WhatRain's Java 2 Examples

Source

import  java.applet.*;
import  java.awt.*;
import  java.awt.event.*;
import javax.swing.*;
import javax.swing.event.*;
import javax.swing.border.*;
import javax.accessibility.*;

/**
 * 	
 * 	An Applet to  convert Celsius to Fahrenheit to Kelvin
 * 	Demo of JSlider class
 * 	@author	http://www.whatrain.com/
 * 	@version	beta 0.1
 * 	@author		Timothy M. Radonich
 * 	@author		WhatRain Internet Services
 *	@see		
 */


public class TemperatureSlider
       extends    Applet
       implements ChangeListener,
                  Runnable
{
  //  ===========================================
  //        APPLET METHODS
  //  ===========================================
  /*  --Initialization----------------- */
 	 public void init()
  	{

  	}
	public TemperatureSlider()
	{
	setBackground( bgColor );

		// Horizontal Slider 
	sliderPanel = new JPanel();
	sliderPanel.setBackground( bgColor );
	sliderPanel.setLayout(new BoxLayout
		(sliderPanel, BoxLayout.Y_AXIS));

	sliderPanel.setBorder(new TitledBorder(
			new EtchedBorder(), 
			"Increase Temperature  >>>",
			TitledBorder.CENTER,
			TitledBorder.ABOVE_TOP,
			boldFont));

	slider = new JSlider( 0, 1000, 10);  
	slider.getAccessibleContext().setAccessibleName
		("Temperature");
	slider.getAccessibleContext().setAccessibleDescription
		("A Temperature slider");
	slider.setBackground( bgColor );
	slider.setPaintTicks(true);
	slider.setMajorTickSpacing(100);
	slider.setMinorTickSpacing(10);
	slider.addChangeListener(this);

	sliderPanel.add(Box.createRigidArea(new Dimension(475,5)));
	sliderPanel.add(slider);	
	sliderPanel.add(Box.createRigidArea(new Dimension(475,5)));

	displayPanel = new JPanel();
	displayPanel.setBackground( bgColor );
	displayPanel.setLayout(new BoxLayout
		(displayPanel, BoxLayout.Y_AXIS));
	displayPanel.setBorder(new EtchedBorder());

	labelPanel = new JPanel();
	labelPanel.setBackground( bgColor );
	labelPanel.setLayout(new GridLayout(1,3));
 	labelPanel.add(  fahrenheitDisplay );
 	labelPanel.add(  kelvinDisplay );
 	labelPanel.add( celsiusDisplay );

	displayPanel.add(Box.createRigidArea(new Dimension(475,5)));
	displayPanel.add(labelPanel);	
	displayPanel.add(Box.createRigidArea(new Dimension(475,5)));





	setLayout( new BorderLayout());


	add("North", sliderPanel);

	
	add("South", displayPanel);
	celsiusDisplay.setFont(boldFont) ;
	fahrenheitDisplay.setFont(boldFont) ;
	kelvinDisplay.setFont(boldFont) ;

        setSize(500, 105);
        setVisible(true);

		

	}

  /*  --Starting and Stopping---------- */
  	public void start()
 	{
    		if ( theThread == null )
    		{
     		 	theThread = new Thread();
     		 	theThread.start();
    		}
  	}

  	public void stop()
  	{
    		if ( theThread != null )
    		{
      			//theThread.destroy();
      			theThread = null;
    		}
  	}

 

  //  ===========================================
  //      IMPLEMENT RUNNABLE
  //  ===========================================
  	public void run()
  	{
    		while ( true )
    		{
      			
     			 try { Thread.sleep( 1000 ); }      
      			catch ( InterruptedException e ) {}
    		}
  	}

  //  ===========================================
  //      implements ChangeListener
  //  ===========================================


	
	public void stateChanged(ChangeEvent e) 
	{
		celsiusDisplay.setText
			("Celsius: " + DoubleFormat.toString
				((slider.getValue() - 273.15), -4));

		fahrenheitDisplay.setText
			("    Fahrenheit: " + DoubleFormat.toString
				(((slider.getValue
				() - 273.15) * 1.8 + 32), -4));

		kelvinDisplay.setText
			("Kelvin: " + (slider.getValue()));
	   	

	}



  //  ===========================================
  //      CLASS ATTRIBUTES
  //  ===========================================
	Font boldFont = new Font("Hevetica", Font.BOLD, 16 ) ;

 	private Thread theThread = null;
 	private JSlider slider;
 	private JPanel sliderPanel;
 	private JPanel displayPanel;	
 	private JPanel labelPanel;	
 	private JLabel celsiusDisplay =
		 new JLabel("Celsius: -273.15",JLabel.CENTER);
 	private JLabel fahrenheitDisplay =
		 new JLabel("    Fahrenheit: -459.67",JLabel.CENTER);
 	private JLabel kelvinDisplay =
		 new JLabel("Kelvin: 0",JLabel.CENTER);

	GridBagLayout gbLayout = new GridBagLayout () ;
	GridBagConstraints gbConstraints = new GridBagConstraints();
	Color bgColor = new Color(152,215,225 ) ;//blue


}
/**
 * 
 * 
 * 
 *      copyright(c)1997 Jamsa Press
 *       
 * 
 *       
 *      
 *      @version        1
 *      @author 1001 Java Programmer's Tips
 *      
 *      @since jdk1.0
 */
class DoubleFormat {
   public static String toString(double inValue, int precision) {
      return toString(inValue, precision, false);
    }

   public static String toString (double inValue, int precision,
      boolean use_comma)
    {
      boolean trailing_zero;
      double absval= Math.abs(inValue); // get positive portion

      if (precision < 0)
        {
          precision = -precision;
          trailing_zero = false;
        }
      else
         trailing_zero = true;

      String signStr = "";

      if (inValue < 0)
         signStr= "-";

	// get integer part
      long intDigit = (long) Math.floor(absval); 

      String intDigitStr = String.valueOf(intDigit);

      if (use_comma)
        {
          int intDigitStrLen= intDigitStr.length();
          int dig_index= (intDigitStrLen - 1) % 3;

          dig_index++;

          String intCommaDigitStr = intDigitStr.substring(0,
            dig_index);

         while (dig_index < intDigitStrLen)
           {
             intCommaDigitStr += "," +
               intDigitStr.substring(dig_index, dig_index+3);

             dig_index+= 3;
           }
         intDigitStr= intCommaDigitStr;
       }

     String precDigitStr= "";

     long precDigit= Math.round((absval - intDigit) * 
           Math.pow(10.0, precision));

     precDigitStr= String.valueOf(precDigit);

     // pad zeros between decimal and precision digits
     String zeroFilling= "";

     for (int i= 0; i < precision-precDigitStr.length(); i++)
         zeroFilling += "0";

      precDigitStr= zeroFilling + precDigitStr;

      if (!trailing_zero)
        {
           int lastZero;

           for (lastZero = precDigitStr.length() - 1; 
                lastZero >= 0; lastZero--)
             if (precDigitStr.charAt(lastZero)!= '0')
                break;

           precDigitStr= precDigitStr.substring(0, lastZero + 1);
        }

      if (precDigitStr.equals(""))
         return signStr + intDigitStr;
      else
         return signStr + intDigitStr + "." + precDigitStr;
    }
  }