lukynkacze / kotlin-bindables

Bindables library for kotlin

kotlin-bindables

bindables library for kotlin inspired by the osu!framework bindable system

what are bindables

Bindables are objects that hold a value and provide following listeners:

• Bindable
  • value change
• BindableList
  • value added to list
  • value removed from list
  • value set by index in list
• BindableMap
  • value set
  • value removed

why not use kotlin delegate?

To use delegate with decent syntax the library would have to do reflection which is not very good for performance

Installation

Kotlin DSL

repositories {
    maven {
        name = "devOS"
        url = uri("https://mvn.devos.one/releases")
    }
}

dependencies {
    implementation("cz.lukynka:kotlin-bindables:1.1")
}

Gradle Groovy

repositories {
  maven {
    name "devOS"
    url "https://mvn.devos.one/releases"
  }
}

dependencies {
  implementation 'cz.lukynka:kotlin-bindables:1.1'
}

---

Usage

There are different types of bindables, each with their own events

Bindable

// give initial value of 5
val playerHealth = Bindable<Int>(5)

// Register a listener
playerHealth.valueChanged {
    println("Player health changed from ${it.oldValue} to ${it.newValue}!")
}

// Set the value
playerHealth.value = 20

BindableList

val playersOnline = BindableList<String>()

// called when item gets added
playersOnline.itemAdded {
    println("Player ${it.item} has joined!")
}


// called when item gets removed
playersOnline.itemRemoved {
    println("Player ${it.item} has left!")
}

// called when item at index is set
playersOnline.itemChanged {
    println("object at index ${it.index} has been changed to ${it.item}!")
}

playersOnline.add("AsoDesu_")
playersOnline.add("LukynkaCZE")
playersOnline.remove("AsoDesu_")
playersOnline.setIndex(1, "ColleiImpact")

BindableMap

val uuidToPlayerName = BindableMap<UUID, String>()

// Is both called from BindableMap.set and BindableMap.add
uuidToPlayerName.itemSet {
    println("Player with uuid ${it.key} (${it.value}) has joined!")
}

// called when item is removed
uuidToPlayerName.itemRemoved {
    println("Player with uuid ${it.key} (${it.value}) has left!")
}

// called when the map is updated 
uuidToPlayerName.mapUpdated {
    println("The player list has been updated!")
}

uuidToPlayerName[UUID.fromString("aeb19a9c-a64a-4255-bb42-e74f05f9d30f")] = "AsoDesu_"
uuidToPlayerName[UUID.fromString("0c9151e4-7083-418d-a29c-bbc58f7c741b")] = "LukynkaCZE"
uuidToPlayerName.remove(UUID.fromString("aeb19a9c-a64a-4255-bb42-e74f05f9d30f"))
uuidToPlayerName.set(UUID.fromString("0c9151e4-7083-418d-a29c-bbc58f7c741b"), "ColleiImpact")

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Extras

On all the types, you can also use .triggerUpdate() to call the listeners without actually causing any update to the value(s)

Both BindableList and BindableMap have .addIfNotPresent(value) and .removeIfPresent(value) functions

All of the bindable types provide .setSilently(value) which will set the value of the bindable without calling any of the listeners

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