Skiko (short for Skia for Kotlin) is the graphical library exposing significant part of Skia library APIs to Kotlin, along with the gluing code for rendering context. At the moment, Linux(x86_64 and arm64), Windows(x86_64) and macOS(x86_64 and arm64) builds for Kotlin/JVM are available.
To use in build scripts one has to compute appropriate target platform and version, i.e. something like this
repositories {
maven("https://maven.pkg.jetbrains.space/public/p/compose/dev")
}
val osName = System.getProperty("os.name")
val targetOs = when {
osName == "Mac OS X" -> "macos"
osName.startsWith("Win") -> "windows"
osName.startsWith("Linux") -> "linux"
else -> error("Unsupported OS: $osName")
}
val osArch = System.getProperty("os.arch")
var targetArch = when (osArch) {
"x86_64", "amd64" -> "x64"
"aarch64" -> "arm64"
else -> error("Unsupported arch: $osArch")
}
val version = "0.5.3"
val target = "${targetOs}-${targetArch}"
dependencies {
implementation("org.jetbrains.skiko:skiko-jvm-runtime-$target:$version")
}
Simple example for Kotlin/JVM
fun main() {
val skiaLayer = SkiaLayer()
skiaLayer.skikoView = GenericSkikoView(skiaLayer, object : SkikoView {
val paint = Paint().apply {
color = Color.RED
}
override fun onRender(canvas: Canvas, width: Int, height: Int, nanoTime: Long) {
canvas.clear(Color.CYAN)
val ts = nanoTime / 5_000_000
canvas.drawCircle( (ts % width).toFloat(), (ts % height).toFloat(), 20f, paint )
}
})
SwingUtilities.invokeLater {
val window = JFrame("Skiko example").apply {
defaultCloseOperation = WindowConstants.EXIT_ON_CLOSE
preferredSize = Dimension(800, 600)
}
skiaLayer.attachTo(window.contentPane)
skiaLayer.needRedraw()
window.pack()
window.isVisible = true
}
}
To use latest development snapshot use version 0.0.0-SNAPSHOT
.
- Set JAVA_HOME to location of JDK, at least version 11
cd skiko && ./gradlew publishToMavenLocal
will build the artefact and publish it to local Maven repo
To build with debug symbols and debug Skia build use -Pskiko.debug=true
Gradle argument.
Gradle build downloads the necessary version of Skia by default.
However, if downloaded sources are modified, changes are discarded (Gradle
re-evaluates tasks, when outputs are changed).
To use custom version of the dependencies, specify SKIA_DIR
environment variable.
- Install Visual Studio Build Tools or Visual Studio C++.
- If Gradle fails to find Visual C++ toolchain:
Execution failed for task ':compileDebugWindowsCpp'.
> No tool chain is available to build C++ for host operating system 'Windows 10' architecture 'x86-64':
- Tool chain 'visualCpp' (Visual Studio):
- Could not locate a Visual Studio installation, using the command line tool, Windows registry or system path.
set SKIKO_VSBT_PATH
environment variable to the location of installed Visual Studio Build Tools.
This could be done in the UI:
Control Panel|All Control Panel Items|System|Advanced system settings|Environment variables
or by running cmd
as administrator:
setx /M SKIKO_VSBT_PATH "C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools"