как да извлечете стойността от мрежовата клетка в GXT

Създадох редактируема решетка със само 3 от колоните от 5 като редактируеми. Не разбирам как да извличам стойности от конкретните клетки, така че стойностите да могат да се добавят динамично и да се показват в друга клетка от същата мрежа. Опитах този код в eclipse galileo. Но не работи. Моля, помогни ми.

package org.openxdata.analyzer.client;

import java.util.ArrayList;
import com.extjs.gxt.ui.client.widget.grid.ColumnConfig;  
import com.google.gwt.user.client.Element;
import com.extjs.gxt.ui.client.widget.grid.ColumnModel;  
import com.extjs.gxt.ui.client.Style.HorizontalAlignment;  
import java.util.List;
import com.extjs.gxt.ui.client.store.ListStore;
import com.extjs.gxt.ui.client.widget.MessageBox;
import com.extjs.gxt.ui.client.widget.Window;
import com.extjs.gxt.ui.client.widget.button.Button;
import com.extjs.gxt.ui.client.widget.form.TextField;  
import com.extjs.gxt.ui.client.widget.grid.CellEditor;  
import com.extjs.gxt.ui.client.widget.grid.EditorGrid;  
import com.extjs.gxt.ui.client.widget.layout.FitLayout;  
import com.extjs.gxt.ui.client.widget.layout.FormData;
import com.extjs.gxt.ui.client.data.BaseModel;
import com.extjs.gxt.ui.client.event.ButtonEvent;
import com.extjs.gxt.ui.client.event.SelectionListener;
import com.extjs.gxt.ui.client.widget.Viewport;
import com.extjs.gxt.ui.client.widget.form.NumberField;


public class Grid1 extends Viewport {

    @Override
    protected void onRender(Element parent, int index) {
        super.onRender(parent, index);
        setStyleAttribute("margin", "10px");



        final Window w = new Window();
        w.setHeading("grids");
        w.setSize(600,250);
        w.setModal(true);
        //w.setLayout(new RowLayout(Orientation.VERTICAL)); 
        w.setLayout(new FitLayout());
        w.setResizable(false);

        FormData formData = new FormData("98%");


        List<ColumnConfig> col = new ArrayList<ColumnConfig>();
        ColumnConfig column = new ColumnConfig();
        column.setId("disease");
        column.setWidth(150);
        TextField<String> text = new TextField<String>();    
        text.setAllowBlank(false);    
        text.setAutoValidate(true);    
        //column.setEditor(new CellEditor(text));  
        col.add(column);


        column = new ColumnConfig();
        column.setId("exposure");
        column.setWidth(120);
        TextField<String> text1 = new TextField<String>();    
        text1.setAllowBlank(false);    
        text1.setAutoValidate(true);    
        //column.setEditor(new CellEditor(text1));  
        col.add(column);

        column = new ColumnConfig();
        column.setId("plus");
        column.setHeader("Exposure");
        column.setWidth(80);
    final NumberField text2 = new NumberField();    
        text2.setAllowBlank(false);    
        text2.setAutoValidate(true);    
        column.setEditor(new CellEditor(text2));  
        col.add(column);

        column = new ColumnConfig();
        column.setId("minus");
        column.setHeader("Exposure");
        column.setWidth(80);
        final NumberField text3 = new NumberField();   
        text3.setAllowBlank(false);    
        text3.setAutoValidate(true);    
        column.setEditor(new CellEditor(text3));  
        col.add(column);

        column = new ColumnConfig();
        column.setId("total");
        column.setHeader("Totals");
        column.setWidth(80);
        final NumberField text4 = new NumberField();      
        text4.setAllowBlank(false);    
        text4.setAutoValidate(true);    
        column.setEditor(new CellEditor(text4));  
        column.setAlignment(HorizontalAlignment.RIGHT);
        col.add(column);
        //ColumnModel cm = new ColumnModel(col);

        ListStore<Grid2> employeeList = new ListStore<Grid2>();    
        employeeList.add(cool.getgrid());


        ColumnModel cm = new ColumnModel(col);  


        final EditorGrid<Grid2> grid = new EditorGrid<Grid2>(employeeList, cm);  
        //grid.setStyleAttribute("borderTop", "none");  
        //grid.setAutoExpandColumn("name");  
        grid.setBorders(true);  
        grid.setStripeRows(true);  
          Button calculate = new Button("Calculate");
            w.addButton(calculate);



            calculate.addSelectionListener( new SelectionListener<ButtonEvent>()

                    {


                 @Override  
                    public void componentSelected(ButtonEvent ce) {  
                    {   

                        Double   p=(Double)text2.getValue();
                        Double m=(Double)text3.getValue();


                        Double t=p+m;

                        text4.setValue(t);

                        }  
                 }

                    });



        w.add(grid);
        w.show();
    }
}


class Grid2 extends BaseModel {
    private static final long serialVersionUID = 1L;
    public Grid2(){
    }
    public Grid2  ( String  dis, String exp, Integer x,Integer y) {
        set("disease", dis);
        set("exposure", exp);
        set("plus", x);
        set("minus", y);
    }

    public Grid2 (String  dis, String exp, Integer x,
            Integer y, Double v) {
        // this(dis, exp, x,y,v);
        set("disease", dis);
        set("exposure", exp);
        set("plus", x);
        set("minus", y);
        set("total", v);
    }
    public Grid2(String a,String b,String c,String d,String t){
        set("disease",a);
        set("exposure",b);
        set("plus",c);
        set("minus",d);
        set("total",t);
    }
    public  Integer getplus() {
        return (Integer)get("plus");
    }
    public Integer getminus() {
        return (Integer)get("minus");
    }


    public class TestData {  

        public  List<Grid2> getData()  
        {  
            List<Grid2> lt= new ArrayList<Grid2>();  



            lt.add(new Grid2("Christina Blake","Information Technology",1,2,1.23));  
            lt.add(new Grid2("Heriberto Rush","Information Technology",3,4,1.334));  

            return lt;  
        }  
    }  

}

class cool {  

    public static  List<Grid2> getgrid()  
    {  
        List<Grid2> data = new ArrayList<Grid2>();  

        //data.add(new Grid(" "," ","Exposure"," ","Totals"));  
        data.add(new Grid2(" "," ","(+)","(-)"," "));  
        data.add(new Grid2("'Disease'","(+)",0,0,0.00));  
        data.add(new Grid2(" ","(-)",0,0,0.00));  
        data.add(new Grid2("Totals"," ",0,0,0.00));  


        return data;  
    }  

}