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
* this method.
     * </p>
     *
     * @return the shell
     */
    protected Shell getShell() {
        if (addButton == null) {
			return null;
		}
        return addButton.getShell();
    }
    /**
     * Splits the given string into a list of strings.
     * This method is the converse of <code>createList</code>. 
     * <p>
     * Subclasses must implement this method.
     * </p>
     *
     * @param stringList the string
     * @return an array of <code>String</code>
     * @see #createList
     */
    protected abstract String[] parseString(String stringList);
    /**
     * Notifies that the Remove button has been pressed.
     */
    private void removePressed() {
        setPresentsDefaultValue(false);
        int index = list.getSelectionIndex();
        if (index >= 0) {