Sheldon

Key concepts:

• Preferences should not be tied to concrete implementation, they should be an interface that you can easily mock in your tests
• You should be able to provide implementation gateway in your platform layer
• Get your values through RxJava's Observable
• Get rid of always specifying a string key when you get or set preference, this should be strongly typed so that your IDE can help with autocompletion and your key<->value pair is always in sync
• Leverage annotation processing to automatically generate the wiring code between your preferences and platform gateway

Define your interface:

@Preferences(name = "temp")
public interface SomePreferences {
    @Default(name = "name") String DEFAULT_VALUE = "DEFAULT_VALUE";
    @Get(name = "name") Observable<String> getValueName();
    @Set(name = "name") void setValue(String newValue);
    ...
    @Contains Observable<Boolean> contains(String key);
    @Delete void remove(String key);
}

Adapters

Natively supported types are Boolean, Float, Integer, Long and String.

For everything else you have to extend IPreferenceAdapter and implement storing your entity via supported types. You can look at example of generic EnumAdapter. To include your adapter into processing just annotate it with @Adapter.

Each adapter should have a no-args constructor

Defaults

For each parameter you have to always supply a default value as a field in an interface annotated with @Default. Type of parameter should be the same as in getter and setter.

Instantiate the generated implementation

Temp_Preferences preferences = new Temp_Preferences(new SharedPreferencesGatewayBuilder(contextRef));

Probably you'd store this in your dependency graph and inject it by interface For additional info look at the sample

Get it

Gradle:

repositories {
    ...
    mavenCentral()
    ...
}
...
dependencies {
    ...
    apt "com.malinskiy.sheldon2:compiler:$version"
    compile "com.malinskiy.sheldon2:core:$version"
    compile "com.malinskiy.sheldon2:gateway-sharedpreferences:$version"
    ...
}

License

Copyright 2017 Anton Malinskiy

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.