very useful Class for Shared Preferences

SharedPref.kt

class SharedPref(context: Context) {



    private var sharedPreferences: SharedPreferences? =null
    private var editor: SharedPreferences.Editor? =null

    init {
        val prefsFile = context.packageName
        sharedPreferences = context.getSharedPreferences(prefsFile, Context.MODE_PRIVATE)
        editor = sharedPreferences?.edit()
    }
    
    fun savePref(key: String , value: Any?) {

        delete(key)

        when {
            value is Boolean -> editor?.putBoolean(key, ((value as Boolean?)!!))
            value is Int -> editor?.putInt(key, (value as Int?)!!)
            value is Float -> editor?.putFloat(key, (value as Float?)!!)
            value is Long -> editor?.putLong(key, (value as Long?)!!)
            value is String -> editor?.putString(key, value as String?)
            value is Enum<*> -> editor?.putString(key, value.toString())
            value != null -> throw RuntimeException("Attempting to save non-primitive preference")
        }

        editor?.commit()
    }

    fun delete(key: String) {

        if (sharedPreferences != null) {
            if (sharedPreferences?.contains(key)!!) {
                editor?.remove(key)?.commit()
            }
        }
    }

    fun reset() {

        editor?.clear()?.commit()
    }

//        fun <T> getPref(key: String): T {
//
//            return sharedPreferences?.all?.get(key) as T
//        }

    fun <T> getPref(key: String , defValue: T): T {

        val returnValue = sharedPreferences?.all?.get(key) as T
        return returnValue ?: defValue
    }

    fun saveSetPref(key: String , value: Set<String>) {

        delete(key)

        editor?.putStringSet(key , value)

        editor?.commit()
    }

    fun isPrefExists(key: String): Boolean {

        return sharedPreferences?.contains(key)!!
    }

//    private var instance: SharedPref = this
}