Bug 9818 Java Browsing: Editor with non-java resource flushes views
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/browsing/JavaBrowsingPart.java
fDeleteAction= new DeleteAction(provider);
		fRefreshAction= new RefreshAction(getShell());
		
		IActionBars actionService= getViewSite().getActionBars();
		actionService.setGlobalActionHandler(IWorkbenchActionConstants.DELETE, fDeleteAction);
	}
	/**
	 * Returns the shell to use for opening dialogs.
	 * Used in this class, and in the actions.
	 */
	private Shell getShell() {
		return fViewer.getControl().getShell();
	}
	protected final Display getDisplay() {
		return fViewer.getControl().getDisplay();
	}	
	/**
	 * Answers if the given <code>element</code> is a valid
	 * input for this part.
	 * 
	 * @param 	element	the object to test
	 * @return	<true> if the given element is a valid input
	 */
	abstract protected boolean isValidInput(Object element);
	/**
	 * Answers if the given <code>element</code> is a valid
	 * element for this part.
	 * 
	 * @param 	element	the object to test