MVC Pattern in Java 2
//[C] 2002 Sun Microsystems, Inc.---
import java.awt.BorderLayout;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.util.ArrayList;
import java.util.Iterator;
import javax.swing.BoxLayout;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
public class RunMVCPattern {
public static void main(String [] arguments){
System.out.println("Example for the MVC pattern");
System.out.println();
System.out.println("In this example, a Contact is divided into");
System.out.println(" Model, View and Controller components.");
System.out.println();
System.out.println("To illustrate the flexibility of MVC, the same");
System.out.println(" Model will be used to provide information");
System.out.println(" to two View components.");
System.out.println();
System.out.println("One view, ContactEditView, will provide a Contact");
System.out.println(" editor window and will be paired with a controller");
System.out.println(" called ContactEditController.");
System.out.println();
System.out.println("The other view, ContactDisplayView, will provide a");
System.out.println(" display window which will reflect the changes made");
System.out.println(" in the editor window. This view does not support");
System.out.println(" user interaction, and so does not provide a controller.");
System.out.println();
System.out.println("Creating ContactModel");
ContactModel model = new ContactModel();
System.out.println("Creating ContactEditView and ContactEditController");
ContactEditView editorView = new ContactEditView(model);
model.addContactView(editorView);
createGui(editorView, "Contact Edit Window");
System.out.println("Creating ContactDisplayView");
ContactDisplayView displayView = new ContactDisplayView();
model.addContactView(displayView);
createGui(displayView, "Contact Display Window");
}
private static void createGui(JPanel contents, String title){
JFrame applicationFrame = new JFrame(title);
applicationFrame.getContentPane().add(contents);
applicationFrame.addWindowListener(new WindowCloseManager());
applicationFrame.pack();
applicationFrame.setVisible(true);
}
private static class WindowCloseManager extends WindowAdapter{
public void windowClosing(WindowEvent evt){
System.exit(0);
}
}
}
//Model
class Contact{
private String firstName;
private String lastName;
private String title;
private String organization;
private ContactView view;
public Contact(ContactView v){
firstName = "";
lastName = "";
title = "";
organization = "";
view = v;
}
public String getFirstName(){
return firstName;
}
public String getLastName(){
return lastName;
}
public String getTitle(){
return title;
}
public String getOrganization(){
return organization;
}
public void setFirstName(String newFirstName){
firstName = newFirstName;
}
public void setLastName(String newLastName){
lastName = newLastName;
}
public void setTitle(String newTitle){
title = newTitle;
}
public void setOrganization(String newOrganization){
organization = newOrganization;
}
public void updateModel(String newFirstName,
String newLastName, String newTitle,
String newOrganization){
if ((newFirstName != null) && !newFirstName.equals("")){
setFirstName(newFirstName);
}
if ((newLastName != null) && !newLastName.equals("")){
setLastName(newLastName);
}
if ((newTitle != null) && !newTitle.equals("")){
setTitle(newTitle);
}
if ((newOrganization != null) && !newOrganization.equals("")){
setOrganization(newOrganization);
}
updateView();
}
private void updateView(){
view.refreshContactView(firstName, lastName, title, organization);
}
}
interface ContactView{
public void refreshContactView(String firstName,
String lastName, String title, String organization);
}
class ContactModel{
private String firstName;
private String lastName;
private String title;
private String organization;
private ArrayList contactViews = new ArrayList();
public ContactModel(){
this(null);
}
public ContactModel(ContactView view){
firstName = "";
lastName = "";
title = "";
organization = "";
if (view != null){
contactViews.add(view);
}
}
public void addContactView(ContactView view){
if (!contactViews.contains(view)){
contactViews.add(view);
}
}
public void removeContactView(ContactView view){
contactViews.remove(view);
}
public String getFirstName(){ return firstName; }
public String getLastName(){ return lastName; }
public String getTitle(){ return title; }
public String getOrganization(){ return organization; }
public void setFirstName(String newFirstName){ firstName = newFirstName; }
public void setLastName(String newLastName){ lastName = newLastName; }
public void setTitle(String newTitle){ title = newTitle; }
public void setOrganization(String newOrganization){ organization = newOrganization; }
public void updateModel(String newFirstName, String newLastName,
String newTitle, String newOrganization){
if (!isEmptyString(newFirstName)){
setFirstName(newFirstName);
}
if (!isEmptyString(newLastName)){
setLastName(newLastName);
}
if (!isEmptyString(newTitle)){
setTitle(newTitle);
}
if (!isEmptyString(newOrganization)){
setOrganization(newOrganization);
}
updateView();
}
private boolean isEmptyString(String input){
return ((input == null) || input.equals(""));
}
private void updateView(){
Iterator notifyViews = contactViews.iterator();
while (notifyViews.hasNext()){
((ContactView)notifyViews.next()).refreshContactView(firstName, lastName, title, organization);
}
}
}
class ContactEditView extends JPanel implements ContactView{
private static final String UPDATE_BUTTON = "Update";
private static final String EXIT_BUTTON = "Exit";
private static final String CONTACT_FIRST_NAME = "First Name ";
private static final String CONTACT_LAST_NAME = "Last Name ";
private static final String CONTACT_TITLE = "Title ";
private static final String CONTACT_ORG = "Organization ";
private static final int FNAME_COL_WIDTH = 25;
private static final int LNAME_COL_WIDTH = 40;
private static final int TITLE_COL_WIDTH = 25;
private static final int ORG_COL_WIDTH = 40;
private ContactEditController controller;
private JLabel firstNameLabel, lastNameLabel, titleLabel, organizationLabel;
private JTextField firstName, lastName, title, organization;
private JButton update, exit;
public ContactEditView(ContactModel model){
controller = new ContactEditController(model, this);
createGui();
}
public ContactEditView(ContactModel model, ContactEditController newController){
controller = newController;
createGui();
}
public void createGui(){
update = new JButton(UPDATE_BUTTON);
exit = new JButton(EXIT_BUTTON);
firstNameLabel = new JLabel(CONTACT_FIRST_NAME);
lastNameLabel = new JLabel(CONTACT_LAST_NAME);
titleLabel = new JLabel(CONTACT_TITLE);
organizationLabel = new JLabel(CONTACT_ORG);
firstName = new JTextField(FNAME_COL_WIDTH);
lastName = new JTextField(LNAME_COL_WIDTH);
title = new JTextField(TITLE_COL_WIDTH);
organization = new JTextField(ORG_COL_WIDTH);
JPanel editPanel = new JPanel();
editPanel.setLayout(new BoxLayout(editPanel, BoxLayout.X_AXIS));
JPanel labelPanel = new JPanel();
labelPanel.setLayout(new GridLayout(0, 1));
labelPanel.add(firstNameLabel);
labelPanel.add(lastNameLabel);
labelPanel.add(titleLabel);
labelPanel.add(organizationLabel);
editPanel.add(labelPanel);
JPanel fieldPanel = new JPanel();
fieldPanel.setLayout(new GridLayout(0, 1));
fieldPanel.add(firstName);
fieldPanel.add(lastName);
fieldPanel.add(title);
fieldPanel.add(organization);
editPanel.add(fieldPanel);
JPanel controlPanel = new JPanel();
controlPanel.add(update);
controlPanel.add(exit);
update.addActionListener(controller);
exit.addActionListener(new ExitHandler());
setLayout(new BorderLayout());
add(editPanel, BorderLayout.CENTER);
add(controlPanel, BorderLayout.SOUTH);
}
public Object getUpdateRef(){ return update; }
public String getFirstName(){ return firstName.getText(); }
public String getLastName(){ return lastName.getText(); }
public String getTitle(){ return title.getText(); }
public String getOrganization(){ return organization.getText(); }
public void refreshContactView(String newFirstName,
String newLastName, String newTitle,
String newOrganization){
firstName.setText(newFirstName);
lastName.setText(newLastName);
title.setText(newTitle);
organization.setText(newOrganization);
}
private class ExitHandler implements ActionListener{
public void actionPerformed(ActionEvent event){
System.exit(0);
}
}
}
class ContactEditController implements ActionListener{
private ContactModel model;
private ContactEditView view;
public ContactEditController(ContactModel m, ContactEditView v){
model = m;
view = v;
}
public void actionPerformed(ActionEvent evt){
Object source = evt.getSource();
if (source == view.getUpdateRef()){
updateModel();
}
}
private void updateModel(){
String firstName = null;
String lastName = null;
if (isAlphabetic(view.getFirstName())){
firstName = view.getFirstName();
}
if (isAlphabetic(view.getLastName())){
lastName = view.getLastName();
}
model.updateModel( firstName, lastName,
view.getTitle(), view.getOrganization());
}
private boolean isAlphabetic(String input){
char [] testChars = {'1', '2', '3', '4', '5', '6', '7', '8', '9', '0'};
for (int i = 0; i < testChars.length; i++){
if (input.indexOf(testChars[i]) != -1){
return false;
}
}
return true;
}
}
class ContactDisplayView extends JPanel implements ContactView{
private JTextArea display;
public ContactDisplayView(){
createGui();
}
public void createGui(){
setLayout(new BorderLayout());
display = new JTextArea(10, 40);
display.setEditable(false);
JScrollPane scrollDisplay = new JScrollPane(display);
this.add(scrollDisplay, BorderLayout.CENTER);
}
public void refreshContactView(String newFirstName,
String newLastName, String newTitle, String newOrganization){
display.setText("UPDATED CONTACT:\nNEW VALUES:\n" +
"\tName: " + newFirstName + " " + newLastName +
"\n" + "\tTitle: " + newTitle + "\n" +
"\tOrganization: " + newOrganization);
}
}
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