Envío de mensajes entre dos objetos JPanel

Tengo un Java JFrame que contiene un JPanel. Dentro de ese JPanel, hay dos JPanels separados. Cuando el usuario hace clic en un botón en el primer JPanel, se debe enviar un mensaje al otro JPanel notificándole en qué botón se hizo clic. ¿Cuál es la forma más fácil de enviar mensajes entre objetos como este?

Para mKorbel (y el póster original):
Lo que recomiendo es un acoplamiento más flexible, que el único JPanel no tiene conocimiento del otro JPanel y que todas las conexiones se realizan a través de un control de algún tipo. Por ejemplo, para tomar prestado parte de tu código:

CopyTextNorthPanel2.java

import java.awt.*; import javax.swing.*; public class CopyTextNorthPanel2 extends JPanel { private static final long serialVersionUID = 1L; public JTextField northField; public CopyTextNorthPanel2() { northField = new JTextField("Welcome World"); northField.setFont(new Font("Serif", Font.BOLD, 20)); northField.setPreferredSize(new Dimension(300, 25)); add(northField); } public String getNorthFieldText() { return northField.getText(); } } 

CopyTextSouthPanel2.java

 import java.awt.event.*; import javax.swing.*; public class CopyTextSouthPanel2 extends JPanel { private static final long serialVersionUID = 1L; private JTextField firstText = new JTextField("Desired TextField"); private JButton copyButton = new JButton("Copy text from JTextFields"); private CopyTextControl2 control; public CopyTextSouthPanel2() { copyButton.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { if (control != null) { control.copyAction(); } } }); add(firstText); add(copyButton); } public void setControl(CopyTextControl2 control) { this.control = control; } public void setFirstText(String text) { firstText.setText(text); } } 

CopyTextControl2.java

 public class CopyTextControl2 { private CopyTextNorthPanel2 northPanel; private CopyTextSouthPanel2 southPanel; public void copyAction() { if (northPanel != null && southPanel != null) { southPanel.setFirstText(northPanel.getNorthFieldText()); } } public void setNorthPanel(CopyTextNorthPanel2 northPanel) { this.northPanel = northPanel; } public void setSouthPanel(CopyTextSouthPanel2 southPanel) { this.southPanel = southPanel; } } 

CopyText2.java

 import java.awt.*; import javax.swing.*; public class CopyText2 { private static void createAndShowUI() { CopyTextNorthPanel2 northPanel = new CopyTextNorthPanel2(); CopyTextSouthPanel2 southPanel = new CopyTextSouthPanel2(); CopyTextControl2 control = new CopyTextControl2(); southPanel.setControl(control); control.setNorthPanel(northPanel); control.setSouthPanel(southPanel); JPanel mainPanel = new JPanel(new BorderLayout()); mainPanel.add(northPanel, BorderLayout.NORTH); mainPanel.add(Box.createRigidArea(new Dimension(100, 100)), BorderLayout.CENTER); mainPanel.add(southPanel, BorderLayout.SOUTH); JFrame frame = new JFrame("Copy Text"); frame.getContentPane().add(mainPanel); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); frame.pack(); frame.setLocationRelativeTo(null); frame.setVisible(true); } public static void main(String[] args) { java.awt.EventQueue.invokeLater(new Runnable() { public void run() { createAndShowUI(); } }); } } 

Puede crear un evento personalizado y adjuntar uno o más oyentes.

La forma correcta de implementar es hacer que Button ActionListener active el evento y luego haga que sus dos paneles sean oyentes para ese evento.

en la cima de tu clase

 public MyClass implements ActionListener { ... myButton.addActionListener(this); ... public void actionPerformed(ActionEvent e) { //for example if you have more than one events that you need to handle if(e.getSource().equals(myButton) { //update your do some work on you jpanels } } 

Pero realmente, creo que es hora de empezar a pensar en los patrones de diseño. Lo que está describiendo es candidato perfecto para el patrón de observador y posiblemente el patrón de comando

por ejemplo, mediante el uso de las clases de JComponent o (para el problema de JComponent ) extraer el valor de JComponent (s) deseado mediante el uso de getParent()

 import java.awt.*; import javax.swing.*; public class CopyTextFrame extends JFrame { private static final long serialVersionUID = 1L; private CopyTextNorthPanel northPanel; private CopyTextCenterPanel centerPanel; private CopyTextSouthPanel southPanel; public void makeUI() { northPanel = new CopyTextNorthPanel(); centerPanel = new CopyTextCenterPanel(); southPanel = new CopyTextSouthPanel(); northPanel.setName("northPanel"); centerPanel.setName("centerPanel"); southPanel.setName("southPanel"); centerPanel = new CopyTextCenterPanel(); centerPanel.setPreferredSize(new Dimension(300, 40)); southPanel = new CopyTextSouthPanel(); southPanel.setSourceTextField(northPanel.desText); northPanel.setBorder(BorderFactory.createLineBorder(Color.BLACK, 1)); centerPanel.setBorder(BorderFactory.createLineBorder(Color.BLACK, 1)); southPanel.setBorder(BorderFactory.createLineBorder(Color.BLACK, 1)); setLayout(new BorderLayout(5, 5)); setDefaultCloseOperation(EXIT_ON_CLOSE); add(northPanel, BorderLayout.NORTH); add(centerPanel, BorderLayout.CENTER); add(southPanel, BorderLayout.SOUTH); pack(); setVisible(true); } public static void main(String[] args) { SwingUtilities.invokeLater(new Runnable() { @Override public void run() { new CopyTextFrame().makeUI(); } }); } } 

+

 import javax.swing.*; public class CopyTextCenterPanel extends JPanel { private static final long serialVersionUID = 1L; public CopyTextCenterPanel() { } } 

+

 import java.awt.*; import javax.swing.*; public class CopyTextNorthPanel extends JPanel { private static final long serialVersionUID = 1L; public JTextField desText; public CopyTextNorthPanel() { desText = new JTextField("Welcome World"); desText.setFont(new Font("Serif", Font.BOLD, 20)); desText.setPreferredSize(new Dimension(300, 25)); desText.setBorder(BorderFactory.createLineBorder(Color.BLACK, 1)); desText.addComponentListener(null); desText.setName("desText"); add(desText); } public JTextField getDesText() { return desText; } } 

+

 import java.awt.*; import java.awt.event.ActionEvent; import javax.swing.*; public class CopyTextSouthPanel extends JPanel { private static final long serialVersionUID = 1L; private JTextField firstText; private JButton copyButton; private JTextField sourceTextField; private String lds = ""; public CopyTextSouthPanel() { firstText = new JTextField("Desired TextField"); firstText.setMinimumSize(new Dimension(300, 25)); firstText.setPreferredSize(new Dimension(300, 25)); firstText.setMaximumSize(new Dimension(300, 25)); copyButton = new JButton("Copy text from JTextFields"); copyButton.setMinimumSize(new Dimension(200, 25)); copyButton.setPreferredSize(new Dimension(200, 25)); copyButton.setMaximumSize(new Dimension(200, 25)); copyButton.addActionListener(new java.awt.event.ActionListener() { @Override public void actionPerformed(java.awt.event.ActionEvent evt) { copyButtonActionPerformed(evt); } private void copyButtonActionPerformed(ActionEvent evt) { System.out.print("Button pressed" + "\n"); Component[] comp = CopyTextSouthPanel.this.getParent().getComponents(); int nO = comp.length; for (int i = 0; i < comp.length; ++i) { if (comp[i] instanceof JPanel) { String name = ((JPanel) comp[i]).getName(); if (name.equals("northPanel")) { JPanel panel = (JPanel) comp[i]; Component[] comp1 = panel.getComponents(); int nO1 = comp1.length; for (int ii = 0; ii < comp1.length; ++ii) { if (comp1[ii] instanceof JTextField) { String name1 = ((JTextField) comp1[ii]).getName(); if (!(name1 == null)) { if (name1.equals("desText")) { JTextField text = (JTextField) comp1[ii]; String str = text.getText(); firstText.setText(str); System.out.print("set value -> " + str + "\n"); break; } } } } break; } } } lds = sourceTextField.getText(); if (lds != null || (!(lds.isEmpty()))) { firstText.setText(" Msg -> " + lds); } } }); add(firstText, BorderLayout.EAST); add(copyButton, BorderLayout.WEST); } public void setSourceTextField(JTextField source) { this.sourceTextField = source; } }