/*
 * pHCalculator.java
 *
 * Created on November 17, 2007, 7:55 PM
 */
 
import javax.microedition.midlet.*;
import javax.microedition.lcdui.*;
import java.io.*;
 
/**
 *
 * @author  Eirik
 * @version
 */
public class pHCalculator extends MIDlet implements javax.microedition.lcdui.CommandListener
              {
 
    public pHCalculator() {
}  
    private Form calcForm;                     
    private Command exitcommand;
    private Command helpcommand;
    private Form help;
    private Command backfromhelp;
    private TextField input_ka;
    private TextField input_m;
    private TextField input_ph;
    double ph = 0, K = 0, M = 0;
 
private void initialize() {
  getDisplay().setCurrent(get_calcForm());
}
 
public void commandAction(Command command, Displayable displayable) {                    
        if (displayable == calcForm) {                     
            if (command == exitcommand) {                   
                exitMIDlet();                       
            } else if (command == helpcommand) {                     
                getDisplay().setCurrent(get_help());                       
            }                      
        } else if (displayable == help) {
            if (command == backfromhelp) {                    
                getDisplay().setCurrent(get_calcForm());                        
            }                       
        }                     
}                   
 
    public Display getDisplay() {
        return Display.getDisplay(this);
    }                            
 
    public void exitMIDlet() {                         
        getDisplay().setCurrent(null);
        destroyApp(true);
        notifyDestroyed();
    }    
 
    public Form get_calcForm() {
        if (calcForm == null) {                      
            calcForm = new Form(null, new Item[] {
                new StringItem("pH Calculator",""),
                input_area_ka(),
                input_area_m(),
                input_area_ph()
            });                       
            calcForm.addCommand(get_exitcommand());
            calcForm.addCommand(get_helpcommand());
            calcForm.setCommandListener(this);                     
        }                      
        return calcForm;
    }                    
 
    public TextField input_area_ka() {
        if (input_ka == null) {                       
            input_ka = new TextField("Ka", "0", 120, TextField.NUMERIC);
        }
        return input_ka;
    }        
 
    public TextField input_area_m() {
        if (input_m == null) {                       
            input_m = new TextField("Acid Concentration (M)", "0", 120, TextField.NUMERIC);
        }                       
        return input_m;
    } 
 
     public TextField input_area_ph() {
        if (input_ph == null) {                       
            input_ph = new TextField("pH of Solution", "0", 120, TextField.NUMERIC);                       
        }                       
        return input_ph;
    }
 
    public Command get_exitcommand() {
        if (exitcommand == null) {                      
            exitcommand = new Command("Exit", Command.EXIT, 1);                      
        }                      
        return exitcommand;
    } 
 
    public Command get_helpcommand() {
        if (helpcommand == null) {                      
            helpcommand = new Command("Help", Command.HELP, 1);                      
        }                      
        return helpcommand;
    }
 
    public Form get_help() {
        if (help == null) {                      
            help = new Form(null, new Item[] {
                new StringItem("Help Contents", ""),
                new StringItem("", "Enter Ka first. Then acid concentration or pH depending on which is known. Mark unknowns with 0.")
            });                       
            help.addCommand(get_backfromhelp());
            help.setCommandListener(this);                     
        }                      
        return help;
    }
 
 
        public Command get_backfromhelp() {
        if (backfromhelp == null) {                      
            backfromhelp = new Command("Back", Command.BACK, 1);                      
        }                      
        return backfromhelp;
    }                  
 
    public void startApp() {
        initialize();
    }
 
    public void pauseApp() {
    }
 
    public void destroyApp(boolean unconditional) {
    }
}

/*
 * Main.java
 *
 * Created on November 14, 2007, 5:35 PM
 *
 * To change this template, choose Tools | Template Manager
 * and open the template in the editor.
 */
 
package phcalc;
 
/**
 *
 * @author Eirik
 */
import java.io.*;
 
public class Main {
 
    /** Creates a new instance of Main */
    public Main() {      
    }
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) throws IOException {
        double ph = 0, K = 0, M = 0;
        System.out.println("Enter Ka first. Then acid concentration or pH depending on which is known. Mark unknowns with 0.");
		try
		{
		InputStreamReader inputStreamReader = new InputStreamReader ( System.in );
                BufferedReader in = new BufferedReader ( inputStreamReader );
                    System.out.println("Enter Ka ");
                    String acidk = in.readLine();
                    K = Double.parseDouble(acidk);
                        System.out.println("Enter acid concentration ");
                        String acidmolar = in.readLine();
                        M = Double.parseDouble(acidmolar);
                            System.out.println("Enter pH ");
                            String solutionpH = in.readLine();
                            ph = Double.parseDouble(solutionpH);
		}
		catch(IOException ioex)
		{
			System.out.println("Input error");
			System.exit(1);
		}
		catch(NumberFormatException nfex)
		{
			System.out.println("\"" + 
				nfex.getMessage() + 
				"\" is not numeric");
			System.exit(1);
		}       
         if ( M == 0 ) {
                M = (((Math.pow((K+2*(Math.pow(10,-ph))),2))-K*K)/(4*K));
		System.out.println("Concentration: " + M );
		System.exit(0);
                }
                if ( ph == 0) {
                     ph = (-Math.log10((-K+Math.sqrt((K*K)-4*-K*M))/2));
		System.out.println("pH: " + ph );
		System.exit(0);
 
              }
    }
 
}

K = Double.parseDouble(((TextField)input_ka).getString());