/scenic_new

mix scenic.new task for Scenic apps

Primary LanguageElixirApache License 2.0Apache-2.0

ScenicNew

The scenic.new mix task, which generates a starter application for you. This is the easiest way to set up a new Scenic project.

Erlang/Elixir versions

Please note, it currently needs OTP 21 and Elixir 1.7. If you have trouble compiling, please check that you are running those versions first.

Install Prerequisites

The design of Scenic goes to great lengths to minimize its dependencies to just the minimum. Namely, it needs Erlang/Elixir and OpenGL.

Rendering your application into a window on your local computer (MacOS, Ubuntu and others) is done by the scenic_driver_glfw driver. It uses the GLFW and GLEW libraries to connect to OpenGL.

The instructions below assume you have already installed Elixir/Erlang. If you need to install Elixir/Erlang there are instructions on the elixir-lang website.

Installing on MacOS

The easiest way to install on MacOS is to use Homebrew. Just run the following in a terminal:

brew update
brew install glfw3 glew pkg-config

Once these components have been installed, you should be able to build the scenic_driver_glfw driver.

Installing on Ubuntu 16

The easiest way to install on Ubuntu is to use apt-get. Just run the following:

sudo apt-get update
sudo apt-get install pkgconf libglfw3 libglfw3-dev libglew1.13 libglew-dev

Once these components have been installed, you should be able to build the scenic_driver_glfw driver.

Installing on Ubuntu 18

The easiest way to install on Ubuntu is to use apt-get. Just run the following:

sudo apt-get update
sudo apt-get install pkgconf libglfw3 libglfw3-dev libglew2.0 libglew-dev

Once these components have been installed, you should be able to build the scenic_driver_glfw driver.

Installing on Arch Linux

glew and glfw-x11 are available in Extra and Community, respectively. Ensure that these are enabled in your pacman.conf, then run:

sudo pacman -S pkgconf glew glfw-x11

Once these components have been installed, you should be able to build the scenic_driver_glfw driver.

Installing on FreeBSD

The easiest way to install on FreeBSD is to use pkg. Just run the following, to install development toolchain, and build/runtime graphics libraries:

sudo pkg install devel/gmake devel/pkgconf devel/elixir-hex devel/rebar3 \
  graphics/glew graphics/glfw

Once these components have been installed, you should be able to build the scenic_driver_glfw driver.

Installing on NixOS 18.09

The easiest way to install on NixOS is with a custom shell. Create a file titled shell.nix that includes the following:

{ pkgs ? import <nixpkgs> {} }:

with pkgs;

let
  inherit (lib) optional optionals;
  elixir = beam.packages.erlangR21.elixir_1_7;
in

mkShell {
  buildInputs = [
    elixir
    glew glfw
    git
    pkgconfig
    x11
    xorg.libpthreadstubs
    xorg.libXcursor
    xorg.libXdmcp
    xorg.libXfixes
    xorg.libXinerama
    xorg.libXrandr
    xorg.xrandr
  ];
}

Then use nix-shell to build and run the shell as your development environment:

nix-shell shell.nix

Install scenic.new

mix archive.install hex scenic_new

To build and run scenic applications, you will also need to install a few dependencies. See the Getting started for more information.

Build and install locally

To build and install this archive locally ensure any previous archive versions are removed:

mix archive.uninstall scenic_new

Then run:

cd scenic_new
MIX_ENV=prod mix do archive.build, archive.install

Build the Basic Application

First, navigate the command-line to the directory where you want to create your new Scenic application. Then run the following commands: (change my_app to the name of your application)

mix scenic.new my_app
cd my_app
mix do deps.get, scenic.run

This will create a bare-bones application

Build the Example Application

First, navigate the command-line to the directory where you want to create your new Scenic application. Then run the following commands: (change my_app to the name of your application)

mix scenic.new.example my_app
cd my_app
mix do deps.get, scenic.run

Build the Basic Nerves Application

This assumes you are already familiar with the basics of Nerves applications.

Note: You will first need to install the standard Nerves build tools for this to work. You can find instructions here.

Navigate the command-line to the directory where you want to create your new Scenic application. Then run the following commands: (change my_app to the name of your application)

mix scenic.new.nerves my_app
cd my_app
mix do deps.get, scenic.run

Then navigate into the new app directory. Once there you can build the app.

To run on the "host", which is your dev machine do this:

export MIX_TARGET=host
mix deps.get
mix scenic.run

To run on a Raspberry Pi 3 computer, do this:

export MIX_TARGET=rpi3
mix deps.get
mix nerves.release.init
mix firmware.burn

Running and Debugging on Your Dev Machine

Once the application and its dependencies are set up, there are two main ways to run it.

If you want to run your application under IEx so that you can debug it, simply run

iex -S mix

This works just like any other Elixir application.

If you want to run your application outside of IEx, you should start it like this:

mix scenic.run

The Example Application

The starter application created by the generator above shows the basics of building a Scenic application. It has four scenes, two components, and a simulated sensor.

Scene Description
Splash The Splash scene is configured to run when the application is started in the config/config.exs file. It runs a simple animation, then transitions to the Sensor scene. It also shows how intercept basic user input to exit the scene early.
Sensor The Sensor scene depicts a simulated temperature sensor. The sensor is always running and updates it's data through the Scenic.SensorPubSub server.
Primitives The Primitives scenes displays an overview of the basic primitive types and some of the styles that can be applied to them.
Components The Components scene shows the basic components that come with Scenic. The crash button will cause a match error that will crash the scene, showing how the supervision tree restarts the scene. It also shows how to receive events from components.
Component Description
Nav The navigation bar at the top of the main scenes shows how to navigate between scenes and how to construct a simple component and pass a parameter to it. Note that it references a clock, creating a nested component. The clock is positioned by dynamically querying the width of the ViewPort
Notes The notes section at the bottom of each scene is very simple and also shows passing in custom data from the parent.

The simulated temperature sensor doesn't collect any actual data, but does show how you would set up a real sensor and publish data from it into the Scenic.SensorPubSub service.

What to read next

Next, you should read the guides describing the overall Scenic structure. This is in the documentation for Scenic itself.