Kotlin Intro & Starting the Koans

Tomás Hanley

20th August 2018

Drone Delivery App

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