Bug 25768 Package Explorer flashes too much on refresh and delete
build I20021105 - extracted a zip containing 22 non-Java files (.mxsd files from Dejan) into org.eclipse.ui - in Package Explorer, refreshed org.eclipse.ui - it flashed alot while refreshing - selected the 22 files and deleted them - it flashed even more
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerContentProvider.java
import org.eclipse.jface.viewers.StructuredSelection;
import org.eclipse.jface.viewers.TreeViewer;
import org.eclipse.jface.viewers.Viewer;
import org.eclipse.jdt.core.ElementChangedEvent;
import org.eclipse.jdt.core.IClassFile;
import org.eclipse.jdt.core.ICompilationUnit;
import org.eclipse.jdt.core.IElementChangedListener;
import org.eclipse.jdt.core.IJavaElement;
import org.eclipse.jdt.core.IJavaElementDelta;
import org.eclipse.jdt.core.IJavaProject;
import org.eclipse.jdt.core.IPackageFragment;
import org.eclipse.jdt.core.IPackageFragmentRoot;
import org.eclipse.jdt.core.IWorkingCopy;
import org.eclipse.jdt.core.JavaCore;
import org.eclipse.jdt.core.JavaModelException;
import org.eclipse.jdt.ui.StandardJavaElementContentProvider;
import org.eclipse.jdt.internal.ui.JavaPlugin;
 
/**
 * Content provider for the PackageExplorer.
 * 
 * <p>
 * Since 2.1 this content provider can provide the children for flat or hierarchical
 * layout. The hierarchical layout is done by delegating to the <code>PackageFragmentProvider</code>.
 * </p>
 * 
 * @see org.eclipse.jdt.ui.StandardJavaElementContentProvider
 * @see org.eclipse.jdt.internal.ui.packageview.PackageFragmentProvider
 */
class PackageExplorerContentProvider extends StandardJavaElementContentProvider implements ITreeContentProvider, IElementChangedListener {