ByteSizeCellRenderer.java

/*
 ** 2012 June 7
 **
 ** The author disclaims copyright to this source code.  In place of
 ** a legal notice, here is a blessing:
 **    May you do good and not evil.
 **    May you find forgiveness for yourself and forgive others.
 **    May you share freely, never taking more than you give.
 */
package info.ata4.util.gui.components;

import java.awt.Component;
import javax.swing.JLabel;
import javax.swing.JTable;
import javax.swing.table.DefaultTableCellRenderer;

/**
 *
 * @author Nico Bergemann <barracuda415 at yahoo.de>
 */
public class ByteSizeCellRenderer extends DefaultTableCellRenderer {
    
    private boolean si;
    
    public ByteSizeCellRenderer(boolean si) {
        this.si = si;
    }

    @Override
    public Component getTableCellRendererComponent(JTable table, Object value, boolean isSelected, boolean hasFocus, int row, int column) {
        if (value instanceof Long) {
            value = humanReadableByteCount((Long) value);
        } else if (value instanceof Integer) {
            value = humanReadableByteCount((Integer) value);
        }
        
        JLabel c = (JLabel) super.getTableCellRendererComponent(table, value, isSelected, hasFocus, row, column);
        c.setHorizontalAlignment(javax.swing.SwingConstants.RIGHT);
        return c;
    }
    
    private String humanReadableByteCount(long bytes) {
        int unit = si ? 1000 : 1024;
        if (bytes < unit) {
            return bytes + " B";
        }
        int exp = (int) (Math.log(bytes) / Math.log(unit));
        String pre = (si ? "kMGTPE" : "KMGTPE").charAt(exp-1) + (si ? "" : "i");
        return String.format("%.1f %sB", bytes / Math.pow(unit, exp), pre);
    }
}