '>', pos);
	break;
	case '[':
	pos= indexOfClosingPeer(code, '[', ']', pos);
	break;
	case '{':
	pos= indexOfClosingPeer(code, '{', '}', pos);
	break;
	default:
	break;
	}
	if (pos != -1)
	pos++;
	}
	positions.add(Integer.valueOf(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 indexOfClosingPeer(String code, char left, char right, int pos) {
	int level= 0;
	final int length= code.length();
	while (pos < length) {
	char ch= code.charAt(pos);
	if (ch == left) {
	++level;
	} else if (ch == right) {
	if (--level == 0) {
	return pos;
	}
	}
	++pos;
	}
	return -1;
	}
	}