LifecycleAware

Annotation based triggers that automatically hook observers into the Android lifecycle.

• Pick and choose different lifecycle events for each annotated observer
• Leverages android.arch.lifecycle components and is compatible with the very same Lifecycle.Events
• Automatic binding in one step
• Works out of the box with Activity and Fragment classes

Getting Started

Marking your Observers

In order to properly facilitate auto binding, your observers need two things:

1. Your observers needs to implement LifecycleEventObserver
2. Your observers needs to be initialized before you call LifecycleBinder.bind(...)

Once you meet those prerequisites, you can tag any of your observers like this:

public class MyActivity extends AppCompatActivity {
  // myObserver will automatically trigger during onStart(...)
  @LifecycleAware(Lifecycle.Event.ON_START)
  LifecycleEventObserver myObserver = new MyObserver();

  @Override
  protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      // bind all observers to this Activity's lifecycle
      LifecycleBinder.bind(this);
  }
}

Method based Observers

It is possible quickly register any variable as LifecycleAware as long as you provide the method that should be called during the lifecycle event.

// myList will automatically clear() during onResume(...)
@LifecycleAware(value = Lifecycle.Event.ON_RESUME, method = "clear")
List<String> myList = new ArrayList<>();

Custom Targets

In the case that your target class is not a core Android component (ie not an Activity), you can still perform auto binding. You just need to properly provide the target when binding:

class MyTarget {
  @LifecycleAware(Lifecycle.Event.ON_DESTROY)
  LifecycleEventObserver observer = new MyObserver();
}

MyTarget myTarget = new MyTarget();
LifecycleBinder.bind(myTarget, MyActivity.this);

Custom Lifecycles

In the case that your Lifecycle is customized, you can still perform auto binding. You just need to properly provide the LifecycleOwner or Lifecycle when binding:

LifecycleBinder.bind(someTarget, myCustomOwner);
// or
LifecycleBinder.bind(someTarget, myCustomLifecycle);

Samples

You can find examples in the included sample app.

Dependencies

dependencies {
    implementation 'com.jzallas:lifecycleaware:0.1.0'
    annotationProcessor 'com.jzallas:lifecycleaware-compiler:0.1.0'
}

License

Copyright 2017 Jon Zallas

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
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.