Android Libraries: Pros, Cons, and Gotchas

By Ryan Cooke

This is Important● Long term consequence● Months productivity● Google expects it

“If that ecosystem is already enabled, what value are we adding by just adding something else to it?”

- Chet Haase

General Tips● Reversibility● Wrapper

General Tips● Unit Test 3rd Party Libraries● Method Count

○ Methods Count○ Dex-method-counts○ Apk-method-count○ Pull out the core of the library

● Popular & Mature Libraries● Beware of Unusual Approaches

Social Login● Facebook

○ Test Users○ Email not guaranteed○ Key hashes○ Review is a pain○ Log errors

Social Login● Twitter

○ Not very popular <2%○ https://support.twitter.com/forms/platform

● LinkedIn○ Not very popular <2%○ Challenging api

● Google○ Multiple email choices○ Design limitations○ Works well with smart lock

Login Various● Smart Lock

○ Email Hint○ Cross platform○ Great experience ideal case○ Not on iOS○ Assets.json requires server upload

Networking● Retrofit● Volley

● OkHttp○ Behind the scenes○ Android 4.4

Networking Debugging - Stetho

Network Debugging - HttpLoggingInterceptor

Images● Picasso

○ Very small library (2.5.2/849) ○ Simple to Use

● Glide○ Gif support○ Various nice to haves○ Larger (3.7.0/2879)

● Tips○ Prefetch on lists○ Memory

■ Profile■ Resize

● Cloudinary■ Bytes used = pixel width * pixel height * 4■ largeHeap (Large Heap App Detector)

ARGB_8888 RGB_565

Images - Fresco● Magic memory cleverness

○ Pre-lollipop (api 21)

● Progressive jpg● Drawees instead of imageViews

Memory - Leaks● Leak Canary

○ Difficult to read○ Not easiest to share○ Don’t forget to set watchers

●●●●●● WeakHandler

UI● Activities

○ Where it all began

● Fragments○ Solution or Problem?

● Views○ Swap content of frame layout

View-Based-Architecture● Mortar + Flow

○ MVP○ Lacks solutions to common issues

● Conductor○ Built solving common view based

architecture issues

● Scoop○ Limited Transition○ Can’t Save State○ Most Production Tested

Model View Presenter (MVP)● Mosby

○ Tutorial○ ViewState

● Nucleus● Mortar● Build it yourself

Testing - Unit Testing● MVP (Model View Presenter)● Dependency Injection (DI)● Roboelectirc

○ Rewrote core android libraries with shadow classes

● Junit4○ Assertj-Android○ MoreAsserts○ ViewAsserts

Testing - Instrumentation Testing● Espresso

○ Espresso Screen Recorder

● Inferior options● okhttp/mockwebserver

Device Labs● Have your own

○ Spoon

● AWS Device Farm○ $0.17 per minute ($250/mo unlimited 1

device)

● Firebase○ $5 per device hour physical, $1 per hour

virtual

● Lots of others

Build Systems● Jenkins● BuddyBuild● CircleCI

Build System Extras● Checkstyle

○ Use the plugin○ Enforce style in your team

● Findbugs○ Bytecode

● PMD○ Source code

● Android Lint○ Lots of hidden capabilities

● Autoformatter○ Fix style no enforcement needed

Testing - Performance - NimbeDroid

Database - SQL● SQLite● SQLBrite

○ Reactive sqlIte○ Update with changes

● SQLDelight○ Work with SQL easier○ Organizing sql statements○ TypeSafe Api for read/write

● ORMs○ GreenDAO○ OrmLite○ DBFlow

Database - NoSQL● Realm

○ Documentation and support○ Is super fast

● LevelDB○ Key-Value pair by Google

Database - Mobile Platform● Firebase● Realm

○ Offline first

● Gson● Jackson● Moshi● LoganSquare

○ Compile time work

● Flatbuffer○ Json alternative

Json

Deeplinking● Services

○ Yozio○ Branch○ Firebase Dynamic

Links

● App link● Deep Link Dispatch

Analytics● Wrapping 3rd party tools● Log screens● If you can measure you can

optimize● Don’t get lost

○ Adding too many○ Untested○ Confusing naming○ Delaying easy decisions○ Finding too large of conclusions

Analytics - Firebase● Firebase Analytics

○ Underlies all of firebase○ Free○ Actively Improving

Analytics● Google Analytics

○ Basic○ Behavior Flow

● Play Store Console○ Basic Core Questions

● Answers○ Great for the office tv

● Mixpanel○ Paid, but very good

● Lots more

Attribution● Adjust

○ For when Facebook makes attribution hard

● Play Store Url builder○ https://play.google.com/store/apps/details?id=com.exa

mple.application&referrer=utm_source%3Dgoogle%26utm_medium%3Dcpc%26utm_campaign%3Dspring_sale

adb shell am broadcast -a com.android.vending.INSTALL_REFERRER -n <your.package>/.<path.up.until.your.BroadcastReceiver> --es "referrer" "utm_source=test_source\&utm_medium=test_medium\&utm_term=test_term\&utm_content=test_content\&utm_campaign=test_name"

A/B Testing● Disclaimer

○ Overhyped○ Slow learning○ Great for making bugs

● Services○ Optimizely○ Firebase Remote Config○ Apptimize

● Store Listing

Crash Reporting● Play Store

○ Misses most crashes○ Occasionally very useful

● Crashlytics○ Free

● Bugsnag○ Paid○ Query crashes

● Instabug or Telescope○ Easy to report bugs

Feedback● Zendesk● Intercom● Android-Rate

○ Strategic review prompt○ Non 5 star reviews to feedback○ Significantly more reviews

Push Notifications● GCM/FCM

○ Not great for marketing people

● Analytic Services○ Firebase Notifications○ Mixpanel

● Push Services○ UrbanAirship○ Kahuna

■ AI

Other Notifications● Email

○ Campaign■ MailChimp

○ Interaction■ SendGrid■ ManDrill■ MailGun

● SMS○ Twilio

Easier● Butterknife

○ Zelezny

● Hugo● Dart & Henson● Retrolambda

Harder (at First)● RxJava

○ React to stuff○ Learning curve○ Misused

● Kotlin○ Cleaner code○ Null pointer○ New language

● EventBus

Logging● Logger

○ Pretty logs

● Timber○ Custom logging behavior○ Combined logging options

Camera● Camera Intent● Material

Camera○ Easy to fork

● Android Crop

Thinking Globally● Network Emulation

○ Emulator○ Charles Proxy○ Augmented Traffic Control (ATC)

● AutoFitTextView● Year Class

○ 2015 is the max

● Connection Class○ Sampling is wonky

Android-KnitHave lunch with Pinterest Android

Questionsryancooke@pinterest.com

Video● ExoPlayer

○ DASH (adaptive bitrate streaming)○ SmoothStreaming○ Customizable○ API 16

● YouTube ○ Easy○ SEO

Building the app● Gradle

○ Staying standard is good

● OkBuck○ Converts Gradle to Buck

● Buck● Bazel

Building the app● Instant Run

○ Doesn’t work

● JRebel○ First run is very slow○ Does work○ Annotation processing on incremental

build for popular libraries○ 14 day free trial

● hannesstruss/godot○ Track time lost to builds

Emulator● Genymotion● Native (Avd)

○ Generally comparable to genymotion and free

Dependency Injection● Dagger 2● Dagger 1

○ Like Dagger 2, but slower

● Roboguice○ Like Dagger 1, but slower

Social Login● Easier to implement● More secure● Easier to signup● More information on signup

Layout Processor● Anko

○ 400% faster■ No Benchmarks

○ Newer devices handful of ms○ No Preview○ Kotlin

Login● Firebase Auth UI

○ Limited Properties○ Vendor Lock

● AuthZero○ Better UI○ Costs Money

Memory● Memory Monitor● Hprof

Images - Memory● Profile● Resize● Width * Height * 4

Images - Memory● android:largeHeap=”true”

○ Large Heap App Detector

● drawable-nodpi

Referral● Firebase Invites● Do It Yourself

Maps● AirMapView

○ Chooses the best map

● Google Maps

Obfuscation● Proguard

○ Shrinks○ Optimizes○ Obfuscates

■ Mapping

● Dexguard○ Obfuscation

Chat● Layer

○ Handle everything○ Very custom

● Sinch○ Great Support○ Doesn’t solve all problems○ 1 on 1 chat

● PubNub○ Built for real time

● Firebase○ Misses lots of flare

● Twilio● Chateau

Text● Calligraphy

○ Font

● Android AutoFitTextView

Date & Time● Joda Time

○ Joda-time-android○ Java devs goto fix for Date

● ThreeTenABP○ Java 8 solution

● Java 8○ Doesn’t have improvements

Payment● Stripe● Braintree

○ Braintree cc

● Card.io

Graphs● Spark● MPAndroidChart