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
/*
		 * @see org.eclipse.jface.viewers.ISelectionChangedListener#selectionChanged(org.eclipse.jface.viewers.SelectionChangedEvent)
		 */
		public void selectionChanged(SelectionChangedEvent event) {
			
			JavaEditor.this.selectionChanged();
		}
	}
		
	/**
	 * Updates the selection in the editor's widget with the selection of the outline page. 
	 */
	class OutlineSelectionChangedListener  extends AbstractSelectionChangedListener {
		public void selectionChanged(SelectionChangedEvent event) {
			doSelectionChanged(event);
		}
	}
	
	
	/**
	 * Adapts an options {@link java.util.Map} to {@link org.eclipse.jface.preference.IPreferenceStore}.
	 * <p>
	 * This preference store is read-only i.e. write access
	 * throws an {@link java.lang.UnsupportedOperationException}.
	 * </p>
	 * 
	 * @since 3.0
	 */
	private static class OptionsAdapter implements IPreferenceStore {