Retainer


Source link: https://github.com/hananrh/retainer

Retainer

An android library which enables activity/fragment fields retention through configuration changes (e.g screen rotatio) by generating boilerplate code for you.

  • Retain any object and maintain reference through configuration changes (no need for slow serialization-deserialization process).
  • Makes MVVM implemntation cleaner and shorter by retaining the ViewModel.
  • Simple and straight forward use.
class MainActivity extends AppCompatActivity{

@Retain
  ViewModel mViewModel; //This field will be retained through configuration changes

@Override
  protected void onCreate(Bundle savedInstanceState)
  {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

Retainer.restore(this);

  
}

  @Override
  protected void onSaveInstanceState(Bundle outState)
  {

super.onSaveInstanceState(outState);

Retainer.retain(this);

  
}

 //Calls to retain() and restore() can be made from a base activity class 
}
 

Download

dependencies {

compile 'com.hrh:retainer:0.0.56'
annotationProcessor 'com.hrh:retainer-compiler:0.0.56' 
}

How does it work

Retainer creates and handles an headless retained fragment which wraps a mapping of all your @Retain fields, as simple as that.

In order to keep runtime impact minimal, Retainer uses mostly code generation while reflection is only used for constructing and caching a retainer object for your activity/fragment when it is first created.

Watch out for memory (especially Context) leaks

Marking a non-primitive field as @Retained means it won't be released when a configuration change occures.

Although Retainer makes sure at compile time that non of your @Retain fields is or is a subclass of Context, you should watch out for memory leaks and never retain an object holding a refernce to an android Context.

When not to use

Retainer is useful only in cases where your activty/fragment is recreated due to a configuration change.

If you wish to retain fields for an activity/fragment which is recreated after being destroyed by the OS then you should use the plain old savedInstanceState.

I recommend taking a look at IcePick

License

Copyright 2017 Hanan Rofe Haim  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. 

Resources

Android library listening available WiFi Access Points and related information with RxJava Observables.

ViewPager replacement with dynamic height support and smooth animations for the few edge cases where a standard ViewPager doesn't fulfill your needs.

An Android Keyboard visibility listener.

A pretty pull down view.

Easy info about Android device.

Collection of tools for RecyclerView. Includes headers, sections, pull to refresh, etc.

Topics


2D Engines   3D Engines   9-Patch   Action Bars   Activities   ADB   Advertisements   Analytics   Animations   ANR   AOP   API   APK   APT   Architecture   Audio   Autocomplete   Background Processing   Backward Compatibility   Badges   Bar Codes   Benchmarking   Bitmaps   Bluetooth   Blur Effects   Bread Crumbs   BRMS   Browser Extensions   Build Systems   Bundles   Buttons   Caching   Camera   Canvas   Cards   Carousels   Changelog   Checkboxes   Cloud Storages   Color Analysis   Color Pickers   Colors   Comet/Push   Compass Sensors   Conferences   Content Providers   Continuous Integration   Crash Reports   Credit Cards   Credits   CSV   Curl/Flip   Data Binding   Data Generators   Data Structures   Database   Database Browsers   Date &   Debugging   Decompilers   Deep Links   Dependency Injections   Design   Design Patterns   Dex   Dialogs   Distributed Computing   Distribution Platforms   Download Managers   Drawables   Emoji   Emulators   EPUB   Equalizers &   Event Buses   Exception Handling   Face Recognition   Feedback &   File System   File/Directory   Fingerprint   Floating Action   Fonts   Forms   Fragments   FRP   FSM   Functional Programming   Gamepads   Games   Geocaching   Gestures   GIF   Glow Pad   Gradle Plugins   Graphics   Grid Views   Highlighting   HTML   HTTP Mocking   Icons   IDE   IDE Plugins   Image Croppers   Image Loaders   Image Pickers   Image Processing   Image Views   Instrumentation   Intents   Job Schedulers   JSON   Keyboard   Kotlin   Layouts   Library Demos   List View   List Views   Localization   Location   Lock Patterns   Logcat   Logging   Mails   Maps   Markdown   Mathematics   Maven Plugins   MBaaS   Media   Menus   Messaging   MIME   Mobile Web   Native Image   Navigation   NDK   Networking   NFC   NoSQL   Number Pickers   OAuth   Object Mocking   OCR Engines   OpenGL   ORM   Other Pickers   Parallax List   Parcelables   Particle Systems   Password Inputs   PDF   Permissions   Physics Engines   Platforms   Plugin Frameworks   Preferences   Progress Indicators   ProGuard   Properties   Protocol Buffer   Pull To   Purchases   Push/Pull   QR Codes   Quick Return   Radio Buttons   Range Bars   Ratings   Recycler Views   Resources   REST   Ripple Effects   RSS   Screenshots   Scripting   Scroll Views   SDK   Search Inputs   Security   Sensors   Services   Showcase Views   Signatures   Sliding Panels   Snackbars   SOAP   Social Networks   Spannable   Spinners   Splash Screens   SSH   Static Analysis   Status Bars   Styling   SVG   System   Tags   Task Managers   TDD &   Template Engines   Testing   Testing Tools   Text Formatting   Text Views   Text Watchers   Text-to   Toasts   Toolkits For   Tools   Tooltips   Trainings   TV   Twitter   Updaters   USB   User Stories   Utils   Validation   Video   View Adapters   View Pagers   Views   Watch Face   Wearable Data   Wearables   Weather   Web Tools   Web Views   WebRTC   WebSockets   Wheel Widgets   Wi-Fi   Widgets   Windows   Wizards   XML   XMPP   YAML   ZIP Codes