Bug 40772 [plan item] Smart tab on empty lines
When having the caret on an empty line, pressing tab cleans up the line and sets the caret it the right indentation column.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/WorkInProgressPreferencePage.java
/** 
	 * All FieldEditors except <code>smartTyping</code>, whose enable state
	 * is controlled by the smartTyping preference.
	 */
	private Set fSmartTypingItems= new HashSet();
	
	private List fCheckBoxes;
	private List fRadioButtons;
	private List fTextControls;
	
	
	private org.eclipse.swt.widgets.List fQuickDiffProviderList;
	
	private String[][] fQuickDiffProviderListModel;
	
	private Button fSetDefaultButton;
	/**
	 * creates a new preference page.
	 */
	public WorkInProgressPreferencePage() {
		setPreferenceStore(getPreferenceStore());
		fRadioButtons= new ArrayList();
		fCheckBoxes= new ArrayList();
		fTextControls= new ArrayList();
		List providers= new QuickDiff().getReferenceProviderDescriptors();
		fQuickDiffProviderListModel= createQuickDiffReferenceListModel(providers);
	}
	private String[][] createQuickDiffReferenceListModel(List providers) {
		ArrayList listModelItems= new ArrayList();
		for (Iterator it= providers.iterator(); it.hasNext();) {