Droidcon 2013: Ship Faster With Open Source from Square

Pierre-Yves Ricau, Square @piwai

Sample project: http://github.com/pyricau/shipfaster

• look out for talk later at devoxx about how square got rid of fragments
• debug panel in app, slides from right
  • lets you adjust the settings

dagger dependency injection

https://github.com/square/dagger

• create object graph in application
• injection happens in activity onCreate (prob. base class)
• can switch between modules when create graph (e.g. using build settings)
• resolves dependencies at compile time as it’s annotation based
  • don’t get errors at run time
  • doesn’t use reflection so faster
• also generates dot files so can view dependency graph

otto

https://github.com/square/otto

• (the bus driver in the Simpsons…)
• broadcasts are not type safe and fragile
• define event classes
• the bus then calls the event methods for all subscribers
• also provides an event logger
• events are called synchronously

dagger & otto together

• use a custom annotation with dagger bindings
• can then add subscription/unsubscription easily

robolectric

http://robolectric.org/

• main developer now at square…

retrofit REST client

https://github.com/square/retrofit

• define an interface for API
• methods take a callback method
• callback will happen on UI thread
• suggestion: use otto bus to fire events on return
• create a RestAdapter and plug it in using dagger
• has a log level to show you all headers
• also works with protocol buffers
• async by default, but can also do sync if you want to do multiple serialized calls from a background thread
• can use underneath robospice

picasso

https://github.com/square/picasso

• image loader from URLs
• placeholder & error images
• resize dimensions
• don’t need to deal with http or caching at all!
• has debug indicator corners on images:
  • green from memory
  • yellow from filesystem
  • red from network
• can apply transforms to images
• handles large images well
• adjusts threads for downloading & encoding according to network status (wifi, 3G)
• but may not respect cache expiry headers… (poss only when not used with OkHttp)

OkHttp

https://github.com/square/okhttp

• Android has switched from Apache HttpClient to URLConnection
• HttpClient no longer maintained in Android :-(
• OkHttp now part of AOSP!
• create a client and retrieve an HttpURLConnection
• used by retrofit and picasso by default

more info available

• http://square.github.io
• http://piwai.info