[Android] SharedPreferences generic (kotlin)

Reference

https://blog.naver.com/PostView.naver?blogId=tkddlf4209&logNo=222181366697&categoryNo=0&parentCategoryNo=0&viewDate=&currentPage=1&postListTopCurrentPage=1&from=postView

[Android] SharedPreference with Generic

 

 
import android.content.Context
import android.content.Context.MODE_PRIVATE
import android.content.SharedPreferences
fun <T> setPreference(pref_name: String?, value: T) {
    PreferenceManager.getInstance()[pref_name] = value
}
@Suppress("UNCHECKED_CAST")
fun <T> getPreference(pref_name: String?, default_value: T): T {
    return PreferenceManager.getInstance()[pref_name, default_value] as T
}
@Suppress("UNCHECKED_CAST")
sealed class PreferenceManager<T>(context: Context) {
    object Instance: PreferenceManager<Any?>(DreamforaApplication.applicationContext())
    var sp: SharedPreferences = context.getSharedPreferences("pref", MODE_PRIVATE)
    var editor: SharedPreferences.Editor = sp.edit()
    /**
     * Set any type of shared preferences value
     * @param key of the shared preferences which the caller is desire to set
     * @param value types:
     * Boolean ,
     * StringSet,
     * String,
     * Float,
     * Long,
     * Int
     */
    operator fun set(key: String?, value: T) {
        when (value) {
            is Boolean -> {
                editor.putBoolean(key, (value as Boolean))
            }
            is Set<*> -> {
                editor.putStringSet(key, value as Set<String?>)
            }
            is String -> {
                editor.putString(key, value as String)
            }
            is Float -> {
                editor.putFloat(key, (value as Float))
            }
            is Long -> {
                editor.putLong(key, (value as Long))
            }
            is Int -> {
                editor.putInt(key, (value as Int))
            }
        }
        editor.apply()
    }
    /**
     * Get any type of value from the shared preference
     * @param key the key of the shared preference
     * @param defaultValue types:
     * Boolean ,
     * StringSet,
     * String,
     * Float,
     * Long,
     * Int
     * @return same type of the default value which has been passed in
     */
    operator fun get(key: String?, defaultValue: T): T? {
        when (defaultValue) {
            is Boolean -> {
                val ret = sp.getBoolean(key, (defaultValue as Boolean))
                return ret as T
            }
            is Collection<*> -> {
                val result = sp.getStringSet(key, HashSet())
                return result as T?
            }
            is String -> {
                val ret = sp.getString(key, defaultValue as String)
                return ret as T?
            }
            is Float -> {
                val result = sp.getFloat(key, (defaultValue as Float))
                return result as T
            }
            is Long -> {
                val result = sp.getLong(key, (defaultValue as Long))
                return result as T
            }
            is Int -> {
                val result = sp.getInt(key, (defaultValue as Int))
                return result as T
            }
            else -> return null
        }
    }
    companion object {
        fun getInstance() = Instance
    }
}