trunk/core/src/main/java/org/apache/struts2/components/table/renderer/NumericCellRenderer.java

/*
 * $Id$
 *
 * Copyright 2006 The Apache Software Foundation.
 *
 * Licensed 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,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.struts2.components.table.renderer;

import java.text.DecimalFormat;

import org.apache.struts2.components.table.WebTable;


/**
 */
public class NumericCellRenderer extends AbstractCellRenderer {

    DecimalFormat _formater = new DecimalFormat();

    /**
     * this is the format string that DecimalFormat would use.
     *
     * @see DecimalFormat
     */
    String _formatString = null;

    /**
     * if set the is the color to use if Number is negative.
     */
    String _negativeColor = null;

    /**
     * if set this is the color to render if number is positive
     */
    String _positiveColor = null;


    public NumericCellRenderer() {
        super();
    }


    public String getCellValue(WebTable table, Object data, int row, int col) {
        StringBuffer retVal = new StringBuffer(128);

        if (data == null) {
            return "";
        }

        if (data instanceof Number) {
            double cellValue = ((Number) data).doubleValue();

            if (cellValue >= 0) {
                processNumber(retVal, _positiveColor, cellValue);
            } else {
                processNumber(retVal, _negativeColor, cellValue);
            }

            return retVal.toString();
        }

        return data.toString();
    }

    public void setFormatString(String format) {
        _formatString = format;
        _formater.applyPattern(_formatString);
    }

    public void setNegativeColor(String color) {
        _negativeColor = color;
    }

    public void setPositiveColor(String color) {
        _positiveColor = color;
    }

    protected void processNumber(StringBuffer buf, String color, double cellValue) {
        if (color != null) {
            buf.append(" <font color='").append(color).append("'>");
        }

        buf.append(_formater.format(cellValue));

        if (color != null) {
            buf.append("</font>");
        }
    }
}