Bug 43488 [typing] BadPositionCategoryException in LinkedPositionManager
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/text/link/contentassist/ContentAssistant2.java
* 1GGYYWK: ITPJUI:ALL - Dismissing editor with code assist up causes lots of Internal Errors
			 */
			hide();
		}
		/*
		 * @see IViewportListener#viewportChanged(int)
		 */
		public void viewportChanged(int topIndex) {
			hide();
		}
		
		/**
		 * Hides any open popups.
		 */
		protected void hide() {
			fProposalPopup.hide();
			fContextInfoPopup.hide();
		}
	}
	
	/**
	 * An implementation of <code>IContentAssistListener</code>, this class is
	 * used to monitor key events in support of automatic activation
	 * of the content assistant. If enabled, the implementation utilizes a
	 * thread to watch for input characters matching the activation
	 * characters specified by the content assist processor, and if
	 * detected, will wait the indicated delay interval before
	 * activating the content assistant.
	 */
	class AutoAssistListener implements VerifyKeyListener, Runnable {