apache-poi/src/java/org/apache/poi/hssf/model/LinkTable.java

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   The ASF licenses this file to You under the Apache License, Version 2.0
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package org.apache.poi.hssf.model;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.apache.poi.hssf.record.CRNCountRecord;
import org.apache.poi.hssf.record.CRNRecord;
import org.apache.poi.hssf.record.CountryRecord;
import org.apache.poi.hssf.record.ExternSheetRecord;
import org.apache.poi.hssf.record.ExternSheetSubRecord;
import org.apache.poi.hssf.record.ExternalNameRecord;
import org.apache.poi.hssf.record.NameRecord;
import org.apache.poi.hssf.record.Record;
import org.apache.poi.hssf.record.SupBookRecord;

/**
 * Link Table (OOO pdf reference: 4.10.3 ) <p/>
 *
 * The main data of all types of references is stored in the Link Table inside the Workbook Globals
 * Substream (4.2.5). The Link Table itself is optional and occurs only, if  there are any
 * references in the document.
 *  <p/>
 *
 *  In BIFF8 the Link Table consists of
 *  <ul>
 *  <li>zero or more EXTERNALBOOK Blocks<p/>
 *  	each consisting of
 *  	<ul>
 *  	<li>exactly one EXTERNALBOOK (0x01AE) record</li>
 *  	<li>zero or more EXTERNALNAME (0x0023) records</li>
 *  	<li>zero or more CRN Blocks<p/>
 *			each consisting of
 *  		<ul>
 *  		<li>exactly one XCT (0x0059)record</li>
 *  		<li>zero or more CRN (0x005A) records (documentation says one or more)</li>
 *  		</ul>
 *  	</li>
 *  	</ul>
 *  </li>
 *  <li>zero or one EXTERNSHEET (0x0017) record</li>
 *  <li>zero or more DEFINEDNAME (0x0018) records</li>
 *  </ul>
 *
 *
 * @author Josh Micich
 */
final class LinkTable {
	// TODO make this class into a record aggregate

	private static final class CRNBlock {

		private final CRNCountRecord _countRecord;
		private final CRNRecord[] _crns;

		public CRNBlock(RecordStream rs) {
			_countRecord = (CRNCountRecord) rs.getNext();
			int nCRNs = _countRecord.getNumberOfCRNs();
			CRNRecord[] crns = new CRNRecord[nCRNs];
			for (int i = 0; i < crns.length; i++) {
				crns[i] = (CRNRecord) rs.getNext();
			}
			_crns = crns;
		}
		public CRNRecord[] getCrns() {
			return (CRNRecord[]) _crns.clone();
		}
	}

	private static final class ExternalBookBlock {
		private final SupBookRecord _externalBookRecord;
		private final ExternalNameRecord[] _externalNameRecords;
		private final CRNBlock[] _crnBlocks;

		public ExternalBookBlock(RecordStream rs) {
			_externalBookRecord = (SupBookRecord) rs.getNext();
			List temp = new ArrayList();
			while(rs.peekNextClass() == ExternalNameRecord.class) {
			   temp.add(rs.getNext());
			}
			_externalNameRecords = new ExternalNameRecord[temp.size()];
			temp.toArray(_externalNameRecords);

			temp.clear();

			while(rs.peekNextClass() == CRNCountRecord.class) {
				temp.add(new CRNBlock(rs));
			}
			_crnBlocks = new CRNBlock[temp.size()];
			temp.toArray(_crnBlocks);
		}

		public ExternalBookBlock(short numberOfSheets) {
			_externalBookRecord = SupBookRecord.createInternalReferences(numberOfSheets);
			_externalNameRecords = new ExternalNameRecord[0];
			_crnBlocks = new CRNBlock[0];
		}

		public SupBookRecord getExternalBookRecord() {
			return _externalBookRecord;
		}

		public String getNameText(int definedNameIndex) {
			return _externalNameRecords[definedNameIndex].getText();
		}
	}

	private final ExternalBookBlock[] _externalBookBlocks;
	private final ExternSheetRecord _externSheetRecord;
	private final List _definedNames;
	private final int _recordCount;
	private final WorkbookRecordList _workbookRecordList; // TODO - would be nice to remove this

	public LinkTable(List inputList, int startIndex, WorkbookRecordList workbookRecordList) {

		_workbookRecordList = workbookRecordList;
		RecordStream rs = new RecordStream(inputList, startIndex);

		List temp = new ArrayList();
		while(rs.peekNextClass() == SupBookRecord.class) {
		   temp.add(new ExternalBookBlock(rs));
		}
		
		_externalBookBlocks = new ExternalBookBlock[temp.size()];
		temp.toArray(_externalBookBlocks);
		temp.clear();
		
		if (_externalBookBlocks.length > 0) {
			// If any ExternalBookBlock present, there is always 1 of ExternSheetRecord
			Record next = rs.getNext();
			_externSheetRecord = (ExternSheetRecord) next;
		} else {
			_externSheetRecord = null;
		}
		
		_definedNames = new ArrayList();
		// collect zero or more DEFINEDNAMEs id=0x18
		while(rs.peekNextClass() == NameRecord.class) {
			NameRecord nr = (NameRecord)rs.getNext();
			_definedNames.add(nr);
		}

		_recordCount = rs.getCountRead();
		_workbookRecordList.getRecords().addAll(inputList.subList(startIndex, startIndex + _recordCount));
	}

	public LinkTable(short numberOfSheets, WorkbookRecordList workbookRecordList) {
		_workbookRecordList = workbookRecordList;
		_definedNames = new ArrayList();
		_externalBookBlocks = new ExternalBookBlock[] {
				new ExternalBookBlock(numberOfSheets),
		};
		_externSheetRecord = new ExternSheetRecord();
		_recordCount = 2;

		// tell _workbookRecordList about the 2 new records

		SupBookRecord supbook = _externalBookBlocks[0].getExternalBookRecord();

		int idx = findFirstRecordLocBySid(CountryRecord.sid);
		if(idx < 0) {
			throw new RuntimeException("CountryRecord not found");
		}
		_workbookRecordList.add(idx+1, _externSheetRecord);
		_workbookRecordList.add(idx+1, supbook);
	}

	/**
	 * TODO - would not be required if calling code used RecordStream or similar
	 */
	public int getRecordCount() {
		return _recordCount;
	}


	public NameRecord getSpecificBuiltinRecord(byte name, int sheetIndex) {

		Iterator iterator = _definedNames.iterator();
		while (iterator.hasNext()) {
			NameRecord record = ( NameRecord ) iterator.next();

			//print areas are one based
			if (record.getBuiltInName() == name && record.getIndexToSheet() == sheetIndex) {
				return record;
			}
		}

		return null;
	}

	public void removeBuiltinRecord(byte name, int sheetIndex) {
		//the name array is smaller so searching through it should be faster than
		//using the findFirstXXXX methods
		NameRecord record = getSpecificBuiltinRecord(name, sheetIndex);
		if (record != null) {
			_definedNames.remove(record);
		}
		// TODO - do we need "Workbook.records.remove(...);" similar to that in Workbook.removeName(int namenum) {}?
	}

	public int getNumNames() {
		return _definedNames.size();
	}

	public NameRecord getNameRecord(int index) {
		return (NameRecord) _definedNames.get(index);
	}

	public void addName(NameRecord name) {
		_definedNames.add(name);

		// TODO - this is messy
		// Not the most efficient way but the other way was causing too many bugs
		int idx = findFirstRecordLocBySid(ExternSheetRecord.sid);
		if (idx == -1) idx = findFirstRecordLocBySid(SupBookRecord.sid);
		if (idx == -1) idx = findFirstRecordLocBySid(CountryRecord.sid);
		int countNames = _definedNames.size();
		_workbookRecordList.add(idx+countNames, name);

	}

	public void removeName(int namenum) {
		_definedNames.remove(namenum);
	}

	public short getIndexToSheet(short num) {
		return _externSheetRecord.getREFRecordAt(num).getIndexToFirstSupBook();
	}

	public int getSheetIndexFromExternSheetIndex(int externSheetNumber) {
		if (externSheetNumber >= _externSheetRecord.getNumOfREFStructures()) {
			return -1;
		}
		return _externSheetRecord.getREFRecordAt(externSheetNumber).getIndexToFirstSupBook();
	}

	public short addSheetIndexToExternSheet(short sheetNumber) {

		ExternSheetSubRecord record = new ExternSheetSubRecord();
		record.setIndexToFirstSupBook(sheetNumber);
		record.setIndexToLastSupBook(sheetNumber);
		_externSheetRecord.addREFRecord(record);
		_externSheetRecord.setNumOfREFStructures((short)(_externSheetRecord.getNumOfREFStructures() + 1));
		return (short)(_externSheetRecord.getNumOfREFStructures() - 1);
	}

	public short checkExternSheet(int sheetNumber) {

		//Trying to find reference to this sheet
		int nESRs = _externSheetRecord.getNumOfREFStructures();
		for(short i=0; i< nESRs; i++) {
			ExternSheetSubRecord esr = _externSheetRecord.getREFRecordAt(i);

			if (esr.getIndexToFirstSupBook() ==  sheetNumber
					&& esr.getIndexToLastSupBook() == sheetNumber){
				return i;
			}
		}

		//We Haven't found reference to this sheet
		return addSheetIndexToExternSheet((short) sheetNumber);
	}


	/**
	 * copied from Workbook
	 */
	private int findFirstRecordLocBySid(short sid) {
		int index = 0;
		for (Iterator iterator = _workbookRecordList.iterator(); iterator.hasNext(); ) {
			Record record = ( Record ) iterator.next();

			if (record.getSid() == sid) {
				return index;
			}
			index ++;
		}
		return -1;
	}

	public int getNumberOfREFStructures() {
		return _externSheetRecord.getNumOfREFStructures();
	}

	public String resolveNameXText(int refIndex, int definedNameIndex) {
		short extBookIndex = _externSheetRecord.getREFRecordAt(refIndex).getIndexToSupBook();
		return _externalBookBlocks[extBookIndex].getNameText(definedNameIndex);
	}
}