Bug 125516 [KeyBindings] misc: API to return a KeySequence string for a command id
The KeyAssistDialog contains code that returns the formatted string for the active key binding for the "show key assist" command. It would be nice if this were generalized to a utility method that returns the string for the active key binding given a command id. Or, if you'd rather put this at the JFace keys level, code that returns the formatted string given the array of TriggerSequences (so that the client has to look up the binding with the right service). Right now I have copied this code into the WorkbenchContentAssistAdapter. There is similar code in JDT that does this (but not as thoroughly as the code in KeyAssistDialog).
bundles/org.eclipse.jface/src/org/eclipse/jface/bindings/BindingManager.java
* 
	 * @param map
	 *            The map to modify; if this value is <code>null</code>, then
	 *            this method simply returns.
	 * @param key
	 *            The key to look up in the map; may be <code>null</code>.
	 * @param value
	 *            The value to look up in the map; may be <code>null</code>.
	 */
	private static final void addReverseLookup(final Map map, final Object key,
			final Object value) {
		if (map == null) {
			return;
		}
		final Object currentValue = map.get(key);
		if (currentValue != null) {
			final Collection values = (Collection) currentValue;
			values.add(value);
		} else { 
			final Collection values = new ArrayList(1);
			values.add(value);
			map.put(key, values);
		}
	}
	/**
	 * <p>
	 * Takes a fully-specified string, and converts it into an array of
	 * increasingly less-specific strings. So, for example, "en_GB" would become
	 * ["en_GB", "en", "", null].
	 * </p>