SharedPreferences with singleton in Kotlin

PrefUtils.kr

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

class PrefUtils {

    companion object {
        private var singleton: PrefUtils? = null
        private lateinit var preferences: SharedPreferences
        private lateinit var editor: SharedPreferences.Editor

        fun with(context: Context) : PrefUtils {
            if (null == singleton)
                singleton = Builder(context, null, -1).build()
            return singleton as PrefUtils
        }

        fun with(context: Context, name: String, mode: Int) : PrefUtils {
            if (null == singleton)
                singleton = Builder(context, name, mode).build()
            return singleton as PrefUtils
        }

    }

    constructor()

    @SuppressLint("CommitPrefEdits")
    constructor(context: Context) {
        preferences = PreferenceManager.getDefaultSharedPreferences(context)
        editor = preferences.edit()
    }

    @SuppressLint("CommitPrefEdits")
    constructor(context: Context, name: String, mode: Int) {
        preferences = context.getSharedPreferences(name, mode)
        editor = preferences.edit()
    }

    fun save(key: String, value: Boolean) {
        editor.putBoolean(key, value).apply()
    }

    fun save(key: String, value: Float) {
        editor.putFloat(key, value).apply()
    }

    fun save(key: String, value: Int) {
        editor.putInt(key, value).apply()
    }

    fun save(key: String, value: Long) {
        editor.putLong(key, value).apply()
    }

    fun save(key: String, value: String) {
        editor.putString(key, value).apply()
    }

    fun save(key: String, value: Set<String>) {
        editor.putStringSet(key, value).apply()
    }

    fun getBoolean(key: String, defValue: Boolean) : Boolean {
        return preferences.getBoolean(key, defValue)
    }

    fun getFloat(key: String, defValue: Float) : Float {
        return try {
            preferences.getFloat(key, defValue)
        } catch (ex: ClassCastException) {
            preferences.getString(key, defValue.toString())!!.toFloat()
        }
    }

    fun getInt(key: String, defValue: Int) : Int {
        return try {
            preferences.getInt(key, defValue)
        } catch (ex: ClassCastException) {
            preferences.getString(key, defValue.toString())!!.toInt()
        }
    }

    fun getLong(key: String, defValue: Long) : Long {
        return try {
            preferences.getLong(key, defValue)
        } catch (ex: ClassCastException) {
            preferences.getString(key, defValue.toString())!!.toLong()
        }
    }

    fun getString(key: String, defValue: String) : String? {
        return preferences.getString(key, defValue)
    }

    fun getStringSet(key: String, defValue: Set<String>) : Set<String>? {
        return preferences.getStringSet(key, defValue)
    }

    fun getAll(): MutableMap<String, *>? {
        return preferences.all
    }

    fun remove(key: String) {
        editor.remove(key).apply()
    }

    fun clear() {
        editor.clear().apply()
    }

    private class Builder(val context: Context, val name: String?, val mode: Int) {

        fun build() : PrefUtils {
            if (mode == -1 || name == null) {
                return PrefUtils(context)
            }
            return PrefUtils(context, name, mode)
        }
    }


}

Do you have an example, how to use this?

You can use it like this

PrefUtils.with(context).save("ANY_KEY", "Hello world!") // for saving value
PrefUtils.with(context). getString("ANY_KEY", "default value if there is any") // for getting value
PrefUtils.with(context). remove("ANY_KEY") // for removing

Is this only possible in the MainActivity.kt? I create an MyApiAuthenticationInterceptor kotlin class and want to use the PrefUtils there, but I dont know how to pass the context? Its working in my MainActivity but not in my separate classes.

Any hints?

https://stackoverflow.com/questions/32546024/how-to-access-context-in-a-interceptor