/*
* Copyright 2004-2014 SmartBear Software
*
* Licensed under the EUPL, Version 1.1 or - as soon as they will be approved by the European Commission - subsequent
* versions of the EUPL (the "Licence");
* You may not use this work except in compliance with the Licence.
* You may obtain a copy of the Licence at:
*
* http://ec.europa.eu/idabc/eupl
*
* Unless required by applicable law or agreed to in writing, software distributed under the Licence is
* distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
* express or implied. See the Licence for the specific language governing permissions and limitations
* under the Licence.
*/
package org.syntax.jedit.tokenmarker;
import javax.swing.text.Segment;
/**
* A token marker that splits lines of text into tokens. Each token carries a
* length field and an indentification tag that can be mapped to a color for
* painting that token.
* <p/>
* <p/>
* For performance reasons, the linked list of tokens is reused after each line
* is tokenized. Therefore, the return value of <code>markTokens</code> should
* only be used for immediate painting. Notably, it cannot be cached.
*
* @author Slava Pestov
* @version $Id$
* @see org.syntax.jedit.Token
*/
public abstract class TokenMarker {
/**
* A wrapper for the lower-level <code>markTokensImpl</code> method that is
* called to split a line up into tokens.
*
* @param line The line
* @param lineIndex The line number
*/
public Token markTokens(Segment line, int lineIndex) {
if (lineIndex >= length) {
throw new IllegalArgumentException("Tokenizing invalid line: " + lineIndex);
}
lastToken = null;
LineInfo info = lineInfo[lineIndex];
LineInfo prev;
if (lineIndex == 0) {
prev = null;
} else {
prev = lineInfo[lineIndex - 1];
}
byte oldToken = info.token;
byte token = markTokensImpl(prev == null ? Token.NULL : prev.token, line, lineIndex);
info.token = token;
/*
* This is a foul hack. It stops nextLineRequested from being cleared if
* the same line is marked twice.
*
* Why is this necessary? It's all JEditTextArea's fault. When something
* is inserted into the text, firing a document event, the insertUpdate()
* method shifts the caret (if necessary) by the amount inserted.
*
* All caret movement is handled by the select() method, which eventually
* pipes the new position to scrollTo() and calls repaint().
*
* Note that at this point in time, the new line hasn't yet been painted;
* the caret is moved first.
*
* scrollTo() calls offsetToX(), which tokenizes the line unless it is
* being called on the last line painted (in which case it uses the text
* area's painter cached token list). What scrollTo() does next is
* irrelevant.
*
* After scrollTo() has done it's job, repaint() is called, and eventually
* we end up in paintLine(), whose job is to paint the changed line. It,
* too, calls markTokens().
*
* The problem was that if the line started a multiline token, the first
* markTokens() (done in offsetToX()) would set nextLineRequested (because
* the line end token had changed) but the second would clear it (because
* the line was the same that time) and therefore paintLine() would never
* know that it needed to repaint subsequent lines.
*
* This bug took me ages to track down, that's why I wrote all the
* relevant info down so that others wouldn't duplicate it.
*/
if (!(lastLine == lineIndex && nextLineRequested)) {
nextLineRequested = (oldToken != token);
}
lastLine = lineIndex;
addToken(0, Token.END);
return firstToken;
}
/**
* An abstract method that splits a line up into tokens. It should parse the
* line, and call <code>addToken()</code> to add syntax tokens to the token
* list. Then, it should return the initial token type for the next line.
* <p/>
* <p/>
* For example if the current line contains the start of a multiline comment
* that doesn't end on that line, this method should return the comment token
* type so that it continues on the next line.
*
* @param token The initial token type for this line
* @param line The line to be tokenized
* @param lineIndex The index of the line in the document, starting at 0
* @return The initial token type for the next line
*/
protected abstract byte markTokensImpl(byte token, Segment line, int lineIndex);
/**
* Returns if the token marker supports tokens that span multiple lines. If
* this is true, the object using this token marker is required to pass all
* lines in the document to the <code>markTokens()</code> method (in turn).
* <p/>
* <p/>
* The default implementation returns true; it should be overridden to return
* false on simpler token markers for increased speed.
*/
public boolean supportsMultilineTokens() {
return true;
}
/**
* Informs the token marker that lines have been inserted into the document.
* This inserts a gap in the <code>lineInfo</code> array.
*
* @param index The first line number
* @param lines The number of lines
*/
public void insertLines(int index, int lines) {
if (lines <= 0) {
return;
}
length += lines;
ensureCapacity(length);
int len = index + lines;
System.arraycopy(lineInfo, index, lineInfo, len, lineInfo.length - len);
for (int i = index + lines - 1; i >= index; i--) {
lineInfo[i] = new LineInfo();
}
}
/**
* Informs the token marker that line have been deleted from the document.
* This removes the lines in question from the <code>lineInfo</code> array.
*
* @param index The first line number
* @param lines The number of lines
*/
public void deleteLines(int index, int lines) {
if (lines <= 0) {
return;
}
int len = index + lines;
length -= lines;
System.arraycopy(lineInfo, len, lineInfo, index, lineInfo.length - len);
}
/**
* Returns the number of lines in this token marker.
*/
public int getLineCount() {
return length;
}
/**
* Returns true if the next line should be repainted. This will return true
* after a line has been tokenized that starts a multiline token that
* continues onto the next line.
*/
public boolean isNextLineRequested() {
return nextLineRequested;
}
// protected members
/**
* The first token in the list. This should be used as the return value from
* <code>markTokens()</code>.
*/
protected Token firstToken;
/**
* The last token in the list. New tokens are added here. This should be set
* to null before a new line is to be tokenized.
*/
protected Token lastToken;
/**
* An array for storing information about lines. It is enlarged and shrunk
* automatically by the <code>insertLines()</code> and
* <code>deleteLines()</code> methods.
*/
protected LineInfo[] lineInfo;
/**
* The number of lines in the model being tokenized. This can be less than
* the length of the <code>lineInfo</code> array.
*/
protected int length;
/**
* The last tokenized line.
*/
protected int lastLine;
/**
* True if the next line should be painted.
*/
protected boolean nextLineRequested;
/**
* Creates a new <code>TokenMarker</code>. This DOES NOT create a lineInfo
* array; an initial call to <code>insertLines()</code> does that.
*/
protected TokenMarker() {
lastLine = -1;
}
/**
* Ensures that the <code>lineInfo</code> array can contain the specified
* index. This enlarges it if necessary. No action is taken if the array is
* large enough already.
* <p/>
* <p/>
* It should be unnecessary to call this under normal circumstances;
* <code>insertLine()</code> should take care of enlarging the line info
* array automatically.
*
* @param index The array index
*/
protected void ensureCapacity(int index) {
if (lineInfo == null) {
lineInfo = new LineInfo[index + 1];
} else if (lineInfo.length <= index) {
LineInfo[] lineInfoN = new LineInfo[(index + 1) * 2];
System.arraycopy(lineInfo, 0, lineInfoN, 0, lineInfo.length);
lineInfo = lineInfoN;
}
}
/**
* Adds a token to the token list.
*
* @param length The length of the token
* @param id The id of the token
*/
protected void addToken(int length, byte id) {
if (id >= Token.INTERNAL_FIRST && id <= Token.INTERNAL_LAST) {
throw new InternalError("Invalid id: " + id);
}
if (length == 0 && id != Token.END) {
return;
}
if (firstToken == null) {
firstToken = new Token(length, id);
lastToken = firstToken;
} else if (lastToken == null) {
lastToken = firstToken;
firstToken.length = length;
firstToken.id = id;
} else if (lastToken.next == null) {
lastToken.next = new Token(length, id);
lastToken = lastToken.next;
} else {
lastToken = lastToken.next;
lastToken.length = length;
lastToken.id = id;
}
}
/**
* Inner class for storing information about tokenized lines.
*/
public class LineInfo {
/**
* Creates a new LineInfo object with token = Token.NULL and obj = null.
*/
public LineInfo() {
}
/**
* Creates a new LineInfo object with the specified parameters.
*/
public LineInfo(byte token, Object obj) {
this.token = token;
this.obj = obj;
}
/**
* The id of the last token of the line.
*/
public byte token;
/**
* This is for use by the token marker implementations themselves. It can
* be used to store anything that is an object and that needs to exist on
* a per-line basis.
*/
public Object obj;
}
}