Bug 73083 [Encoding] Need to verify encodings and indicate unavailable ones
When the encodings are set up we need to ensure that they are in the list of valid encodings available from the VM. Those that are not should be indicated as such and not be selectable in the UI.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/dialogs/AbstractEncodingFieldEditor.java
import org.eclipse.ui.ide.IDEEncoding;
import org.eclipse.ui.internal.ide.IDEWorkbenchMessages;
/**
 * The abstract superclass of editors used to set an 
 * enconding. Any user entered
 * encodings will be added to the list of encodings in the 
 * IDEEncoding.
 * @since 3.1
 * @see org.eclipse.ui.ide.IDEEncoding
 */
public abstract class AbstractEncodingFieldEditor extends FieldEditor {
	private Composite container;
	private Button defaultEncodingButton;
	private String defaultEnc;
	private Button otherEncodingButton;
	private Combo encodingCombo;
	private boolean isValid = true;
	private String oldSelectedEncoding;
	/**
	 * Create an instance of the receiver with no parameters
	 * set.
	 */
	public AbstractEncodingFieldEditor() {
		super();
	}
	/**
	 * Create a new instance of the receiver on the preference called name
	 * with a label of labelText.
	 * @param name
	 * @param labelText