Basic usage example of Scala's async/await (https://github.com/scala/async) on Android

Test.scala

/*
Copyright (c) 2013 Wes Lanning, http://codingcreation.com

Permission is hereby granted, free of charge, to any person obtaining
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"Software"), to deal in the Software without restriction, including
without limitation the rights to use, copy, modify, merge, publish,
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permit persons to whom the Software is furnished to do so, subject to
the following conditions:

The above copyright notice and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
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OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

http://www.opensource.org/licenses/mit-license.php
*/
package com.example.android_scala

import android.app.Activity
import android.os.Bundle

import android.widget.{Toast, TextView}
import scala.async.Async.{async, await}
import scala.concurrent.{Await, Future, ExecutionContext, future}
import scala.concurrent.ExecutionContext.Implicits.global
import scala.concurrent.duration._
import scala.io.Source
import android.util.Log

/**
 * Test converting a Java Interface to a Scala Lambda
 * via implicits.
 *
 * @author Wes Lanning
 * @version 2013-10-10
 */
class AsyncActivity extends Activity
{
    /**
     * Auto converts a Java Runnable interface to a Scala Lambda
     * Just an example of removing the bloat from Java when using Scala
     *
     * @param funct - the function to implement for run()
     * @return the implemented Runnable object
     */
    implicit def runnableAsLambda(funct: () => Unit) = new Runnable {
        def run() = funct
    }

    override def onCreate(savedInstanceState: Bundle)
    {
        super.onCreate(savedInstanceState)
        val TEST_URL = "https://raw.github.com/yareally/android-scala-intellij-no-sbt-plugin/testing/test-download-1.txt"
        val TEST_URL_2 = "https://raw.github.com/yareally/android-scala-intellij-no-sbt-plugin/testing/test-download-2.txt"

        /**
         * Fetches the contents of a file as a string and wraps it in a Future.
         * This function will run asynchronously.
         *
         * @param url - the url to fetch
         * @return a string wrapped in a Future result
         */
        def getRemoteFile(url: String): Future[String] = future {
            val readme = Source.fromURL(url)
            readme.mkString
        }

        /**
         * This function denotes that we have asynchronous code we want to run via the "async" keyword
         * the "async" keyword tells the compiler to look for any "await" areas and make them non-blocking
         * in our example, we wish to fetch the contents of 2 files via http in a non-blocking manner
         *
         * @return a string wrapped in a Future result
         */
        def httpResult: Future[String] = async {
            // stop here and wait for the result from above if it's not done yet
            // fetch the files in parallel via separate threads simultaneously for efficiency
            val resultPage = await(getRemoteFile(TEST_URL)) + await(getRemoteFile(TEST_URL_2))
            // return the file as a string (variable creation was for clarity purposes)
            resultPage
        }
        
        // Below line serves no purposes other than to demonstrate how to use the implicit function runnableAsLambda
        //runOnUiThread(() => Toast.makeText(this, "Toast Message here", Toast.LENGTH_SHORT).show())
        
        setContentView(R.layout.main)
        Toast.makeText(getApplicationContext, s"fetching remote test file from: $TEST_URL and $TEST_URL_2", Toast.LENGTH_SHORT).show()
        val textView = findViewById(R.id.async_result).asInstanceOf[TextView]
        textView.setText("When the http result is done, this will be replaced with the content of the page.")

        // wait for the asynchronously fetched http results
        // then unwrap the result from the future to get the string
        val pageContent: String = Await.result(httpResult, 10.seconds)

        Toast.makeText(this, "Test file download complete!", Toast.LENGTH_SHORT).show()

        textView.setText(pageContent)
    }
}