A Kotlin class that can handle Preferences easily by enabling clean code in your project.

PreferencesManager.kt

import android.content.Context
import android.content.SharedPreferences
import android.preference.PreferenceManager

object PreferencesManager {
    fun defaultPrefs(context: Context): SharedPreferences = PreferenceManager.getDefaultSharedPreferences(context)

    fun customPrefs(context: Context, name: String): SharedPreferences = context.getSharedPreferences(name, Context.MODE_PRIVATE)

    inline fun SharedPreferences.edit(operation: (SharedPreferences.Editor) -> Unit) {
        val editor = this.edit()
        operation(editor)
        editor.apply()
    }

    operator fun SharedPreferences.set(key: String, value: Any?) {
        when (value) {
            is String? -> edit { it.putString(key, value) }
            is Int -> edit { it.putInt(key, value) }
            is Boolean -> edit { it.putBoolean(key, value) }
            is Float -> edit { it.putFloat(key, value) }
            is Long -> edit { it.putLong(key, value) }
            is MutableSet<*> -> edit { it.putStringSet(key, value as MutableSet<String>) }
            else -> throw UnsupportedOperationException("Not yet implemented")
        }
    }

    inline operator fun <reified T : Any> SharedPreferences.get(key: String, defaultValue: T): T {
        return when (T::class) {
            String::class -> getString(key, defaultValue as? String) as T
            Int::class -> getInt(key, defaultValue as? Int ?: -1) as T
            Boolean::class -> getBoolean(key, defaultValue as? Boolean ?: false) as T
            Float::class -> getFloat(key, defaultValue as? Float ?: -1f) as T
            Long::class -> getLong(key, defaultValue as? Long ?: -1) as T
            MutableSet::class.java -> getStringSet(key, defaultValue as? MutableSet<String>) as T
            else -> throw UnsupportedOperationException("Not yet implemented")
        }
    }
}

USAGE

INSTANCE
val prefs = PreferencesManager.customPrefs(this, Preference Name)

GET
val theme = prefs[Preference Name, Default Value]

SET
prefs[Preference Name] = VALUE