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   this work for additional information regarding copyright ownership.
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   (the "License"); you may not use this file except in compliance with
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package org.apache.poi.ss.formula.functions;

import org.apache.poi.ss.formula.TwoDEval;
import org.apache.poi.ss.formula.eval.BlankEval;
import org.apache.poi.ss.formula.eval.ErrorEval;
import org.apache.poi.ss.formula.eval.NumberEval;
import org.apache.poi.ss.formula.eval.ValueEval;
import org.apache.poi.ss.formula.functions.CountUtils.I_MatchPredicate;
import org.apache.poi.ss.formula.functions.CountUtils.I_MatchAreaPredicate;

Counts the number of cells that contain data within the list of arguments.
Excel Syntax
COUNTA(value1,value2,...)
Value1, value2, ...   are 1 to 30 arguments representing the values or ranges to be counted.
Author:
Josh Micich/**
 * Counts the number of cells that contain data within the list of arguments.
 *
 * Excel Syntax
 * COUNTA(value1,value2,...)
 * Value1, value2, ...   are 1 to 30 arguments representing the values or ranges to be counted.
 *
 * @author Josh Micich
 */
public final class Counta implements Function {
    private final I_MatchPredicate _predicate;

    public Counta(){
        _predicate = defaultPredicate;
    }

    private Counta(I_MatchPredicate criteriaPredicate){
        _predicate = criteriaPredicate;
    }

	public ValueEval evaluate(ValueEval[] args, int srcCellRow, int srcCellCol) {
		int nArgs = args.length;
		if (nArgs < 1) {
			// too few arguments
			return ErrorEval.VALUE_INVALID;
		}

		if (nArgs > 30) {
			// too many arguments
			return ErrorEval.VALUE_INVALID;
		}

		int temp = 0;

		for(int i=0; i<nArgs; i++) {
			temp += CountUtils.countArg(args[i], _predicate);

		}
		return new NumberEval(temp);
	}

	private static final I_MatchPredicate defaultPredicate = new I_MatchPredicate() {

		public boolean matches(ValueEval valueEval) {
			// Note - observed behavior of Excel:
			// Error values like #VALUE!, #REF!, #DIV/0!, #NAME? etc don't cause this COUNTA to return an error
			// in fact, they seem to get counted

			if(valueEval == BlankEval.instance) {
				return false;
			}
			// Note - everything but BlankEval counts
			return true;
		}
	};

	private static final I_MatchPredicate subtotalPredicate = new I_MatchAreaPredicate() {
        public boolean matches(ValueEval valueEval) {
            return defaultPredicate.matches(valueEval);
        }

        
don't count cells that are subtotals
/**
         * don't count cells that are subtotals
         */
        public boolean matches(TwoDEval areEval, int rowIndex, int columnIndex) {
            return !areEval.isSubTotal(rowIndex, columnIndex);
        }
    };

    private static final I_MatchPredicate subtotalVisibleOnlyPredicate = new I_MatchAreaPredicate() {
        public boolean matches(ValueEval valueEval) {
            return defaultPredicate.matches(valueEval);
        }
        
        
don't count cells in rows that are hidden or subtotal cells
/**
         * don't count cells in rows that are hidden or subtotal cells
         */
        public boolean matches(TwoDEval areEval, int rowIndex, int columnIndex) {
            return !areEval.isSubTotal(rowIndex, columnIndex) && ! areEval.isRowHidden(rowIndex);
        }
    };
    
    public static Counta subtotalInstance(boolean includeHiddenRows) {
        return new Counta(includeHiddenRows ? subtotalPredicate : subtotalVisibleOnlyPredicate);
    }

}