Preferences

To have persistent preferences/settings that are persisted between game calls, similar to android’s SharedPreferences, you can either use files to store them, or use the NativeStorage functionality provided by KorGE.

applicationDataVfs

applicationDataVfs is a LocalVfs that will point to a folder or virtual filesystem for storing persistent files four our specific application/game.

So for example you can:

val myJsonString = applicationDataVfs["prefs.json"].readString()
applicationDataVfs["prefs.json"].writeString(myJsonString)

NativeStorage

NativeStorage in its basics, acts as a MutableMap<String, String> that is automatically persisted. You can get an instance with views.storage.

Getting an instance

val storage: NativeStorage = views.storage

Checking if a key is defined

storage.contains("key") //
"key" in storage

Getting the value for a key

val value: String = storage["key"] // or KeyNotFoundException thrown
val value: String? = storage.getOrNull("key")

Setting the value of a key

storage["hello"] = "world"

Removing a pair key/value

storage.remove("key")
storage.removeAll() // This will clear all the preferences!

Getting all the defined keys

val keys = storage.keys()
val map: Map<String, String?> = storage.toMap()

NativeStorage StorageKey

StorageKey is a simplified way to store string and non-string values and access them easily.

val itemString = storage.itemString("keyString", default = "")
val itemBool = storage.itemBool("keyBool", default = false)
val itemInt = storage.itemInt("keyInt", default = 0)
val itemDouble = storage.itemDouble("keyDouble", default = 0.0)

itemDouble.isDefined // false
println(itemDouble.value) // 0.0
itemDouble.value = 10.0
println(itemDouble.value) // 10.0
itemDouble.isDefined // true

It can also be used as a delegated property:

var itemBool by storage.itemBool("keyBool", default = false)
itemBool // false
itemBool = true
itemBool // true