Grid with components had an issue in vaadin8.1.0

General
1

I had a grid with textfield and checkbox and amount as its columns and when
enter amount in textfield out of grid and
 when I click the header checkbox the amount should be compared with textfieldvalue and check only particular checkboxes.its working fine, but if I have 1000 rows for suppose user entered amount is equal to sum of 2 columns amount, only particular checkboxes are checked and amount is stored in that column textfield.The problem is when i scroll down the grid and again scroll up the checkboxes are unchecked and values in textfields are empty. Here is my code

[code]
final VerticalLayout layout = new VerticalLayout();
final HorizontalLayout hlayout = new HorizontalLayout();
final TextField txtamount = new TextField(“Amount”);
Label lbl = new Label();
/**

  • adding components that need to display horizontally to horizontal layout
    /
    hlayout.addComponents(txtamount, lbl);
    /    *
    *Create list of person type where person is a class.
    adding values to list
    /
    List people = new ArrayList();
    for (int i = 0; i < 100; i++) {
    people.add(new Person(“Galileo Galilei”, 1564, 1000));
    }
    people.add(new Person(“Galileo Galilei”, 1564, 2000));
    CheckBox CheckBox1 = new CheckBox(“All”);
    CheckBox1.setValue(false);
    /
  • creating grid of person type,
  • set list items to grid
  • use addColumns to get the values
  • use addComponentColumns to get components like CheckBox,TextField.
    /
    Grid grid = new Grid();
    grid.setWidth(“1000px”);
    grid.setItems(people);
    grid.addColumn(Person::getName).setCaption(“Name”);
    grid.addColumn(Person::getYear).setCaption(“Year of birth”).setId(“year”);
    grid.addColumn(Person::getAmount).setCaption(“Amount”).setId(“amount”);
    /    *
  • creating HashMap with key as person class type and
  • value as Chk_Txt class type where Chk_Txt class contains
  • ChechBox and TextField.
    /
    HashMap<Person, Chk_Txt> hmChks = new HashMap<Person,Chk_Txt>();
    /    *
    * addValueChangeListener fires event everytime, when value is changed
    /
    CheckBox1.addValueChangeListener(e ->{
    //if CheckBox is not checked,every column CheckBoxes and TextFields are empty
    if(!CheckBox1.getValue()){
    for(Person p:people){
    hmChks.get(p).getChk().setValue(CheckBox1.getValue());
    hmChks.get(p).getTxt().setValue(“”);
    }
    }
    /    *
  • if amount is not entered in TextField, displays notification message
  • if value entered in TextField, store value in amount_entered,
  • compare it with amount of each column
    /
    else{
    if(txtamount.getValue().isEmpty())
    Notification.show(“Please enter amount”);
    else
    try{
    int amount_entered = new Integer(txtamount.getValue());
    System.out.println("bg: "+amount_entered);
    for(Person p:people){
    //check the CheckBoxes if amount matches
    hmChks.get(p).getChk().setValue(CheckBox1.getValue());
    /    *
  • if amount entered by user is greater than amount in column
  • set amount of that column, in TextField of grid
  • else set user entered amount in TextField of grid
    */
    if(amount_entered>=p.amount)
    hmChks.get(p).getTxt().setValue(p.amount+“”);
    else
    hmChks.get(p).getTxt().setValue(amount_entered+“”);
    amount_entered=amount_entered -(p.amount);
    if(amount_entered<=0){
    break;
    }
    }
    }
    catch(Exception ex){
    Notification.show(“Invalid amount”);
    }
    }
    }
    );

/**

  • add CheckBox to column using addComponentColumn
    /
    grid.addComponentColumn(Person → {
    CheckBox chk = new CheckBox(“Chk 2”);
    if(hmChks.containsKey(Person)){
    hmChks.get(Person).setChk(chk);
    }
    else{
    hmChks.put(Person, new Chk_Txt(chk));
    }
    Registration listenerRegistration = chk.addValueChangeListener(e->System.out.println("Person.amount: "+ Person.amount));
    chk.addDetachListener(event → listenerRegistration.remove());
    return chk;
    }).setCaption(“ch2”).setId(“CH2”);
    /    *
  • add TextField to column using addComponentColumn
    /
    grid.addComponentColumn(Person → {
    TextField text = new TextField();
    if(hmChks.containsKey(Person)){
    hmChks.get(Person).setTxt(text);
    }
    else{
    hmChks.put(Person, new Chk_Txt(text));
    }
    return text;
    }).setId(“2”);
    // set CheckBox as Column header using column id Ch2.
    grid.getHeaderRow(0).getCell(“CH2”).setComponent(CheckBox1);
    /    *
  • adding components to VerticalLayout
    /
    layout.addComponents(hlayout, grid);
    setContent(layout);
    }
    @WebServlet(urlPatterns = "/    ", name = “MyUIServlet”, asyncSupported = true)
    @VaadinServletConfiguration(ui = MyUI.class, productionMode = false)
    public static class MyUIServlet extends VaadinServlet {
    }
    //creating class Chk_Txt which has CheckBox and TextField
    class Chk_Txt{
    private CheckBox chk;
    private TextField txt;
    public Chk_Txt(CheckBox chk){
    setChk(chk);
    }
    public Chk_Txt(TextField txt){
    setTxt(txt);
    }
    public CheckBox getChk() {
    return chk;
    }
    public void setChk(CheckBox chk) {
    this.chk = chk;
    }
    public TextField getTxt() {
    return txt;
    }
    public void setTxt(TextField txt) {
    this.txt = txt;
    }
    }
    }
    [/code]Please, Help me out!