mosaic

0.18.0-1indexed

Experimental console UI builder using Jetpack Compose compiler/runtime — declarative composable primitives, state-driven rendering, live terminal redraws, built-in effects and sample interactive apps.

JVMNative·yschimke/mosaic

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Mosaic

An experimental tool for building console UI in Kotlin using the Jetpack Compose compiler/runtime. Inspired by Ink.

Jump to: Introduction | Usage | Samples | FAQ | License

Introduction

The entrypoint to Mosaic is the runMosaic function. The lambda passed to this function is responsible for both output and performing work.

suspend fun main() = runMosaic {
  Text("The count is: 0")
}

To change the output dynamically we can use local properties to hold state. Let's update our counter to actually count to 20.

suspend fun main() = runMosaic {
  var count by remember { mutableIntStateOf(0) }

  Text("The count is: $count")

  LaunchedEffect(Unit) {
    for (i in 1..20) {
      delay(250.milliseconds)
      count = i
    }
  }
}

(Note: You may need to add imports for androidx.compose.runtime.getValue and import androidx.compose.runtime.setValue manually.)

That is the most basic sample of Mosaic. From there, the limit is only your imagination.

(Note: graphs in the above have rendering problems due to asciinema/agg which do not appear in the real output)

Usage

Mosaic is a library for Compose, and it relies on JetBrains' Kotlin Compose plugin to be present for use. Any module which wants to call runMosaic or define @Composable functions for use with Mosaic must have this plugin applied. For more information, see the JetBrains Compose compiler documentation.

Mosaic itself can then be added like any other dependency:

dependencies {
  implementation("com.jakewharton.mosaic:mosaic-runtime:0.18.0")
}

Documentation is available at jakewharton.github.io/mosaic/docs/0.x/.

Snapshots of the development version are available in the Central Portal Snapshots repository.

repository {
  mavenCentral()
  maven {
    url 'https://central.sonatype.com/repository/maven-snapshots/'
  }
}
dependencies {
  implementation("com.jakewharton.mosaic:mosaic-runtime:0.19.0-SNAPSHOT")
}

Snapshot documentation is available at jakewharton.github.io/mosaic/docs/latest/.

Samples

Run ./gradlew installDist to build the sample binaries.

FAQ

I thought Compose was a UI toolkit for Android?

Compose is, at its core, a general-purpose compiler and runtime to do state tracking and tree node and property manipulation. This can be used on any platform supported by Kotlin for any kind of state or with any tree. It's an amazing piece of technology.

Compose UI is the modern UI toolkit for Android which also runs on the desktop, iOS, and the web. The lack of differentiation between these two technologies has unfortunately caused Compose UI to overshadow the core under the single "Compose" moniker in an unforced marketing error.

Other examples of non-Compose UI-based Compose projects are Cash App's Redwood, JetBrains' Compose HTML, or Google's Jetpack Glance.

Broken output with `./gradlew run` and/or inside IntelliJ IDEA

Running within Gradle or IntelliJ IDEA will not work. These tools do not provide access to the TTY in order to be interactive. And for non-interactive programs, both will strip ANSI control characters which prevent Mosaic from redrawing over a previous frame. The output will likely just render in successive lines instead.

Run your programs directly in a terminal emulator–no IDE and no Gradle.

License

Copyright 2020 Jake Wharton

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance  the License.
You may obtain a copy of the License at

   http:

Unless   applicable law  agreed to  writing, software
distributed under the License  distributed  an  BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express  implied.
See the License  the specific language governing permissions 
limitations under the License.