Bug 305703 [Viewers][CommonNavigator] remembered contributions can leak when using filters
bundles/org.eclipse.jface/src/org/eclipse/jface/viewers/StructuredViewer.java
}
	}
	
	/**
	 * Creates a structured element viewer. The viewer has no input, no content
	 * provider, a default label provider, no sorter, and no filters.
	 */
	protected StructuredViewer() {
		
	}
	/**
	 * Adds a listener for double-clicks in this viewer. Has no effect if an
	 * identical listener is already registered.
	 * 
	 * @param listener
	 *            a double-click listener
	 */
	public void addDoubleClickListener(IDoubleClickListener listener) {
		doubleClickListeners.add(listener);
	}
	/**
	 * Adds a listener for selection-open in this viewer. Has no effect if an
	 * identical listener is already registered.
	 * 
	 * @param listener
	 *            an open listener
	 */
	public void addOpenListener(IOpenListener listener) {
		openListeners.add(listener);
	}