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Parse PPDrawing more deterministically 

The [MS-PPT] spec is very clear about what the format of the PPDrawing record must be, and parsing deterministically makes for clearer code.

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@1887396 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Marius Volkhart 2021-03-09 20:59:24 +00:00
parent 7db6fa4ba1
commit e4f6756c93
1 changed files with 27 additions and 114 deletions
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119
src/scratchpad/src/org/apache/poi/hslf/record/PPDrawing.java
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@ -19,8 +19,8 @@ package org.apache.poi.hslf.record;
import java.io.IOException;
import java.io.OutputStream;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
@ -46,11 +46,8 @@ import org.apache.poi.ddf.EscherSpgrRecord;
import org.apache.poi.ddf.EscherTextboxRecord;
import org.apache.poi.sl.usermodel.ShapeType;
import org.apache.poi.util.GenericRecordUtil;
import org.apache.poi.util.IOUtils;
import org.apache.poi.util.LittleEndian;
import static org.apache.logging.log4j.util.Unbox.box;
/**
* These are actually wrappers onto Escher drawings. Make use of
* the DDF classes to do useful things with them.
@ -58,23 +55,22 @@ import static org.apache.logging.log4j.util.Unbox.box;
* PowerPoint (hslf) records found within the EscherTextboxRecord
* (msofbtClientTextbox) records.
* Also provides easy access to the EscherTextboxRecords, so that their
* text may be extracted and used in Sheets
* text may be extracted and used in Sheets.
* <p>
* {@code [MS-PPT] - v20210216} refers to this as a {@code DrawingContainer}.
*/
// For now, pretending to be an atom. Might not always be, but that
// would require a wrapping class
public final class PPDrawing extends RecordAtom implements Iterable<EscherRecord> {
//arbitrarily selected; may need to increase
private static final int MAX_RECORD_LENGTH = 10_485_760;
private byte[] _header;
private final byte[] _header;
private long _type;
private final List<EscherRecord> childRecords = new ArrayList<>();
private EscherTextboxWrapper[] textboxWrappers;
private final EscherContainerRecord dgContainer = new EscherContainerRecord();
//cached EscherDgRecord
private EscherDgRecord dg;
@ -82,11 +78,11 @@ public final class PPDrawing extends RecordAtom implements Iterable<EscherRecord
* Get access to the underlying Escher Records
*/
@SuppressWarnings("WeakerAccess")
public List<EscherRecord> getEscherRecords() { return childRecords; }
public List<EscherRecord> getEscherRecords() { return Collections.singletonList(dgContainer); }
@Override
public Iterator<EscherRecord> iterator() {
return childRecords.iterator();
return getEscherRecords().iterator();
}
/**
@ -121,26 +117,17 @@ public final class PPDrawing extends RecordAtom implements Iterable<EscherRecord
// Get the type
_type = LittleEndian.getUShort(_header,2);
// Get the contents for now
final byte[] contents = IOUtils.safelyClone(source, start, len, MAX_RECORD_LENGTH);
// Build up a tree of Escher records contained within
final DefaultEscherRecordFactory erf = new HSLFEscherRecordFactory();
findEscherChildren(erf, contents, 8, len-8, childRecords);
EscherContainerRecord dgContainer = getDgContainer();
dgContainer.fillFields(source, start + 8, erf);
assert dgContainer.getRecordId() == EscherRecordTypes.DG_CONTAINER.typeID;
dg = dgContainer.getChildById(EscherRecordTypes.DG.typeID);
if (dgContainer != null) {
textboxWrappers = Stream.of(dgContainer).
flatMap(findEscherContainer(EscherRecordTypes.SPGR_CONTAINER)).
flatMap(findEscherContainer(EscherRecordTypes.SP_CONTAINER)).
flatMap(PPDrawing::getTextboxHelper).
toArray(EscherTextboxWrapper[]::new);
} else {
// Find and EscherTextboxRecord's, and wrap them up
final List<EscherTextboxWrapper> textboxes = new ArrayList<>();
findEscherTextboxRecord(childRecords, textboxes);
this.textboxWrappers = textboxes.toArray(new EscherTextboxWrapper[0]);
}
}
private static Stream<EscherTextboxWrapper> getTextboxHelper(EscherContainerRecord spContainer) {
@ -185,66 +172,6 @@ public final class PPDrawing extends RecordAtom implements Iterable<EscherRecord
return Stream.empty();
}
/**
* Tree walking way of finding Escher Child Records
*/
private void findEscherChildren(DefaultEscherRecordFactory erf, byte[] source, int startPos, int lenToGo, List<EscherRecord> found) {
int escherBytes = LittleEndian.getInt( source, startPos + 4 ) + 8;
// Find the record
EscherRecord r = erf.createRecord(source,startPos);
// Fill it in
r.fillFields( source, startPos, erf );
// Save it
found.add(r);
// Wind on
int size = r.getRecordSize();
if(size < 8) {
LOG.atWarn().log("Hit short DDF record at {} - {}", box(startPos),box(size));
}
/*
* Sanity check. Always advance the cursor by the correct value.
*
* getRecordSize() must return exactly the same number of bytes that was written in fillFields.
* Sometimes it is not so, see an example in bug #44770. Most likely reason is that one of ddf records calculates wrong size.
*/
if(size != escherBytes){
LOG.atWarn().log("Record length={} but getRecordSize() returned {}; record: {}", box(escherBytes),box(r.getRecordSize()),r.getClass());
size = escherBytes;
}
startPos += size;
lenToGo -= size;
if(lenToGo >= 8) {
findEscherChildren(erf, source, startPos, lenToGo, found);
}
}
/**
* Look for EscherTextboxRecords
*/
private void findEscherTextboxRecord(List<EscherRecord> toSearch, List<EscherTextboxWrapper> found) {
EscherSpRecord sp = null;
for (EscherRecord r : toSearch) {
if (r instanceof EscherSpRecord) {
sp = (EscherSpRecord)r;
} else if (r instanceof EscherTextboxRecord) {
EscherTextboxRecord tbr = (EscherTextboxRecord)r;
EscherTextboxWrapper w = new EscherTextboxWrapper(tbr);
if (sp != null) {
w.setShapeId(sp.getShapeId());
}
found.add(w);
} else if (r.isContainerRecord()) {
// If it has children, walk them
List<EscherRecord> children = r.getChildRecords();
findEscherTextboxRecord(children,found);
}
}
}
/**
* We are type 1036
*/
@ -268,9 +195,7 @@ public final class PPDrawing extends RecordAtom implements Iterable<EscherRecord
// Find the new size of the escher children;
int newSize = 0;
for(EscherRecord er : childRecords) {
newSize += er.getRecordSize();
}
newSize += dgContainer.getRecordSize();
// Update the size (header bytes 5-8)
LittleEndian.putInt(_header,4,newSize);
@ -281,9 +206,7 @@ public final class PPDrawing extends RecordAtom implements Iterable<EscherRecord
// Now grab the children's data
byte[] b = new byte[newSize];
int done = 0;
for(EscherRecord r : childRecords) {
done += r.serialize( done, b );
}
dgContainer.serialize(done, b);
// Finally, write out the children
out.write(b);
@ -293,7 +216,6 @@ public final class PPDrawing extends RecordAtom implements Iterable<EscherRecord
* Create the Escher records associated with a new PPDrawing
*/
private void create(){
EscherContainerRecord dgContainer = new EscherContainerRecord();
dgContainer.setRecordId( EscherContainerRecord.DG_CONTAINER );
dgContainer.setOptions((short)15);
@ -342,8 +264,6 @@ public final class PPDrawing extends RecordAtom implements Iterable<EscherRecord
spContainer.addChildRecord(opt);
dgContainer.addChildRecord(spContainer);
childRecords.add(dgContainer);
}
/**
@ -362,7 +282,7 @@ public final class PPDrawing extends RecordAtom implements Iterable<EscherRecord
* @since POI 3.14-Beta2
*/
public EscherContainerRecord getDgContainer() {
return (EscherContainerRecord)firstEscherRecord(this, EscherRecordTypes.DG_CONTAINER).orElse(null);
return dgContainer;
}
/**
@ -371,18 +291,11 @@ public final class PPDrawing extends RecordAtom implements Iterable<EscherRecord
* @return EscherDgRecord
*/
public EscherDgRecord getEscherDgRecord(){
if (dg == null) {
firstEscherRecord(this, EscherRecordTypes.DG_CONTAINER).
flatMap(c -> firstEscherRecord((EscherContainerRecord)c, EscherRecordTypes.DG)).
ifPresent(c -> dg = (EscherDgRecord)c);
}
return dg;
}
public StyleTextProp9Atom[] getNumberedListInfo() {
EscherContainerRecord dgContainer = getDgContainer();
return (dgContainer == null) ? new StyleTextProp9Atom[0] : Stream.of(dgContainer).
return Stream.of(dgContainer).
flatMap(findEscherContainer(EscherRecordTypes.SPGR_CONTAINER)).
flatMap(findEscherContainer(EscherRecordTypes.SP_CONTAINER)).
map(PPDrawing::findInSpContainer).