Wrapper class around SharedPreferences

PreferencesManager.java

/*
 * Copyright (c) 2015, Arseny Nasokin
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

import android.content.Context;
import android.content.SharedPreferences;
import android.preference.PreferenceManager;
import com.google.common.base.Preconditions;

/**
 * Wrapper class around SharedPreferences.
 *
 * @author eirnym
 */
public final class PreferencesManager {

    /**
     * Available preference types. Checkout {@link SharedPreferences} for all supported types
     */
    private enum DefaultsType {
        Boolean, Integer, String
    }

    /**
     * Keys, which you can write to preferences with this class
     */
    public enum Defaults {
        /* TODO: add your preferences here */
        ;

        private final DefaultsType type;
        private final boolean secure;

        /**
         * Creates enum value
         * @param type value type
         * @param secure {@code true} if you to force commit(), otherwise apply() method will be called.
         */

        Defaults(DefaultsType type, boolean secure) {
            Preconditions.checkNotNull(type);

            this.type = type;
            this.secure = secure;
        }

        /**
         * Remove this key from preferences
         */
        public void remove() {
            PreferencesManager.removeKey(this.toString(), secure);
        }

        /**
         * Puts int value
         * @param value value to put
         */
        public void put(int value) {
            Preconditions.checkState(type == DefaultsType.Integer);
            PreferencesManager.putInt(this.toString(), value, secure);
        }

        /**
         * Puts boolean value
         * @param value value to put
         */
        public void put(boolean value) {
            Preconditions.checkState(type == DefaultsType.Boolean);
            PreferencesManager.putBoolean(this.toString(), value, secure);
        }

        /**
         * Puts String value
         * @param value value to put
         */
        public void put(String value) {
            Preconditions.checkState(type == DefaultsType.String);
            if (value == null) {
                PreferencesManager.removeKey(this.toString(), secure);
            }
            PreferencesManager.putString(this.toString(), value, secure);
        }

        /**
         * Retrieves int value
         */
        public int getInt() {
            Preconditions.checkState(type == DefaultsType.Integer);
            return PreferencesManager.getInt(this.toString());
        }

        /**
         * Retrieves boolean value
         */
        public boolean getBoolean() {
            Preconditions.checkState(type == DefaultsType.Boolean);
            return PreferencesManager.getBoolean(this.toString());
        }

        /**
         * Retrieves string value
         */
        public String getString() {
            Preconditions.checkState(type == DefaultsType.String);
            return PreferencesManager.getString(this.toString());
        }
    }

    private static SharedPreferences preferences;

    /**
     * Default boolean value to use
     */
    private static final boolean DEFAULT_BOOLEAN = false;
    /**
     * Default boolean value to use
     */
    private static final int DEFAULT_INT = 0;
    /**
     * Default boolean value to use
     */
    private static final String DEFAULT_STRING = null;


    /**
     * This is utility class managed with enum.
     */
    private PreferencesManager() {
        throw new UnsupportedOperationException("Please, don't instantiate this utility class");
    }

    /**
     * Initializes preferences with default shared preferences
     * @param context context to use
     */
    public static void setup(Context context) {
        preferences = PreferenceManager.getDefaultSharedPreferences(context);
    }

    private static boolean getBoolean(String key) {
        return preferences.getBoolean(key, DEFAULT_BOOLEAN);
    }

    private static int getInt(String key) {
        return preferences.getInt(key, DEFAULT_INT);
    }

    private static String getString(String key) {
        return preferences.getString(key, DEFAULT_STRING);
    }

    private static void putBoolean(String key, boolean value, boolean forceCommit) {
        forceCommit(preferences.edit().putBoolean(key, value), forceCommit);
    }

    private static void putInt(String key, int value, boolean forceCommit) {
        forceCommit(preferences.edit().putInt(key, value), forceCommit);
    }

    private static void putString(String key, String value, boolean forceCommit) {
        forceCommit(preferences.edit().putString(key, value), forceCommit);
    }

    private static void removeKey(String key, boolean forceCommit) {
        forceCommit(preferences.edit().remove(key), forceCommit);
    }

    private static void forceCommit(SharedPreferences.Editor editor, boolean forceCommit) {
        if (forceCommit) {
            editor.commit();
        } else {
            editor.apply();
        }
    }

    /**
     * Removes all keys and commit.
     */
    public static void clear() {
        preferences.edit().clear().commit();
    }
}