/*******************************************************************************
* 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 org.eclipse.jface.text.BadLocationException;
import org.eclipse.jface.text.DefaultTextDoubleClickStrategy;
import org.eclipse.jface.text.IDocument;
import org.eclipse.jface.text.IRegion;
import org.eclipse.jface.text.Region;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.internal.ui.text.ISourceVersionDependent;
import org.eclipse.jdt.internal.ui.text.JavaPairMatcher;
/**
* Double click strategy aware of Java identifier syntax rules.
*/
public class JavaDoubleClickSelector extends DefaultTextDoubleClickStrategy implements ISourceVersionDependent {
/**
* Detects java words depending on the source level. In 1.4 mode, detects
* <code>[[:ID:]]*</code>. In 1.5 mode, it also detects
* <code>@\s*[[:IDS:]][[:ID:]]*</code>.
*
* Character class definitions:
* <dl>
* <dt>[[:IDS:]]</dt><dd>a java identifier start character</dd>
* <dt>[[:ID:]]</dt><dd>a java identifier part character</dd>
* <dt>\s</dt><dd>a white space character</dd>
* <dt>@</dt><dd>the at symbol</dd>
* </dl>
*
* @since 3.1
*/
private static final class AtJavaIdentifierDetector implements ISourceVersionDependent {
private boolean fSelectAnnotations;
private static final int UNKNOWN= -1;
/* states */
private static final int WS= 0;
private static final int ID= 1;
private static final int IDS= 2;
private static final int AT= 3;
/* directions */
private static final int FORWARD= 0;
private static final int BACKWARD= 1;
/** The current state. */
private int fState;
/**
* The state at the anchor (if already detected by going the other way),
* or <code>UNKNOWN</code>.
*/
private int fAnchorState;
/** The current direction. */
private int fDirection;
/** The start of the detected word. */
private int fStart;
/** The end of the word. */
private int fEnd;
/**
* Initializes the detector at offset <code>anchor</code>.
*
* @param anchor the offset of the double click
*/
private void setAnchor(int anchor) {
fState= UNKNOWN;
fAnchorState= UNKNOWN;
fDirection= UNKNOWN;
fStart= anchor;
fEnd= anchor - 1;
}
private boolean isAt(char c) {
return fSelectAnnotations && c == '@';
}
private boolean isIdentifierStart(char c) {
return Character.isJavaIdentifierStart(c);
}
private boolean isIdentifierPart(char c) {
return Character.isJavaIdentifierPart(c);
}
private boolean isWhitespace(char c) {
return fSelectAnnotations && Character.isWhitespace(c);
}
/*
* @see org.eclipse.jdt.internal.ui.text.ISourceVersionDependent#setSourceVersion(java.lang.String)
*/
public void setSourceVersion(String version) {
if (JavaCore.VERSION_1_5.compareTo(version) <= 0)
fSelectAnnotations= true;
else
fSelectAnnotations= false;
}
/**
* Try to add a character to the word going backward. Only call after
* forward calls!
*
* @param c the character to add
* @param offset the offset of the character
* @return <code>true</code> if further characters may be added to the
* word
*/
private boolean backward(char c, int offset) {
checkDirection(BACKWARD);
switch (fState) {
case AT:
return false;
case IDS:
if (isAt(c)) {
fStart= offset;
fState= AT;
return false;
}
if (isWhitespace(c)) {
fState= WS;
return true;
}
if (isIdentifierStart(c)) {
fStart= offset;
fState= IDS;
return true;
}
if (isIdentifierPart(c)) {
fStart= offset;
fState= ID;
return true;
}
return false;
case ID:
if (isIdentifierStart(c)) {
fStart= offset;
fState= IDS;
return true;
}
if (isIdentifierPart(c)) {
fStart= offset;
fState= ID;
return true;
}
return false;
case WS:
if (isWhitespace(c)) {
return true;
}
if (isAt(c)) {
fStart= offset;
fState= AT;
return false;
}
return false;
default:
return false;
}
}
/**
* Try to add a character to the word going forward.
*
* @param c the character to add
* @param offset the offset of the character
* @return <code>true</code> if further characters may be added to the
* word
*/
private boolean forward(char c, int offset) {
checkDirection(FORWARD);
switch (fState) {
case WS:
case AT:
if (isWhitespace(c)) {
fState= WS;
return true;
}
if (isIdentifierStart(c)) {
fEnd= offset;
fState= IDS;
return true;
}
return false;
case IDS:
case ID:
if (isIdentifierStart(c)) {
fEnd= offset;
fState= IDS;
return true;
}
if (isIdentifierPart(c)) {
fEnd= offset;
fState= ID;
return true;
}
return false;
case UNKNOWN:
if (isIdentifierStart(c)) {
fEnd= offset;
fState= IDS;
fAnchorState= fState;
return true;
}
if (isIdentifierPart(c)) {
fEnd= offset;
fState= ID;
fAnchorState= fState;
return true;
}
if (isWhitespace(c)) {
fState= WS;
fAnchorState= fState;
return true;
}
if (isAt(c)) {
fStart= offset;
fState= AT;
fAnchorState= fState;
return true;
}
return false;
default:
return false;
}
}
/**
* If the direction changes, set state to be the previous anchor state.
*
* @param direction the new direction
*/
private void checkDirection(int direction) {
if (fDirection == direction)
return;
if (direction == FORWARD) {
if (fStart <= fEnd)
fState= fAnchorState;
else
fState= UNKNOWN;
} else if (direction == BACKWARD) {
if (fEnd >= fStart)
fState= fAnchorState;
else
fState= UNKNOWN;
}
fDirection= direction;
}
/**
* Returns the region containing <code>anchor</code> that is a java
* word.
*
* @param document the document from which to read characters
* @param anchor the offset around which to select a word
* @return the region describing a java word around <code>anchor</code>
*/
public IRegion getWordSelection(IDocument document, int anchor) {
try {
final int min= 0;
final int max= document.getLength();
setAnchor(anchor);
char c;
int offset= anchor;
while (offset < max) {
c= document.getChar(offset);
if (!forward(c, offset))
break;
++offset;
}
offset= anchor; // use to not select the previous word when right behind it
// offset= anchor - 1; // use to select the previous word when right behind it
while (offset >= min) {
c= document.getChar(offset);
if (!backward(c, offset))
break;
--offset;
}
return new Region(fStart, fEnd - fStart + 1);
} catch (BadLocationException x) {
return new Region(anchor, 0);
}
}
}
protected static final char[] BRACKETS= {'{', '}', '(', ')', '[', ']', '<', '>' };
protected JavaPairMatcher fPairMatcher= new JavaPairMatcher(BRACKETS);
protected final AtJavaIdentifierDetector fWordDetector= new AtJavaIdentifierDetector();
@Override
protected IRegion findWord(IDocument document, int anchor) {
return fWordDetector.getWordSelection(document, anchor);
}
/*
* @see org.eclipse.jdt.internal.ui.text.ISourceVersionDependent#setSourceVersion(java.lang.String)
*/
public void setSourceVersion(String version) {
fPairMatcher.setSourceVersion(version);
fWordDetector.setSourceVersion(version);
}
@Override
protected IRegion findExtendedDoubleClickSelection(IDocument document, int offset) {
IRegion match= fPairMatcher.match(document, offset);
if (match != null && match.getLength() >= 2)
return new Region(match.getOffset() + 1, match.getLength() - 2);
return findWord(document, offset);
}
}