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
* 
		 * @param position Position where the action should move the caret
		 */
		protected abstract void setCaretPosition(int position);
	}
	/**
	 * Text navigation action to navigate to the next sub-word.
	 * 
	 * @since 3.0
	 */
	protected class NavigateNextSubWordAction extends NextSubWordAction {
		/**
		 * Creates a new navigate next sub-word action.
		 */
		public NavigateNextSubWordAction() {
			super(ST.WORD_NEXT);
		}
		/*
		 * @see org.eclipse.jdt.internal.ui.javaeditor.JavaEditor.NextSubWordAction#setCaretPosition(int)
		 */
		protected void setCaretPosition(final int position) {
			getTextWidget().setCaretOffset(modelOffset2WidgetOffset(getSourceViewer(), position));
		}
	}
	/**
	 * Text operation action to delete the next sub-word.
	 * 
	 * @since 3.0
	 */
	protected class DeleteNextSubWordAction extends NextSubWordAction implements IUpdate {