alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

What this is

This file is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Other links

The source code

/*
 * Copyright (c) 1998 Tal Davidson. All rights reserved.
 *
 * JSLineBreaker 0.4.0
 * by Tal Davidson (davidsont@bigfoot.com)
 *
 * JSLineBreaker 0.4.0 is distributed under the "Artistic Licence" detailed below:
 *
 *
 *                           The ``Artistic License''
 *
 * Preamble
 * The intent of this document is to state the conditions under which a Package may
 * be copied, such that the Copyright Holder maintains some semblance of artistic
 * control over the development of the package, while giving the users of the
 * package the right to use and distribute the Package in a more-or-less customary
 * fashion, plus the right to make reasonable modifications.
 *
 * Definitions
 *     ``Package'' refers to the collection of files distributed by the Copyright
 *     Holder, and derivatives of that collection of files created through textual
 *     modification.
 *     ``Standard Version'' refers to such a Package if it has not been modified,
 *     or has been modified in accordance with the wishes of the Copyright Holder
 *     as specified below.
 *     ``Copyright Holder'' is whoever is named in the copyright or copyrights for
 *     the package.
 *     ``You'' is you, if you're thinking about copying or distributing this
 *     Package.
 *     ``Reasonable copying fee'' is whatever you can justify on the basis of media
 *     cost, duplication charges, time of people involved, and so on. (You will not
 *     be required to justify it to the Copyright Holder, but only to the computing
 *     community at large as a market that must bear the fee.)
 *     ``Freely Available'' means that no fee is charged for the item itself,
 *     though there may be fees involved in handling the item. It also means that
 *     recipients of the item may redistribute it under the same conditions they
 *     received it.
 *
 *     1. You may make and give away verbatim copies of the source form of the
 *        Standard Version of this Package without restriction, provided that you
 *        duplicate all of the original copyright notices and associated disclaimers.
 *     2. You may apply bug fixes, portability fixes and other modifications derived
 *        from the Public Domain or from the Copyright Holder. A Package modified in
 *        such a way shall still be considered the Standard Version.
 *     3. You may otherwise modify your copy of this Package in any way, provided that
 *        you insert a prominent notice in each changed file stating how and when you
 *        changed that file, and provided that you do at least ONE of the following:
 *         a. place your modifications in the Public Domain or otherwise make them
 *            Freely Available, such as by posting said modifications to Usenet or an
 *            equivalent medium, or placing the modifications on a major archive site
 *            such as uunet.uu.net, or by allowing the Copyright Holder to include
 *            your modifications in the Standard Version of the Package.
 *         b. use the modified Package only within your corporation or organization.
 *         c. rename any non-standard executables so the names do not conflict with
 *            standard executables, which must also be provided, and provide a
 *            separate manual page for each non-standard executable that clearly
 *            documents how it differs from the Standard Version.
 *         d. make other distribution arrangements with the Copyright Holder.
 *     4. You may distribute the programs of this Package in object code or executable
 *        form, provided that you do at least ONE of the following:
 *         a. distribute a Standard Version of the executables and library files,
 *            together with instructions (in the manual page or equivalent) on where
 *            to get the Standard Version.
 *         b. accompany the distribution with the machine-readable source of the
 *            Package with your modifications.
 *         c. give non-standard executables non-standard names, and clearly document
 *            the differences in manual pages (or equivalent), together with
 *            instructions on where to get the Standard Version.
 *         d. make other distribution arrangements with the Copyright Holder.
 *     5. You may charge a reasonable copying fee for any distribution of this
 *        Package. You may charge any fee you choose for support of this Package. You
 *        may not charge a fee for this Package itself. However, you may distribute
 *        this Package in aggregate with other (possibly commercial) programs as part
 *        of a larger (possibly commercial) software distribution provided that you do
 *        not advertise this Package as a product of your own. You may embed this
 *        Package's interpreter within an executable of yours (by linking); this shall
 *        be construed as a mere form of aggregation, provided that the complete
 *        Standard Version of the interpreter is so embedded.
 *     6. The scripts and library files supplied as input to or produced as output
 *        from the programs of this Package do not automatically fall under the
 *        copyright of this Package, but belong to whomever generated them, and may be
 *        sold commercially, and may be aggregated with this Package. If such scripts
 *        or library files are aggregated with this Package via the so-called "undump"
 *        or "unexec" methods of producing a binary executable image, then
 *        distribution of such an image shall neither be construed as a distribution
 *        of this Package nor shall it fall under the restrictions of Paragraphs 3 and
 *        4, provided that you do not represent such an executable image as a Standard
 *        Version of this Package.
 *     7. C subroutines (or comparably compiled subroutines in other languages)
 *        supplied by you and linked into this Package in order to emulate subroutines
 *        and variables of the language defined by this Package shall not be
 *        considered part of this Package, but are the equivalent of input as in
 *        Paragraph 6, provided these subroutines do not change the language in any
 *        way that would cause it to fail the regression tests for the language.
 *     8. Aggregation of this Package with a commercial distribution is always
 *        permitted provided that the use of this Package is embedded; that is, when
 *        no overt attempt is made to make this Package's interfaces visible to the
 *        end user of the commercial distribution. Such use shall not be construed as
 *        a distribution of this Package.
 *     9. The name of the Copyright Holder may not be used to endorse or promote
 *        products derived from this software without specific prior written
 *        permission.
 *        THIS PACKAGE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED
 *        WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
 *        MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
 * The End
 */

import java.util.*;

class JSLineBreaker
{
    private static final int BEFORE = 0;
    private static final int AFTER = 1;

    private String prefs[] = {
        "().", "()", ").", "+=", "-=", "*=", "/=", "%=", "^=", "||", "&&", "==", "!=", ">=", "<=",
        "(", ")", "[", "]", "?", ":", ",", ";", "=", "<", ">", "+", "-", "*", "/", "&", "|", /*"!",*/ "^"
    };
    private static Hashtable prefTable;
    static
    {
        prefTable = new Hashtable();
        prefTable.put("()", new Integer(80/*35*/)); // () appears here so that it will not be cut in the middle...

        prefTable.put("().", new Integer(90)); // () appears here so that it will not be cut in the middle...
        prefTable.put(").", new Integer(90)); // () appears here so that it will not be cut in the middle...

        prefTable.put("(", new Integer(80));//<--
        prefTable.put(")", new Integer(80));
        prefTable.put("[", new Integer(80));
        prefTable.put("]", new Integer(80));
        prefTable.put(",", new Integer(10));
        prefTable.put(";", new Integer(5));


        prefTable.put("=", new Integer(20));
        prefTable.put("+=", new Integer(20));
        prefTable.put("-=", new Integer(20));
        prefTable.put("*=", new Integer(20));
        prefTable.put("/=", new Integer(20));
        prefTable.put("|=", new Integer(20));
        prefTable.put("&=", new Integer(20));
        prefTable.put("^=", new Integer(20));

        prefTable.put("?", new Integer(25));
        prefTable.put(":", new Integer(25));

        prefTable.put("||", new Integer(30));
        prefTable.put("&&", new Integer(30));

        prefTable.put("==", new Integer(40));
        prefTable.put("!=", new Integer(40));
        prefTable.put(">=", new Integer(40));
        prefTable.put("<=", new Integer(40));
        prefTable.put(">", new Integer(40));
        prefTable.put("<", new Integer(40));

        prefTable.put("+", new Integer(50));
        prefTable.put("-", new Integer(50));
        prefTable.put("*", new Integer(60));
        prefTable.put("/", new Integer(60));
        prefTable.put("%", new Integer(60));
        //prefTable.put("!", new Integer(70));
        prefTable.put("&", new Integer(70));
        prefTable.put("|", new Integer(70));
        prefTable.put("^", new Integer(70));
    }


    private Vector brokenLineVector;
    private StringBuffer wsBuffer;
    private char quoteChar;
    private boolean isInQuote;
    private boolean isInComment;
    private boolean isNestedConnection = true;
    private boolean isCut;
    private boolean isLineComment; // true when the current character is in a // comment (such as this line ...)
    private int parenDepth;
    private int breakDepth;
    private int preferredLineLength = 70;
    private int lineLengthDeviation = 5;




    JSLineBreaker()
    {
        init();
    }

    void init()
    {
        brokenLineVector = new Vector();

        parenDepth = 0;
        breakDepth = 0; // <------ 2

        isInQuote = false;
        isInComment = false;
        isCut = false;
        isLineComment = false;
        wsBuffer = new StringBuffer();

    }

    void setPreferredLineLength(int length)
    {
        preferredLineLength = length;
    }

    void setLineLengthDeviation(int dev)
    {
        lineLengthDeviation = dev;
    }

    void setNestedConnection(boolean nest)
    {
        isNestedConnection = nest;
    }

    void breakLine(String line)
    {
        StringBuffer outBuffer = new StringBuffer();
        Stack lineBreakStack = new Stack();
        String previousAfterCut = "";
         boolean isSpecialChar = false;
        char ch = ' ';       // the current character
        char prevCh = 0;
        int i;
        int ws;
        int regBreak = 0;
        int wsBreak = 0;
        int chosenBreak = 0;
        int BufLength;
        int bufferStart = 0;

//System.out.println("line length: " + line.length() + " line: " + line );
        if ( line.trim().length() == 0)
        {
            brokenLineVector.addElement("");
            return;
        }

        ch = line.charAt(0);
        ws = 0;

        if (!isLineComment)
            isCut = false;
        isLineComment = false;

        if (!isCut)
        {
        wsBuffer = new StringBuffer();

        while ( (ch == ' ' || ch == '\t') && ws='a' &&prevCh<='z')
                                    || (prevCh>='A' &&prevCh<='Z')
                                    || (prevCh>='0' &&prevCh<='9')
                                    || (prevCh=='.'))
                                breakType = AFTER;
                            else
                                breakType = BEFORE;
                        else
                            breakType = AFTER;
                    }

                    if (key.length() > 1)
                    {
                        outBuffer.append(key.substring(1));
                        i += key.length() - 1;
                    }
                    registerLineBreak(lineBreakStack,
                            new LineBreak(key, outBuffer.length()+bufferStart, breakDepth, breakType));

                    breakDepth = parenDepth;

                    break;
                }
            }


            int bufLength = outBuffer.length() + wsBuffer.length() + previousAfterCut.length() + (isCut ? 8 : 0);

            LineBreak curBreak = null;
            if (bufLength > preferredLineLength && i < line.length() - lineLengthDeviation)
            {
                while (!lineBreakStack.isEmpty())
                {
                    curBreak = (LineBreak) lineBreakStack.elementAt(0);
                    if (curBreak.breakWhere-bufferStart < 1) // <-----
                    {
                        curBreak = null;
                        lineBreakStack.removeElementAt(0);
                    }
                    else
                        break;
                }
                if (curBreak != null)
                    lineBreakStack.removeElementAt(0);
            }

            if (curBreak != null) // in future, think of: && line.length()>i+10) (that was used in the past...)
            {
                int cutWhere = curBreak.breakWhere - bufferStart - (curBreak.breakType == BEFORE ? curBreak.breakStr.length() : 0);
                if (cutWhere < 8)
                    continue;
                StringBuffer brokenLineBuffer = new StringBuffer();
                String outString = outBuffer.toString();
                String beforeCut = outString.substring(0, cutWhere);

                //brokenLineBuffer.append(wsBuffer);

                /*
                if (isCut)
                    brokenLineBuffer.append("        ");
                brokenLineBuffer.append(beforeCut);
                brokenLineVector.addElement(brokenLineBuffer.toString());
                */
                brokenLineBuffer.append(beforeCut);
                addBrokenLine(wsBuffer.toString(), brokenLineBuffer.toString(), curBreak, breakDepth, isCut);

                //previousAfterCut = outString.substring(cutWhere);
                bufferStart += cutWhere;
                outBuffer = new StringBuffer(outString.substring(cutWhere));

                //lineBreakStack = new Stack();
                isCut = true;
            }
        }

        // at end of line:
        StringBuffer brokenLineBuffer = new StringBuffer();
        //brokenLineBuffer.append(wsBuffer);
        /*
        if (isCut)
            brokenLineBuffer.append("        ");
        brokenLineBuffer.append(outBuffer);
        brokenLineVector.addElement(brokenLineBuffer.toString());
        */
        brokenLineBuffer.append(outBuffer);
        addBrokenLine(wsBuffer.toString(), brokenLineBuffer.toString(), null, breakDepth, isCut);

    }

    private void registerLineBreak(Stack lineBreakStack, LineBreak newBreak)
    {
        LineBreak lastBreak;
        while (!lineBreakStack.isEmpty())
        {
            lastBreak = (LineBreak) lineBreakStack.peek();
            if (compare(lastBreak, newBreak) < 0)
                lineBreakStack.pop();
            else
                break;
        }
        lineBreakStack.push(newBreak);
        //newBreak.dump();

 /*       System.out.println("for " + newBreak.breakStr);
        for (int s=0; s 0)
        {
            String previousBrokenLine = (String) brokenLineVector.lastElement();
            if (brokenLine.length() + previousBrokenLine.length() <= preferredLineLength + lineLengthDeviation
                    || brokenLine.startsWith("{"))
            {
                if (lineBreak == null ||
                        (isNestedConnection && !",".equals(previousLineBreak.breakStr)) ||
                        (lineBreak.breakDepth < previousLineBreak.breakDepth) || //dfds
                        (lineBreak.breakDepth == previousLineBreak.breakDepth &&
                        ((!isNestedConnection && !",".equals(previousLineBreak.breakStr)) ||
                             ",".equals(lineBreak.breakStr) || ";".equals(lineBreak.breakStr) ||
                             ")".equals(lineBreak.breakStr) || "]".equals(lineBreak.breakStr)))
                   )
                {
                    brokenLineVector.setElementAt( (previousBrokenLine + " " + brokenLine),
                            brokenLineVector.size()-1);
                    isLineAppended = true;
                }
            }
        }

        if (!isLineAppended)
        {
            if (isCut &&
                    !(previousLineBreak != null && ",".equals(previousLineBreak.breakStr) &&
                    previousLineBreak.breakDepth == 0))
                brokenLine = "        " + brokenLine;
            brokenLine = whiteSpace + brokenLine;
            brokenLineVector.addElement(brokenLine);
        }

        previousLineBreak = lineBreak;
    }

    private int compare(LineBreak br1, LineBreak br2)
    {
        if (br1.breakDepth < br2.breakDepth)
                return 1;
            else if (br1.breakDepth > br2.breakDepth)
                return -1;

        int ord1 = ((Integer) prefTable.get(br1.breakStr)).intValue();
        int ord2 = ((Integer) prefTable.get(br2.breakStr)).intValue();
        if (ord1 < ord2)
            return 1;
        else
            return -1;


    }

    boolean hasMoreBrokenLines()
    {
        return brokenLineVector.size() > 0;
    }

    String nextBrokenLine()
    {
        String nextLine;

        if (hasMoreBrokenLines())
        {
            nextLine = (String) brokenLineVector.firstElement();
            brokenLineVector.removeElementAt(0);
        }
        else
            return nextLine = "";

        return nextLine;
    }


    class LineBreak
    {
        String breakStr;
        int breakWhere;
        int breakDepth;
        int breakType;

        LineBreak(String str, int wh, int dp, int tp)
        {
            breakStr = str;
            breakWhere = wh;
            breakDepth = dp;
            breakType = tp;
        }

        void dump()
        {
            System.out.println("LB: str="+breakStr+" wh="+breakWhere+" dep="+breakDepth+" tp="+breakType);
        }
    }

}
... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.