How can I add that the user will specify the quantity of the item into the GUI?

Question

Basically I want to create a GUI that allows the user to select an item from a given list then displays the total amount of the added items which is the price. So, it will be quantity*price of the item. The quantity will be entered from the user. SO far, this is the code and I want to modify the code in a way that the user will enter the quantity and it will be overall calculated and displayed in the GUI.

Class `Item`

public class Item {

private String itemName;
private Integer itemPrice;

public Item(){}
public Item(String itemName, int itemPrice){
    this.itemName = itemName;
    this.itemPrice = itemPrice;
}
public String getItemName() {
    return itemName;
}
public void setItemName(String itemName) {
    this.itemName = itemName;
}
public Integer getItemPrice() {
    return itemPrice;
}
public void setItemPrice(Integer itemPrice) {
    this.itemPrice = itemPrice;
}
@Override

public String toString(){
    return this.itemName;
}
}

Class `ShoppingCart`

import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.LinkedHashSet;
import java.util.List;
import java.util.Set;
import javax.swing.*;

public class ShoppingCart extends JFrame {
    private JList leftlist;
    private JList rightlist;
    private JButton addbutton;
    private JButton totalbutton;
    private JLabel totalLabel;


public ShoppingCart() {

    super("Shopping Cart");
    setLayout(new FlowLayout());

    // preparing item list it might be coming from somewhere else
    List<Item> itemList = new ArrayList<Item>();
    itemList.add(new Item("Apple", 10));
    itemList.add(new Item("Carrot", 40));
    itemList.add(new Item("Cucumber", 50));
    itemList.add(new Item("Iphone 6", 6000));
    itemList.add(new Item("Galaxy S6", 1100));
    itemList.add(new Item("BlackBerry", 1300));
    itemList.add(new Item("HairDryer", 200));
    itemList.add(new Item("Ironer", 300));
    itemList.add(new Item("Vacuum Cleaner", 400));

    leftlist = new JList(itemList.toArray());
    leftlist.setVisibleRowCount(5);
    leftlist
            .setSelectionMode(ListSelectionModel.MULTIPLE_INTERVAL_SELECTION);
    add(new JScrollPane(leftlist));

    addbutton = new JButton("ADD");
    addbutton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent event) {
            //make sure you preserve the previously selected list items
            int size = rightlist.getModel().getSize();
            Set objects = new LinkedHashSet();
            for (int i = 0; i < size; i++) {
                objects.add(rightlist.getModel().getElementAt(i));
            }
            objects.addAll(Arrays.asList(leftlist.getSelectedValues()));

            rightlist.setListData(objects.toArray());
        }
    });
    add(addbutton);

    rightlist = new JList();
    rightlist.setVisibleRowCount(5);
    rightlist.setFixedCellWidth(55);
    rightlist.setFixedCellHeight(20);
    add(new JScrollPane(rightlist));

    totalbutton = new JButton("Total");
    totalbutton.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent event) {
            // iterate over item objects and calculate the total
            int size = rightlist.getModel().getSize();
            Integer totalAmount = 0;
            for (int i = 0; i < size; i++) {
                Object obj = leftlist.getModel().getElementAt(i);
                Item item = (Item) obj;
                totalAmount += item.getItemPrice();
            }
            //update the total Amount label
            totalLabel.setText("Total Amount : " + totalAmount);
        }
    });
    add(totalbutton);

    totalLabel = new JLabel("Total Amount : ");

    add(totalLabel);

}

public static void main(String[] args) {
    ShoppingCart list = new ShoppingCart();
    list.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    list.setSize(300, 300);
    list.setVisible(true);
}
}

Have a `JTextField` or a similar component to get inputs from the user. — Codebender, Jul 04 '15 at 17:53

score 1 · Answer 1 · answered Jul 04 '15 at 22:16

This is basically a scenario for inventory.. first you should prompt the user to select an item from list then on focus out price field should get text automatically according to name of product.. user will enter the quantity.. then use the following code for total price calculation...

 private void total_buttonActionPerformed(java.awt.event.ActionEvent evt) {                                             


        float price=Float.parseFloat(price_txt.getText());
        float quantity=Float.parseFloat(quantity_txt.getText());
        float sum=price*quantity;
        total_txt.setText(""+sum);

}

// Note for inventory you should also have a check on product availability..

private void quantity_txtFocusLost(java.awt.event.FocusEvent evt) {                                       
    int quantity=Integer.parseInt(quantity_txt.getText());
    int available=Integer.parseInt(availability_txt.getText());
    if(quantity>available)
    {
        JOptionPane.showMessageDialog(rootPane, "Entered quantity is unavailable.");
        quantity_txt.requestFocus();
    }

}

How can I add that the user will specify the quantity of the item into the GUI?

Class Item

Class ShoppingCart

1 Answers1

Class `Item`

Class `ShoppingCart`