Kotlin Intro & Starting the Koans

Tomás Hanley

20th August 2018

Drone Delivery App

Why learn Kotlin?

  • Kotlin is a better language for the JVM than Java
    • Really easy to get up and running
    • Simpler language than Java

    • Much safer than Java

      • No more NullPointerExceptions!

      • Streamlines the handling of null values

    • More more clean & concise than Java

    • 100% Interoperable with Java

      • Kotlin & Java classes can live side by side

The Plan

Different Components

  • Android Controller

  • Drone Controller & Delivery Service

  • Food Service & Consumer Service

  • Android Consumer App

  • Merchant Web App

Android Controller

  • Control drone with existing android app

    • Take off, Land

    • Control pitch, yaw, roll, etc.

  • This is already provided in the Parrot SDK

  • We want to convert it to kotlin

Drone Controller & Delivery Service

  • Send higher level commands to drone

    • Move one unit in any direction

    • Fly to coordinate (x, y)

    • Need a higher level android UI to test

  • Can eventually be used for handling delivery requests and scheduling.

Food Service & Consumer Service

  • Embedded Web Servers

  • Handle http requests

  • Async framework would be nice (Ktor)

  • Other option seems like nanohttpd

Android Consumer App

  • Interacts with consumer-service

    • Get delivery options

    • Send delivery requests

Merchant Web App

  • Interacts with food-service

  • Tells food-service where food is available

  • Written in Kotlin and compiled to Javascript

Implementing drone commands

Requires pauses in code

  • e.g. fly forward for one second

Does Kotlin have any awesome way to implement pauses?

What are coroutines?

Coroutines

  • Super Lightweight threads

  • Really cheap (almost free)

  • Experimental in 1.1 (will change)

provide a way to avoid blocking a thread and replace it with a cheaper and more controllable operation: suspension of a coroutine

Made with Slides.com