Java tutorial
/* * 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: FootnoteLayoutManager.java 1296526 2012-03-03 00:18:45Z gadams $ */ package org.apache.fop.layoutmgr.inline; import java.util.LinkedList; import java.util.List; import java.util.ListIterator; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.apache.fop.fo.flow.Footnote; import org.apache.fop.layoutmgr.FootnoteBodyLayoutManager; import org.apache.fop.layoutmgr.InlineKnuthSequence; import org.apache.fop.layoutmgr.KnuthElement; import org.apache.fop.layoutmgr.KnuthSequence; import org.apache.fop.layoutmgr.LayoutContext; import org.apache.fop.layoutmgr.LayoutManager; import org.apache.fop.layoutmgr.ListElement; import org.apache.fop.layoutmgr.NonLeafPosition; import org.apache.fop.layoutmgr.Position; import org.apache.fop.layoutmgr.PositionIterator; /** * Layout manager for fo:footnote. */ public class FootnoteLayoutManager extends InlineStackingLayoutManager { /** * logging instance */ private static Log log = LogFactory.getLog(FootnoteLayoutManager.class); private Footnote footnote; private InlineStackingLayoutManager citationLM; private FootnoteBodyLayoutManager bodyLM; /** Represents the footnote citation **/ private KnuthElement forcedAnchor; /** * Create a new footnote layout manager. * @param node footnote to create the layout manager for */ public FootnoteLayoutManager(Footnote node) { super(node); footnote = node; } /** {@inheritDoc} */ @Override public void initialize() { // create an InlineStackingLM handling the fo:inline child of fo:footnote citationLM = new InlineLayoutManager(footnote.getFootnoteCitation()); // create a FootnoteBodyLM handling the fo:footnote-body child of fo:footnote bodyLM = new FootnoteBodyLayoutManager(footnote.getFootnoteBody()); } /** {@inheritDoc} */ @Override public List getNextKnuthElements(LayoutContext context, int alignment) { // for the moment, this LM is set as the citationLM's parent // later on, when this LM will have nothing more to do, the citationLM's parent // will be set to the fotnoteLM's parent citationLM.setParent(this); citationLM.initialize(); bodyLM.setParent(this); bodyLM.initialize(); // get Knuth elements representing the footnote citation List returnedList = new LinkedList(); while (!citationLM.isFinished()) { List partialList = citationLM.getNextKnuthElements(context, alignment); if (partialList != null) { returnedList.addAll(partialList); } } if (returnedList.size() == 0) { //Inline part of the footnote is empty. Need to send back an auxiliary //zero-width, zero-height inline box so the footnote gets painted. KnuthSequence seq = new InlineKnuthSequence(); //Need to use an aux. box, otherwise, the line height can't be forced to zero height. forcedAnchor = new KnuthInlineBox(0, null, null, true); seq.add(forcedAnchor); returnedList.add(seq); } setFinished(true); addAnchor(returnedList); // "wrap" the Position stored in each list inside returnedList ListIterator listIterator = returnedList.listIterator(); ListIterator elementIterator = null; KnuthSequence list = null; ListElement element = null; while (listIterator.hasNext()) { list = (KnuthSequence) listIterator.next(); elementIterator = list.listIterator(); while (elementIterator.hasNext()) { element = (KnuthElement) elementIterator.next(); element.setPosition(notifyPos(new NonLeafPosition(this, element.getPosition()))); } } return returnedList; } /** {@inheritDoc} */ @Override public List getChangedKnuthElements(List oldList, int alignment, int depth) { List returnedList = super.getChangedKnuthElements(oldList, alignment, depth); addAnchor(returnedList); return returnedList; } /** {@inheritDoc} */ @Override public void addAreas(PositionIterator posIter, LayoutContext context) { // "Unwrap" the NonLeafPositions stored in posIter and put // them in a new list, that will be given to the citationLM LinkedList<Position> positionList = new LinkedList<Position>(); Position pos; while (posIter.hasNext()) { pos = posIter.next(); if (pos != null && pos.getPosition() != null) { positionList.add(pos.getPosition()); } } // FootnoteLM does not create any area, // so the citationLM child will add directly to the FootnoteLM parent area citationLM.setParent(getParent()); // make the citationLM add its areas LayoutContext childContext = new LayoutContext(context); PositionIterator childPosIter = new PositionIterator(positionList.listIterator()); LayoutManager childLM; while ((childLM = childPosIter.getNextChildLM()) != null) { childLM.addAreas(childPosIter, childContext); childContext.setLeadingSpace(childContext.getTrailingSpace()); childContext.setFlags(LayoutContext.RESOLVE_LEADING_SPACE, true); } } /** * Find the last box in the sequence, and add a reference to the FootnoteBodyLM * @param citationList the list of elements representing the footnote citation */ private void addAnchor(List citationList) { KnuthInlineBox lastBox = null; // the list of elements is searched backwards, until we find a box ListIterator citationIterator = citationList.listIterator(citationList.size()); while (citationIterator.hasPrevious() && lastBox == null) { Object obj = citationIterator.previous(); if (obj instanceof KnuthElement) { // obj is an element KnuthElement element = (KnuthElement) obj; if (element instanceof KnuthInlineBox) { lastBox = (KnuthInlineBox) element; } } else { // obj is a sequence of elements KnuthSequence seq = (KnuthSequence) obj; ListIterator nestedIterator = seq.listIterator(seq.size()); while (nestedIterator.hasPrevious() && lastBox == null) { KnuthElement element = (KnuthElement) nestedIterator.previous(); if (element instanceof KnuthInlineBox && !element.isAuxiliary() || element == forcedAnchor) { lastBox = (KnuthInlineBox) element; } } } } if (lastBox != null) { lastBox.setFootnoteBodyLM(bodyLM); } else { //throw new IllegalStateException("No anchor box was found for a footnote."); } } }