kotlin-tools

Gradle Plugins

A collection of Gradle plugins for building applications and libraries using Kotlin.

These plugins all target Kotlin 2.3.10 and Java 17 (for Kotlin/JVM libraries and Gradle plugins) or Java 21 (for Kotlin/JVM apps). The plugins require Gradle 9.0 or later and Java 17 or later.

Settings plugins

net.rubygrapefruit.kotlin-base

A settings plugin that must be applied to the settings of any build that uses these plugins.

• Applies the foojay toolchain convention plugin.

Native desktop applications and libraries

net.rubygrapefruit.native.desktop-lib

Builds a library implemented in Kotlin multiplatform that targets native desktop platforms.

• Adds Linux and Windows x64 targets and macOS x64 and arm64 targets.
• Adds unixMain and unixTest source sets for Kotlin code that is shared by macOS and Linux targets.
• Adds a library { } block.

net.rubygrapefruit.native.cli-app

Builds a command-line application implemented in Kotlin multiplatform that targets native desktop platforms.

• Adds Linux and Windows x64 targets and macOS x64 and arm64 targets.
• Adds unixMain and unixTest source sets for Kotlin code that is shared by macOS and Linux targets.
• Adds an application { } block, see below for the available settings.
• Add dist and install tasks.

This uses the net.rubygrapefruit.native.base-cli-app plugin and adds the targets.

net.rubygrapefruit.native.ui-app

Builds a UI application implemented in Kotlin multiplatform that targets native desktop platforms.

• Adds macOS x64 and arm64 targets.
• Adds an application { } block, see below for the available settings.
• Add dist task.

net.rubygrapefruit.native.base-cli-app

Builds a command-line application implemented in Kotlin multiplatform. Does not define any targets, these have to be explicitly defined.

Native and JVM libraries

net.rubygrapefruit.kmp.lib

Builds a library implemented in Kotlin multiplatform that targets the JVM, browser and native desktop platforms.

• Add JVM target.
• Add browser target.
• Adds Linux and Windows x64 targets and macOS x64 and arm64 targets.
• Adds library { } block, see below for the available settings.
• Adds unixMain and unixTest source sets for Kotlin code that is shared by macOS and Linux targets.
• Adds desktopMain and desktopTest source sets for Kotlin code that is shared by JVM, macOS, Linux and Windows targets.
• Generates a module-info for the JVM target.

This uses the net.rubygrapefruit.kmp.base-lib plugin and adds the targets.

net.rubygrapefruit.kmp.base-lib

Builds a library implemented in Kotlin multiplatform. Does not define any targets, these have to be explicitly defined.

JVM applications and libraries

net.rubygrapefruit.jvm.lib

Builds a library implemented using Kotlin/JVM.

• Adds library { } block, see below for the available settings.
• Generates a module-info.

net.rubygrapefruit.jvm.cli-app

Builds a command-line application implemented using Kotlin/JVM. Expects that the application uses the JVM module system.

• The distribution contains the jars for the application and a launcher script. This script requires that a compatible JVM can be found on the machine’s $PATH, unless one of the plugin below is also used.
• The launcher script starts the application in the debugger when $JVM_DEBUG is set to a non-empty string
• Adds application { } block, see below for the available settings.
• Automatically determines the application main class.
• Generates a module-info.
• Add dist and install tasks.

net.rubygrapefruit.jvm.embedded-jvm

Can be applied with net.rubygrapefruit.jvm.cli-app to include a copy of the JVM in the application distribution. The launcher script uses this embedded JVM. Uses jlink to create the JVM image.

net.rubygrapefruit.jvm.native-binary

Can be applied with net.rubygrapefruit.jvm.cli-app to create a native binary to use in the application distribution, instead of using a launcher script. Uses graalvm to create the native binary.

net.rubygrapefruit.jvm.ui-app

Builds a desktop UI application implemented using Kotlin/JVM and that presents a Swing or JavaFX UI. Expects that the application uses the JVM module system.

• Creates a debug (unsigned) macOS application bundle and a release (signed and notarized) application bundle
• Includes an embedded JVM in the application bundle
• Provides an application icon, default location is src/main/Icon1024.png
• Adds application { } block, see below for the available settings.
• Use dist task to build the debug application bundle.

Gradle plugins

net.rubygrapefruit.gradle-plugin

A convention plugin for implementing Gradle plugins using Kotlin/JVM.

• Adds dependencies and repository definitions so that a fixed version of Kotlin (currently 2.0.0) is used to compile the plugin.
• Targets Java 17.
• Adds versions extension
• Adds a dependency on these plugins, so their API can be used in other plugins.
• Adds a pluginBundle { } block.

Common application settings for all targets

• Adds application { } block
  • application.appName - the base name for the application, used for various default file names.
  • application.distribution.imageDirectory - the directory to create the distribution image in.
• Adds a dist task to create a distribution image containing the app ready for installation. By default, this is created in build/dist-image

JVM application settings

• Adds application { } block
  • application.mainClass - defaults to main class determined by inspecting the bytecode
  • application.module.name - defaults to the application name
  • application.targetJvmVersion - defaults to 17
  • application.dependencies { } - production dependencies
  • application.test { } - test dependencies

JVM library settings

• Adds library { } block
  • library.module.name - defaults to the project name
  • library.module.exports
  • library.module.requires - calculated from compile (implementation) dependencies
  • library.module.requiresTransitive - calculated from the API dependencies
  • library.targetJvmVersion - defaults to 17
  • library.dependencies { } - production dependencies
  • library.test { } - test dependencies

Native application settings

• Adds application { } block
  • application.common { } - production dependencies common to all targets
  • application.test { } - test dependencies common to all targets

Multi-platform library settings

• Adds library { } block
  • library.jvm { } - JVM target settings (same as JVM library above)
  • library.common { } - production dependencies common to all targets
  • library.test { } - test dependencies common to all targets

See ../test-apps for some samples.