How can we draw lines between two panels in a swing

Question

Just want to connect the panels by drawing the line b / w.

I have two panels, and both panels contain Jtable. I want to connect each jtable cell of one panel with another Jtable of another jpanel.

Here I want to draw lines similar to what I highlighted in pink.

and this is the piece of code that I use to create jtables

DefaultTableModel fcdbDataModel = new DefaultTableModel(fcdbIdTxnArray, fcdbIdTxnColumnArray); fcdbIdTxnJTable = new FieldMapperJTable(fcdbDataModel); 

here FieldMapperJTable is my custom jtable class.

Answer 1

You can easily do this using the JFrame / JDialog GlassPane as a drawing field. Just set your custom component as a glass panel for the frame and draw a link directly on it.

You can also do the same using the multi-level frame / dialog panel.

Here is a small working example of how to draw such “links” on a glass panel component:

 import javax.swing.*; import java.awt.*; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.util.HashMap; import java.util.Map; /** * @see http://stackoverflow.com/a/12389479/909085 */ public class ComponentLinkerTest extends JComponent { private Map<JComponent, JComponent> linked; public ComponentLinkerTest () { super (); linked = new HashMap<JComponent, JComponent> (); } public void link ( JComponent c1, JComponent c2 ) { linked.put ( c1, c2 ); repaint (); } protected void paintComponent ( Graphics g ) { Graphics2D g2d = ( Graphics2D ) g; g2d.setRenderingHint ( RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON ); g2d.setPaint ( Color.BLACK ); for ( JComponent c1 : linked.keySet () ) { Point p1 = getRectCenter ( getBoundsInWindow ( c1 ) ); Point p2 = getRectCenter ( getBoundsInWindow ( linked.get ( c1 ) ) ); g2d.drawLine ( p1.x, p1.y, p2.x, p2.y ); } } private Point getRectCenter ( Rectangle rect ) { return new Point ( rect.x + rect.width / 2, rect.y + rect.height / 2 ); } private Rectangle getBoundsInWindow ( Component component ) { return getRelativeBounds ( component, getRootPaneAncestor ( component ) ); } private Rectangle getRelativeBounds ( Component component, Component relativeTo ) { return new Rectangle ( getRelativeLocation ( component, relativeTo ), component.getSize () ); } private Point getRelativeLocation ( Component component, Component relativeTo ) { Point los = component.getLocationOnScreen (); Point rt = relativeTo.getLocationOnScreen (); return new Point ( los.x - rt.x, los.y - rt.y ); } private JRootPane getRootPaneAncestor ( Component c ) { for ( Container p = c.getParent (); p != null; p = p.getParent () ) { if ( p instanceof JRootPane ) { return ( JRootPane ) p; } } return null; } public boolean contains ( int x, int y ) { return false; } private static ComponentLinkerTest linker; public static void main ( String[] args ) { setupLookAndFeel (); JFrame frame = new JFrame (); linker = new ComponentLinkerTest (); frame.setGlassPane ( linker ); linker.setVisible ( true ); JPanel content = new JPanel (); content.setLayout ( new GridLayout ( 10, 5, 5, 5 ) ); content.setBorder ( BorderFactory.createEmptyBorder ( 5, 5, 5, 5 ) ); frame.add ( content ); for ( int i = 0; i < 50; i++ ) { final JButton button = new JButton ( "Button" + i ); button.addActionListener ( new ActionListener () { public void actionPerformed ( ActionEvent e ) { link ( button ); } } ); content.add ( button ); } frame.setDefaultCloseOperation ( JFrame.EXIT_ON_CLOSE ); frame.pack (); frame.setLocationRelativeTo ( null ); frame.setVisible ( true ); } private static JButton last = null; private static void link ( JButton button ) { if ( last == null ) { last = button; } else { linker.link ( last, button ); last = null; } } private static void setupLookAndFeel () { try { UIManager.setLookAndFeel ( UIManager.getSystemLookAndFeelClassName () ); } catch ( ClassNotFoundException e ) { e.printStackTrace (); } catch ( InstantiationException e ) { e.printStackTrace (); } catch ( IllegalAccessException e ) { e.printStackTrace (); } catch ( UnsupportedLookAndFeelException e ) { e.printStackTrace (); } } } 

And the result:
(just press either of the two buttons one by one and they will be connected)

PS To make the lines thicker, you can change the course when drawing:

 g2d.setStroke ( new BasicStroke ( 5f ) );