/*******************************************************************************
* Copyright (c) 2012 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.jface.text.source;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
/**
* Extension interface for {@link org.eclipse.jface.text.source.ICharacterPairMatcher}.
* <p>
* Extends the character pair matcher with the concept of matching peer character and enclosing peer
* characters for a given selection.
*
* @see org.eclipse.jface.text.source.ICharacterPairMatcher
* @since 3.8
*/
public interface ICharacterPairMatcherExtension {
/**
* Starting at the given offset (i.e. length 0) or the selected character, the matcher searches
* for the matching peer character and if it finds one, returns the minimal region of the
* document that contains both characters.
*
* @param document the document to work on
* @param offset the start offset
* @param length the selection length which can be negative indicating right-to-left selection
* @return the minimal region containing the peer characters or <code>null</code> if there is no
* peer character
*/
IRegion match(IDocument document, int offset, int length);
/**
* Starting at the given selection, the matcher searches for a pair of enclosing peer characters
* and if it finds one, returns the minimal region of the document that contains the pair.
*
* @param document the document to work on
* @param offset the start offset
* @param length the selection length which can be negative indicating right-to-left selection
* @return the minimal region containing the peer characters or <code>null</code> if there is no
* enclosing pair
*/
IRegion findEnclosingPeerCharacters(IDocument document, int offset, int length);
/**
* Checks whether the character is one of the characters matched by the pair matcher.
*
* @param ch the character
* @return <code>true</code> if the the character is one of the characters matched by the pair
* matcher, and <code>false</code> otherwise
*/
boolean isMatchedChar(char ch);
/**
* Checks whether the character is one of the characters matched by the pair matcher.
*
* <p>
* Clients can use this method to handle characters which may have special meaning in some
* situations. E.g. in Java, '<' is used as an angular bracket and as well as less-than operator.
* </p>
*
* @param ch the character
* @param document the document
* @param offset the offset in document
* @return <code>true</code> if the the character is one of the characters matched by the pair
* matcher, and <code>false</code> otherwise
*/
boolean isMatchedChar(char ch, IDocument document, int offset);
/**
* Computes whether a client needs to recompute the enclosing pair after a selection change in
* the document.
*
* <p>
* This is intended to be a quick test to determine whether a re-computation of the enclosing pair is
* required, as the re-computation after each selection change via a
* {@link #findEnclosingPeerCharacters(IDocument, int, int)} call can be expensive for some
* clients.
* </p>
*
* @param document the document to work on
* @param currentSelection the current selection in the document
* @param previousSelection the previous selection in the document
* @return <code>true</code> if the enclosing pair needs to be recomputed, <code>false</code>
* otherwise
*/
boolean isRecomputationOfEnclosingPairRequired(IDocument document, IRegion currentSelection, IRegion previousSelection);
}