How do you block a return until a take() timer expires?

[DS0322]

I know there has to be a simple way to do what I am trying to do. In short, I want to call a function, and have that function listen for values for a specified period of time, then return the items it found during that time. Here is the code I have so far:

fun returnAllDevicesStartingWith(devicePrefix: String): List<String> {

    Logger.d(TAG, "About to scan for devices. Will return those starting with $devicePrefix")

    val mutableList = mutableListOf<String>()

    val result = scanForDevices()
           .take(4, TimeUnit.SECONDS, timeoutScheduler)
           
           .subscribe{scanResult ->
               val name = scanResult.bleDevice.name

               Logger.d(TAG, "Potential device match named $name")

               if(name != null) {
                   if(name.startsWith(prefix = devicePrefix)) {
                       Logger.d(TAG, "Match found $name")
                       mutableList.plus(name)
                   }
               }
           }



    return mutableList
}

So I call the above function something like:

val deviceList = returnAllDevicesStartingWith("ABC")

The scanForDevices function returns an Observable<ScanResult> as it finds each device. That function works fine.

How to I keep from returning the mutableList until the take(4, TimeUnit.SECONDS, timeoutScheduler) expires?

[Dávid Karnok]

Why not return Single<List<T>> and keep composing onto that, thus there is no need for blocking?

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Best regards,

David Karnok

[DS0322]

Appreciate the idea. The calling routine needs to have the complete list of devices before it can do its work, so a one time transmit seems to be in order unless I'm missing your point.