apache-poi/src/java/org/apache/poi/hssf/util/CellReference.java

/* ====================================================================
 * The Apache Software License, Version 1.1
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 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
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 *
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 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */

package org.apache.poi.hssf.util;

/**
 *
 * @author  Avik Sengupta
 * @author  Dennis Doubleday (patch to seperateRowColumns())
 */
public class CellReference {

    /** Creates new CellReference */
    private int row;
    private int col;
    private String sheetName;
    private boolean rowAbs;
    private boolean colAbs;

    public CellReference(String cellRef) {
        String[] parts = separateRefParts(cellRef);
        sheetName = parts[0];
        String ref = parts[1];
        if (ref.charAt(0) == '$') {
            colAbs=true;
            ref=ref.substring(1);
        }
        col = convertColStringToNum(ref);
        ref=parts[2];
        if (ref.charAt(0) == '$') {
            rowAbs=true;
            ref=ref.substring(1);
        }
        row = Integer.parseInt(ref)-1;
    }

    public CellReference(int pRow, int pCol) {
        this(pRow,pCol,false,false);
    }

    public CellReference(int pRow, int pCol, boolean pAbsRow, boolean pAbsCol) {
        row=pRow;col=pCol;
        rowAbs = pAbsRow;
        colAbs=pAbsCol;

    }

    public int getRow(){return row;}
    public short getCol(){return (short) col;}
    public boolean isRowAbsolute(){return rowAbs;}
    public boolean isColAbsolute(){return colAbs;}
    public String getSheetName(){return sheetName;}

    /**
     * takes in a column reference portion of a CellRef and converts it from
     * ALPHA-26 number format to 0-based base 10.
     */
    private int convertColStringToNum(String ref) {
        int len = ref.length();
        int retval=0;
        int pos = 0;

        for (int k = ref.length()-1; k > -1; k--) {
            char thechar = ref.charAt(k);
            if ( pos == 0) {
                retval += (Character.getNumericValue(thechar)-9);
            } else {
                retval += (Character.getNumericValue(thechar)-9) * (pos * 26);
            }
            pos++;
        }
        return retval-1;
    }


    /**
     * Seperates the row from the columns and returns an array.  Element in
     * position one is the substring containing the columns still in ALPHA-26
     * number format.
     */
    private String[] separateRefParts(String reference) {

        // Look for end of sheet name. This will either set
        // start to 0 (if no sheet name present) or the
        // index after the sheet reference ends.
        String retval[] = new String[3];

        int start = reference.indexOf("!");
        if (start != -1) retval[0] = reference.substring(0, start);
        start += 1;

        int length = reference.length();


        char[] chars = reference.toCharArray();
        int loc = start;
        if (chars[loc]=='$') loc++;
        for (; loc < chars.length; loc++) {
            if (Character.isDigit(chars[loc]) || chars[loc] == '$') {
                break;
            }
        }

        retval[1] = reference.substring(start,loc);
        retval[2] = reference.substring(loc);
        return retval;
    }

    /**
     * takes in a 0-based base-10 column and returns a ALPHA-26 representation
     */
    private static String convertNumToColString(int col) {
        String retval = null;
        int mod = col % 26;
        int div = col / 26;
        char small=(char)(mod + 65);
        char big = (char)(div + 64);

        if (div == 0) {
            retval = ""+small;
        } else {
            retval = ""+big+""+small;
        }

        return retval;
    }


    public String toString() {
        StringBuffer retval = new StringBuffer();
        retval.append( (colAbs)?"$":"");
        retval.append( convertNumToColString(col));
        retval.append((rowAbs)?"$":"");
        retval.append(row+1);

    return retval.toString();
    }
}