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(the "License"); you may not use this file except in compliance with
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package org.apache.poi.ddf;
import org.apache.poi.util.LittleEndian;
import org.apache.poi.util.HexDump;
/**
* Escher array properties are the most wierd construction ever invented
* with all sorts of special cases. I'm hopeful I've got them all.
*
* @author Glen Stampoultzis (glens at superlinksoftware.com)
*/
public final class EscherArrayProperty extends EscherComplexProperty {
/**
* The size of the header that goes at the
* start of the array, before the data
*/
private static final int FIXED_SIZE = 3 * 2;
/**
* Normally, the size recorded in the simple data (for the complex
* data) includes the size of the header.
* There are a few cases when it doesn't though...
*/
private boolean sizeIncludesHeaderSize = true;
/**
* When reading a property from data stream remeber if the complex part is empty and set this flag.
*/
private boolean emptyComplexPart = false;
public EscherArrayProperty(short id, byte[] complexData) {
super(id, checkComplexData(complexData));
emptyComplexPart = complexData.length == 0;
}
public EscherArrayProperty(short propertyNumber, boolean isBlipId, byte[] complexData) {
super(propertyNumber, isBlipId, checkComplexData(complexData));
}
private static byte[] checkComplexData(byte[] complexData) {
if (complexData == null || complexData.length == 0) {
return new byte[6];
}
return complexData;
}
public int getNumberOfElementsInArray() {
return LittleEndian.getUShort(_complexData, 0);
}
public void setNumberOfElementsInArray(int numberOfElements) {
int expectedArraySize = numberOfElements * getActualSizeOfElements(getSizeOfElements()) + FIXED_SIZE;
if (expectedArraySize != _complexData.length) {
byte[] newArray = new byte[expectedArraySize];
System.arraycopy(_complexData, 0, newArray, 0, _complexData.length);
_complexData = newArray;
}
LittleEndian.putShort(_complexData, 0, (short) numberOfElements);
}
public int getNumberOfElementsInMemory() {
return LittleEndian.getUShort(_complexData, 2);
}
public void setNumberOfElementsInMemory(int numberOfElements) {
int expectedArraySize = numberOfElements * getActualSizeOfElements(getSizeOfElements()) + FIXED_SIZE;
if (expectedArraySize != _complexData.length) {
byte[] newArray = new byte[expectedArraySize];
System.arraycopy(_complexData, 0, newArray, 0, expectedArraySize);
_complexData = newArray;
}
LittleEndian.putShort(_complexData, 2, (short) numberOfElements);
}
public short getSizeOfElements() {
return LittleEndian.getShort( _complexData, 4 );
}
public void setSizeOfElements(int sizeOfElements) {
LittleEndian.putShort( _complexData, 4, (short) sizeOfElements );
int expectedArraySize = getNumberOfElementsInArray() * getActualSizeOfElements(getSizeOfElements()) + FIXED_SIZE;
if (expectedArraySize != _complexData.length) {
// Keep just the first 6 bytes. The rest is no good to us anyway.
byte[] newArray = new byte[expectedArraySize];
System.arraycopy( _complexData, 0, newArray, 0, 6 );
_complexData = newArray;
}
}
public byte[] getElement(int index) {
int actualSize = getActualSizeOfElements(getSizeOfElements());
byte[] result = new byte[actualSize];
System.arraycopy(_complexData, FIXED_SIZE + index * actualSize, result, 0, result.length );
return result;
}
public void setElement(int index, byte[] element) {
int actualSize = getActualSizeOfElements(getSizeOfElements());
System.arraycopy( element, 0, _complexData, FIXED_SIZE + index * actualSize, actualSize);
}
public String toString() {
StringBuffer results = new StringBuffer();
results.append(" {EscherArrayProperty:" + '\n');
results.append(" Num Elements: " + getNumberOfElementsInArray() + '\n');
results.append(" Num Elements In Memory: " + getNumberOfElementsInMemory() + '\n');
results.append(" Size of elements: " + getSizeOfElements() + '\n');
for (int i = 0; i < getNumberOfElementsInArray(); i++) {
results.append(" Element " + i + ": " + HexDump.toHex(getElement(i)) + '\n');
}
results.append("}" + '\n');
return "propNum: " + getPropertyNumber()
+ ", propName: " + EscherProperties.getPropertyName( getPropertyNumber() )
+ ", complex: " + isComplex()
+ ", blipId: " + isBlipId()
+ ", data: " + '\n' + results.toString();
}
/**
* We have this method because the way in which arrays in escher works
* is screwed for seemly arbitary reasons. While most properties are
* fairly consistent and have a predictable array size, escher arrays
* have special cases.
*
* @param data The data array containing the escher array information
* @param offset The offset into the array to start reading from.
* @return the number of bytes used by this complex property.
*/
public int setArrayData(byte[] data, int offset) {
if (emptyComplexPart){
_complexData = new byte[0];
} else {
short numElements = LittleEndian.getShort(data, offset);
LittleEndian.getShort(data, offset + 2); // numReserved
short sizeOfElements = LittleEndian.getShort(data, offset + 4);
int arraySize = getActualSizeOfElements(sizeOfElements) * numElements;
if (arraySize == _complexData.length) {
// The stored data size in the simple block excludes the header size
_complexData = new byte[arraySize + 6];
sizeIncludesHeaderSize = false;
}
System.arraycopy(data, offset, _complexData, 0, _complexData.length );
}
return _complexData.length;
}
/**
* Serializes the simple part of this property. ie the first 6 bytes.
*
* Needs special code to handle the case when the size doesn't
* include the size of the header block
*/
public int serializeSimplePart(byte[] data, int pos) {
LittleEndian.putShort(data, pos, getId());
int recordSize = _complexData.length;
if(!sizeIncludesHeaderSize) {
recordSize -= 6;
}
LittleEndian.putInt(data, pos + 2, recordSize);
return 6;
}
/**
* Sometimes the element size is stored as a negative number. We
* negate it and shift it to get the real value.
*/
public static int getActualSizeOfElements(short sizeOfElements) {
if (sizeOfElements < 0) {
return (short) ( ( -sizeOfElements ) >> 2 );
}
return sizeOfElements;
}
}