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- /*
- * $Id: FlowLayoutManager.java,v 1.21 2003/03/07 07:58:51 jeremias Exp $
- * ============================================================================
- * The Apache Software License, Version 1.1
- * ============================================================================
- *
- * Copyright (C) 1999-2003 The Apache Software Foundation. All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without modifica-
- * tion, are permitted provided that the following conditions are met:
- *
- * 1. Redistributions of source code must retain the above copyright notice,
- * this list of conditions and the following disclaimer.
- *
- * 2. Redistributions in binary form must reproduce the above copyright notice,
- * this list of conditions and the following disclaimer in the documentation
- * and/or other materials provided with the distribution.
- *
- * 3. The end-user documentation included with the redistribution, if any, must
- * include the following acknowledgment: "This product includes software
- * developed by the Apache Software Foundation (http://www.apache.org/)."
- * Alternately, this acknowledgment may appear in the software itself, if
- * and wherever such third-party acknowledgments normally appear.
- *
- * 4. The names "FOP" and "Apache Software Foundation" must not be used to
- * endorse or promote products derived from this software without prior
- * written permission. For written permission, please contact
- * apache@apache.org.
- *
- * 5. Products derived from this software may not be called "Apache", nor may
- * "Apache" appear in their name, without prior written permission of the
- * Apache Software Foundation.
- *
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED WARRANTIES,
- * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
- * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
- * APACHE SOFTWARE FOUNDATION OR ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
- * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLU-
- * DING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
- * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
- * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- * ============================================================================
- *
- * This software consists of voluntary contributions made by many individuals
- * on behalf of the Apache Software Foundation and was originally created by
- * James Tauber <jtauber@jtauber.com>. For more information on the Apache
- * Software Foundation, please see <http://www.apache.org/>.
- */
- package org.apache.fop.layoutmgr;
-
- import org.apache.fop.fo.flow.Marker;
- import org.apache.fop.area.Area;
- import org.apache.fop.area.BlockParent;
-
- import java.util.ArrayList;
- import java.util.List;
- import org.apache.fop.traits.MinOptMax;
-
- /**
- * LayoutManager for an fo:flow object.
- * Its parent LM is the PageLayoutManager.
- * This LM is responsible for getting columns of the appropriate size
- * and filling them with block-level areas generated by its children.
- */
- public class FlowLayoutManager extends BlockStackingLayoutManager {
-
- /** List of break possibilities */
- protected List blockBreaks = new ArrayList();
-
- /** Array of areas currently being filled stored by area class */
- private BlockParent[] currentAreas = new BlockParent[Area.CLASS_MAX];
-
- private int iStartPos = 0;
-
- /**
- * This is the top level layout manager.
- * It is created by the PageSequence FO.
- */
- public FlowLayoutManager() {
- }
-
- /**
- * @see org.apache.fop.layoutmgr.LayoutProcessor#getNextBreakPoss(LayoutContext)
- */
- public BreakPoss getNextBreakPoss(LayoutContext context) {
-
- // currently active LM
- LayoutProcessor curLM;
- MinOptMax stackSize = new MinOptMax();
-
- while ((curLM = getChildLM()) != null) {
- if (curLM.generatesInlineAreas()) {
- getLogger().error("inline area not allowed under flow - ignoring");
- curLM.setFinished(true);
- continue;
- }
-
- // Make break positions and return page break
- // Set up a LayoutContext
- MinOptMax bpd = context.getStackLimit();
- BreakPoss bp;
-
- LayoutContext childLC = new LayoutContext(0);
- boolean breakPage = false;
- childLC.setStackLimit(MinOptMax.subtract(bpd, stackSize));
- childLC.setRefIPD(context.getRefIPD());
-
- if (!curLM.isFinished()) {
- if ((bp = curLM.getNextBreakPoss(childLC)) != null) {
- stackSize.add(bp.getStackingSize());
- blockBreaks.add(bp);
- // set stackLimit for remaining space
- childLC.setStackLimit(MinOptMax.subtract(bpd, stackSize));
-
- if (bp.isForcedBreak() || bp.nextBreakOverflows()) {
- breakPage = true;
- }
- }
- }
-
- // check the stack bpd and if greater than available
- // height then go to the last best break and return
- // break position
- if (stackSize.opt > context.getStackLimit().opt) {
- breakPage = true;
- }
- if (breakPage) {
- return new BreakPoss(
- new LeafPosition(this, blockBreaks.size() - 1));
- }
- }
- setFinished(true);
- if (blockBreaks.size() > 0) {
- return new BreakPoss(
- new LeafPosition(this, blockBreaks.size() - 1));
- }
- return null;
- }
-
- /**
- * @see org.apache.fop.layoutmgr.LayoutProcessor#addAreas(PositionIterator, LayoutContext)
- */
- public void addAreas(PositionIterator parentIter, LayoutContext layoutContext) {
-
- LayoutProcessor childLM;
- LayoutContext lc = new LayoutContext(0);
- while (parentIter.hasNext()) {
- LeafPosition lfp = (LeafPosition) parentIter.next();
- // Add the block areas to Area
- PositionIterator breakPosIter =
- new BreakPossPosIter(blockBreaks, iStartPos,
- lfp.getLeafPos() + 1);
- iStartPos = lfp.getLeafPos() + 1;
- while ((childLM = breakPosIter.getNextChildLM()) != null) {
- childLM.addAreas(breakPosIter, lc);
- }
- }
-
- flush();
- }
-
- /**
- * Add child area to a the correct container, depending on its
- * area class. A Flow can fill at most one area container of any class
- * at any one time. The actual work is done by BlockStackingLM.
- * @param childArea child area to add
- */
- public void addChild(Area childArea) {
- addChildToArea(childArea,
- this.currentAreas[childArea.getAreaClass()]);
- }
-
- /**
- * @see org.apache.fop.layoutmgr.LayoutProcessor#getParentArea(Area)
- */
- public Area getParentArea(Area childArea) {
- // Get an area from the Page
- BlockParent parentArea =
- (BlockParent) parentLM.getParentArea(childArea);
- this.currentAreas[parentArea.getAreaClass()] = parentArea;
- setCurrentArea(parentArea);
- return parentArea;
- }
-
- /**
- * @see org.apache.fop.layoutmgr.LayoutProcessor#resetPosition(Position)
- */
- public void resetPosition(Position resetPos) {
- if (resetPos == null) {
- reset(null);
- }
- }
-
- /**
- * Retrieve marker is not allowed in the flow so this reports an
- * error and returns null.
- *
- * @see org.apache.fop.layoutmgr.LayoutManager
- */
- public Marker retrieveMarker(String name, int pos, int boundary) {
- // error cannot retrieve markers in flow
- getLogger().error("Cannot retrieve a marker from the flow");
- return null;
- }
- }
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