/*******************************************************************************
* Copyright (c) 2000, 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.swt.examples.javaviewer;
import org.eclipse.swt.*;
import org.eclipse.swt.custom.*;
import org.eclipse.swt.graphics.*;
import org.eclipse.swt.widgets.*;
import java.util.*;
import java.io.*;
class JavaLineStyler implements LineStyleListener {
JavaScanner scanner = new JavaScanner();
int[] tokenColors;
Color[] colors;
Vector blockComments = new Vector();
public static final int EOF= -1;
public static final int EOL= 10;
public static final int WORD= 0;
public static final int WHITE= 1;
public static final int KEY= 2;
public static final int COMMENT= 3;
public static final int STRING= 5;
public static final int OTHER= 6;
public static final int NUMBER= 7;
public static final int MAXIMUM_TOKEN= 8;
public JavaLineStyler() {
initializeColors();
scanner = new JavaScanner();
}
Color getColor(int type) {
if (type < 0 || type >= tokenColors.length) {
return null;
}
return colors[tokenColors[type]];
}
boolean inBlockComment(int start, int end) {
for (int i=0; i<blockComments.size(); i++) {
int[] offsets = (int[])blockComments.elementAt(i);
// start of comment in the line
if ((offsets[0] >= start) && (offsets[0] <= end)) return true;
// end of comment in the line
if ((offsets[1] >= start) && (offsets[1] <= end)) return true;
if ((offsets[0] <= start) && (offsets[1] >= end)) return true;
}
return false;
}
void initializeColors() {
Display display = Display.getDefault();
colors= new Color[] {
new Color(display, new RGB(0, 0, 0)), // black
new Color(display, new RGB(255, 0, 0)), // red
new Color(display, new RGB(0, 255, 0)), // green
new Color(display, new RGB(0, 0, 255)) // blue
};
tokenColors= new int[MAXIMUM_TOKEN];
tokenColors[WORD]= 0;
tokenColors[WHITE]= 0;
tokenColors[KEY]= 3;
tokenColors[COMMENT]= 1;
tokenColors[STRING]= 2;
tokenColors[OTHER]= 0;
tokenColors[NUMBER]= 0;
}
void disposeColors() {
for (int i=0;i<colors.length;i++) {
colors[i].dispose();
}
}
/**
* Event.detail line start offset (input)
* Event.text line text (input)
* LineStyleEvent.styles Enumeration of StyleRanges, need to be in order. (output)
* LineStyleEvent.background line background color (output)
*/
public void lineGetStyle(LineStyleEvent event) {
Vector styles = new Vector();
int token;
StyleRange lastStyle;
// If the line is part of a block comment, create one style for the entire line.
if (inBlockComment(event.lineOffset, event.lineOffset + event.lineText.length())) {
styles.addElement(new StyleRange(event.lineOffset, event.lineText.length(), getColor(COMMENT), null));
event.styles = new StyleRange[styles.size()];
styles.copyInto(event.styles);
return;
}
Color defaultFgColor = ((Control)event.widget).getForeground();
scanner.setRange(event.lineText);
token = scanner.nextToken();
while (token != EOF) {
if (token == OTHER) {
// do nothing for non-colored tokens
} else if (token != WHITE) {
Color color = getColor(token);
// Only create a style if the token color is different than the
// widget's default foreground color and the token's style is not
// bold. Keywords are bolded.
if ((!color.equals(defaultFgColor)) || (token == KEY)) {
StyleRange style = new StyleRange(scanner.getStartOffset() + event.lineOffset, scanner.getLength(), color, null);
if (token == KEY) {
style.fontStyle = SWT.BOLD;
}
if (styles.isEmpty()) {
styles.addElement(style);
} else {
// Merge similar styles. Doing so will improve performance.
lastStyle = (StyleRange)styles.lastElement();
if (lastStyle.similarTo(style) && (lastStyle.start + lastStyle.length == style.start)) {
lastStyle.length += style.length;
} else {
styles.addElement(style);
}
}
}
} else if ((!styles.isEmpty()) && ((lastStyle=(StyleRange)styles.lastElement()).fontStyle == SWT.BOLD)) {
int start = scanner.getStartOffset() + event.lineOffset;
lastStyle = (StyleRange)styles.lastElement();
// A font style of SWT.BOLD implies that the last style
// represents a java keyword.
if (lastStyle.start + lastStyle.length == start) {
// Have the white space take on the style before it to
// minimize the number of style ranges created and the
// number of font style changes during rendering.
lastStyle.length += scanner.getLength();
}
}
token= scanner.nextToken();
}
event.styles = new StyleRange[styles.size()];
styles.copyInto(event.styles);
}
public void parseBlockComments(String text) {
blockComments = new Vector();
StringReader buffer = new StringReader(text);
int ch;
boolean blkComment = false;
int cnt = 0;
int[] offsets = new int[2];
boolean done = false;
try {
while (!done) {
switch (ch = buffer.read()) {
case -1 : {
if (blkComment) {
offsets[1] = cnt;
blockComments.addElement(offsets);
}
done = true;
break;
}
case '/' : {
ch = buffer.read();
if ((ch == '*') && (!blkComment)) {
offsets = new int[2];
offsets[0] = cnt;
blkComment = true;
cnt++;
} else {
cnt++;
}
cnt++;
break;
}
case '*' : {
if (blkComment) {
ch = buffer.read();
cnt++;
if (ch == '/') {
blkComment = false;
offsets[1] = cnt;
blockComments.addElement(offsets);
}
}
cnt++;
break;
}
default : {
cnt++;
break;
}
}
}
} catch(IOException e) {
// ignore errors
}
}
/**
* A simple fuzzy scanner for Java
*/
public class JavaScanner {
protected Hashtable fgKeys= null;
protected StringBuffer fBuffer= new StringBuffer();
protected String fDoc;
protected int fPos;
protected int fEnd;
protected int fStartToken;
protected boolean fEofSeen= false;
private String[] fgKeywords= {
"abstract",
"boolean", "break", "byte",
"case", "catch", "char", "class", "continue",
"default", "do", "double",
"else", "extends",
"false", "final", "finally", "float", "for",
"if", "implements", "import", "instanceof", "int", "interface",
"long",
"native", "new", "null",
"package", "private", "protected", "public",
"return",
"short", "static", "super", "switch", "synchronized",
"this", "throw", "throws", "transient", "true", "try",
"void", "volatile",
"while"
};
public JavaScanner() {
initialize();
}
/**
* Returns the ending location of the current token in the document.
*/
public final int getLength() {
return fPos - fStartToken;
}
/**
* Initialize the lookup table.
*/
void initialize() {
fgKeys= new Hashtable();
Integer k= new Integer(KEY);
for (int i= 0; i < fgKeywords.length; i++)
fgKeys.put(fgKeywords[i], k);
}
/**
* Returns the starting location of the current token in the document.
*/
public final int getStartOffset() {
return fStartToken;
}
/**
* Returns the next lexical token in the document.
*/
public int nextToken() {
int c;
fStartToken= fPos;
while (true) {
switch (c= read()) {
case EOF:
return EOF;
case '/': // comment
c= read();
if (c == '/') {
while (true) {
c= read();
if ((c == EOF) || (c == EOL)) {
unread(c);
return COMMENT;
}
}
}
unread(c);
return OTHER;
case '\'': // char const
while(true) {
c= read();
switch (c) {
case '\'':
return STRING;
case EOF:
unread(c);
return STRING;
case '\\':
c= read();
break;
}
}
case '"': // string
while(true) {
c= read();
switch (c) {
case '"':
return STRING;
case EOF:
unread(c);
return STRING;
case '\\':
c= read();
break;
}
}
case '0': case '1': case '2': case '3': case '4':
case '5': case '6': case '7': case '8': case '9':
do {
c= read();
} while(Character.isDigit((char)c));
unread(c);
return NUMBER;
default:
if (Character.isWhitespace((char)c)) {
do {
c= read();
} while(Character.isWhitespace((char)c));
unread(c);
return WHITE;
}
if (Character.isJavaIdentifierStart((char)c)) {
fBuffer.setLength(0);
do {
fBuffer.append((char)c);
c= read();
} while(Character.isJavaIdentifierPart((char)c));
unread(c);
Integer i= (Integer) fgKeys.get(fBuffer.toString());
if (i != null)
return i.intValue();
return WORD;
}
return OTHER;
}
}
}
/**
* Returns next character.
*/
protected int read() {
if (fPos <= fEnd) {
return fDoc.charAt(fPos++);
}
return EOF;
}
public void setRange(String text) {
fDoc= text;
fPos= 0;
fEnd= fDoc.length() -1;
}
protected void unread(int c) {
if (c != EOF)
fPos--;
}
}
}