Navi

Hey, listen!

Adds listeners for Activity and Fragment.

Looking for an RxJava 2 compatible library? Check out the navi 2.x branch.

Why?

In a word: composition.

For applications, you currently have to tie a lot of your functionality directly to each Activity and Fragment. The potential for code reuse is low. Testing is difficult.

For libraries, if you want to interact with the Activity or Fragment at all, good luck. You either have to leave brittle instructions on how to properly implement the library, or you provide your own Activity/ Fragment. Two libraries providing their own components are difficult (or impossible) to use together.

With Navi, you can avoid all these problems. Applications can decouple your code from the underlying Activity or Fragment. Libraries using Navi can write real plugins instead of brittle/coupled solutions.

Usage

The NaviComponent interface is the basis for everything; you can add/remove listeners for any specific callbacks that exist on Activity and Fragment:

naviComponent.addListener(Event.CREATE, new Listener<Bundle>() {

@Override public void call(Bundle bundle) {

  setContentView(R.layout.main);

}
 
}
);

You will either need to implement the NaviComponent interface yourself, or if you're able, you can save time by using one of the default implementations provided (in the form of NaviActivity, NaviAppCompatActivity, NaviFragment and NaviDialogFragment). This flexibility allows you to integrate Navi even if you're already being forced to use a different base Activity or Fragment.

Since RxJava is the bees knees, it also provides Rx bindings for all listeners via RxNavi. Simply pass your NaviComponent to them and it'll do the rest. For example, you could use it to set the content view instead of overriding onCreate():

RxNavi.observe(naviComponent, Event.CREATE)
  .subscribe(bundle -> setContentView(R.layout.main));

Installation

compile 'com.trello:navi:1.0'

License

Copyright (C) 2016 Trello  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.