TransferColumnSorter.java

package edu.washington.cs.oneswarm.ui.gwt.client.newui.transfer_details;

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

import com.google.gwt.gen2.table.client.SortableGrid;
import com.google.gwt.gen2.table.client.SortableGrid.ColumnSorter;
import com.google.gwt.gen2.table.client.SortableGrid.ColumnSorterCallback;
import com.google.gwt.gen2.table.client.TableModelHelper.ColumnSortList;
import com.google.gwt.user.client.ui.Widget;

public class TransferColumnSorter extends ColumnSorter {
    @Override
    public void onSortColumn(SortableGrid grid, ColumnSortList sortList,
            ColumnSorterCallback callback) {
        // Get the primary column and sort order
        int column = sortList.getPrimaryColumn();
        boolean ascending = sortList.isPrimaryAscending();

        Integer[] perm = new Integer[grid.getRowCount()];
        for (int i = 0; i < perm.length; i++)
            perm[i] = new Integer(i);

        final List<Widget> entries = new ArrayList<Widget>(grid.getRowCount());
        boolean comparable = false;
        for (int rItr = 0; rItr < grid.getRowCount(); rItr++) {
            Widget w = grid.getWidget(rItr, column);
            entries.add(w);
            if (w instanceof Comparable)
                comparable = true;
        }

        if (comparable) {
            Arrays.sort(perm, new Comparator<Integer>() {
                public int compare(Integer o1, Integer o2) {
                    /**
                     * Typecheck so we can use labels to indicate completion
                     * instead of 100% progress bars.
                     */
                    if (!(entries.get(o1) instanceof Comparable))
                        return -1;
                    else if (!(entries.get(o2) instanceof Comparable))
                        return 1;

                    return ((Comparable) entries.get(o1)).compareTo(entries.get(o2));
                }
            });
        } else {
            Arrays.sort(perm, new Comparator<Integer>() {
                public int compare(Integer o1, Integer o2) {
                    return entries.get(o1).getElement().getInnerText()
                            .compareTo(entries.get(o2).getElement().getInnerText());
                }
            });
        }

        int[] intperm = new int[perm.length];
        for (int i = 0; i < perm.length; i++) {
            // System.out.println(i + " -> " + perm[i]);
            if (ascending)
                intperm[i] = perm[i];
            else
                intperm[intperm.length - i - 1] = perm[i];
        }

        // Use the callback to complete the sorting
        callback.onSortingComplete(intperm);
    }
}