Still don't know what is happening here

package felipevidal.stormy;

import android.content.Context;
import android.graphics.drawable.Drawable;
import android.net.ConnectivityManager;
import android.net.NetworkInfo;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
import android.view.View;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.TextView;
import android.widget.Toast;

import org.json.JSONException;
import org.json.JSONObject;

import java.io.IOException;

import butterknife.BindView;
import butterknife.ButterKnife;
import okhttp3.Call;
import okhttp3.Callback;
import okhttp3.OkHttpClient;
import okhttp3.Request;
import okhttp3.Response;

public class MainActivity extends AppCompatActivity {

    public static final String TAG = MainActivity.class.getSimpleName();

    private CurrentWeather mCurrentWeather;

    @BindView(R.id.timeLabel) TextView mTimeLabel;
    @BindView(R.id.temperatureLabel) TextView mTemperatureLabel;
    @BindView(R.id.humidityValue) TextView mHumidityValue;
    @BindView(R.id.precipValue) TextView mPrecipValue;
    @BindView(R.id.summaryLabel) TextView mSummaryLabel;
    @BindView(R.id.iconImageView) ImageView mIconImageView;
    @BindView(R.id.refreshImageView) ImageView mRefreshImageView;
    @BindView(R.id.progressBar) ProgressBar mProgressBar;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        ButterKnife.bind(this);

        mProgressBar.setVisibility(View.INVISIBLE);

        final double latitude = 37.8267;
        final double longitude = -122.423;

        mRefreshImageView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                getForecast(latitude, longitude);
            }
        });

        getForecast(latitude, longitude);

        Log.d(TAG, "Main UI code is running!");
    }

    private void getForecast(double latitude, double longitude) {
        String apiKey = "27974c4bc33201748eaf542a6769c3b7";

        String forecastUrl = "https://api.forecast.io/forecast/" + apiKey +
                "/" + latitude + "," + longitude;

        if (isNetworkAvailable()) {
            toggleRefresh();

            OkHttpClient client = new OkHttpClient();
            Request request = new Request.Builder()
                    .url(forecastUrl)
                    .build();

            Call call = client.newCall(request);
            call.enqueue(new Callback() {

                @Override
                public void onFailure(Call call, IOException e) {
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            toggleRefresh();
                        }
                    });
                    alertUserAboutError();
                }

                @Override
                public void onResponse(Call call, Response response) throws IOException {
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            toggleRefresh();
                        }
                    });
                    try {
                        String jsonData = response.body().string();
                        Log.v(TAG, jsonData);
                        if (response.isSuccessful()) {
                            mCurrentWeather = getCurrentDetails(jsonData);
                            runOnUiThread(new Runnable() {
                                @Override
                                public void run() {
                                    updateDisplay();
                                }
                            });
                        } else {
                            alertUserAboutError();
                        }
                    }
                    catch (IOException e) {
                        Log.e(TAG, "Exception caught: ", e);
                    }
                    catch (JSONException e) {
                        Log.e(TAG, "Exception caught: ", e);
                    }
                }
            });
        }
        else {
            Toast.makeText(this, getString(R.string.network_unavailable_message),
                    Toast.LENGTH_LONG).show();
        }
    }

    private void toggleRefresh() {
        if(mProgressBar.getVisibility() == View.INVISIBLE) {
            mProgressBar.setVisibility(View.VISIBLE);
            mRefreshImageView.setVisibility(View.INVISIBLE);

        }else{
            mProgressBar.setVisibility(View.INVISIBLE);
            mRefreshImageView.setVisibility(View.VISIBLE);
        }
    }

    private void updateDisplay() {
        mTemperatureLabel.setText(mCurrentWeather.getTemperature() + "");
        mTimeLabel.setText("At " + mCurrentWeather.getFormattedTime() + " it will be");
        mHumidityValue.setText(mCurrentWeather.getHumidity() + "");
        mPrecipValue.setText(mCurrentWeather.getPrecipChance() + "%");
        mSummaryLabel.setText(mCurrentWeather.getSummary());

        Drawable drawable = getResources().getDrawable(mCurrentWeather.getIconId());
        mIconImageView.setImageDrawable(drawable);
    }

    private CurrentWeather getCurrentDetails(String jsonData) throws JSONException {
        JSONObject forecast = new JSONObject(jsonData);
        String timezone = forecast.getString("timezone");
        Log.i(TAG, "From JSON: " + timezone);

        JSONObject currently = forecast.getJSONObject("currently");

        CurrentWeather currentWeather = new CurrentWeather();
        currentWeather.setHumidity(currently.getDouble("humidity"));
        currentWeather.setTime(currently.getLong("time"));
        currentWeather.setIcon(currently.getString("icon"));
        currentWeather.setPrecipChance(currently.getDouble("precipProbability"));
        currentWeather.setSummary(currently.getString("summary"));
        currentWeather.setTemperature(currently.getDouble("temperature"));
        currentWeather.setTimeZone(timezone);

        Log.d(TAG, currentWeather.getFormattedTime());

        return currentWeather;
    }


    private boolean isNetworkAvailable() {
        ConnectivityManager manager = (ConnectivityManager)
                getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        boolean isAvailable = false;
        if (networkInfo != null && networkInfo.isConnected()) {
            isAvailable = true;
        }

        return isAvailable;
    }

    private void alertUserAboutError() {
        AlertDialogFragment dialog = new AlertDialogFragment();
        dialog.show(getFragmentManager(), "error_dialog");
    }
}

package felipevidal.stormy;

import java.text.SimpleDateFormat;
import java.util.Date;
import java.util.TimeZone;

public class CurrentWeather {
    private String mIcon;
    private long mTime;
    private double mTemperature;
    private double mHumidity;
    private double mPrecipChance;
    private String mSummary;
    private String mTimeZone;

    public String getTimeZone() {
        return mTimeZone;
    }

    public void setTimeZone(String timeZone) {
        mTimeZone = timeZone;
    }

    public String getIcon() {
        return mIcon;
    }

    public void setIcon(String icon) {
        mIcon = icon;
    }

    public int getIconId() {
        // clear-day, clear-night, rain, snow, sleet, wind, fog, cloudy, partly-cloudy-day, or partly-cloudy-night.
        int iconId = R.drawable.clear_day;

        if (mIcon.equals("clear-day")) {
            iconId = R.drawable.clear_day;
        }
        else if (mIcon.equals("clear-night")) {
            iconId = R.drawable.clear_night;
        }
        else if (mIcon.equals("rain")) {
            iconId = R.drawable.rain;
        }
        else if (mIcon.equals("snow")) {
            iconId = R.drawable.snow;
        }
        else if (mIcon.equals("sleet")) {
            iconId = R.drawable.sleet;
        }
        else if (mIcon.equals("wind")) {
            iconId = R.drawable.wind;
        }
        else if (mIcon.equals("fog")) {
            iconId = R.drawable.fog;
        }
        else if (mIcon.equals("cloudy")) {
            iconId = R.drawable.cloudy;
        }
        else if (mIcon.equals("partly-cloudy-day")) {
            iconId = R.drawable.partly_cloudy;
        }
        else if (mIcon.equals("partly-cloudy-night")) {
            iconId = R.drawable.cloudy_night;
        }

        return iconId;
    }

    public long getTime() {
        return mTime;
    }

    public String getFormattedTime() {
        SimpleDateFormat formatter = new SimpleDateFormat("h:mm a");
        formatter.setTimeZone(TimeZone.getTimeZone(getTimeZone()));
        Date dateTime = new Date(getTime() * 1000);
        String timeString = formatter.format(dateTime);

        return timeString;
    }

    public void setTime(long time) {
        mTime = time;
    }

    public int getTemperature() {
        return (int)Math.round(mTemperature);
    }

    public void setTemperature(double temperature) {
        mTemperature = temperature;
    }

    public double getHumidity() {
        return mHumidity;
    }

    public void setHumidity(double humidity) {
        mHumidity = humidity;
    }

    public int getPrecipChance() {
        double precipPercentage = mPrecipChance * 100;
        return (int)Math.round(precipPercentage);
    }

    public void setPrecipChance(double precipChance) {
        mPrecipChance = precipChance;
    }

    public String getSummary() {
        return mSummary;
    }

    public void setSummary(String summary) {
        mSummary = summary;
    }
}

package felipevidal.stormy;

import android.app.AlertDialog;
import android.app.Dialog;
import android.app.DialogFragment;
import android.content.Context;
import android.os.Bundle;

public class AlertDialogFragment extends DialogFragment {

    @Override
    public Dialog onCreateDialog(Bundle savedInstanceState) {
        Context context = getActivity();
        AlertDialog.Builder builder = new AlertDialog.Builder(context)
                .setTitle(context.getString(R.string.error_title))
                .setMessage(context.getString(R.string.error_message))
                .setPositiveButton(context.getString(R.string.error_ok_button_text), null);

        AlertDialog dialog = builder.create();
        return dialog;
    }
}