How to get the value of a CellTable cell

Question

I am working on a GWT app that uses CellTable to display 2 columns for denomination and quantity. The denomination values are not editable while the quantity values are editable.

What I envisage is, if a user selects for instance, 5 for denomination and 20 for quantity, a TextBox for total should populate automatically with 5 * 20 = 100.

My question is is, how can I retrieve the value for a cell so that I can do the multiplication.

PS: The values are all stored in a database table.

Answer 1

You can always attach a selectionModel to the celltable to get currently selected row and then get the current selected object and in turn their values. I am not entirely sure about the next statement but you might want to use the FieldUpdater too. Refer to the GWT docs here

Sample :

Selection Model:

SingleSelectionModel<Contact> selectionModel = new SingleSelectionModel<Contact>();
    table.setSelectionModel(selectionModel);
    selectionModel.addSelectionChangeHandler(new SelectionChangeEvent.Handler() {
      public void onSelectionChange(SelectionChangeEvent event) {
        Contact selected = selectionModel.getSelectedObject();
        if (selected != null) {
          Window.alert("You selected: " + selected.name);
        }
      }
    });

FieldUpdater :

// Add a field updater to be notified when the user enters a new name.
    nameColumn.setFieldUpdater(new FieldUpdater<Contact, String>() {
      @Override
      public void update(int index, Contact object, String value) {
        // Inform the user of the change.
        Window.alert("You changed the name of " + object.name + " to " + value);

        // Push the changes into the Contact. At this point, you could send an
        // asynchronous request to the server to update the database.
        object.name = value;

        // Redraw the table with the new data.
        table.redraw();
      }
    });