Java
🍦 Generate 'onSaveInstanceState' and 'onRestoreInstanceState' methods for your application automatically

SaveState

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Automatically save and restore states of Activities, Fragments and Views.

No boilerplate code like onSaveInstanceState or onRestoreInstanceState any more.

Getting started

Just add the @AutoRestore annotation to your fields that need to be saved and restored in Activities, Fragments and Views.

In Activities:

public class MyActivity extends Activity {

    @AutoRestore
    int myInt;

    @AutoRestore
    IBinder myRpcCall;

    @AutoRestore
    String result;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // Your code here
    }
}

In Fragments：

public class MyFragment extends Fragment {

    @AutoRestore
    User currentLoginUser;

    @AutoRestore
    List<Map<String, Object>> networkResponse;

    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        // Your code here
    }
}

In Views：

public class MyView extends View {

    @AutoRestore
    String someText;

    @AutoRestore
    Size size;

    @AutoRestore
    float[] myFloatArray;

    public MyView(Context context) {
        super(context);
    }

    public MyView(Context context, @Nullable AttributeSet attrs) {
        super(context, attrs);
    }

    public MyView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {
        super(context, attrs, defStyleAttr);
    }

}

Yes, that's all.

Setting up the dependency of SaveState

Add the plugin classpath to the build.gradle file in project root as below:

buildscript {

    repositories {
        google()
        jcenter()
    }
    dependencies {
        // your other dependencies

        // dependency for save-state
        classpath "io.github.prototypez:save-state:${latest_version}"
    }
}

Currently the latest version of SaveState is:

Then apply the SaveState plugin in your build.gradle file of your application module:

apply plugin: 'com.android.application'
apply plugin: 'save.state'

If you have library modules and they also need SaveState support, then the only thing you need to do is applying the plugin in their build.gradle files just as the application module.

apply plugin: 'com.android.library'
apply plugin: 'save.state'

Supported Types

If the type of a field annotated by the @AutoRestore annotation is one of the types below, then there's no configurations any more. SaveState will save and restore your field automatically.

Other types

If the type of a field is not included in what is listed above, but it can be serialized to JSON , then SaveState could still save and restore it automatically by serializing it to JSON and deserializing the JSON string back to object.

For example：

public class User {
    String name;
    int age;
}


public class NetworkResponse<T> {
    int resultCode;

    T data
}

These types are supported by SaveState according to the rule above:

public class MyActivity extends Activity {

    @AutoRestore
    User user;

    @AutoRestore
    NetworkResponse<List<User>> response;
}

But we need extra configurations now：

1. Make sure your have already included one of the dependencies of supported JSON processing library .
2. Add compile options in the build.gradle file ( application module or library module ) as below:

defaultConfig {

    // your other configs

    // config the JSON processing library
    javaCompileOptions {
        annotationProcessorOptions {
            arguments = [ serializer : "/*Supported JSON processing library*/" ]
        }
    }
}

Currently the supported JSON processing library includes：

• gson
• fastjson
• jackson

FAQ

• Q: Does SaveState support Instant Run?

  A: Yes，it's based on Transform API, so no problem。

• Q: Do I need to add any Proguard rules for release?

  A: No, there's no reflection, so you are safe to use Proguard.

• Q: What about the performance of SaveState?

  A: It's based on byte code transforming and annotation processor, so the runtime performance is as good as other compiled code written by you. It will only have a little influence on the compile time, but I think it can be ignored.

• Q: What about the size of SaveState? How much will it increase the APK size?

  A: SaveState do all the jobs at compile time，it doesn't have any runtime dependency, so it won't increase your APK size.

LICENSE

Copyright (c) 2016-present, SateState Contributors.

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.