/*
* $Id: Flow.java,v 1.24 2001/10/14 20:39:54 klease Exp $
* Copyright (C) 2001 The Apache Software Foundation. All rights reserved.
* For details on use and redistribution please refer to the
* LICENSE file included with these sources.
*/
package org.apache.fop.fo.flow;
// FOP
import org.apache.fop.fo.*;
import org.apache.fop.fo.properties.*;
import org.apache.fop.fo.pagination.*;
import org.apache.fop.layout.Area;
import org.apache.fop.layout.BodyAreaContainer;
import org.apache.fop.apps.FOPException;
// Java
import java.util.Hashtable;
import java.util.Enumeration;
import java.util.Vector;
public class Flow extends FObj {
public static class Maker extends FObj.Maker {
public FObj make(FObj parent,
PropertyList propertyList) throws FOPException {
return new Flow(parent, propertyList);
}
}
public static FObj.Maker maker() {
return new Flow.Maker();
}
/**
* PageSequence container
*/
private PageSequence pageSequence;
/**
* Area in which we lay out our kids
*/
private Area area;
/**
* Vector to store snapshot
*/
private Vector markerSnapshot;
/**
* flow-name attribute
*/
private String _flowName;
/**
* Content-width of current column area during layout
*/
private int contentWidth;
private Status _status = new Status(Status.AREA_FULL_NONE);
protected Flow(FObj parent,
PropertyList propertyList) throws FOPException {
super(parent, propertyList);
this.name = getElementName();
if (parent.getName().equals("fo:page-sequence")) {
this.pageSequence = (PageSequence)parent;
} else {
throw new FOPException("flow must be child of "
+ "page-sequence, not "
+ parent.getName());
}
setFlowName(getProperty("flow-name").getString());
// according to communication from Paul Grosso (XSL-List,
// 001228, Number 406), confusion in spec section 6.4.5 about
// multiplicity of fo:flow in XSL 1.0 is cleared up - one (1)
// fo:flow per fo:page-sequence only.
if (pageSequence.isFlowSet()) {
if (this.name.equals("fo:flow")) {
throw new FOPException("Only a single fo:flow permitted"
+ " per fo:page-sequence");
} else {
throw new FOPException(this.name
+ " not allowed after fo:flow");
}
}
pageSequence.addFlow(this);
}
protected void setFlowName(String name) throws FOPException {
if (name == null || name.equals("")) {
log.warn("A 'flow-name' is required for "
+ getElementName()
+ ". This constraint will be enforced in future versions of FOP");
_flowName = "xsl-region-body";
} else {
_flowName = name;
}
}
public String getFlowName() {
return _flowName;
}
public Status layout(Area area) throws FOPException {
return layout(area, null);
}
public Status layout(Area area, Region region) throws FOPException {
if (this.marker == START) {
this.marker = 0;
}
// flow is *always* laid out into a BodyAreaContainer
BodyAreaContainer bac = (BodyAreaContainer)area;
boolean prevChildMustKeepWithNext = false;
Vector pageMarker = this.getMarkerSnapshot(new Vector());
int numChildren = this.children.size();
if (numChildren == 0) {
throw new FOPException("fo:flow must contain block-level children");
}
for (int i = this.marker; i < numChildren; i++) {
FObj fo = (FObj)children.elementAt(i);
if (bac.isBalancingRequired(fo)) {
// reset the the just-done span area in preparation
// for a backtrack for balancing
bac.resetSpanArea();
this.rollback(markerSnapshot);
// one less because of the "continue"
i = this.marker - 1;
continue;
}
// current column area
Area currentArea = bac.getNextArea(fo);
// temporary hack for IDReferences
currentArea.setIDReferences(bac.getIDReferences());
if (bac.isNewSpanArea()) {
this.marker = i;
markerSnapshot = this.getMarkerSnapshot(new Vector());
}
// Set current content width for percent-based lengths in children
setContentWidth(currentArea.getContentWidth());
_status = fo.layout(currentArea);
/*
* if((_status.isPageBreak() || i == numChildren - 1) && bac.needsFootnoteAdjusting()) {
* bac.adjustFootnoteArea();
* this.rollback(pageMarker);
* i = this.marker - 1;
* Area mainReferenceArea = bac.getMainReferenceArea();
* // remove areas
* continue;
* }
*/
if (_status.isIncomplete()) {
if ((prevChildMustKeepWithNext) && (_status.laidOutNone())) {
this.marker = i - 1;
FObj prevChild = (FObj)children.elementAt(this.marker);
prevChild.removeAreas();
prevChild.resetMarker();
prevChild.removeID(area.getIDReferences());
_status = new Status(Status.AREA_FULL_SOME);
return _status;
// should probably return AREA_FULL_NONE if first
// or perhaps an entirely new status code
}
if (bac.isLastColumn())
if (_status.getCode() == Status.FORCE_COLUMN_BREAK) {
this.marker = i;
_status =
new Status(Status.FORCE_PAGE_BREAK); // same thing
return _status;
} else {
this.marker = i;
return _status;
}
else {
// not the last column, but could be page breaks
if (_status.isPageBreak()) {
this.marker = i;
return _status;
}
// I don't much like exposing this. (AHS 001217)
((org.apache.fop.layout.ColumnArea)currentArea).incrementSpanIndex();
i--;
}
}
if (_status.getCode() == Status.KEEP_WITH_NEXT) {
prevChildMustKeepWithNext = true;
} else {
prevChildMustKeepWithNext = false;
}
}
return _status;
}
protected void setContentWidth(int contentWidth) {
this.contentWidth = contentWidth;
}
/**
* Return the content width of this flow (really of the region
* in which it is flowing).
*/
public int getContentWidth() {
return this.contentWidth;
}
protected String getElementName() {
return "fo:flow";
}
public Status getStatus() {
return _status;
}
public boolean generatesReferenceAreas() {
return true;
}
}