Bug 263207 [CommonNavigator] Improve DnD tracing and add DnD test suite
There are no DnD tests for the Common Navigator. Also, the CNF has many test utility classes (basically stolen from JDT), these should be moved into a lower level area, and it looks like org.eclipse.ui.test.harness is a good place. (Perhaps we can get the JDT to use these identical versions as well so there is only one copy that everyone uses). Finally, the DnD tracing needs to be improved to show more information and show it more concisely.
bundles/org.eclipse.ui.navigator/src/org/eclipse/ui/navigator/CommonDropAdapter.java
public Object getCurrentTarget() {
		return super.getCurrentTarget();
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.ui.part.PluginDropAdapter#getCurrentTransfer()
	 */
	public TransferData getCurrentTransfer() {
		return super.getCurrentTransfer();
	}
	
    /**
     * Returns the position of the given event's coordinates relative to its target.
     * The position is determined to be before, after, or on the item, based on
     * some threshold value.
     *
     * @param event the event
     * @return one of the <code>LOCATION_* </code>constants defined in this class
     */
    protected int determineLocation(DropTargetEvent event) {
        if (!(event.item instanceof Item)) {
            return LOCATION_NONE;
        }
        Point coordinates = new Point(event.x, event.y);
        coordinates = getViewer().getControl().toControl(coordinates);
        return LOCATION_ON;
    }
}