Gwt CellTable Sorting page by page only - sorting

Question

GWT CellTable column sorting page by page only, for each page i have to click the column header
for sorting.
How to sort whole data on single header click.
This is my code,
dataProvider = new ListDataProvider<List<NamePair>>();
dataProvider.addDataDisplay(dgrid);
List<List<NamePair>> list = dataProvider.getList();
for (List<NamePair> contact : test) {
dataProvider.setList(test);
list.add(contact);
}
ListHandler<List<NamePair>> columnSortHandler = new ListHandler<List<NamePair>>(dataProvider.getList());
System.out.println("Column count->"+dgrid.getColumnCount());
for(int j=0 ; j<dgrid.getColumnCount();j++){
final int val = j;
columnSortHandler.setComparator(dgrid.getColumn(val), new Comparator<List<NamePair>>() {
public int compare(List<NamePair> o1, List<NamePair> o2) {
if (o1 == o2) {
return 0;
}
// Compare the column.
if (o1 != null) {
int index = val;
return (o2 != null) ? o1.get(index-2).compareTo(o2.get(index-2)) : 1;
}
return -1;
}
});
}
dgrid.addColumnSortHandler(columnSortHandler);

Answer 1

I suggest you override ListHandler , override and call super.onColumnSort(ColumnSortEvent) to debug the onColumnSort(ColumnSortEvent) method, you'll understand what is happening very fast.
The source code of the method is pretty direct
public void onColumnSort(ColumnSortEvent event) {
// Get the sorted column.
Column<?, ?> column = event.getColumn();
if (column == null) {
return;
}
// Get the comparator.
final Comparator<T> comparator = comparators.get(column);
if (comparator == null) {
return;
}
// Sort using the comparator.
if (event.isSortAscending()) {
Collections.sort(list, comparator);
} else {
Collections.sort(list, new Comparator<T>() {
public int compare(T o1, T o2) {
return -comparator.compare(o1, o2);
}
});
}
}