Jewel: a Compose for Desktop theme

Jewel aims at recreating the IntelliJ Platform's New UI Swing Look and Feel in Compose for Desktop, providing a desktop-optimized theme and set of components.

Warning

This project is in active development, and caution is advised when considering it for production uses. You can use it, but you should expect APIs to change often, things to move around and/or break, and all that jazz. Binary compatibility is not guaranteed across releases, and APIs are still in flux and subject to change.

Writing 3rd party IntelliJ Plugins in Compose for Desktop is currently not officially supported by the IntelliJ Platform. It should work, but your mileage may vary, and if things break you're on your own.

Use at your own risk!

Jewel provides an implementation of the IntelliJ Platform themes that can be used in any Compose for Desktop application. Additionally, it has a Swing LaF Bridge that only works in the IntelliJ Platform (i.e., used to create IDE plugins), but automatically mirrors the current Swing LaF into Compose for a native-looking, consistent UI.

Tip

If you want to learn more about Jewel and Compose for Desktop and why they're a great, modern solution for your desktop UI needs, check out this talk by Jewel contributors Sebastiano and Chris.

It covers why Compose is a viable choice, and an overview of the Jewel project, plus some real-life use cases.

Getting started

The first thing to add is the necessary Gradle plugins, including the Compose Multiplatform plugin. You need to add a custom repository for it in settings.gradle.kts:

pluginManagement {
    repositories {
        google()
        gradlePluginPortal()
        maven("https://maven.pkg.jetbrains.space/public/p/compose/dev")
        mavenCentral()
    }
}

Then, in your app's build.gradle.kts:

plugins {
    // MUST align with the Kotlin and Compose dependencies in Jewel
    kotlin("jvm") version "..."
    id("org.jetbrains.compose") version "..."
}

repositories {
    maven("https://packages.jetbrains.team/maven/p/kpm/public/")
    // Any other repositories you need (e.g., mavenCentral())
}

Warning

If you use convention plugins to configure your project you might run into issues such as this. To solve it, make sure the plugins are only initialized once — for example, by declaring them in the root build.gradle.kts with apply false, and then applying them in all the submodules that need them.

To use Jewel in your app, you only need to add the relevant dependency. There are two scenarios: standalone Compose for Desktop app, and IntelliJ Platform plugin.

If you're writing a standalone app, then you should depend on the latest int-ui-standalone-* artifact:

dependencies {
    // See https://github.com/JetBrains/Jewel/releases for the release notes
    implementation("org.jetbrains.jewel:jewel-int-ui-standalone-[latest platform version]:[jewel version]")

    // Optional, for custom decorated windows:
    implementation("org.jetbrains.jewel:jewel-int-ui-decorated-window-[latest platform version]:[jewel version]")

    // Do not bring in Material (we use Jewel)
    implementation(compose.desktop.currentOs) {
        exclude(group = "org.jetbrains.compose.material")
    }
}

For an IntelliJ Platform plugin, then you should depend on the appropriate ide-laf-bridge-* artifact:

dependencies {
    // See https://github.com/JetBrains/Jewel/releases for the release notes
    // The platform version is a supported major IJP version (e.g., 232 or 233 for 2023.2 and 2023.3 respectively)
    implementation("org.jetbrains.jewel:jewel-ide-laf-bridge-[platform version]:[jewel version]")

    // Do not bring in Material (we use Jewel) and Coroutines (the IDE has its own)
    api(compose.desktop.currentOs) {
        exclude(group = "org.jetbrains.compose.material")
        exclude(group = "org.jetbrains.kotlinx")
    }
}

Tip

It's easier to use version catalogs — you can use the Jewel version catalog as reference.

Using ProGuard/obfuscation/minification

Jewel doesn't officially support using ProGuard to minimize and/or obfuscate your code, and there is currently no plan to. That said, people are reporting successes in using it. Please note that there is no guarantee that it will keep working, and you most definitely need to have some rules in place. We don't provide any official rule set, but these have been known to work for some: https://github.com/romainguy/kotlin-explorer/blob/main/compose-desktop.pro

Important

We won't accept bug reports for issues caused by the use of ProGuard or similar tools.

Dependencies matrix

Jewel is in continuous development and we focus on supporting only the Compose version we use internally. You can see the latest supported version in libs.versions.toml.

Different versions of Compose are not guaranteed to work with different versions of Jewel.

The Compose Compiler version used is the latest compatible with the given Kotlin version. See here for the Compose Compiler release notes, which indicate the compatibility.

The minimum supported Kotlin version is dictated by the minimum supported IntelliJ IDEA platform.

Project structure

The project is split in modules:

1. buildSrc contains the build logic, including:
   • The jewel and jewel-publish configuration plugins
   • The jewel-check-public-api and jewel-linting configuration plugins
   • The Theme Palette generator plugin
   • The Studio Releases generator plugin
2. foundation contains the foundational Jewel functionality:
   • Basic components without strong styling (e.g., SelectableLazyColumn, BasicLazyTree)
   • The JewelTheme interface with a few basic composition locals
   • The state management primitives
   • The Jewel annotations
   • A few other primitives
3. ui contains all the styled components and custom painters logic
4. decorated-window contains basic, unstyled functionality to have custom window decoration on the JetBrains Runtime
5. int-ui contains two modules:
   • int-ui-standalone has a standalone version of the Int UI styling values that can be used in any Compose for Desktop app
   • int-ui-decorated-window has a standalone version of the Int UI styling values for the custom window decoration that can be used in any Compose for Desktop app
6. ide-laf-bridge contains the Swing LaF bridge to use in IntelliJ Platform plugins (see more below)
7. markdown contains a few modules:
   • core the core logic for parsing and rendering Markdown documents with Jewel, using GitHub-like styling
   • extension contains several extensions to the base CommonMark specs that can be used to add more features
   • ide-laf-bridge-styling contains the IntelliJ Platform bridge theming for the Markdown renderer
   • int-ui-standalone-styling contains the standalone Int UI theming for the Markdown renderer
8. samples contains the example apps, which showcase the available components:
   • standalone is a regular CfD app, using the standalone theme definitions and custom window decoration
   • ide-plugin is an IntelliJ plugin that showcases the use of the Swing Bridge

Branching strategy and IJ Platforms

Code on the main branch is developed and tested against the current latest IntelliJ Platform version.

When the EAP for a new major version starts, we cut a releases/xxx release branch, where xxx is the tracked major IJP version. At that point, the main branch starts tracking the latest available major IJP version, and changes are cherry-picked into each release branch as needed. All active release branches have the same functionality (where supported by the corresponding IJP version), but might differ in platform version-specific fixes and internals.

The standalone Int UI theme will always work the same way as the latest major IJP version; release branches will not include the int-ui module, which is always released from the main branch.

Releases of Jewel are always cut from a tag on the main branch; the HEAD of each releases/xxx branch is then tagged as [mainTag]-xxx, and used to publish the artifacts for that major IJP version.

Important

We only support the latest build of IJP for each major IJP version. If the latest 233 version is 2023.3.3, for example, we will only guarantee that Jewel works on that. Versions 2023.3.0–2023.3.2 might or might not work.

Caution

When you target Android Studio, you might encounter issues due to Studio shipping its own (older) version of Jewel and Compose for Desktop. If you want to target Android Studio, you'll need to shadow the CfD and Jewel dependencies until that dependency isn't leaked on the classpath by Studio anymore. You can look at how the Package Search plugin implements shadowing.

Int UI Standalone theme

The standalone theme can be used in any Compose for Desktop app. You use it as a normal theme, and you can customise it to your heart's content. By default, it matches the official Int UI specs.

For an example on how to set up a standalone app, you can refer to the standalone sample.

Warning

Note that Jewel requires the JetBrains Runtime to work correctly. Some features like font loading depend on it, as it has extra features and patches for UI functionalities that aren't available in other JDKs. We do not support running Jewel on any other JDK.

To use Jewel components in a non-IntelliJ Platform environment, you need to wrap your UI hierarchy in a IntUiTheme composable:

IntUiTheme(isDark = false) {
    // ...
}

If you want more control over the theming, you can use other IntUiTheme overloads, like the standalone sample does.

Custom window decoration

The JetBrains Runtime allows windows to have a custom decoration instead of the regular title bar.

The standalone sample app shows how to easily get something that looks like a JetBrains IDE; if you want to go very custom, you only need to depend on the decorated-window module, which contains all the required primitives, but not the Int UI styling.

To get an IntelliJ-like custom title bar, you need to pass the window decoration styling to your theme call, and add the DecoratedWindow composable at the top level of the theme:

IntUiTheme(
    theme = themeDefinition,
    styling = ComponentStyling.default().decoratedWindow(
        titleBarStyle = TitleBarStyle.light()
    ),
) {
    DecoratedWindow(
        onCloseRequest = { exitApplication() },
    ) {
        // ...
    }
}

Running on the IntelliJ Platform: the Swing bridge

Jewel includes a crucial element for proper integration with the IDE: a bridge between the Swing components — theme and LaF — and the Compose world.

This bridge ensures that we pick up the colours, typography, metrics, and images as defined in the current IntelliJ theme, and apply them to the Compose components as well. This means Jewel will automatically adapt to IntelliJ Platform themes that use the standard theming mechanisms.

Note

IntelliJ themes that use non-standard mechanisms (such as providing custom UI implementations for Swing components) are not, and can never, be supported.

If you're writing an IntelliJ Platform plugin, you should use the SwingBridgeTheme instead of the standalone theme:

SwingBridgeTheme {
    // ...
}

Supported IntelliJ Platform versions

To use Jewel in the IntelliJ Platform, you should depend on the appropriate jewel-ide-laf-bridge-* artifact, which will bring in the necessary transitive dependencies. These are the currently supported versions of the IntelliJ Platform and the branch on which the corresponding bridge code lives:

IntelliJ Platform version(s)	Branch to use
2024.2 (beta 1+)	main
2024.1 (EAP 3+)	releases/241
2023.3	releases/233
2023.2 (deprecated)	archived-releases/232
2023.1 or older	Not supported

For an example on how to set up an IntelliJ Plugin, you can refer to the ide-plugin sample.

Icons

Loading icons is best done with the Icon composable, which offers a key-based API that is portable across bridge and standalone modules. Icon keys implement the IconKey interface, which is then internally used to obtain a resource path to load the icon from.

Icon(key = MyIconKeys.myIcon, contentDescription = "My icon")

Loading icons from the IntelliJ Platform

If you want to load an IJ platform icon, you can use AllIconsKeys, which is generated from the AllIcons platform file. When using this in an IJ plugin, make sure you are using a version of the Jewel library matching the platform version, because icons are known to shift between major versions — and sometimes, minor versions, too.

To use icons from AllIconsKeys in an IJ plugin, you don't need to do anything, as the icons are in the classpath by default. If you want to use icons in a standalone app, you'll need to make sure the icons you want are on the classpath. You can either copy the necessary icons in your resources, matching exactly the path they have in the IDE, or you can add a dependency to the com.jetbrains.intellij.platform:icons artifact, which contains all the icons that end up in AllIconsKeys. The latter is the recommended approach, since it's easy and the icons don't take up much disk space.

Add this to your standalone app build script:

dependencies {
    implementation("com.jetbrains.intellij.platform:icons:[ijpVersion]")
    // ...
}

repositories {
    // Choose either of these two, depending on whether you're using a stable IJP or not
    maven("https://www.jetbrains.com/intellij-repository/releases")
    maven("https://www.jetbrains.com/intellij-repository/snapshots")
}

Note

If you are targeting an IntelliJ plugin, you don't need this additional setup since the icons are provided by the platform itself.

Loading your own icons

To access your own icons, you'll need to create and maintain the IconKeys for them. We found that the easiest way when you have up to a few dozen icons is to manually create an icon keys holder, like the ones we have in our samples. If you have many more, you should consider generating these holders, instead.

In your holders, you can choose which implementation of IconKey to use:

• If your icons do not need to change between old UI and new UI, you can use the simpler PathIconKey
• If your icons are different in old and new UI, you should use IntelliJIconKey, which accepts two paths, one per variant
• If you have different needs, you can also implement your own version of IconKey

Painter hints

Jewel has an API to influence the loading and drawing of icons, called PainterHint. Icon composables have overloads that take zero, one or more PainterHints that will be used to compute the end result that shows up on screen.

PainterHints can change the icon path (by adding a prefix/suffix, or changing it completely), tweak the contents of an image (SVG patching, XML patching, bitmap patching), add decorations (e.g., badges), or do nothing at all (None). We have several types of built-in PainterHints which should cover all needs; if you find some use case that is not yet handled, please file a feature request and we'll evaluate it.

Both standalone and bridge themes provide a default set of implicit PainterHints, for example to implement runtime patching, like the IDE does. You can also use PainterHints to affect how an icon will be drawn, or to select a specific icon file, based on some criteria (e.g., Size).

If you have a stateful icon, that is if you need to display different icons based on some state, you can use the Icon(..., hint) and Icon(..., hints) overloads. You can then use one of the state-mapping PainterHint to let Jewel load the appropriate icon automatically:

// myState implements SelectableComponentState and has a ToggleableState property
val indeterminateHint = 
    if (myState.toggleableState == ToggleableState.Indeterminate) {
        IndeterminateHint
    } else {
        PainterHint.None
    }
    
Icon(
    key = myKey,
    contentDescription = "My icon",
    indeterminateHint,
    Selected(myState),
    Stateful(myState),
)

Where the IndeterminateHint looks like this:

private object IndeterminateHint : PainterSuffixHint() {
    override fun suffix(): String = "Indeterminate"
}

Assuming the PainterProvider has a base path of components/myIcon.svg, Jewel will automatically translate it to the right path based on the state. If you want to learn more about this system, look at the PainterHint interface and its implementations.

Please look at the PainterHint implementations and our samples for further information.

Default icon runtime patching

Jewel emulates the under-the-hood machinations that happen in the IntelliJ Platform when loading icons. Specifically, the resource will be subject to some transformations before being loaded. This is built on the PainterHint API we described above.

For example, in the IDE, if New UI is active, the icon path may be replaced with a different one. Some key colors in SVG icons will also be replaced based on the current theme. See the docs.

Beyond that, even in standalone, Jewel will pick up icons with the appropriate dark/light variant for the current theme, and for bitmap icons it will try to pick the 2x variants based on the LocalDensity.

Fonts

To load a system font, you can obtain it by its family name:

val myFamily = FontFamily("My Family")

If you want to use a font embedded in the JetBrains Runtime, you can use the EmbeddedFontFamily API instead:

import javax.swing.text.StyledEditorKit.FontFamilyAction

// Will return null if no matching font family exists in the JBR
val myEmbeddedFamily = EmbeddedFontFamily("Embedded family")

// It's recommended to load a fallback family when dealing with embedded familes
val myFamily = myEmbeddedFamily ?: FontFamily("Fallback family")

You can obtain a FontFamily from any java.awt.Font — including from JBFonts — by using the asComposeFontFamily() API:

val myAwtFamily = myFont.asComposeFontFamily()

// This will attempt to resolve the logical AWT font
val myLogicalFamily = Font("Dialog").asComposeFontFamily()

// This only works in the IntelliJ Platform,
// since JBFont is only available there
val myLabelFamily = JBFont.label().asComposeFontFamily()

Swing interoperability

As this is Compose for Desktop, you get a good degree of interoperability with Swing. To avoid glitches and z-order issues, you should enable the experimental Swing rendering pipeline before you initialize Compose content.

The ToolWindow.addComposeTab() extension function provided by the ide-laf-bridge module will take care of that for you. However, if you want to also enable it in other scenarios and in standalone applications, you can call the enableNewSwingCompositing() function in your Compose entry points (that is, right before creating a ComposePanel).

Note

The new Swing rendering pipeline is experimental and may have performance repercussions when using infinitely repeating animations. This is a known issue by the Compose Multiplatform team, that requires changes in the Java runtime to fix. Once the required changes are made in the JetBrains Runtime, we'll remove this notice.

Written with Jewel

Here is a small selection of projects that use Compose for Desktop and Jewel:

• Package Search (IntelliJ Platform plugin)
• Kotlin Explorer (standalone app)
• New task-based Profiler UI in Android Studio Koala
• ...and more to come!

Need help?

You can find help on the #jewel channel on the Kotlin Slack. If you don't already have access to the Kotlin Slack, you can request it here.

License

Jewel is licensed under the Apache 2.0 license.

Copyright 2022–4 JetBrains s.r.o.

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.