gwt cell table dynamic columns - sorting need an example

Question

I'm new to GWT and I need to create a sortable dynamic celltable.

I saw an example of IndexedColumn class. I generated a Dynamic cell table (List of ArrayList of String), but couldn't make it sort. does anybody have a simple implementation example?
Thanks

Answer 1

Found my mistake...
Here is my working example:

import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;


import com.google.gwt.core.client.EntryPoint;
import com.google.gwt.user.cellview.client.CellTable;
import com.google.gwt.user.cellview.client.ColumnSortEvent.ListHandler;
import com.google.gwt.user.client.ui.RootPanel;
import com.google.gwt.view.client.ListDataProvider;



/**
 * Entry point classes define <code>onModuleLoad()</code>.
 */
public class DynamicTable implements EntryPoint {


    /**
     * This is the entry point method.
     */
    public void onModuleLoad() {
        List<ArrayList<String>> data = this.getThedata();

        CellTable<List<String>> table = new CellTable<List<String>>();
        ArrayList<String> dataHeaders = data.remove(0);

        ArrayList<IdxColumn> columnList = new ArrayList<IdxColumn>();

        ListDataProvider<List<String>> dataProvider = new ListDataProvider<List<String>>();
        dataProvider.addDataDisplay(table);


        List<List<String>> list = dataProvider.getList();
        for (List<String> l : data) {
            list.add(l);
        }


        ListHandler<List<String>> columnSortHandler = new ListHandler<List<String>>(list);
        table.getColumnSortList().clear();



        for (int i = 0; i < data.get(0).size(); i++) {
            final int index = i; 
            IdxColumn iCol = new IdxColumn(index);
            columnList.add(iCol);                   

            table.addColumn(iCol, dataHeaders.get(index) + " (" +iCol.getIndex() + ")");
            columnSortHandler.setComparator(iCol, new Comparator<List<String>>() {

                public int compare(List<String> o1, List<String> o2) {         
                  if (o1 == o2) {                   
                    return 0;
                  }

                  if (o1 != null) {             
                    return (o2 != null) ? o1.get(0).compareTo(o2.get(0)) : 1;
                  }

                  return -1;
                }
            });
            iCol.setSortable(true);
            table.getColumnSortList().push(iCol);                       
        }


        table.addColumnSortHandler(columnSortHandler);

        table.setRowCount(data.size(), true);
        table.setRowData(0, data);

        RootPanel.get().add(table);
    }

    // build the data
    private List<ArrayList<String>> getThedata() {

        List<ArrayList<String>> data = new ArrayList<ArrayList<String>>();
        ArrayList<String> dataHeaders = new ArrayList<String>();
        dataHeaders.add("Header 1");
        dataHeaders.add("Header 2");
        dataHeaders.add("Header 3");
        dataHeaders.add("Header 4");
        dataHeaders.add("Header 5");
        dataHeaders.add("Header 6");
        data.add(dataHeaders);
        for (int i = 0; i < 20; i++) {
            ArrayList<String> dataRow = new ArrayList<String>();
            dataRow.add("Col1 Row" + i);
            dataRow.add("Col2 Row" + i);
            dataRow.add("Col3 Row" + i);
            dataRow.add("Col4 Row" + i);
            dataRow.add("Col5 Row" + i);
            dataRow.add("Col6 Row" + i);
            data.add(dataRow);
        }

        return data;
    }
}

And the IdxColumn class:

import java.util.List;

import com.google.gwt.cell.client.TextCell;
import com.google.gwt.user.cellview.client.Column;

public class IdxColumn extends Column<List<String>, String> {
    private final int index;

    public IdxColumn( int index) {
        super(new TextCell());
          this.index = index;
    }

    @Override
    public String getValue(List<String> object) {
        return object.get(index);
    }

    public int getIndex() {     
        return this.index;
    }
}