LightCycle is an Android library that helps break logic out of Activity and Fragment classes into small, self-contained components called LightCycles.
Fields that are annotated @LightCycle and implement the LightCycle API within a LightCycleActivity or LightCycleFragment will be bound to that Activity or Fragment lifecycle.
LightCycle lets self-contained classes respond to Android’s lifecycle events. This supports composition over inheritance and promotes components that follow the single responsibility principle. We believe it helps us write more readable, maintainable and testable code. It works particularly well alongside dependency injection.
● Activity and Fragment classes: ○ Inflate layouts and configure Android specifics ○ Declare LightCycles ● A LightCycle component is responsible for an isolated chunk of logic (such as presentation, tracking etc.)
A LightCycle doesn't know about other LightCycles. There is no guarantee for ordering when multiple LightCycles receive the same lifecycle callback.
Do your view initialization in your Activity
public class MyActivity extends LightCycleAppCompatActivity {
@LightCycle MyController controller = new MyController();
@Override
protected void setActivityContentView() {
setContentView(R.layout.main);
}
} And put your logic inside your LightCycle
public class MyController extends DefaultActivityLightCycle {
@Override
public void onPause(MyActivity activity) {
// MyActivity was paused
}
[...]
@Override
public void onResume(MyActivity activity) {
// MyActivity was resumed
}
} ● Basic
There are 3 types of LightCycles - the API is comparable to the ActivityLifecycleCallbacks from the Android SDK:
● ActivityLightCycle ● FragmentLightCycle ● SupportFragmentLightCycle
For convenience, default implementations are provided:
● DefaultActivityLightCycle ● DefaultFragmentLightCycle ● DefaultSupportFragmentLightCycle
This dispatches an Activity or Fragment lifecycle callback to attached LightCycles. The API defines a single bind method. See the LightCycleDispatcher interface.
Three types of dispatchers are provided:
● ActivityLightCycleDispatcher ● FragmentLightCycleDispatcher ● SupportFragmentLightCycleDispatcher
Note: these built-in classes are both dispatchers and LightCycles, meaning that you can nest LightCycles.
Do your view initialization in your activity as usual
public class MyActivity extends LightCycleAppCompatActivity {
@LightCycle MyController controller = new MyController();
@Override
protected void setActivityContentView() {
setContentView(R.layout.main);
}
} Extend your logic class to matching Dispatcher class based on the type (Activity with ActivityLightCycleDispatcher, Fragment with FragmentLightCycleDispatcher, etc) and then you can nest another LightCycles too inside your Dispatcher
public class MyController extends ActivityLightCycleDispatcher {
@LightCycle MySubController1 controller = new MyController1();
@LightCycle MySubController2 controller = new MyController2();
@Override
public void onCreate(Bundle savedInstanceState) {
[...] // <- specific init
super.onCreate(savedInstanceState) // <- call super to dispatch.
}
} The following base dispatcher classes are provided so far:
● LightCycleActivity ● LightCycleAppCompatActivity ● LightCycleActionBarActivity ● LightCycleFragment ● LightCycleSupportFragment ● LightCycleSupportDialogFragment ● LightCyclePreferenceFragmentCompat
⚠ Please, read carefully the following steps (item 2 in particular). ⚠
To add LightCycles to your MyBaseActivity, your Activity must:
● Implement the LightCycleDispatcher interface.
Note: The processor needs to know the exact type being dispatched,
so if your base activity is templated then the activities inheriting
from it must explicitly implements LightCycleDispatcher
The same technique applies for Fragment.
Example
public class MyBaseActivity extends Activity implements LightCycleDispatcher> {
private final ActivityLightCycleDispatcher lightCycleDispatcher;
@Override
public void bind(ActivityLightCycle lightCycle) {
lightCycleDispatcher.bind(lightCycle);
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
LightCycles.bind(this);
lightCycleDispatcher.onCreate((MyBaseActivity) this, savedInstanceState);
}
[...]
@Override
protected void onDestroy() {
lightCycleDispatcher.onDestroy((MyBaseActivity) this);
super.onDestroy();
}
} See LightCycleActionBarActivity and LightCycleSupportFragment for example
You can check full source code of LightCycle on GitHub.
dependencies {
compile 'com.soundcloud.lightcycle:lightcycle-lib:(insert latest version)'
annotationProcessor 'com.soundcloud.lightcycle:lightcycle-processor:(insert latest version)'
}Or if you're using a version of the Android gradle plugin below 2.2.0
buildscript {
dependencies {
classpath 'com.neenbedankt.gradle.plugins:android-apt:1.8'
}
}
apply plugin: 'com.neenbedankt.android-apt'
ext.lightCycleVersion=
dependencies {
compile 'com.soundcloud.lightcycle:lightcycle-lib:(insert latest version)'
apt 'com.soundcloud.lightcycle:lightcycle-processor:(insert latest version)'
} Copyright 2016 SoundCloud Limited 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.
