package com.mbz.ui;

import javax.swing.table.AbstractTableModel;

public class CartTableModel extends AbstractTableModel{

	//表格列表名columnNames
    private  String[] columnNames = {"商品编号","商品名","商品单价","数量","商品应付金额"};

    //表格中数据保存在data二维数组中
    private  Object[][] data = null;

    public CartTableModel(Object [][] data) {
        this.data = data;
    }

    //返回列数
    @Override
    public int getColumnCount() {
        return columnNames.length;
    }

    //返回行数
    @Override
    public int getRowCount() {
        return data.length;
    }


    //获得某行某列的数据，而数据保存在对象数组data中
    @Override
    public Object getValueAt(int rowIndex, int columnIndex) {
        return data[rowIndex][columnIndex];
    }

    @Override
    public String getColumnName(int columnIndex){
        return columnNames[columnIndex];
    }

    @Override
    public  boolean isCellEditable(int rowIndex, int columnIndex) {
        //数量列可以修改
        if(columnIndex == 3){
            return true;
        }
        return false;
    }
    @Override
    public  void setValueAt(Object aValue, int rowIndex, int columnIndex) {
        //只允许修改数量列
        if(columnIndex != 3){
            return;
        }
        try{
            //从表中获得修改之后的商品数量，从表而来的数据都String类型
            int quantity = new Integer((String) aValue);
            //商品数量不能小于0
            if(quantity < 0){
                return;
            }
            //更新数量列
            data[rowIndex][3] = quantity;
            //计算商品应付金额
            double unitcost = (double) data[rowIndex][2];
            double totalPrice = unitcost * quantity;
            //更新商品应付金额列
            data[rowIndex][4] = new Double(totalPrice);
        }catch(Exception e){

        }
    }
}