GWT CellList with dynamic DataProvider

Question

Is it possible to make a standard CellList, that he was working with a dynamic DataProvider? On the likeness of the search engine Google

I leaf through the pages, and CellList pulls information from the server . In the standard example in the beginning is full DataProvider

Number of lines per page - 10 The number of items I can get from the server.

Answer 1

Since the data are coming from the server every time you press Next or Previous you can use Async Data Provider.

Here is an example

import java.util.Arrays;
import java.util.Date;
import java.util.List;

import com.google.gwt.cell.client.DateCell;
import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.cellview.client.CellTable;
import com.google.gwt.user.cellview.client.Column;
import com.google.gwt.user.cellview.client.SimplePager;
import com.google.gwt.user.cellview.client.TextColumn;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.user.client.ui.VerticalPanel;
import com.google.gwt.view.client.AsyncDataProvider;
import com.google.gwt.view.client.HasData;

public class CellTableExample implements EntryPoint {

  /**
   * A simple data type that represents a contact.
   */
  private static class Contact {
    private final String address;
    private final Date birthday;
    private final String name;

    public Contact(String name, Date birthday, String address) {
      this.name = name;
      this.birthday = birthday;
      this.address = address;
    }
  }

  /**
   * The list of data to display.
   */
  @SuppressWarnings("deprecation")
  private static final List<Contact> CONTACTS = Arrays.asList(
      new Contact("John", new Date(80, 4, 12), "123 Abc Avenue"), 
      new Contact("Joe", new Date(85, 2, 22), "22 Lance Ln"), 
      new Contact("Tom", new Date(85, 3, 22), "33 Lance Ln"), 
      new Contact("Jack", new Date(85, 4, 22), "44 Lance Ln"), 
      new Contact("Tim", new Date(85, 5, 22), "55 Lance Ln"), 
      new Contact("Mike", new Date(85, 6, 22), "66 Lance Ln"), 
      new Contact("George", new Date(46, 6, 6),"77 Lance Ln"));

  public void onModuleLoad() {
    // Create a CellTable.
    final CellTable<Contact> table = new CellTable<Contact>();
    // Display 3 rows in one page
    table.setPageSize(3);

    // Add a text column to show the name.
    TextColumn<Contact> nameColumn = new TextColumn<Contact>() {
      @Override
      public String getValue(Contact object) {
        return object.name;
      }
    };
    table.addColumn(nameColumn, "Name");

    // Add a date column to show the birthday.
    DateCell dateCell = new DateCell();
    Column<Contact, Date> dateColumn = new Column<Contact, Date>(dateCell) {
      @Override
      public Date getValue(Contact object) {
        return object.birthday;
      }
    };
    table.addColumn(dateColumn, "Birthday");

    // Add a text column to show the address.
    TextColumn<Contact> addressColumn = new TextColumn<Contact>() {
      @Override
      public String getValue(Contact object) {
        return object.address;
      }
    };
    table.addColumn(addressColumn, "Address");

    // Associate an async data provider to the table
    // XXX: Use AsyncCallback in the method onRangeChanged
    // to actaully get the data from the server side
    AsyncDataProvider<Contact> provider = new AsyncDataProvider<Contact>() {
      @Override
      protected void onRangeChanged(HasData<Contact> display) {
        int start = display.getVisibleRange().getStart();
        int end = start + display.getVisibleRange().getLength();
        end = end >= CONTACTS.size() ? CONTACTS.size() : end;
        List<Contact> sub = CONTACTS.subList(start, end);
        updateRowData(start, sub);
      }
    };
    provider.addDataDisplay(table);
    provider.updateRowCount(CONTACTS.size(), true);

    SimplePager pager = new SimplePager();
    pager.setDisplay(table);

    VerticalPanel vp = new VerticalPanel();
    vp.add(table);
    vp.add(pager);

    // Add it to the root panel.
    RootPanel.get().add(vp);
  }
}

---

// Associate an async data provider to the table
    AsyncDataProvider<Contact> provider = new AsyncDataProvider<Contact>() {
      @Override
      protected void onRangeChanged(HasData<Contact> display) {
        final int start = display.getVisibleRange().getStart();
        int length = display.getVisibleRange().getLength();
        AsyncCallback<List<Contact>> callback = new AsyncCallback<List<Contact>>() {
          @Override
          public void onFailure(Throwable caught) {
            Window.alert(caught.getMessage());
          }
          @Override
          public void onSuccess(List<Contact> result) {
            updateRowData(start, result);
          }
        };
        // The remote service that should be implemented
        remoteService.fetchPage(start, length, callback);
      }
    };