org.apache.fop.layoutmgr.AreaAdditionUtil Maven / Gradle / Ivy
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* 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: AreaAdditionUtil.java 1562429 2014-01-29 12:52:26Z vhennebert $ */
package org.apache.fop.layoutmgr;
import java.util.LinkedList;
import org.apache.fop.layoutmgr.SpaceResolver.SpaceHandlingBreakPosition;
/**
* Utility class which provides common code for the addAreas stage.
*/
public final class AreaAdditionUtil {
private AreaAdditionUtil() {
}
/**
* Creates the child areas for the given layout manager.
* @param parentLM the parent layout manager
* @param parentIter the position iterator
* @param layoutContext the layout context
*/
public static void addAreas(AbstractLayoutManager parentLM,
PositionIterator parentIter, LayoutContext layoutContext) {
LayoutManager childLM;
LayoutContext lc = LayoutContext.offspringOf(layoutContext);
LayoutManager firstLM = null;
LayoutManager lastLM = null;
Position firstPos = null;
Position lastPos = null;
if (parentLM != null) {
parentLM.addId();
}
// "unwrap" the NonLeafPositions stored in parentIter
// and put them in a new list;
LinkedList positionList = new LinkedList();
Position pos;
while (parentIter.hasNext()) {
pos = parentIter.next();
if (pos == null) {
continue;
}
if (pos.getIndex() >= 0) {
if (firstPos == null) {
firstPos = pos;
}
lastPos = pos;
}
if (pos instanceof NonLeafPosition) {
// pos was created by a child of this FlowLM
positionList.add(pos.getPosition());
lastLM = (pos.getPosition().getLM());
if (firstLM == null) {
firstLM = lastLM;
}
} else if (pos instanceof SpaceHandlingBreakPosition) {
positionList.add(pos);
} else {
// pos was created by this LM, so it must be ignored
}
}
if (firstPos == null) {
return; //Nothing to do, return early
//TODO This is a hack to avoid an NPE in the code block below.
//If there's no firstPos/lastPos there's currently no way to
//correctly determine first and last conditions. The Iterator
//doesn't give us that info.
}
if (parentLM != null) {
parentLM.registerMarkers(
true,
parentLM.isFirst(firstPos),
parentLM.isLast(lastPos));
}
PositionIterator childPosIter = new PositionIterator(positionList.listIterator());
while ((childLM = childPosIter.getNextChildLM()) != null) {
// TODO vh: the test above might be problematic in some cases. See comment in
// the TableCellLM.getNextKnuthElements method
// Add the block areas to Area
lc.setFlags(LayoutContext.FIRST_AREA, childLM == firstLM);
lc.setFlags(LayoutContext.LAST_AREA, childLM == lastLM);
// set the space adjustment ratio
lc.setSpaceAdjust(layoutContext.getSpaceAdjust());
// set space before for the first LM, in order to implement
// display-align = center or after
lc.setSpaceBefore((childLM == firstLM ? layoutContext.getSpaceBefore() : 0));
// set space after for each LM, in order to implement
// display-align = distribute
lc.setSpaceAfter(layoutContext.getSpaceAfter());
lc.setStackLimitBP(layoutContext.getStackLimitBP());
childLM.addAreas(childPosIter, lc);
}
if (parentLM != null) {
parentLM.registerMarkers(
false,
parentLM.isFirst(firstPos),
parentLM.isLast(lastPos));
}
}
}