AutoPreferences

This library generates a preferences class to manage preferences in Android based on annotations.

Installation

This library requires Java 8 to run the annotation processor.

Check the latest version in the badge above.

compile "com.github.kakai248.AutoPreferences:library:${LATEST_VERSION}"
annotationProcessor "com.github.kakai248.AutoPreferences:compiler:${LATEST_VERSION}"

Backup (optional):

compile "com.github.kakai248.AutoPreferences:backup:${LATEST_VERSION}"

Usage

@AutoPreferences(annotateMethods = true, className = "PreferencesManager")
public abstract class AbstractPreferencesManager {

    public static final int GROUP1 = 1;

    @Preference(stringRes = R.string.test_boolean, remove = true, contains = true, tag = GROUP1)
    boolean testBoolean = true;
}

You need to create a class and annotate it with @AutoPreferences. If you also use annotateMethods = true, it will annotate each getter and setter generated with @PreferenceGetter and @PreferenceSetter (this is needed to use the backup feature).

You can use className = "PreferencesManager" to choose the name of the generated class. If you pass an empty string or don't override this method, the processor will generate the class name based on the name of the abstract one:

• If you prefix the class name with Abstract, like in the example, the processor will generate a class with the same name except the prefix.
• If it doesn't start with Abstract, it will have the same name and the processor will add the prefix Auto.

Annotated class name	Generated class name
AbstractPreferencesManager	PreferencesManager
PreferencesManager	AutoPreferencesManager

To define a preferences, annotate a field with @Preference. Give the preference a key (using a string resource, to be compatible with PreferenceFragments) using stringRes = R.string.test_boolean.

You can pass omitGetterPrefix = true to let the processor generate getters without prefix, i.e. without get or is for booleans.

There is also remove = true and contains = true to generate a remove and a contains method for that preference.

Finally you can define an int (tag = 10) to be used as tag. This tag will be in the @PreferenceGetter and @PreferenceSetter annotations.

The value that you assign to the field will be the default value of the preference. It is recommended that you assign a protected visibility to the field to avoid accidental access.

The previous example will generate the following class:

public class PreferencesManager extends AbstractPreferencesManager {
  private Context context;

  private PreferencesHelper helper;

  public PreferencesManager(Context context) {
    super();
    this.context = context;
    this.helper = PreferencesHelper.with(context);
  }

  @PreferenceGetter(
      stringRes = 2131099689,
      tag = 1
  )
  public boolean isTestBoolean() {
    return helper.getBoolean(context.getString(2131099689), testBoolean);
  }

  @PreferenceSetter(
      stringRes = 2131099689,
      tag = 1
  )
  public void setTestBoolean(boolean testBoolean) {
    helper.putBoolean(context.getString(2131099689), testBoolean);
  }

  public void removeTestBoolean() {
    helper.remove(context.getString(2131099689));
  }

  public boolean hasTestBoolean() {
    return helper.contains(context.getString(2131099689));
  }
}

The library support all the types that the Android SharedPreferences support plus Enum.

Supported types
Boolean
String
Int
Float
Long
StringSet
Enum

Backup (optional)

It is also included a backup feature. As said before, you need to use @AutoPreferences(annotate = true). There is a BackupHelper that provides methods to get/set the values of the generated class. You can retrieve or store the values using a Map<String, Object>, a Json string or a File (saves as Json).

You can pass the tags to the read/backup methods of the BackupHelper to only save the fields that are annotated with those tags.

It uses Jackson to create/read the Json. Ideally it would support any Json parser.

Example

See the included sample app.

License

Copyright 2016 Ricardo Carrapiço

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.