//how to add items and prices to a listbox
//and keep running totals and counts
   
import javax.swing.*;

import java.util.*;                    //used to sort list box items
import java.text.*;                   //so we can format strings

public class frmCounts extends javax.swing.JFrame
  {

        //**********CLASS-LEVEL VARIABLES***********
        //---create the new model to hold our listbox items
        DefaultListModel model = new DefaultListModel();
    
        //--- class varaible to hold our total amt due
        double runningTotal = 0.00;
        int numItems = 0;
    
        //---create my decimal format to use when we display totals
        NumberFormat currency = new DecimalFormat("$#.00");
           
    
    public frmCounts()
      {
        initComponents();
        
          // center the form
        this.setLocationRelativeTo(null);
        
        lbItems.setModel(model);                //tell listbox which model to use so it will display data in Jlist
        
        
        txtItem.requestFocusInWindow();    //set cursor to first box
        
        
        initializeForm();       //add our initial items to the listbox
        
      }

private void initializeForm()
      {
            //Note the ScrollBar Policies CAN be set in the Properties Winddow. I just wanted to make sure to remember to show them to you
            
        //---do not allow scrolling horizontal so they can't see prices. But allow vertical scrolling
            jScrollPane1.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER);
            jScrollPane1.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED);
        
            //---Add some initial items to our model. Model is the object that holds our data. 
            //     Notice how I added prices. Make them spaced to the right so they won't be visible on the form
          
             model.addElement("Hats                             14.95");
             model.addElement("Golf tees                        2.98");
             model.addElement("Balls                             47.69");
             model.addElement("Shirts                            28.75");
             model.addElement("Wind Breaker                      19.59");
             model.addElement("Putters                           89.79");
             
                       
             sortListBox(model);
           
      }
    
    
      private void sortListBox (DefaultListModel dlm)
      {
            //since you cannot sort the JLIST control, you read the data from the model, convert to an array,
            // and sort the temp array. Then you have to put the sorted array elements back into the model.
        
        
             Object[] myArray = dlm.toArray();   //grab all items, put into an object array
             
             Arrays.sort(myArray);                    //sort the new array
             
             dlm.clear();                                    //start clean
             
             for (Object x : myArray)                   //enhanced for loop (for-each loop)
                dlm.addElement(x);                      //add the elements back into the model in sorted order
           
              lbItems.setSelectedIndex(0);
 
              
        
      }


 private void btnAddActionPerformed(java.awt.event.ActionEvent evt)
    {		//Add item to cart

          // get the entire string that was selected
            String theItem = lbItems.getSelectedValue().toString();
            
            //---now take the first 15 chars and put in the textbox
            txtItem.setText(theItem.substring(0, 15).trim());
            
            //---now grab the price & display it
            String thePrice = theItem.substring(20).trim();
            txtCost.setText(thePrice);
            
            //---now add item to our total
            runningTotal += Double.parseDouble(thePrice);
            
            //---increment numItems
            numItems ++;
            
    }

    private void btnCheckoutActionPerformed(java.awt.event.ActionEvent evt)
    {
        // Display totals
        lblNumItems.setText("You purchased " + numItems + " items today.");
        
        lblTotalSpent.setText("You spent " + currency.format(runningTotal) + " today. Thanks.");
        
        
      
    }

    private void btnClearActionPerformed(java.awt.event.ActionEvent evt)                                         
    {                                             
           // reset the form
        txtItem.setText("");
        txtCost.setText("");
        lblTotalSpent.setText("");
        lblNumItems.setText("");
        
        lbItems.setSelectedIndex(0);    // reset to first item
        
        //---reset running total and count
        runningTotal = 0.0;
        numItems = 0;
        
        //---set cursor
        txtItem.requestFocusInWindow();
        
        
    }