Here you can find the source of createMarker(int span, String tooltip)
static JComponent createMarker(int span, String tooltip)
//package com.java2s; // Licensed under the Apache License, Version 2.0 (the "License"); import java.awt.Color; import javax.swing.JComponent; import javax.swing.JLabel; public class Main { static final private String MARKER_LABEL = "spanRow()"; static final private String MARKER_NAME = "DesignGridLayout.spanRow-Marker"; static JComponent createMarker(int span, String tooltip) { JLabel marker = new JLabel(MARKER_LABEL); marker.setName(MARKER_NAME);/*from w w w . j a v a2s.co m*/ marker.setHorizontalAlignment(JLabel.CENTER); marker.setOpaque(true); marker.setBackground(Color.RED); marker.setToolTipText(tooltip); return marker; } }