vogella.de

This chapter explains how to to sort the columns of the table ascending/descending.

Create a new Class "de.vogella.jface.tableviewer.sorter.TableSorter.java"

			
package de.vogella.jface.tableviewer.sorter;

import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jface.viewers.ViewerSorter;

import de.vogella.jface.tableviewer.model.Person;

public class TableSorter extends ViewerSorter {
	private int propertyIndex;
	// private static final int ASCENDING = 0;
	private static final int DESCENDING = 1;

	private int direction = DESCENDING;

	public TableSorter() {
		this.propertyIndex = 0;
		direction = DESCENDING;
	}

	public void setColumn(int column) {
		if (column == this.propertyIndex) {
			// Same column as last sort; toggle the direction
			direction = 1 - direction;
		} else {
			// New column; do an ascending sort
			this.propertyIndex = column;
			direction = DESCENDING;
		}
	}

	@Override
	public int compare(Viewer viewer, Object e1, Object e2) {
		Person p1 = (Person) e1;
		Person p2 = (Person) e2;
		int rc = 0;
		switch (propertyIndex) {
		case 0:
			rc = p1.getFirstName().compareTo(p2.getFirstName());
			break;
		case 1:
			rc = p1.getLastName().compareTo(p2.getLastName());
			break;
		case 2:
			rc = p1.getGender().compareTo(p2.getGender());
			break;
		case 3:
			if (p1.isMarried() == p2.isMarried()) {
				rc = 0;
			} else
				rc = (p1.isMarried() ? 1 : -1);
			break;
		default:
			rc = 0;
		}
		// If descending order, flip the direction
		if (direction == DESCENDING) {
			rc = -rc;
		}
		return rc;
	}
}
		

Add a listener to the view for setting the information which column should be sorted. Change View.java to the following-

			
package de.vogella.jface.tableviewer;

import org.eclipse.jface.viewers.TableViewer;
import org.eclipse.jface.viewers.TableViewerColumn;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Table;
import org.eclipse.swt.widgets.TableColumn;
import org.eclipse.ui.part.ViewPart;

import de.vogella.jface.tableviewer.model.ModelProvider;
import de.vogella.jface.tableviewer.providers.PersonContentProvider;
import de.vogella.jface.tableviewer.providers.PersonEditingSupport;
import de.vogella.jface.tableviewer.providers.PersonLabelProvider;
import de.vogella.jface.tableviewer.sorter.TableSorter;

public class View extends ViewPart {
	public static final String ID = "de.vogella.jface.tableviewer.view";

	private TableViewer viewer;

	private TableSorter tableSorter;

	public void createPartControl(Composite parent) {
		createViewer(parent);
		// Get the content for the viewer, setInput will call getElements in the
		// contentProvider
		viewer.setInput(ModelProvider.getInstance().getPersons());
		// Make the selection available
		getSite().setSelectionProvider(viewer);
		// Set the sorter for the table
		tableSorter = new TableSorter();
		viewer.setSorter(tableSorter);

	}
	
	private void createViewer(Composite parent) {
		viewer = new TableViewer(parent, SWT.MULTI | SWT.H_SCROLL
				| SWT.V_SCROLL | SWT.FULL_SELECTION);
		createColumns(viewer);
		viewer.setContentProvider(new PersonContentProvider());
		viewer.setLabelProvider(new PersonLabelProvider());
	}

	public TableViewer getViewer() {
		return viewer;
	}

	// This will create the columns for the table
	private void createColumns(final TableViewer viewer) {
		Table table = viewer.getTable();
		String[] titles = { "First name", "Last name", "Gender", "Married" };
		int[] bounds = { 100, 100, 100, 100 };

		for (int i = 0; i < titles.length; i++) {
			final int index = i;
			final TableViewerColumn viewerColumn = new TableViewerColumn(
					viewer, SWT.NONE);
			final TableColumn column = viewerColumn.getColumn();
			column.setText(titles[i]);
			column.setWidth(bounds[i]);
			column.setResizable(true);
			column.setMoveable(true);
			// Setting the right sorter
			column.addSelectionListener(new SelectionAdapter() {
				@Override
				public void widgetSelected(SelectionEvent e) {
					tableSorter.setColumn(index);
					int dir = viewer.getTable().getSortDirection();
					if (viewer.getTable().getSortColumn() == column) {
						dir = dir == SWT.UP ? SWT.DOWN : SWT.UP;
					} else {

						dir = SWT.DOWN;
					}
					viewer.getTable().setSortDirection(dir);
					viewer.getTable().setSortColumn(column);
					viewer.refresh();
				}
			});
			viewerColumn.setEditingSupport(new PersonEditingSupport(viewer, i));
		}
		table.setHeaderVisible(true);
		table.setLinesVisible(true);
	}

	/**
	 * Passing the focus request to the viewer's control.
	 */
	public void setFocus() {
		viewer.getControl().setFocus();
	}
}
		

Run the example, click on a column, there will appear a sort-direction signifier and your items are ordered ascending or descending.