HowItWorks

Overview

AndroidAnnotations works in a very simple way. It automatically adds an extra compilation step that generates source code, using the standard Java Annotation Processing Tool.

What source code ? For each enhanced class, for example each @EActivity annotated activity, a subclass of this activity is generated, with the same name plus an underscore appended at the end.

For instance, the following class:

package com.some.company;
@EActivity
public class MyActivity extends Activity {
  // ...
}

Will generate the following subclass, in the same package but in another source folder:

package com.some.company;
public final class MyActivity_ extends MyActivity {
  // ...
}

This subclass adds behavior to your activity by overriding some methods (for instance onCreate()), yet delegating the calls to super.

That is the reason why you must add _ to your activity names in AndroidManifest.xml:

<activity android:name=".MyListActivity_" />

Starting an annotated activity

In Android, you usually start an activity this way:

startActivity(this, MyListActivity.class);

However, with AndroidAnnotations, the real activity that must be started is MyListActivity_:

startActivity(this, MyListActivity_.class);

Intent Builder

Since AndroidAnnotations 2.4

We provide a static helper to let you start the generated activity:

// Starting the activity
MyListActivity_.intent(context).start();

// Building an intent from the activity
Intent intent = MyListActivity_.intent(context).get();

// You can provide flags
MyListActivity_.intent(context).flags(FLAG_ACTIVITY_CLEAR_TOP).start();

// You can even provide extras defined with @Extra in the activity
MyListActivity_.intent(context).myDateExtra(someDate).start();

Since AndroidAnnotations 2.7

You can also use the startActivityForResult() equivalent:

MyListActivity_.intent(context).startForResult(REQUEST_CODE);

Note that you can use the @OnActivityResult annotation to get result code and extra value.

@OnActivityResult(REQUEST_CODE)
void onResult(int resultCode) {
}

Since AndroidAnnotations 3.3

You can easily pass options Bundle parameter using the intent builder:

MyListActivity_.intent(context).withOptions(bundle).start();

Since AndroidAnnotations 4.0.0

Activity [transition animations](http://developer.android.com/reference/android/app/Activity.html#overridePendingTransition(int, int)) can be added using the fluent intent builder.

MyListActivity_.intent(context).start().withAnimation(enterAnimRes, exitAnimRes));

Starting an annotated Service

In Android, you usually start a service this way:

startService(this, MyService.class);

However, with AndroidAnnotations, the real Service that must be started is MyService_:

startService(this, MyService_.class);

Intent Builder

Since AndroidAnnotations 2.7

We provide a static helper to let you start the generated service:

// Starting the service
MyService_.intent(context).start();

// Building an intent from the activity
Intent intent = MyService_.intent(context).build();

// You can provide flags
MyService_.intent(context).flags(Intent.FLAG_GRANT_READ_URI_PERMISSION).start();

Is there any performance impact?

The short answer is no. More on this subject in the FAQ.

Now that you get the basics, let's see how to enhance Activities.