Bug 30751 [Viewers] Closing all projects doesnt clear package browser list [browsing]
In the java browsing perspective, if you close all projects, the packages browser still has a list of all the packages from the last opened project.
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
* <code>null</code> if there is no item at that location.
 * <p>
 * The default implementation of this method returns <code>null</code>.
 * </p>
 *
 * @param x horizontal coordinate
 * @param y vertical coordinate
 * @return the item, or <code>null</code> if there is no item at the
 *  given coordinates
 */
protected Item getItem(int x, int y) {
	return null;
}
/**
 * Returns the children of the given parent without sorting and 
 * filtering them.  
 * The resulting array must not be modified,
 * as it may come directly from the model's internal state.
 * <p>
 * Returns an empty array if the given parent is <code>null</code>.
 * </p>
 *
 * @param parent the parent element
 * @return the child elements
 */
protected Object[] getRawChildren(Object parent) {
	Object[] result = null;
	if (parent != null) {
		result = ((IStructuredContentProvider) getContentProvider()).getElements(parent);
		Assert.isNotNull(result);