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/javaeditor/CompilationUnitEditor.java
if (accept)
				return;
			
			try {
								
				final ISourceViewer sourceViewer= getSourceViewer();
				IDocument document= sourceViewer.getDocument();	
				document.replace(level.fOffset, level.fLength, null);
				
			} catch (BadLocationException e) {
			}
		}
	}
	
	
	private final static String CODE_FORMATTER_TAB_SIZE= JavaCore.FORMATTER_TAB_SIZE;
	
	private final static String SPACES_FOR_TABS= PreferenceConstants.EDITOR_SPACES_FOR_TABS;
	
	private final static String CLOSE_STRINGS= PreferenceConstants.EDITOR_CLOSE_STRINGS;
	
	private final static String CLOSE_BRACKETS= PreferenceConstants.EDITOR_CLOSE_BRACKETS;
	
	
	
	protected ISavePolicy fSavePolicy;
	
	private JavaEditorErrorTickUpdater fJavaEditorErrorTickUpdater;
	
	private TabConverter fTabConverter;