Smashing Android UI

Chapter 6: Android Intents

Android’s intent system is probably the most powerful platform feature that the Android has. The intents tie apps together internally and externally. The intent system makes it possible for developers to call functionality from the Android platform and from any other installed apps. It also allows your app to provide functionality to other apps.

This chapter explains what Android intents are and where they are used. The goal of this chapter is to give you a good understanding of how the intent mechanism affects Android user interface design. This chapter explains some examples but does not cover the full intent specification and all use cases. I encourage you to see Android documentation for deeper technical information (see http://developer.android.com/reference/android/content/Intent.html).

Intents allow apps to work together

In short, an intent is a technical and formally defined message sent to an application component. The message can be internal in one app or sent between different apps or even between the operating system and apps. An app can, for example, message the operating system that it wants to dial a phone number.

The most powerful implication of the intent mechanism is that the apps are all capable of working together and sharing each other’s functionality in a very easy and seamless way. Any app can ask the platform to identify other apps that provide certain functionality, and then use one of them or let the user pick one.

One of ...