http://xmlgraphics.apache.org/fop/: Apache FOP (Formatting Objects Processor) is the world's first print formatter driven by XSL formatting objects (XSL-FO) and the world's first output independent formatter. It is a Java application that reads a formatting object (FO) tree and renders the resulting pages to a specified output. Output formats currently supported include PDF, PCL, PS, AFP, TIFF, PNG, SVG, XML (area tree representation), Print, AWT and TXT. The primary output target is PDF. (Apache Software Foundation) 
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/* $Id: KnuthPenalty.java 1345838 2012-06-04 05:42:06Z gadams $ */

package org.apache.fop.layoutmgr;


An instance of this class represents information about a feasible
breaking point; it does not represent any piece of content.
A KnuthPenalty is a feasible breaking point unless its value is infinity;
a KnuthPenalty whose value is -infinity represents a forced break.
A KnuthPenalty is suppressed, and its width is ignored, if it is not a
chosen breaking point; for example, a KnuthPenalty representing a
hyphenation point has a width (the "-" width), which must be ignored if
that point is not chosen as a breaking point.
Besides the inherited methods and attributes, this class has two more
attributes and the methods used to get them: the penalty value, which is
a kind of "aesthetic cost" (the higher the value, the more unsightly the
breaking point), and a boolean that marks KnuthPenalties which should not
be chosen as breaking points for consecutive lines.

/**
 * An instance of this class represents information about a feasible
 * breaking point; it does not represent any piece of content.
 *
 * A KnuthPenalty is a feasible breaking point unless its value is infinity;
 * a KnuthPenalty whose value is -infinity represents a forced break.
 *
 * A KnuthPenalty is suppressed, and its width is ignored, if it is not a
 * chosen breaking point; for example, a KnuthPenalty representing a
 * hyphenation point has a width (the "-" width), which must be ignored if
 * that point is not chosen as a breaking point.
 *
 * Besides the inherited methods and attributes, this class has two more
 * attributes and the methods used to get them: the penalty value, which is
 * a kind of "aesthetic cost" (the higher the value, the more unsightly the
 * breaking point), and a boolean that marks KnuthPenalties which should not
 * be chosen as breaking points for consecutive lines.
 */
public class KnuthPenalty extends KnuthElement {

    
Used for flagged penalties. See Knuth algorithm. 
/** Used for flagged penalties. See Knuth algorithm. */
    public static final int FLAGGED_PENALTY = 50;
    
Dummy, zero-width penalty 
/** Dummy, zero-width penalty */
    public static final KnuthPenalty DUMMY_ZERO_PENALTY
            = new KnuthPenalty(0, 0, false, null, true);

    private int penalty;
    private boolean penaltyFlagged;
    private int breakClass = -1;

    
Create a new KnuthPenalty.

Params:
  • width – the width of this penalty
  • penalty – the penalty value of this penalty
  • penaltyFlagged – is this penalty flagged?
  • pos – the Position stored in this penalty
  • auxiliary – is this penalty auxiliary?
/**
     * Create a new KnuthPenalty.
     *
     * @param width the width of this penalty
     * @param penalty the penalty value of this penalty
     * @param penaltyFlagged is this penalty flagged?
     * @param pos the Position stored in this penalty
     * @param auxiliary is this penalty auxiliary?
     */
    public KnuthPenalty(int width, int penalty, boolean penaltyFlagged, Position pos,
                        boolean auxiliary) {
        super(width, pos, auxiliary);
        this.penalty = penalty;
        this.penaltyFlagged = penaltyFlagged;
    }

    
Create a new KnuthPenalty.

Params:
/**
     * Create a new KnuthPenalty.
     *
     * @param width the width of this penalty
     * @param penalty the penalty value of this penalty
     * @param penaltyFlagged is this penalty flagged?
     * @param breakClass the break class of this penalty (one of
     *   {@link org.apache.fop.fo.Constants#EN_AUTO},
     *   {@link org.apache.fop.fo.Constants#EN_COLUMN},
     *   {@link org.apache.fop.fo.Constants#EN_PAGE},
     *   {@link org.apache.fop.fo.Constants#EN_EVEN_PAGE},
     *   {@link org.apache.fop.fo.Constants#EN_ODD_PAGE}).
     * @param pos the Position stored in this penalty
     * @param isAuxiliary is this penalty auxiliary?
     */
    public KnuthPenalty(int width, int penalty, boolean penaltyFlagged, int breakClass,
                        Position pos, boolean isAuxiliary) {
        this(width, penalty, penaltyFlagged, pos, isAuxiliary);
        this.breakClass = breakClass;
    }

    private static String getBreakClassName(int breakClass) {
        return AbstractBreaker.getBreakClassName(breakClass);
    }

    
Get the penalty's value as a String. (Mainly used in toString() methods, to improve readability of the trace logs.) TODO: shouldn't be penalty a class of its own? 
Params:
  • penaltyValue –  the penalty value
Returns: the penalty value as a String
/**
     * Get the penalty's value as a {@link java.lang.String}.
     * (Mainly used in {@link #toString()} methods, to improve readability
     * of the trace logs.)
     *
     * TODO: shouldn't be penalty a class of its own?
     *
     * @param penaltyValue  the penalty value
     * @return  the penalty value as a {@link java.lang.String}
     */
    protected static String valueOf(int penaltyValue) {
        String result = (penaltyValue < 0) ? "-" : "";
        int tmpValue = Math.abs(penaltyValue);
        result += (tmpValue == KnuthElement.INFINITE)
                ? "INFINITE"
                : String.valueOf(tmpValue);
        return result;
    }

    
{@inheritDoc} 
/** {@inheritDoc} */
    public boolean isPenalty() {
        return true;
    }

    
Returns:the penalty value of this penalty.
/**
     * @return the penalty value of this penalty.
     */
    public int getPenalty() {
        return penalty;
    }

    
Sets a new penalty value.

Params:
  • penalty – the new penalty value
/**
     * Sets a new penalty value.
     * @param penalty the new penalty value
     */
    public void setPenalty(int penalty) {
        this.penalty = penalty;
    }

    
Returns:true is this penalty is a flagged one.
/** @return true is this penalty is a flagged one. */
    public boolean isPenaltyFlagged() {
        return penaltyFlagged;
    }

    
{@inheritDoc} 
/** {@inheritDoc} */
    public boolean isForcedBreak() {
        return penalty == -KnuthElement.INFINITE;
    }

    
Returns:the break class of this penalty (EN_AUTO, EN_COLUMN, EN_PAGE, EN_EVEN_PAGE,
EN_ODD_PAGE)
/**
     * @return the break class of this penalty (EN_AUTO, EN_COLUMN, EN_PAGE, EN_EVEN_PAGE,
     * EN_ODD_PAGE)
     */
    public int getBreakClass() {
        return breakClass;
    }

    
{@inheritDoc} 
/** {@inheritDoc} */
    public String toString() {
        StringBuffer buffer = new StringBuffer(64);
        if (isAuxiliary()) {
            buffer.append("aux. ");
        }
        buffer.append("penalty");
        buffer.append(" p=");
        buffer.append(valueOf(this.penalty));
        if (this.penaltyFlagged) {
            buffer.append(" [flagged]");
        }
        buffer.append(" w=");
        buffer.append(getWidth());
        if (isForcedBreak()) {
            buffer.append(" (forced break, ")
                    .append(getBreakClassName(this.breakClass))
                    .append(")");
        } else if (this.penalty >= 0 && this.breakClass != -1) {
            //penalty corresponding to a keep constraint
            buffer.append(" (keep constraint, ")
                    .append(getBreakClassName(this.breakClass))
                    .append(")");
        }
        return buffer.toString();
    }
}