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
return delta.getElement();
		
		IJavaElementDelta[] affectedChildren= delta.getAffectedChildren();
		for (int i= 0; i < affectedChildren.length; i++) 
			return findAddedElement(affectedChildren[i]);
			
		return null;
	}
	/**
	 * Refreshes the Compilation unit corresponding to the workging copy
	 * @param iWorkingCopy
	 */
	private void refreshWorkingCopy(IWorkingCopy workingCopy) {
		IJavaElement original= workingCopy.getOriginalElement();
		if (original != null)
			postRefresh(original);
	}
	private boolean isWorkingCopy(IJavaElement element) {
		return (element instanceof IWorkingCopy) && ((IWorkingCopy)element).isWorkingCopy();
	}
	
	/**
	 * Updates the package icon
	 */
	 private void postUpdateIcon(final IJavaElement element) {
	 	postRunnable(new Runnable() {
			public void run() {
				
				Control ctrl= fViewer.getControl();
				if (ctrl != null && !ctrl.isDisposed())