Bug 251517 [Preferences] Increase visibility for the ListEditor fields or methods
Build ID: M20080911-1700 Steps To Reproduce: I am trying to create a specialized org.eclipse.jface.preference.ListEditor. I want to specialize the 'remove' button so that I can disable it in a case where it we shouldn't allow them to remove the entry. However, currently all methods and fields that provide access to the buttons or event handling are all private, and thus can not be overridden by subclasses. Expected result is that protected access is provided for dealing with selection changes, button presses, and protected access is provided for access to the buttons so we can enable/disable them as needed. More information:
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/ListEditor.java
* The button box containing the Add, Remove, Up, and Down buttons;
     * <code>null</code> if none (before creation or after disposal).
     */
    private Composite buttonBox;
    /**
     * The Add button.
     */
    private Button addButton;
    /**
     * The Remove button.
     */
    private Button removeButton;
    /**
     * The Up button.
     */
    private Button upButton;
    /**
     * The Down button.
     */
    private Button downButton;
    /**
     * The selection listener.
     */
    private SelectionListener selectionListener;
    /**
     * Creates a new list field editor 
     */
    protected ListEditor() {
    }
    /**