Bug 221337 [Markers] MarkerItem has too much API
We are exposing too much as API in MarkerItem. We should only provide getAtttributeValue and the methods that support PATH_ATTRIBUTE and NAME_ATTRIBUTE as they are tricky. Everything else needs to be pushed down to an internal class. We should mention the relevant IMarker constants for those removed.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/views/markers/MarkerField.java
int width = gc.getFontMetrics().getAverageCharWidth();
		gc.dispose();
		return width;
	}
	/**
	 * Return the id for the receiver.
	 * 
	 * @return String
	 */
	public String getId() {
		return configurationElement
				.getAttribute(MarkerSupportConstants.ATTRIBUTE_ID);
	}
	/**
	 * Return the value for a marker.
	 * 
	 * @param marker
	 * @return String
	 */
	public String getMarkerValue(IMarker marker) {
		return getValue(new MarkerEntry(marker));
	}
	/**
	 * Get the severity of the element.
	 * 
	 * @param element
	 * @return int
	 * @see IMarker#SEVERITY_ERROR
	 * @see IMarker#SEVERITY_WARNING
	 * @see IMarker#SEVERITY_INFO