Prog2_U6_A1

README..

Jeg indser at det er super åndssvagt at putte mine textboxes ind i containers, bare for at få layout til at se rigtigt ud, for det er super besværligt at få fat i dem og dermed deres indhold, når det skal bruges senere... men det virker, så jeg gider ikke optimere det yderligere... :)

BinomialApplet.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class BinomialApplet extends JApplet {

	  //init the two binomial algorithms:
	  private Binomial1 algo1 = new Binomial1();
	  private Binomial2 algo2 = new Binomial2();

	  private Integer n=null,k=null;

	  private ButtonGroup g = new ButtonGroup(); //group of mutually exclusive radio button
	  private Container txtFieldContainer = new Container(); //graphical container for the n and k input fields
	  private Container cp = getContentPane(); //graphical container for the entire applet.



	  //text fields are added to a container (in this case called txtFieldContainer)
	  private void addTextField(int columns, String label, Container pane)
	  {
		  JTextField field = new JTextField(columns);
		  field.setName(label); //for ease of identification when pulling fields from group later...
		  //field.setAlignmentX(Component.CENTER_ALIGNMENT);

		  JLabel lbl=new JLabel(label);

		  pane.add(field);
		  pane.add(lbl);
	  }

	  //radio buttons are added to a container (in this case called radioContainer), they are also added to a group called g
	  private void addRadioBtn(String label, Container pane, boolean isActive)
	  {
		  JRadioButton rb = new JRadioButton(label, isActive);
		  //rb.setAlignmentX(Component.CENTER_ALIGNMENT);
		  rb.setActionCommand(label); //stored as a string... used a sort of a label to ID which button in the group is active
		  g.add(rb);
		  pane.add(rb);

	  }

     //extracts the textfields from the txtFieldContainer... it's silly, I know..
	  private boolean parseNK(){
		    for (Component c : txtFieldContainer.getComponents())
	    	{
	          if (c instanceof JTextField)
	          {
	        	  String name=((JTextField)c).getName();
	        	  String contents=((JTextField) c).getText();

	        	  //validate that input is actually parseable as integers:
	        	  try{
	    	    	  if (name.equals("n")) n = new Integer(contents);
	    	    	  else if(name.equals("k")) k = new Integer(contents);
	    	    	  }
	        	  catch(NumberFormatException err) {
	        		  JOptionPane.showMessageDialog(cp,"Input for " + name + " er ikke et heltal!",err.getMessage(),JOptionPane.ERROR_MESSAGE);
	        		  return false;
	        	  	  }
	          }
	    	}
		    return true;
	  }

	  //checks that the inputs obeys all the rules, and tells the user about each breach.
	  private boolean validateInput()
	  {
		  boolean returnVal=true;
		  if(n>60){ JOptionPane.showMessageDialog(cp,"n må ikke være større end 60!","n er for stor!",JOptionPane.ERROR_MESSAGE); returnVal=false; }
		  if(n<0){ JOptionPane.showMessageDialog(cp,"n må ikke være mindre end 0!","n er for lille!",JOptionPane.ERROR_MESSAGE); returnVal=false; }
		  if(k<0){ JOptionPane.showMessageDialog(cp,"k må ikke være mindre end 0!","k er for lille!",JOptionPane.ERROR_MESSAGE); returnVal=false; }
		  if(k>n){ JOptionPane.showMessageDialog(cp,"k må ikke være større end n!","k er for stor!",JOptionPane.ERROR_MESSAGE); returnVal=false; }
		  return returnVal;
	  }


	  private ActionListener al = new ActionListener() {
		    public void actionPerformed(ActionEvent e) {

		    if(parseNK()==false) return;

		    if(validateInput()==false) return;

		    //actully do the thing:
		    String resultat="";
		    String action=g.getSelection().getActionCommand(); //get the actionCommand of the currently selected radiobutton in the radiogroup

		    if(action.equals("Algoritme 1")) resultat+=algo1.binomial(n,k);
		    else if(action.equals("Algoritme 2")) resultat+=algo2.binomial(n,k);
		    JOptionPane.showMessageDialog(cp,"Resultat for n=" + n +" og k=" + k + ":\n\n" + resultat ,"Resultatvindue",JOptionPane.PLAIN_MESSAGE);
		    }
		  };

	  public void init() {

		  	Button calculate = new Button("Calculate!");
			calculate.addActionListener(al); //this is where the magic happens

		    //Radio button stuff:
			Container radioContainer = new Container();
		    radioContainer.setLayout(new FlowLayout());
		    addRadioBtn("Algoritme 1",radioContainer,true);
		    addRadioBtn("Algoritme 2",radioContainer,false);

		    //Text field stuff:
		    txtFieldContainer.setLayout(new FlowLayout());
		    addTextField(2,"n",txtFieldContainer);
		    addTextField(2,"k",txtFieldContainer);

		    cp.setLayout(new BoxLayout(cp, BoxLayout.Y_AXIS));
		    cp.add(txtFieldContainer);
		    cp.add(radioContainer);
		    cp.add(calculate);
		  }
		}