Cleaning up Android Main Activity Code

Question

I'm a real noob when it comes to Java and OOP in general. I'm having issues with my app crashing and I think it's because my Main Activity is cluttered and my overall program is not structured properly. Can anyone advise me on how to clean up the following code to make things run smoother and have a better app structure? I think I need to separate things into different classes and keep most of the functions in different classes, but I'm new and really not sure. I keep getting an ANR error when I run the app on a phone (keyDispatchingTimedOut error) and I think my unorganized code is causing this. Any help would be great! Thanks.

    package com.example.www;

public class MainActivity extends Activity {

    Button mCloseButton;
    Button mOpenButton;
    MultiDirectionSlidingDrawer mDrawer;

    private Button send_button;
    EditText msgTextField;

    private LocationManager locManager;
    private LocationListener locListener;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature( Window.FEATURE_NO_TITLE );
        setContentView(R.layout.main);

        mDrawer.open();

        final SharedPreferences shared = getSharedPreferences("PEOPLE_PREFERENCES", MODE_PRIVATE);
        final String phone = shared.getString("PHONE", "");

        String usr_id = shared.getString("USR_ID", null);

        if(phone == null) {
            TextView text = (TextView)findViewById(R.id.textView1); 
            text.setText("Please Enter Your Phone Number");

            AlertDialog.Builder alert = new AlertDialog.Builder(this);

            alert.setTitle("Please Enter Your Phone Number");
            alert.setMessage("You must enter your phone number in order to use this application");

            final EditText input = new EditText(this);
            alert.setView(input);

            alert.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
            public void onClick(DialogInterface dialog, int whichButton) {
                String value = input.getText().toString();
                if (value.length() == 10) {
                    Editor editor = shared.edit();
                    editor.putString("PHONE", value);
                    editor.commit();
                }
             }
            });
            alert.show();     
        }

        Button profile = (Button) findViewById(R.id.button1);
        profile.setOnClickListener(new OnClickListener() {

            public void onClick(View v) {
                startActivity(new Intent(MainActivity.this, PreferencesActivity.class));
            }
        });



        if (usr_id == null) {

            char[] chars = "abcdefghijklmnopqrstuvwxyzABSDEFGHIJKLMNOPQRSTUVWXYZ1234567890".toCharArray();
            Random r = new Random(System.currentTimeMillis());
            char[] id = new char[8];
            for (int i = 0;  i < 8;  i++) {
                id[i] = chars[r.nextInt(chars.length)];
            }
            usr_id = new String(id);
            Editor editor = shared.edit();
            editor.putString("USR_ID", usr_id);
            editor.commit();
        }

        final String usr_id1 = shared.getString("USR_ID", "none");

        send_button = (Button)findViewById(R.id.button2);

        send_button.setOnClickListener(new OnClickListener() {
            private boolean running = false;
            private CountDownTimer timer;
            public void onClick(View v) {
              if(!running)
              {
                running = true;
                timer = new CountDownTimer(4000, 1000) {

                    @Override
                    public void onFinish() {
                        send_button.setText("GPS Sent");  
                        startLocation();
                        sendId(usr_id1, phone);
                    }

                    @Override
                    public void onTick(long sec) {
                        send_button.setText("CANCEL (" + sec / 1000 + ")");

                    }
                }.start();
              }
              else
              {
                 timer.cancel();
                 send_button.setText("Send GPS");
                 running = false;
              }
            }
        });
    }  


    private void startLocation()
    {

        //get a reference to the LocationManager
        locManager = 
            (LocationManager)getSystemService(Context.LOCATION_SERVICE);

        //get the last known position
        Location loc = 
            locManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

        //show the last known position
        //showPosition(loc);

        //checked to receive updates from the position
        locListener = new LocationListener() {
            public void onLocationChanged(Location location) {
                showPosition(location);
            }
            public void onProviderDisabled(String provider){
                //labelState.setText("Provider OFF");
            }
            public void onProviderEnabled(String provider){
                //labelState.setText("Provider ON ");
            }
            public void onStatusChanged(String provider, int status, Bundle extras){
                //Log.i("", "Provider Status: " + status);
                //labelState.setText("Provider Status: " + status);
            }
        };

        locManager.requestLocationUpdates(
                LocationManager.GPS_PROVIDER, 0, 0, locListener);
    }

    private void showPosition(Location loc) {
        if(loc != null)
        {

            Log.i("", String.valueOf(loc.getLatitude() + " - " + String.valueOf(loc.getLongitude())));

            send(loc);
        }

    }

    private void send(Location loc)
    {
         String lat = String.valueOf(loc.getLatitude()); 
         String lon = String.valueOf(loc.getLongitude());

        SharedPreferences shared = getSharedPreferences("PEOPLE_PREFERENCES", MODE_PRIVATE);
        final String usr_id2 = shared.getString("USR_ID", "none");

        if (lat != "0" && lon != "0")   
        {
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("http://example.com/test/example1.php");
            //HttpPost httppost = new HttpPost("http://kblapdesk.com/myers27/receive.php");
         try {
           List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2); //changed to 4
           nameValuePairs.add(new BasicNameValuePair("lat", lat)); //changed "message" to "lat" changed "msg" to "lat"
           nameValuePairs.add(new BasicNameValuePair("lon", lon)); //added this line
           nameValuePairs.add(new BasicNameValuePair("id", usr_id2));
           httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
           httpclient.execute(httppost);
         } catch (ClientProtocolException e) {
             // TODO Auto-generated catch block
         } catch (IOException e) {
             // TODO Auto-generated catch block
         }

        }
        else
        {
            // display message if text fields are empty
            Toast.makeText(getBaseContext(),"All field are required",Toast.LENGTH_SHORT).show();
        }

    }

    private void sendId(String usr_id1, String phone)
    {
            HttpClient httpclient = new DefaultHttpClient();
            HttpPost httppost = new HttpPost("http://example.com/test/example.php");
            //HttpPost httppost = new HttpPost("http://kblapdesk.com/myers27/receive_user.php");
         try {
           List<NameValuePair> nameValuePairs = new ArrayList<NameValuePair>(2); //changed to 4

           nameValuePairs.add(new BasicNameValuePair("id", usr_id1));

           httppost.setEntity(new UrlEncodedFormEntity(nameValuePairs));
           httpclient.execute(httppost);
           //msgTextField.setText(""); // clear text box
         } catch (ClientProtocolException e) {
             // TODO Auto-generated catch block
         } catch (IOException e) {
             // TODO Auto-generated catch block
         }

        mCloseButton.setOnClickListener( new OnClickListener() {
            public void onClick( View v )
            {
                mDrawer.animateClose();
            }
        });

        mOpenButton.setOnClickListener( new OnClickListener() {

            public void onClick( View v )
            {
                if( !mDrawer.isOpened() )
                    mDrawer.animateOpen();
            }
        });
    }

    @Override
   public void onContentChanged()
   {
    super.onContentChanged();
    mCloseButton = (Button) findViewById( R.id.button_open );
    mOpenButton = (Button) findViewById( R.id.button_open );
    mDrawer = (MultiDirectionSlidingDrawer) findViewById( R.id.drawer );
   }
}

Answer 1

I would encapsulate the LocationListener in a totally different class. That should shorten up most of your code and leave you with a manageable chunk to work with.

Additionally, you seem to have some HTTP post or web-request methods in your MainActivity. Take those out and put them in a different class as well. Name it something like ActivityServer or something akin to that.

In your ActivityServer class, you should make a callback and asynchronous interfaces so that you don't block the UI thread when doing web requests.