Bug 268533 [Viewers] Weird painting when using MOUSE_CLICK_ACTIVATION
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/SWTFocusCellManager.java
import org.eclipse.swt.events.DisposeEvent;
import org.eclipse.swt.events.DisposeListener;
import org.eclipse.swt.graphics.Point;
import org.eclipse.swt.widgets.Event;
import org.eclipse.swt.widgets.Listener;
/**
 * This class is responsible to provide cell management base features for the
 * SWT-Controls {@link org.eclipse.swt.widgets.Table} and
 * {@link org.eclipse.swt.widgets.Tree}.
 *
 * @since 3.3
 *
 */
abstract class SWTFocusCellManager {
	private CellNavigationStrategy navigationStrategy;
	private ColumnViewer viewer;
	private ViewerCell focusCell;
	private FocusCellHighlighter cellHighlighter;
	private DisposeListener itemDeletionListener = new DisposeListener() {
		public void widgetDisposed(DisposeEvent e) {
			setFocusCell(null);
		}
	};
	/**
	 * @param viewer
	 * @param focusDrawingDelegate
	 * @param navigationDelegate
	 */
	public SWTFocusCellManager(ColumnViewer viewer,
			FocusCellHighlighter focusDrawingDelegate,