Bug 75711 AstProvider should not create AST if requested by SelectionListenerWithASTManager
3.1 M2 If SelectionListenerWithASTManager waits for an AST and the editor closes we should not create an AST for that one but return null instead.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/javaeditor/JavaEditor.java
*/
				public IInformationControlCreator getInformationPresenterControlCreator() {
					return fControlCreator;
				}
			}
			ISourceViewer sourceViewer= getSourceViewer();
			if (sourceViewer == null) {	
				fTextOperationAction.run();
				return;
			}
				
			if (sourceViewer instanceof ITextViewerExtension4)  {
				ITextViewerExtension4 extension4= (ITextViewerExtension4) sourceViewer;
				if (extension4.moveFocusToWidgetToken())
					return;
			}
			
			if (! (sourceViewer instanceof ITextViewerExtension2)) {
				fTextOperationAction.run();
				return;
			}
				
			ITextViewerExtension2 textViewerExtension2= (ITextViewerExtension2) sourceViewer;
			
			
			ITextHover textHover= textViewerExtension2.getCurrentTextHover();
			if (textHover == null) {
				fTextOperationAction.run();
				return;				
			}