Adding a row-number column to GWT CellTable - gwt

Question

I need to insert a new first-column into a CellTable, and display the RowNumber of the current row in it. What is the best way to do this in GWT?

Answer 1

Get the index of the element from the list wrapped by your ListDataProvider. Like this:
final CellTable<Row> table = new CellTable<Row>();
final ListDataProvider<Row> dataProvider = new ListDataProvider<Starter.Row>(getList());
dataProvider.addDataDisplay(table);
TextColumn<Row> numColumn = new TextColumn<Starter.Row>() {
#Override
public String getValue(Row object) {
return Integer.toString(dataProvider.getList().indexOf(object) + 1);
}
};
See here for the rest of the example.

Answer 2

Solution from z00bs is wrong, because row number calculating from object's index in data List. For example, for List of Strings with elements: ["Str1", "Str2", "Str2"], the row numbers will be [1, 2, 2]. It is wrong.
This solution uses the index of row in celltable for row number.
public class RowNumberColumn extends Column {
public RowNumberColumn() {
super(new AbstractCell() {
#Override
public void render(Context context, Object o, SafeHtmlBuilder safeHtmlBuilder) {
safeHtmlBuilder.append(context.getIndex() + 1);
}
});
}
#Override
public String getValue(Object s) {
return null;
}
}
and
cellTable.addColumn(new RowNumberColumn());