compartment

Overview

Compartment is an extemely lightweight MVP (Model View Presenter) library for Android. It aims to make scoping really easy for Presenters so that each fragment has an associated presenter and that presenter instance doesn't get destroyed on configuration changes.

Usage

Step 1:

Make your Activity (or Activities) extend ComponentCacheActivity or build a custom class that implements ComponentCache.

Step 2:

Create a view interface

public interface MyView {
  void doSomething();
  void showLoading();
  void hideLoading();
  ...
}

Step 3:

Create a presenter that implements Presenter or uses the convenience class BasePresenter

public class MyPresenter extends BasePresenter<MyView> {
  public void someLongTask() {
    view.showLoading();
    
    new AsyncTask<Void, Void, Void>() {
      public Void doInBackground(Void... args) {
        // Simulate some long task
        Thread.sleep(5000);
      }
      
      public void onPostExecute(Void result) {
        view.doSomething();
        view.hideLoading();
      }
    }.execute();
  }
}

Step 4:

Create an object to hold a presenter (implements HasPresenter)

public class MyPresenterComponent implements HasPresenter<MyPresenter> {
  private MyPresenter presenter = new MyPresenter();
  
  @Override MyPresenter getPresenter() {
    return presenter;
  }
}

Step 5:

Create a Fragment that extends PresenterControllerFragment and implements your view interface.

public class MyFragment extends PresenterControllerFragment<MyPresenterComponent, MyPresenter> implements MyView {
  @Override protected MyPresenterComponent onCreateNonConfigurationComponent() {
    return new MyPresenterComponent();
  }
  ...
}

If you made a custom ComponentCache in step 1, you need to override getComponentCache() in this Fragment too.

Your fragment now has an associated presenter that you can access using getPresenter(). This presenter will survive configuration changes and will have it's lifecycle methods called automatically.

Note that PresenterControllerFragment is another convenience class. If you need to extend ListFragment, MapFragment, or any other type of Fragment, you can use the PresenterControllerDelegate class and forward all of the events just like PresenterControllerFragment does internally.

Tips

This library works well when combined with Dagger 2 as you can use Dagger 2 components for Step 4.
The components can hold more than just presenters, they could hold any object you want to survive a configuration change. The components can be accessed at any point by calling getComponent in the Fragment.

Example

https://github.com/grandstaish/hello-mvp-dagger-2

Gradle

repositories {
  jcenter()
}

dependencies {
  compile 'nz.bradcampbell.compartment:compartment:0.0.4'
}

License

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.

chennemann/compartment