SwipeRefreshLayout example

activity_main.xml

<android.support.v4.widget.SwipeRefreshLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/srl_main"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:id="@+id/lv_main"/>

</android.support.v4.widget.SwipeRefreshLayout>

ApiManager.java

package com.andraskindler.sandbox.activity;

import retrofit.RestAdapter;
import retrofit.http.GET;
import retrofit.http.Query;
import rx.Observable;
import rx.Subscriber;
import rx.schedulers.Schedulers;

public class ApiManager {

    private interface ApiManagerService {
        @GET("/weather")
        WeatherData getWeather(@Query("q") String place, @Query("units") String units);
    }

    private static final RestAdapter restAdapter = new RestAdapter.Builder()
        .setEndpoint("http://api.openweathermap.org/data/2.5")
        .build();

    private static final ApiManagerService apiManager = restAdapter.create(ApiManagerService.class);

    public static Observable<WeatherData> getWeatherData(final String city) {
        return Observable.create(new Observable.OnSubscribe<WeatherData>() {
            @Override
            public void call(Subscriber<? super WeatherData> subscriber) {
                if (!subscriber.isUnsubscribed())
                    try {
                        subscriber.onNext(apiManager.getWeather(city, "metric"));
                        subscriber.onCompleted();
                    } catch (Exception e) {
                        subscriber.onError(e);
                    }
            }
        }).subscribeOn(Schedulers.io());
    }

}

MainActivity.java

package com.andraskindler.sandbox.activity;

import android.app.Activity;
import android.os.Bundle;
import android.support.v4.widget.SwipeRefreshLayout;
import android.widget.ListView;

import com.andraskindler.sandbox.R;

import rx.Observable;
import rx.Observer;
import rx.Subscription;
import rx.android.schedulers.AndroidSchedulers;
import rx.functions.Func1;
import rx.schedulers.Schedulers;

public class MainActivity extends Activity {

    private WeatherListAdapter adapter;
    private SwipeRefreshLayout swipeRefreshLayout;
    private Subscription subscription;
    private final String[] cities = new String[]{"Budapest", "Santiago", "Barcelona", "Madrid", "London", "Moscow", "Berlin", "New York", "San Francisco", "Dublin"};

    private Observable<WeatherData> observable = Observable.from(cities)
        .flatMap(new Func1<String, Observable<WeatherData>>() {
            @Override
            public Observable<WeatherData> call(String s) {
                return ApiManager.getWeatherData(s);
            }
        }).subscribeOn(Schedulers.io()).observeOn(AndroidSchedulers.mainThread());

    private final Observer<WeatherData> observer = new Observer<WeatherData>() {
        @Override
        public void onCompleted() {
            if (swipeRefreshLayout.isRefreshing())
                swipeRefreshLayout.setRefreshing(false);
        }

        @Override
        public void onError(Throwable e) {

        }

        @Override
        public void onNext(WeatherData weatherData) {
            adapter.update(weatherData);
        }
    };

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

        swipeRefreshLayout = (SwipeRefreshLayout) findViewById(R.id.srl_main);
        swipeRefreshLayout.setColorScheme(R.color.blue, R.color.green, R.color.red, R.color.yellow);
        swipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
            @Override
            public void onRefresh() {
                if (!subscription.isUnsubscribed())
                    subscription.unsubscribe();
                adapter.clear();
                subscription = observable.subscribe(observer);
            }
        });

        adapter = new WeatherListAdapter();
        ((ListView) findViewById(R.id.lv_main)).setAdapter(adapter);

        swipeRefreshLayout.setRefreshing(true);
        subscription = observable.subscribe(observer);

    }

}

WeatherListAdapter.java

package com.andraskindler.sandbox.activity;

import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;


import java.util.ArrayList;
import java.util.List;

public class WeatherListAdapter extends BaseAdapter {

    private List<WeatherData> items;

    public WeatherListAdapter() {
        items = new ArrayList<>();
    }

    public void update(final WeatherData weatherData){
        items.add(weatherData);
        notifyDataSetChanged();
    }

    public void clear(){
        items.clear();
        notifyDataSetChanged();
    }

    @Override
    public int getCount() {
        return items.size();
    }

    @Override
    public WeatherData getItem(int position) {
        return items.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        final TextView textView = new TextView(parent.getContext());
        textView.setText(items.get(position).name + "\n" + items.get(position).main.temp);

        return textView;
    }
}