Helper.java [src/usda/weru/util/table] Revision: default  Date:
/*
 * Helper.java
 *
 * Created on June 8, 2006, 11:54 AM
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */

package usda.weru.util.table;

import java.io.File;
import java.io.IOException;
import java.io.UTFDataFormatException;
import org.jdom.Document;
import org.jdom.Element;
import org.jdom.JDOMException;
import org.jdom.input.SAXBuilder;

/**
 * A collection of static helper methods.
 * @author Joseph Levin
 */
public class Helper {
    
//    /**
//     * Converts a String to the Color it specifies.
//     * @param color The String to be decoded.
//     * @return The decoded Color.
//     */
//    public static Color parseColor(String color){        
//        if (color == null) return null;
//        try {                        
//            return Color.decode(color);            
//        }
//        catch (NumberFormatException nfe){
//            return null;
//        }        
//    }
//    
//    /**
//     * Return an array of Colors that have been decoded from the List of jdom Elements provided.
//     * @param list A List of org.jdom.Elements containing Color information.
//     * @return An array of Colors.
//     */
//    public static Color[] parseColorList(List <Element> list){
//        Color[] colors = new Color[list.size()];        
//        for (int i = 0; i < list.size(); i++){
//            colors[i] = parseColor(list.get(i).getText());
//        }
//        return colors;        
//    }
//    
    private static String[] c_trueStrings = {"1", "true", "yes", "t", "y"};
    /**
     * Test whether the supplied object is considered true.  Valid values returning true are "1", "true", "yes", "t", "y", and the number 1.
     * @param o An Object to be tested.
     * @return <b>true</b> if the object represents the value "true", <b>false</b> otherwise.
     */
    public static boolean isTrue(Object o){
        if (o == null) return false;
        if (o instanceof String){
            String string = (String) o;
            for (String test : c_trueStrings){
                if (test.equalsIgnoreCase(string)) return true;
            }
            return false;
        }
        if (o instanceof Number){
            Number number = (Number) o;
            if (number.intValue() == 1) return true;
            else return false;
        }
        return Boolean.parseBoolean(o.toString());
    }
    
    
    
    /**
     * Loads the root node from an XML file into a jdom Element.
     * @param file A File pointing to an XML document.
     * @return The root node of the XML document.
     */
    public static Element getRootNode(File file){
        //TODO: Notify of fail
        if (file == null) return null;
        try{
            if (!file.exists()) return null;
            SAXBuilder builder = new SAXBuilder();
            Document document = builder.build(file);
            Element root = document.getRootElement();
            return root;
        }
        catch (UTFDataFormatException udfe){
            //udfe.printStackTrace();
        }
        catch (JDOMException jde){
            //jde.printStackTrace();
        }
        catch (IOException ioe){
            //ioe.printStackTrace();
        }
        return null;
    }   
    
    /**
     * Test a flag in a set of flags.
     * @param flags The bitfield to be tested.
     * @param flag The flag to be tested.
     * @return <B>true</B> if the flag is set, <B>false</B> otherwise.
     */
    public static boolean bitFlag(int flags, int flag){
        return (flags & flag) == flag;
    }
}