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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.
- */
-
- /* $Id$ */
-
- package org.apache.fop.layoutmgr;
-
- import java.util.List;
- import java.util.Stack;
-
- import org.apache.commons.logging.Log;
- import org.apache.commons.logging.LogFactory;
-
- import org.apache.fop.datatypes.LengthBase;
- import org.apache.fop.datatypes.PercentBaseContext;
- import org.apache.fop.fo.FObj;
-
- /**
- * The base class for nearly all LayoutManagers.
- * Provides the functionality for merging the {@link LayoutManager}
- * and the {@link org.apache.fop.datatypes.PercentBaseContext} interfaces
- * into a common base class for all higher LayoutManagers.
- */
- public abstract class AbstractBaseLayoutManager
- implements LayoutManager, PercentBaseContext {
-
- /** Indicator if this LM generates reference areas. */
- protected boolean generatesReferenceArea = false;
- /** Indicator if this LM generates block areas. */
- protected boolean generatesBlockArea = false;
- /** The formatting object for this LM. */
- protected final FObj fobj;
-
- /**
- * logging instance
- */
- private static final Log LOG = LogFactory.getLog(AbstractBaseLayoutManager.class);
-
- /**
- * Abstract base layout manager.
- */
- public AbstractBaseLayoutManager() {
- fobj = null;
- }
-
- /**
- * Abstract base layout manager.
- *
- * @param fo the formatting object for this layout manager
- */
- public AbstractBaseLayoutManager(FObj fo) {
- this.fobj = fo;
- setGeneratesReferenceArea(fo.generatesReferenceAreas());
- }
-
- // --------- Property Resolution related functions --------- //
-
- /** {@inheritDoc} */
- public int getBaseLength(int lengthBase, FObj fobjx) {
- if (fobjx == this.fobj) {
- switch (lengthBase) {
- case LengthBase.CONTAINING_BLOCK_WIDTH:
- return getAncestorBlockAreaIPD();
- case LengthBase.CONTAINING_BLOCK_HEIGHT:
- return getAncestorBlockAreaBPD();
- case LengthBase.PARENT_AREA_WIDTH:
- return getParentAreaIPD();
- case LengthBase.CONTAINING_REFAREA_WIDTH:
- return getReferenceAreaIPD();
- default:
- LOG.error("Unknown base type for LengthBase:" + lengthBase);
- return 0;
- }
- } else {
- LayoutManager lm = getParent();
- while (lm != null && fobjx != lm.getFObj()) {
- lm = lm.getParent();
- }
- if (lm != null) {
- return lm.getBaseLength(lengthBase, fobjx);
- }
- }
- LOG.error("Cannot find LM to handle given FO for LengthBase. ("
- + fobjx.getContextInfo() + ")");
- return 0;
- }
-
- /**
- * Find the first ancestor area that is a block area
- * and returns its IPD.
- * @return the ipd of the ancestor block area
- */
- protected int getAncestorBlockAreaIPD() {
- LayoutManager lm = getParent();
- while (lm != null) {
- if (lm.getGeneratesBlockArea() && !lm.getGeneratesLineArea()) {
- return lm.getContentAreaIPD();
- }
- lm = lm.getParent();
- }
- LOG.error("No parent LM found");
- return 0;
- }
-
- /**
- * Find the first ancestor area that is a block area
- * and returns its BPD.
- * @return the bpd of the ancestor block area
- */
- protected int getAncestorBlockAreaBPD() {
- LayoutManager lm = getParent();
- while (lm != null) {
- if (lm.getGeneratesBlockArea() && !lm.getGeneratesLineArea()) {
- return lm.getContentAreaBPD();
- }
- lm = lm.getParent();
- }
- LOG.error("No parent LM found");
- return 0;
- }
-
- /**
- * Find the parent area and returns its IPD.
- * @return the ipd of the parent area
- */
- protected int getParentAreaIPD() {
- LayoutManager lm = getParent();
- if (lm != null) {
- return lm.getContentAreaIPD();
- }
- LOG.error("No parent LM found");
- return 0;
- }
-
- /**
- * Find the parent area and returns its BPD.
- * @return the bpd of the parent area
- */
- protected int getParentAreaBPD() {
- LayoutManager lm = getParent();
- if (lm != null) {
- return lm.getContentAreaBPD();
- }
- LOG.error("No parent LM found");
- return 0;
- }
-
- /**
- * Find the first ancestor area that is a reference area
- * and returns its IPD.
- * @return the ipd of the ancestor reference area
- */
- public int getReferenceAreaIPD() {
- LayoutManager lm = getParent();
- while (lm != null) {
- if (lm.getGeneratesReferenceArea()) {
- return lm.getContentAreaIPD();
- }
- lm = lm.getParent();
- }
- LOG.error("No parent LM found");
- return 0;
- }
-
- /**
- * Find the first ancestor area that is a reference area
- * and returns its BPD.
- * @return the bpd of the ancestor reference area
- */
- protected int getReferenceAreaBPD() {
- LayoutManager lm = getParent();
- while (lm != null) {
- if (lm.getGeneratesReferenceArea()) {
- return lm.getContentAreaBPD();
- }
- lm = lm.getParent();
- }
- LOG.error("No parent LM found");
- return 0;
- }
-
- /**
- * {@inheritDoc}
- * <i>NOTE: Should be overridden by subclasses.
- * Default implementation throws an <code>UnsupportedOperationException</code>.</i>
- */
- public int getContentAreaIPD() {
- throw new UnsupportedOperationException(
- "getContentAreaIPD() called when it should have been overridden");
- }
-
- /**
- * {@inheritDoc}
- * <i>NOTE: Should be overridden by subclasses.
- * Default implementation throws an <code>UnsupportedOperationException</code>.</i>
- */
- public int getContentAreaBPD() {
- throw new UnsupportedOperationException(
- "getContentAreaBPD() called when it should have been overridden");
- }
-
- /** {@inheritDoc} */
- public boolean getGeneratesReferenceArea() {
- return generatesReferenceArea;
- }
-
- /**
- * Lets implementing LM set the flag indicating if they
- * generate reference areas.
- * @param generatesReferenceArea if true the areas generates by this LM are
- * reference areas.
- */
- protected void setGeneratesReferenceArea(boolean generatesReferenceArea) {
- this.generatesReferenceArea = generatesReferenceArea;
- }
-
- /** {@inheritDoc} */
- public boolean getGeneratesBlockArea() {
- return generatesBlockArea;
- }
-
- /**
- * Lets implementing LM set the flag indicating if they
- * generate block areas.
- * @param generatesBlockArea if true the areas generates by this LM are block areas.
- */
- protected void setGeneratesBlockArea(boolean generatesBlockArea) {
- this.generatesBlockArea = generatesBlockArea;
- }
-
- /** {@inheritDoc} */
- public boolean getGeneratesLineArea() {
- return false;
- }
-
- /**
- * {@inheritDoc}
- */
- public FObj getFObj() {
- return fobj;
- }
-
- /** {@inheritDoc} */
- public void reset() {
- throw new UnsupportedOperationException("Not implemented");
- }
-
- /** {@inheritDoc} */
- public boolean isRestartable() {
- return false;
- }
-
- /** {@inheritDoc} */
- public List getNextKnuthElements(LayoutContext context, int alignment, Stack lmStack,
- Position positionAtIPDChange, LayoutManager restartAtLM) {
- throw new UnsupportedOperationException("Not implemented");
- }
-
- public void preserveChildrenAtEndOfLayout() {
-
- }
-
- public void recreateChildrenLMs() {
-
- }
- }
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