org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/JavaPairMatcher.java - jdt/eclipse.jdt.ui - Git at Google

 /*******************************************************************************
  * Copyright (c) 2000, 2018 IBM Corporation and others.
  *
  * This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License 2.0
  * which accompanies this distribution, and is available at
  * https://www.eclipse.org/legal/epl-2.0/
  *
  * SPDX-License-Identifier: EPL-2.0
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
  *     Christian Plesner Hansen (plesner@quenta.org) - changed implementation to use DefaultCharacterPairMatcher
  *******************************************************************************/
 package org.eclipse.jdt.internal.ui.text;

 import org.eclipse.jface.text.BadLocationException;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IRegion;
 import org.eclipse.jface.text.TextUtilities;
 import org.eclipse.jface.text.source.DefaultCharacterPairMatcher;

 import org.eclipse.jdt.core.JavaCore;

 import org.eclipse.jdt.ui.text.IJavaPartitions;

 /**
  * Helper class for match pairs of characters.
  */
 public final class JavaPairMatcher extends DefaultCharacterPairMatcher implements ISourceVersionDependent {

 	/**
 	 * Stores the source version state.
 	 * @since 3.1
 	 */
 	private boolean fHighlightAngularBrackets= false;


 	public JavaPairMatcher(char[] pairs) {
 		super(pairs, IJavaPartitions.JAVA_PARTITIONING, true);
 	}

 	/* @see ICharacterPairMatcher#match(IDocument, int) */
 	@Override
 	public IRegion match(IDocument document, int offset) {
 		try {
 			return performMatch(document, offset);
 		} catch (BadLocationException ble) {
 			return null;
 		}
 	}

 	/*
 	 * Performs the actual work of matching for #match(IDocument, int).
 	 */
 	private IRegion performMatch(IDocument document, int offset) throws BadLocationException {
 		if (offset < 0 || document == null) return null;
 		char prevChar= document.getChar(Math.max(offset - 1, 0));
 		char currChar= (offset != document.getLength()) ? document.getChar(offset) : Character.MIN_VALUE;

 		if (prevChar == '>' && currChar != '>') { //https://bugs.eclipse.org/bugs/show_bug.cgi?id=372516
 			offset--;
 			currChar= prevChar;
 			prevChar= document.getChar(Math.max(offset - 1, 0));
 		} else if (currChar == '<' && (prevChar != '>' && prevChar != '<')) {
 			offset++;
 			prevChar= currChar;
 			currChar= document.getChar(offset);
 		}

 		if ((prevChar == '<' || currChar == '>') && !fHighlightAngularBrackets)
 			return null;
 		if (prevChar == '<' && isLessThanOperator(document, offset - 1))
 			return null;
 		final IRegion region= super.match(document, offset);
 		if (region == null) return region;
 		if (currChar == '>') {
 			final int peer= region.getOffset();
 			if (isLessThanOperator(document, peer)) return null;
 		}
 		return region;
 	}

 	/**
 	 * Returns <code>true</code> if the character at the specified offset is a less-than sign, rather than
 	 * the opening angle bracket of a type parameter list.
 	 *
 	 * @param document a document
 	 * @param offset an offset within the document
 	 * @return <code>true</code> if the character at the specified offset is a less-than sign
 	 * @throws BadLocationException if offset is invalid in the document
 	 */
 	private boolean isLessThanOperator(IDocument document, int offset) throws BadLocationException {
 		if (offset < 0) return false;
 		String contentType= TextUtilities.getContentType(document, IJavaPartitions.JAVA_PARTITIONING, offset, false);
 		if (!IDocument.DEFAULT_CONTENT_TYPE.equals(contentType)) {
 			return false;
 		}
 		JavaHeuristicScanner scanner= new JavaHeuristicScanner(document, IJavaPartitions.JAVA_PARTITIONING, contentType);
 		return !isTypeParameterOpeningBracket(offset, document, scanner);
 	}

 	/**
 	 * Checks if the angular bracket at <code>offset</code> is a type parameter opening bracket.
 	 *
 	 * @param offset the offset of the opening bracket
 	 * @param document the document
 	 * @param scanner a java heuristic scanner on <code>document</code>
 	 * @return <code>true</code> if the bracket is part of a type parameter, <code>false</code>
 	 *         otherwise
 	 * @since 3.1
 	 */
 	private boolean isTypeParameterOpeningBracket(int offset, IDocument document, JavaHeuristicScanner scanner) {
 		/*
 		 * type parameter come after braces (closing or opening), semicolons, or after
 		 * a Type name (heuristic: starts with capital character), or after a modifier
 		 * keyword in a method declaration (visibility, static, synchronized, final)
 		 */

 		try {
 			IRegion line= document.getLineInformationOfOffset(offset);

 			int prevToken= scanner.previousToken(offset - 1, line.getOffset());
 			int prevTokenOffset= scanner.getPosition() + 1;
 			String previous= prevToken == Symbols.TokenEOF ? null : document.get(prevTokenOffset, offset - prevTokenOffset).trim();

 			if (	   prevToken == Symbols.TokenLBRACE
 					|| prevToken == Symbols.TokenRBRACE
 					|| prevToken == Symbols.TokenSEMICOLON
 					|| prevToken == Symbols.TokenSYNCHRONIZED
 					|| prevToken == Symbols.TokenSTATIC
 					|| (prevToken == Symbols.TokenIDENT && isTypeParameterIntroducer(previous))
 					|| prevToken == Symbols.TokenEOF)
 				return true;
 		} catch (BadLocationException e) {
 			return false;
 		}

 		return false;
 	}

 	/**
 	 * Returns true if the character at the specified offset is a greater-than sign, rather than an
 	 * type parameter list close angle bracket.
 	 *
 	 * @param document a document
 	 * @param offset an offset within the document
 	 * @return true if the character at the specified offset is a greater-than sign
 	 * @throws BadLocationException if offset is invalid in the document
 	 */
 	private boolean isGreaterThanOperator(IDocument document, int offset) throws BadLocationException {
 		if (offset < 0)
 			return false;
 		String contentType= TextUtilities.getContentType(document, IJavaPartitions.JAVA_PARTITIONING, offset, false);
 		if (!IDocument.DEFAULT_CONTENT_TYPE.equals(contentType)) {
 			return false;
 		}
 		JavaHeuristicScanner scanner= new JavaHeuristicScanner(document, IJavaPartitions.JAVA_PARTITIONING, contentType);
 		return !isTypeParameterClosingBracket(offset, document, scanner);
 	}

 	/**
 	 * Checks if the angular bracket at <code>offset</code> is a type parameter closing bracket.
 	 *
 	 * @param offset the offset of the closing bracket
 	 * @param document the document
 	 * @param scanner a java heuristic scanner on <code>document</code>
 	 * @return <code>true</code> if the bracket is part of a type parameter, <code>false</code>
 	 *         otherwise
 	 * @since 3.8
 	 */
 	private boolean isTypeParameterClosingBracket(int offset, IDocument document, JavaHeuristicScanner scanner) {
 		/*
 		 * type parameter closing brackets come after question marks, other type parameter
 		 * closing brackets, or after a Type name (heuristic: starts with capital character)
 		 */

 		try {
 			IRegion line= document.getLineInformationOfOffset(offset);

 			int prevToken= scanner.previousToken(offset - 1, line.getOffset());
 			int prevTokenOffset= scanner.getPosition() + 1;
 			String previous= prevToken == Symbols.TokenEOF ? null : document.get(prevTokenOffset, offset - prevTokenOffset).trim();

 			if ((prevToken == Symbols.TokenIDENT && (previous.length() > 0 && Character.isUpperCase(previous.charAt(0))))
 					|| prevToken == Symbols.TokenEOF
 					|| prevToken == Symbols.TokenGREATERTHAN
 					|| prevToken == Symbols.TokenQUESTIONMARK)
 				return true;
 		} catch (BadLocationException e) {
 			return false;
 		}

 		return false;
 	}

 	/**
 	 * Returns <code>true</code> if <code>identifier</code> is an identifier
 	 * that could come right before a type parameter list. It uses a heuristic:
 	 * if the identifier starts with an upper case, it is assumed a type name.
 	 * Also, if <code>identifier</code> is a method modifier, it is assumed
 	 * that the angular bracket is part of the generic type parameter of a
 	 * method.
 	 *
 	 * @param identifier the identifier to check
 	 * @return <code>true</code> if the identifier could introduce a type
 	 *         parameter list
 	 * @since 3.1
 	 */
 	private boolean isTypeParameterIntroducer(String identifier) {
 		return identifier.length() > 0
 				&& (Character.isUpperCase(identifier.charAt(0))
 						|| identifier.startsWith("final") //$NON-NLS-1$
 						|| identifier.startsWith("public") //$NON-NLS-1$
 						|| identifier.startsWith("protected") //$NON-NLS-1$
 						|| identifier.startsWith("private")); //$NON-NLS-1$
 	}

 	/*
 	 * @see org.eclipse.jdt.internal.ui.text.ISourceVersionDependent#setSourceVersion(java.lang.String)
 	 */
 	@Override
 	public void setSourceVersion(String version) {
 		if (JavaCore.compareJavaVersions(JavaCore.VERSION_1_5, version) <= 0)
 			fHighlightAngularBrackets= true;
 		else
 			fHighlightAngularBrackets= false;
 	}

 	/*
 	 * @see org.eclipse.jface.text.source.ICharacterPairMatcherExtension#isMatchedChar(char, org.eclipse.jface.text.IDocument, int)
 	 */
 	@Override
 	public boolean isMatchedChar(char ch, IDocument document, int offset) {
 		try {
 			if (ch == '<') {
 				if (isLessThanOperator(document, offset)) {
 					return false;
 				}
 			} else if (ch == '>') {
 				if (isGreaterThanOperator(document, offset)) {
 					return false;
 				}
 			}
 		} catch (BadLocationException e) {
 			// do nothing
 		}
 		return super.isMatchedChar(ch, document, offset);
 	}
 }
	/*******************************************************************************
	* Copyright (c) 2000, 2018 IBM Corporation and others.
	*
	* This program and the accompanying materials
	* are made available under the terms of the Eclipse Public License 2.0
	* which accompanies this distribution, and is available at
	* https://www.eclipse.org/legal/epl-2.0/
	*
	* SPDX-License-Identifier: EPL-2.0
	*
	* Contributors:
	* IBM Corporation - initial API and implementation
	* Christian Plesner Hansen (plesner@quenta.org) - changed implementation to use DefaultCharacterPairMatcher
	*******************************************************************************/
	package org.eclipse.jdt.internal.ui.text;

	import org.eclipse.jface.text.BadLocationException;
	import org.eclipse.jface.text.IDocument;
	import org.eclipse.jface.text.IRegion;
	import org.eclipse.jface.text.TextUtilities;
	import org.eclipse.jface.text.source.DefaultCharacterPairMatcher;

	import org.eclipse.jdt.core.JavaCore;

	import org.eclipse.jdt.ui.text.IJavaPartitions;

	/**
	* Helper class for match pairs of characters.
	*/
	public final class JavaPairMatcher extends DefaultCharacterPairMatcher implements ISourceVersionDependent {

	/**
	* Stores the source version state.
	* @since 3.1
	*/
	private boolean fHighlightAngularBrackets= false;


	public JavaPairMatcher(char[] pairs) {
	super(pairs, IJavaPartitions.JAVA_PARTITIONING, true);
	}

	/* @see ICharacterPairMatcher#match(IDocument, int) */
	@Override
	public IRegion match(IDocument document, int offset) {
	try {
	return performMatch(document, offset);
	} catch (BadLocationException ble) {
	return null;
	}
	}

	/*
	* Performs the actual work of matching for #match(IDocument, int).
	*/
	private IRegion performMatch(IDocument document, int offset) throws BadLocationException {
	if (offset < 0 \|\| document == null) return null;
	char prevChar= document.getChar(Math.max(offset - 1, 0));
	char currChar= (offset != document.getLength()) ? document.getChar(offset) : Character.MIN_VALUE;

	if (prevChar == '>' && currChar != '>') { //https://bugs.eclipse.org/bugs/show_bug.cgi?id=372516
	offset--;
	currChar= prevChar;
	prevChar= document.getChar(Math.max(offset - 1, 0));
	} else if (currChar == '<' && (prevChar != '>' && prevChar != '<')) {
	offset++;
	prevChar= currChar;
	currChar= document.getChar(offset);
	}

	if ((prevChar == '<' \|\| currChar == '>') && !fHighlightAngularBrackets)
	return null;
	if (prevChar == '<' && isLessThanOperator(document, offset - 1))
	return null;
	final IRegion region= super.match(document, offset);
	if (region == null) return region;
	if (currChar == '>') {
	final int peer= region.getOffset();
	if (isLessThanOperator(document, peer)) return null;
	}
	return region;
	}

	/**
	* Returns <code>true</code> if the character at the specified offset is a less-than sign, rather than
	* the opening angle bracket of a type parameter list.
	*
	* @param document a document
	* @param offset an offset within the document
	* @return <code>true</code> if the character at the specified offset is a less-than sign
	* @throws BadLocationException if offset is invalid in the document
	*/
	private boolean isLessThanOperator(IDocument document, int offset) throws BadLocationException {
	if (offset < 0) return false;
	String contentType= TextUtilities.getContentType(document, IJavaPartitions.JAVA_PARTITIONING, offset, false);
	if (!IDocument.DEFAULT_CONTENT_TYPE.equals(contentType)) {
	return false;
	}
	JavaHeuristicScanner scanner= new JavaHeuristicScanner(document, IJavaPartitions.JAVA_PARTITIONING, contentType);
	return !isTypeParameterOpeningBracket(offset, document, scanner);
	}

	/**
	* Checks if the angular bracket at <code>offset</code> is a type parameter opening bracket.
	*
	* @param offset the offset of the opening bracket
	* @param document the document
	* @param scanner a java heuristic scanner on <code>document</code>
	* @return <code>true</code> if the bracket is part of a type parameter, <code>false</code>
	* otherwise
	* @since 3.1
	*/
	private boolean isTypeParameterOpeningBracket(int offset, IDocument document, JavaHeuristicScanner scanner) {
	/*
	* type parameter come after braces (closing or opening), semicolons, or after
	* a Type name (heuristic: starts with capital character), or after a modifier
	* keyword in a method declaration (visibility, static, synchronized, final)
	*/

	try {
	IRegion line= document.getLineInformationOfOffset(offset);

	int prevToken= scanner.previousToken(offset - 1, line.getOffset());
	int prevTokenOffset= scanner.getPosition() + 1;
	String previous= prevToken == Symbols.TokenEOF ? null : document.get(prevTokenOffset, offset - prevTokenOffset).trim();

	if ( prevToken == Symbols.TokenLBRACE
	\|\| prevToken == Symbols.TokenRBRACE
	\|\| prevToken == Symbols.TokenSEMICOLON
	\|\| prevToken == Symbols.TokenSYNCHRONIZED
	\|\| prevToken == Symbols.TokenSTATIC
	\|\| (prevToken == Symbols.TokenIDENT && isTypeParameterIntroducer(previous))
	\|\| prevToken == Symbols.TokenEOF)
	return true;
	} catch (BadLocationException e) {
	return false;
	}

	return false;
	}

	/**
	* Returns true if the character at the specified offset is a greater-than sign, rather than an
	* type parameter list close angle bracket.
	*
	* @param document a document
	* @param offset an offset within the document
	* @return true if the character at the specified offset is a greater-than sign
	* @throws BadLocationException if offset is invalid in the document
	*/
	private boolean isGreaterThanOperator(IDocument document, int offset) throws BadLocationException {
	if (offset < 0)
	return false;
	String contentType= TextUtilities.getContentType(document, IJavaPartitions.JAVA_PARTITIONING, offset, false);
	if (!IDocument.DEFAULT_CONTENT_TYPE.equals(contentType)) {
	return false;
	}
	JavaHeuristicScanner scanner= new JavaHeuristicScanner(document, IJavaPartitions.JAVA_PARTITIONING, contentType);
	return !isTypeParameterClosingBracket(offset, document, scanner);
	}

	/**
	* Checks if the angular bracket at <code>offset</code> is a type parameter closing bracket.
	*
	* @param offset the offset of the closing bracket
	* @param document the document
	* @param scanner a java heuristic scanner on <code>document</code>
	* @return <code>true</code> if the bracket is part of a type parameter, <code>false</code>
	* otherwise
	* @since 3.8
	*/
	private boolean isTypeParameterClosingBracket(int offset, IDocument document, JavaHeuristicScanner scanner) {
	/*
	* type parameter closing brackets come after question marks, other type parameter
	* closing brackets, or after a Type name (heuristic: starts with capital character)
	*/

	try {
	IRegion line= document.getLineInformationOfOffset(offset);

	int prevToken= scanner.previousToken(offset - 1, line.getOffset());
	int prevTokenOffset= scanner.getPosition() + 1;
	String previous= prevToken == Symbols.TokenEOF ? null : document.get(prevTokenOffset, offset - prevTokenOffset).trim();

	if ((prevToken == Symbols.TokenIDENT && (previous.length() > 0 && Character.isUpperCase(previous.charAt(0))))
	\|\| prevToken == Symbols.TokenEOF
	\|\| prevToken == Symbols.TokenGREATERTHAN
	\|\| prevToken == Symbols.TokenQUESTIONMARK)
	return true;
	} catch (BadLocationException e) {
	return false;
	}

	return false;
	}

	/**
	* Returns <code>true</code> if <code>identifier</code> is an identifier
	* that could come right before a type parameter list. It uses a heuristic:
	* if the identifier starts with an upper case, it is assumed a type name.
	* Also, if <code>identifier</code> is a method modifier, it is assumed
	* that the angular bracket is part of the generic type parameter of a
	* method.
	*
	* @param identifier the identifier to check
	* @return <code>true</code> if the identifier could introduce a type
	* parameter list
	* @since 3.1
	*/
	private boolean isTypeParameterIntroducer(String identifier) {
	return identifier.length() > 0
	&& (Character.isUpperCase(identifier.charAt(0))
	\|\| identifier.startsWith("final") //$NON-NLS-1$
	\|\| identifier.startsWith("public") //$NON-NLS-1$
	\|\| identifier.startsWith("protected") //$NON-NLS-1$
	\|\| identifier.startsWith("private")); //$NON-NLS-1$
	}

	/*
	* @see org.eclipse.jdt.internal.ui.text.ISourceVersionDependent#setSourceVersion(java.lang.String)
	*/
	@Override
	public void setSourceVersion(String version) {
	if (JavaCore.compareJavaVersions(JavaCore.VERSION_1_5, version) <= 0)
	fHighlightAngularBrackets= true;
	else
	fHighlightAngularBrackets= false;
	}

	/*
	* @see org.eclipse.jface.text.source.ICharacterPairMatcherExtension#isMatchedChar(char, org.eclipse.jface.text.IDocument, int)
	*/
	@Override
	public boolean isMatchedChar(char ch, IDocument document, int offset) {
	try {
	if (ch == '<') {
	if (isLessThanOperator(document, offset)) {
	return false;
	}
	} else if (ch == '>') {
	if (isGreaterThanOperator(document, offset)) {
	return false;
	}
	}
	} catch (BadLocationException e) {
	// do nothing
	}
	return super.isMatchedChar(ch, document, offset);
	}
	}