/* ====================================================================
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   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,
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   See the License for the specific language governing permissions and
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package org.apache.poi.ss.formula;

import org.apache.poi.ss.formula.eval.ValueEval;

Tests can implement this class to track the internal working of the WorkbookEvaluator.

For POI internal testing use only
Author:
Josh Micich/**
 * Tests can implement this class to track the internal working of the {@link WorkbookEvaluator}.<br>
 *
 * For POI internal testing use only
 *
 * @author Josh Micich
 */
interface IEvaluationListener {
	
A (mostly) opaque interface to allow test clients to trace cache values Each spreadsheet cell gets one unique cache entry instance. These objects are safe to use as keys in HashMaps /**
	 * A (mostly) opaque interface to allow test clients to trace cache values
	 * Each spreadsheet cell gets one unique cache entry instance.  These objects
	 * are safe to use as keys in {@link java.util.HashMap}s
	 */
	interface ICacheEntry {
		ValueEval getValue();
	}

	void onCacheHit(int sheetIndex, int rowIndex, int columnIndex, ValueEval result);
	void onReadPlainValue(int sheetIndex, int rowIndex, int columnIndex, ICacheEntry entry);
	void onStartEvaluate(EvaluationCell cell, ICacheEntry entry);
	void onEndEvaluate(ICacheEntry entry, ValueEval result);
	void onClearWholeCache();
	void onClearCachedValue(ICacheEntry entry);
	
Internally, formula ICacheEntrys are stored in sets which may change ordering due to seemingly trivial changes. This method is provided to make the order of call-backs to onClearDependentCachedValue(ICacheEntry, int) more deterministic. /**
	 * Internally, formula {@link ICacheEntry}s are stored in sets which may change ordering due
	 * to seemingly trivial changes.  This method is provided to make the order of call-backs to
	 * {@link #onClearDependentCachedValue(ICacheEntry, int)} more deterministic.
	 */
	void sortDependentCachedValues(ICacheEntry[] formulaCells);
	void onClearDependentCachedValue(ICacheEntry formulaCell, int depth);
	void onChangeFromBlankValue(int sheetIndex, int rowIndex, int columnIndex,
			EvaluationCell cell, ICacheEntry entry);
}