AddressBookScreen.java

/*
 * Copyright � 2013 Nokia Corporation. All rights reserved.
 * Nokia and Nokia Connecting People are registered trademarks of Nokia Corporation. 
 * Oracle and Java are trademarks or registered trademarks of Oracle and/or its
 * affiliates. Other product and company names mentioned herein may be trademarks
 * or trade names of their respective owners. 
 * See LICENSE.TXT for license information.
 */ 
package com.nokia.example.bcexchanger.ui;

import java.util.Enumeration;
import java.util.Vector;

import javax.microedition.lcdui.Command;
import javax.microedition.lcdui.Displayable;
import javax.microedition.lcdui.Form;
import javax.microedition.lcdui.Gauge;
import javax.microedition.lcdui.Item;
import javax.microedition.lcdui.List;

import com.nokia.example.bcexchanger.*;

/**
 * 
 * This class represents a screen displaying the list of contacts of
 * the address book. The user can either choose the one contact or
 * exit the application
 * 
 * This class performs the reading of address book entries in the 
 * separate thread, because reading the long address book might
 * take significant time
 * 
 * The class is extending an example.BCExchanger.ui.Screen class and
 * implements Runnable interface.
 * 
 * @see example.BCExchanger.ui.Screen Design patterns: State
 */
public class AddressBookScreen extends Screen implements Runnable {

    private Vector names;
    private Vector uids;
    private List list;
    private Command okCommand;
    private Command exitCommand;
    private Gauge gauge;
    private Form progressBar;
    private Thread thread;
    private Command progressExitCommand;

    /**
     * Constructor
     * 
     * @param _midlet -
     *          the parent class which keeps the current UI state
     */
    public AddressBookScreen(BCExchangerMIDlet _midlet) {
        super(_midlet);

        // create and add commands to ui list
        progressBar = new Form("Please wait");

        gauge = new Gauge("Reading contacts", false, Gauge.INDEFINITE, Gauge.CONTINUOUS_RUNNING);
        gauge.setLayout(Item.LAYOUT_CENTER);
        gauge.setLayout(Item.LAYOUT_VCENTER);
        progressBar.append(gauge);

        progressExitCommand = new Command("Exit", Command.EXIT, 1);
        progressBar.addCommand(progressExitCommand);

        progressBar.setCommandListener(this);

        displayable = progressBar;


        // start the thread reading the address book entries
        thread = new Thread(this);
        thread.start();

    }

    public void commandAction(Command command, Displayable _displayable) {

        // in case this callback is called from wrong displayable
        if (_displayable != list && _displayable != progressBar) {
            throw new RuntimeException(
                    "Internal error #14: AddressBookScreen.commandAction()");
        }

        if (command == okCommand) {

            String uid = null;

            // determine the index
            try {
                uid = (String) uids.elementAt(list.getSelectedIndex());
            } catch (Exception e) {
                throw new RuntimeException("Internal error #15");
            }

            // save UID of the chosen card
            try {
                Storage.setBCUID(uid);
                midlet.changeScreen(new MainScreen(midlet));
            } catch (Exception e1) {
                midlet.changeScreen(new AlertMessage(midlet,
                        "Cannot save own business card", null));
            }
        } else if (command == exitCommand || command == progressExitCommand) {
            midlet.quit();
        } else {
            // unknown command
            throw new RuntimeException("Internal error #20");
        }
    }

    /* (non-Javadoc)
     * @see java.lang.Runnable#run()
     */
    public void run() {

       
        // get the list of names and UIDs
        Vector[] v;
        try {
            v = AddressBook.getNamesUIDLists();
            names = v[0];
            uids = v[1];
        } catch (Exception e) {
            midlet.changeScreen(new AlertMessage(midlet,
                    "Cannot read contact list data. Application will exit")); // quit after this alert
            try {
                Thread.sleep(BCExchangerMIDlet.ERROR_ALERT_MESSAGE_TIMEOUT);
            } catch (InterruptedException ex) {
            }
            midlet.quit();
            return;
        }

        midlet.initComm();
        // create a UI list of names
        list = new List("Choose own business card", List.EXCLUSIVE);

        Enumeration e = names.elements();
        if (!e.hasMoreElements()) { // names list is empty
            midlet.changeScreen(new AlertMessage(
                    midlet,
                    "Contact list is empty. Please create own contact. Application will exit")); // quit
            // after
            // this
            // alert
             try {
                Thread.sleep(BCExchangerMIDlet.ERROR_ALERT_MESSAGE_TIMEOUT);
            } catch (InterruptedException ex) {
            }
            midlet.quit();
            return;
        } else {
            while (e.hasMoreElements()) {
                // browse through names list and
                // add them to ui list
                list.append((String) e.nextElement(), null);
            }

            // create and add commands to ui list
            okCommand = new Command("Ok", Command.OK, 1);
            exitCommand = new Command("Exit", Command.EXIT, 1);

            list.addCommand(okCommand);
            list.addCommand(exitCommand);

            list.setCommandListener(this);

            displayable = list;

            midlet.changeScreen(this);
        }

    }
}