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Processing is a programming language, development environment, and online community.
This Java Mode package contains the Java mode for Processing IDE.
/* -*- mode: java; c-basic-offset: 2; indent-tabs-mode: nil -*- */
/*
Part of the Processing project - http://processing.org
Copyright (c) 2012-15 The Processing Foundation
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2
as published by the Free Software Foundation.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software Foundation, Inc.
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
package processing.mode.java.debug;
import java.util.HashSet;
import java.util.Set;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
import javax.swing.text.BadLocationException;
import javax.swing.text.Document;
import javax.swing.text.Element;
import javax.swing.text.Position;
/**
* Describes an ID for a code line. Comprised of a file name and a (0-based)
* line number. Can track changes to the line number due to text editing by
* attaching a {@link Document}. Registered {@link LineListener}s are notified
* of changes to the line number.
*
* @author Martin Leopold
*/
public class LineID implements DocumentListener {
protected String fileName; // the filename
protected int lineIdx; // the line number, 0-based
protected Document doc; // the Document to use for line number tracking
protected Position pos; // the Position acquired during line number tracking
protected Set listeners = new HashSet(); // listeners for line number changes
public LineID(String fileName, int lineIdx) {
this.fileName = fileName;
this.lineIdx = lineIdx;
}
/**
* Get the file name of this line.
*
* @return the file name
*/
public String fileName() {
return fileName;
}
/**
* Get the (0-based) line number of this line.
*
* @return the line index (i.e. line number, starting at 0)
*/
public synchronized int lineIdx() {
return lineIdx;
}
@Override
public int hashCode() {
return toString().hashCode();
}
/**
* Test whether this {@link LineID} is equal to another object. Two
* {@link LineID}'s are equal when both their fileName and lineNo are equal.
*
* @param obj the object to test for equality
* @return {@code true} if equal
*/
@Override
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (getClass() != obj.getClass()) {
return false;
}
final LineID other = (LineID) obj;
if ((this.fileName == null) ? (other.fileName != null) : !this.fileName.equals(other.fileName)) {
return false;
}
if (this.lineIdx != other.lineIdx) {
return false;
}
return true;
}
/**
* Output a string representation in the form fileName:lineIdx+1. Note this
* uses a 1-based line number as is customary for human-readable line
* numbers.
*
* @return the string representation of this line ID
*/
@Override
public String toString() {
return fileName + ":" + (lineIdx + 1);
}
// /**
// * Retrieve a copy of this line ID.
// *
// * @return the copy
// */
// @Override
// public LineID clone() {
// return new LineID(fileName, lineIdx);
// }
/**
* Attach a {@link Document} to enable line number tracking when editing.
* The position to track is before the first non-whitespace character on the
* line. Edits happening before that position will cause the line number to
* update accordingly. Multiple {@link #startTracking} calls will replace
* the tracked document. Whoever wants a tracked line should track it and
* add itself as listener if necessary.
* ({@link LineHighlight}, {@link LineBreakpoint})
*
* @param doc the {@link Document} to use for line number tracking
*/
public synchronized void startTracking(Document doc) {
//System.out.println("tracking: " + this);
if (doc == null) {
return; // null arg
}
if (doc == this.doc) {
return; // already tracking that doc
}
try {
Element line = doc.getDefaultRootElement().getElement(lineIdx);
if (line == null) {
return; // line doesn't exist
}
String lineText = doc.getText(line.getStartOffset(), line.getEndOffset() - line.getStartOffset());
// set tracking position at (=before) first non-white space character on line,
// or, if the line consists of entirely white spaces, just before the newline
// character
pos = doc.createPosition(line.getStartOffset() + nonWhiteSpaceOffset(lineText));
this.doc = doc;
doc.addDocumentListener(this);
} catch (BadLocationException ex) {
Logger.getLogger(LineID.class.getName()).log(Level.SEVERE, null, ex);
pos = null;
this.doc = null;
}
}
/**
* Notify this {@link LineID} that it is no longer in use. Will stop
* position tracking. Call this when this {@link LineID} is no longer
* needed.
*/
public synchronized void stopTracking() {
if (doc != null) {
doc.removeDocumentListener(this);
doc = null;
}
}
/**
* Update the tracked position. Will notify listeners if line number has
* changed.
*/
protected synchronized void updatePosition() {
if (doc != null && pos != null) {
// track position
int offset = pos.getOffset();
int oldLineIdx = lineIdx;
lineIdx = doc.getDefaultRootElement().getElementIndex(offset); // offset to lineNo
if (lineIdx != oldLineIdx) {
for (LineHighlight l : listeners) {
if (l != null) {
l.lineChanged(this, oldLineIdx, lineIdx);
} else {
listeners.remove(l); // remove null listener
}
}
}
}
}
/**
* Add listener to be notified when the line number changes.
*
* @param l the listener to add
*/
public void addListener(LineHighlight l) {
listeners.add(l);
}
/**
* Remove a listener for line number changes.
*
* @param l the listener to remove
*/
public void removeListener(LineHighlight l) {
listeners.remove(l);
}
/**
* Calculate the offset of the first non-whitespace character in a string.
*
* @param str the string to examine
* @return offset of first non-whitespace character in str
*/
protected static int nonWhiteSpaceOffset(String str) {
for (int i = 0; i < str.length(); i++) {
if (!Character.isWhitespace(str.charAt(i))) {
return i;
}
}
/* If we've reached here, that implies the line consists of purely white
* space. So return at a position just after the whitespace (i.e.,
* just before the newline).
*
* The " - 1" part resolves issue #3552
*/
return str.length() - 1;
}
/**
* Called when the {@link Document} registered using {@link #startTracking}
* is edited. This happens when text is inserted or removed.
*
* @param de
*/
protected void editEvent(DocumentEvent de) {
//System.out.println("document edit @ " + de.getOffset());
if (de.getOffset() <= pos.getOffset()) {
updatePosition();
//System.out.println("updating, new line no: " + lineNo);
}
}
/**
* {@link DocumentListener} callback. Called when text is inserted.
*
* @param de
*/
@Override
public void insertUpdate(DocumentEvent de) {
editEvent(de);
}
/**
* {@link DocumentListener} callback. Called when text is removed.
*
* @param de
*/
@Override
public void removeUpdate(DocumentEvent de) {
editEvent(de);
}
/**
* {@link DocumentListener} callback. Called when attributes are changed.
* Not used.
*
* @param de
*/
@Override
public void changedUpdate(DocumentEvent de) {
// not needed.
}
}