Ruler¶

Ruler

Distance measurements library for Kotlin and Android.

TLDR¶

Define a distance and manipulate it.

// Distance is dimensionless.
val distanceFromMeters: Distance = Distance.ofMeters(100)
val distanceFromYards: Distance = Distance.ofYards(50)

// Length has a unit attached to it.
val metersLength: Length<SiLengthUnit.Meter> = distanceFromMeters.toLength(SiLengthUnit.Meter)
val inchesLength: Length<ImperialLengthUnit.Inch> = distanceFromMeters.toLength(ImperialLengthUnit.Inch)

// metersLength and inchesLength represent the same distance but with a different units attached to them.
check(metersLength - inchesLength == Length.ofMeters(0))

Android artifact allows to show a user formatted distances and lengths using appropriate Locale if available.

fun main() {
  val distance = Distance.ofMeters(100)
  val length = distance.toLength(Meter)

  // Assumes en_US Locale on a device.

  // Prints "109yd 1ft 1in".
  val humanReadableDistance: String = distance.format()

  // Prints "100.00m".
  val humanReadableLength: String = length.format()
}

Requirements¶

Ruler requires Java 8 bytecode support. You can enable it with the following configuration in a build.gradle file.

android {
  compileOptions {
    sourceCompatibility JavaVersion.VERSION_1_8
    targetCompatibility JavaVersion.VERSION_1_8
  }

  kotlinOptions {
    jvmTarget = "1.8"
  }
}

Get Ruler¶

Ruler is published to Maven Central Repository.

repositories {
  mavenCentral()
}

dependencies {
  implementation "io.mehow.ruler:ruler:2.0.2"
}

Snapshots of the development version are available on Sonatype’s snapshots repository.

Here is the list of all available artifacts that Ruler library provides.

io.mehow.ruler:ruler:2.0.2: Core of the library. Defines classes and interfaces that represent distances and gives capabilities to format the for a user in a human-readable way.
io.mehow.ruler:ruler-android:2.0.2: Provides formatting behaviour that can be installed at runtime in the core library.
io.mehow.ruler:ruler-android-startup:2.0.2: Uses Jetpack Startup library to initialize Ruler with Android context formatting.

Attribution¶

Logo icon made by Freepik from www.flaticon.com.

License¶

Copyright 2020 Michał Sikora

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

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.