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: BreakElement.java 1380923 2012-09-04 22:25:49Z vhennebert $ */

package org.apache.fop.layoutmgr;

import java.util.List;

import org.apache.fop.fo.Constants;


This class represents an unresolved break possibility.

/**
 * This class represents an unresolved break possibility.
 */
public class BreakElement extends UnresolvedListElement {

    private int penaltyWidth;
    private int penaltyValue;
    private int breakClass;
    private List pendingBeforeMarks;
    private List pendingAfterMarks;

    
Main constructor

Params:
  • position – the Position instance needed by the addAreas stage of the LMs.
  • penaltyValue – the penalty value for the penalty element to be constructed
  • context – the layout context which contains the pending conditional elements
/**
     * Main constructor
     * @param position the Position instance needed by the addAreas stage of the LMs.
     * @param penaltyValue the penalty value for the penalty element to be constructed
     * @param context the layout context which contains the pending conditional elements
     */
    public BreakElement(Position position, int penaltyValue, LayoutContext context) {
        this(position, penaltyValue, Constants.EN_AUTO, context);
    }

    
Create a new BreakElement for the given position, penaltyValue and breakClass. (Used principally to generate break-possibilities in ranges of content that must be kept together within the context corresponding to the breakClass; expected to be one of Constants.EN_AUTO, Constants.EN_LINE, Constants.EN_COLUMN or Constants.EN_PAGE) 
Params:
  • position –  the corresponding Position
  • penaltyValue –  the penalty value
  • breakClass –    the break class
  • context –  the LayoutContext
/**
     * Create a new BreakElement for the given {@code position}, {@code penaltyValue}
     * and {@code breakClass}. (Used principally to generate break-possibilities in
     * ranges of content that must be kept together within the context corresponding
     * to the {@code breakClass}; expected to be one of
     *   {@link org.apache.fop.fo.Constants#EN_AUTO},
     *   {@link org.apache.fop.fo.Constants#EN_LINE},
     *   {@link org.apache.fop.fo.Constants#EN_COLUMN} or
     *   {@link org.apache.fop.fo.Constants#EN_PAGE})
     * @param position  the corresponding {@link Position}
     * @param penaltyValue  the penalty value
     * @param breakClass    the break class
     * @param context       the {@link LayoutContext}
     */
    public BreakElement(Position position, int penaltyValue, int breakClass,
                        LayoutContext context) {
        this(position, 0, penaltyValue, breakClass, context);
    }

    
Constructor for hard breaks.

Params:
/**
     * Constructor for hard breaks.
     *
     * @param position the Position instance needed by the addAreas stage of the LMs.
     * @param penaltyWidth the penalty width
     * @param penaltyValue the penalty value for the penalty element to be constructed
     * @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 context the layout context which contains the pending conditional elements
     */
    public BreakElement(Position position, int penaltyWidth, int penaltyValue,
                int breakClass, LayoutContext context) {
        super(position);
        this.penaltyWidth = penaltyWidth;
        this.penaltyValue = penaltyValue;
        setBreakClass(breakClass);
        this.pendingBeforeMarks = context.getPendingBeforeMarks();
        this.pendingAfterMarks = context.getPendingAfterMarks();
    }

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

    
{@inheritDoc} 
/** {@inheritDoc} */
    public boolean isConditional() {
        return false; //Does not really apply here
    }

    /** {@inheritDoc} */
    /*
    public boolean isPenalty() {
        return true; //not entirely true but a BreakElement will generate a penalty later
    }*/

    
Returns:the penalty width
/** @return the penalty width */
    public int getPenaltyWidth() {
        return this.penaltyWidth;
    }

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

    
Sets the penalty value.

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

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

    
Returns the break class of this penalty.

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

    
Sets the break class.

Params:
/**
     * Sets the break class.
     *
     * @param breakClass one of
     *   {@link org.apache.fop.fo.Constants#EN_AUTO},
     *   {@link org.apache.fop.fo.Constants#EN_LINE},
     *   {@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}.
     */
    public void setBreakClass(int breakClass) {
        switch (breakClass) {
        case Constants.EN_AUTO:
        case Constants.EN_LINE:
        case Constants.EN_COLUMN:
        case Constants.EN_PAGE:
        case Constants.EN_EVEN_PAGE:
        case Constants.EN_ODD_PAGE:
            this.breakClass = breakClass;
            break;
        default: throw new IllegalArgumentException("Illegal value for break class: " + breakClass);
        }
    }

    
Returns:the pending border and padding elements at the before edge
/** @return the pending border and padding elements at the before edge */
    public List getPendingBeforeMarks() {
        return this.pendingBeforeMarks;
    }

    
Returns:the pending border and padding elements at the after edge
/** @return the pending border and padding elements at the after edge */
    public List getPendingAfterMarks() {
        return this.pendingAfterMarks;
    }

    
Clears all pending marks associated with this break element. This is used in break
cases where we only know very late if the break is actually after all the content
of an FO has been generated.

/**
     * Clears all pending marks associated with this break element. This is used in break
     * cases where we only know very late if the break is actually after all the content
     * of an FO has been generated.
     */
    public void clearPendingMarks() {
        this.pendingBeforeMarks = null;
        this.pendingAfterMarks = null;
    }

    
{@inheritDoc} 
/** {@inheritDoc} */
    public String toString() {
        StringBuffer sb = new StringBuffer(64);
        sb.append("BreakPossibility[p:");
        sb.append(KnuthPenalty.valueOf(this.penaltyValue));
        if (isForcedBreak()) {
            sb.append(" (forced break, ")
                    .append(getBreakClassName(this.breakClass))
                    .append(")");
        } else if (this.penaltyValue >= 0 && this.breakClass != -1) {
            sb.append(" (keep constraint, ")
                    .append(getBreakClassName(this.breakClass))
                    .append(")");
        }
        sb.append("; w:");
        sb.append(penaltyWidth);
        sb.append("]");
        return sb.toString();
    }

}