FreKotlin

Example Android Studio project showing how to create Air Native Extensions for Android using Kotlin.

This project is used as the basis for the following ANEs
Google Maps ANE
AdMob ANE
WebViewANE
FirebaseANE
ZipANE

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Getting Started

A basic Hello World starter project is included

How to use

Converting from FREObject args into Kotlin types, returning FREObjects

The following table shows the primitive as3 types which can easily be converted to/from Kotlin types

AS3 type	Kotlin type	AS3 param->Kotlin	return Kotlin->AS3
String	String	val s = String(argv[0])	return s.toFREObject()
int	Int	val i = Int(argv[0])	return i.toFREObject()
Boolean	Boolean	val b = Boolean(argv[0])	return b.toFREObject()
Number	Double	val d = Double(argv[0])	return d.toFREObject()
Number	Float	val fl = Float(argv[0])	return fl.toFREObject()
Date	Date	val dt = Date(argv[0])	return dt.toFREObject()
Rectangle	Rect	val r = Rect(argv[0])	return r.toFREObject()
Rectangle	RectF	val r = RectF(argv[0])	return r.toFREObject()
Point	Point	val pnt = Point(argv[0])	return pnt.toFREObject()
Point	PointF	val pnt = PointF(argv[0])	return pnt.toFREObject()
Vector Int	IntArray	val arr = IntArray(argv[0])	return arr.toFREObject()
Vector Boolean	BooleanArray	val arr = BooleanArray(argv[0])	return arr.toFREObject()
Vector Number	DoubleArray	val arr = DoubleArray(argv[0])	return arr.toFREObject()
Vector String	List	val al = List<String>(argv[0])	return al.toFREObject()
Object	Map<String, Any>?	val dict: Map<String, Any>? = Map(argv[0])
null	null		return null

Basic Types

val myString: String? = String(argv[0])
val myInt = Int(argv[1])
val myBool = Boolean(argv[2])

val kotlinString = "I am a string from Kotlin"
return kotlinString.toFREObject()

Creating new FREObjects

val newPerson = FREObject("com.tuarua.Person")

// create a FREObject passing args
// 
// The following param types are allowed: 
// String, Int, Double, Float, Long, Short, Boolean, Date, FREObject
val frePerson = FREObject("com.tuarua.Person", "Bob", "Doe", 28, myFREObject)

Calling Methods

// call a FREObject method passing args
// 
// The following param types are allowed: 
// String, Int, Double, Float, Long, Short, Boolean, Date, FREObject
val addition = freCalculator.call("add", 100, 31)

Getting / Setting Properties

val oldAge = Int(person["age"])
val newAge = oldAge + 10

// Set property using braces access
person["age"] = newAge

Arrays

val airArray: FREArray? = FREArray(argv[0])
// convert to a Kotlin List<String>
val airStringVector = List<String>(argv[0])

// create a Vector.<com.tuarua.Person> with fixed length of 5
val newFreArray = FREArray("com.tuarua.Person", 5, true)
val len = newFreArray.length

// loop over FREArray
for (fre: FREObject? in airArray) {
    trace(Int(fre))
}

// set element 0 to 123
airArray[0] = 123

// append element FREArray
airArray.push(456)

// return Kotlin IntArray to AIR
val kotArr = intArrayOf(99, 98, 92, 97, 95)
return kotArr.toFREArray()

Sending Events back to AIR

trace("Hi", "There")

// with interpolation
trace("My name is: $name")

dispatchEvent("MY_EVENT", "this is a test")

Bitmapdata

val icon: Bitmap? = Bitmap(argv[0])
return icon.toFREObject()

ByteArrays

val byteArray = ByteArray(argv[0])
if (byteArray != null) {
    val str = String(Base64.encode(byteArray, Base64.NO_WRAP), Charset.forName("utf-8"))
}

Error Handling

FreKotlinLogger.context = this.context
if (inFRE1.type != FreObjectTypeKotlin.INT) {
    return FreException("Oops, we expected the FREObject to be passed as an int but it's not").getError();
}

Advanced Example - Extending. Convert to/from LatLng

package com.tuarua.frekotlin

import com.adobe.fre.FREObject
import com.google.android.gms.maps.model.LatLng

fun LatLng(freObject: FREObject?): LatLng {
    return LatLng(Double(freObject["latitude"]) ?: 0.0,
            Double(freObject["longitude"]) ?: 0.0)
}

fun LatLng.toFREObject(): FREObject? {
    return FREObject("com.tuarua.googlemaps.Coordinate", this.latitude, this.longitude)
}

Prerequisites

You will need

• Android Studio 2022+
• IntelliJ IDEA
• AIR 50.1+