mikkipastel

image: openjdk:8-jdk

variables:
  ANDROID_COMPILE_SDK: "25"
  ANDROID_BUILD_TOOLS: "25.0.2"
  ANDROID_SDK_TOOLS: "25.2.5"

before_script:
    # installing packages
    - apt-get --quiet update --yes

mikkipastel

/*
 * Copyright 2017, The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software

mikkipastel

@Dao
interface UserDao {
    @Query("SELECT * FROM user ORDER BY lastName ASC")
    public abstract LivePagedListProvider<Integer, User> usersByLastName();
}

mikkipastel

class MyViewModel extends ViewModel {
    public final LiveData<PagedList<User>> usersList;
    public MyViewModel(UserDao userDao) {
        usersList = userDao.usersByLastName().create(
                /* initial load position */ 0,
                new PagedList.Config.Builder()
                        .setPageSize(50)
                        .setPrefetchDistance(50)
                        .build());
    }

mikkipastel

class MyActivity extends AppCompatActivity {
    @Override
    public void onCreate(Bundle savedState) {
        super.onCreate(savedState);
        MyViewModel viewModel = ViewModelProviders.of(this).get(MyViewModel.class);
        RecyclerView recyclerView = findViewById(R.id.user_list);
        UserAdapter<User> adapter = new UserAdapter();
        viewModel.usersList.observe(this, pagedList -> adapter.setList(pagedList));
        recyclerView.setAdapter(adapter);
    }

mikkipastel

class UserAdapter extends PagedListAdapter<User, UserViewHolder> {
    public UserAdapter() {
        super(DIFF_CALLBACK);
    }
    @Override
    public void onBindViewHolder(UserViewHolder holder, int position) {
        User user = getItem(position);
        if (user != null) {
            holder.bindTo(user);
        } else {

mikkipastel

public class UserRepository {
    private Webservice webservice;
    // ...
    public LiveData<User> getUser(int userId) {
        // This is not an optimal implementation, we'll fix it below
        final MutableLiveData<User> data = new MutableLiveData<>();
        webservice.getUser(userId).enqueue(new Callback<User>() {
            @Override
            public void onResponse(Call<User> call, Response<User> response) {
                // error case is left out for brevity

mikkipastel

public interface Webservice {
    @GET("/users/{user}")
    Call<User> getUser(@Path("user") String userId);
}

mikkipastel

buildscript {

    project.ext.compileSdkVersion = 26
    project.ext.buildToolsVersion = "26.0.1"

    repositories {
        jcenter()
        google()
    }
    dependencies {

mikkipastel

apply plugin: 'com.android.feature'

android {
    buildToolsVersion '26.0.0'
    compileSdkVersion 26

    dataBinding {
        enabled = true
    }