Bug 159600 [Viewers] Tooltips not working on TreeViewer
TooltipSupport does not map receiver-relative coordinates to display-relative coordinates => TreeViewer#getItem(int x, int y) returns wrong item.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/ToolTipSupport.java
*
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *     Tom Schindl <tom.schindl@bestsolution.at> - initial API and implementation
 ******************************************************************************/
package org.eclipse.jface.viewers;
import java.util.Timer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.custom.CLabel;
import org.eclipse.swt.graphics.Color;
import org.eclipse.swt.graphics.Font;
import org.eclipse.swt.graphics.Image;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.layout.FillLayout;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
import org.eclipse.swt.widgets.Shell;
/**
 * The TooltipSupport is the class that provides tooltips for
 * ColumnViewers.
 * @since 3.3
 * <strong>EXPERIMENTAL</strong> This class or interface has been added as
 * part of a work in progress. This API may change at any given time. Please 
 * do not use this API without consulting with the Platform/UI team.
 *
 */
class ToolTipSupport {
	private ColumnViewer viewer;
	private Listener listener = new MouseListener();
	private static final int DEFAULT_SHIFT_X = 10;