Android support preparational work (#451)

samples/SkiaMultiplatformSample/build.gradle.kts

+buildscript {
+    repositories {
+        mavenLocal()
+        google()
+        mavenCentral()
+        maven("https://maven.pkg.jetbrains.space/public/p/compose/dev")
+    }
+
+    dependencies {
+        // __KOTLIN_COMPOSE_VERSION__
+        classpath(kotlin("gradle-plugin", version = "1.6.10"))
+    }
+}
+
 plugins {
     kotlin("multiplatform") version "1.6.10"
 }
@@ -6,6 +20,7 @@ val coroutinesVersion = "1.5.2"
 
 repositories {
     mavenLocal()
+    google()
     mavenCentral()
     maven("https://maven.pkg.jetbrains.space/public/p/compose/dev")
 }

samples/SkiaMultiplatformSample/settings.gradle.kts

@@ -2,9 +2,7 @@ pluginManagement {
     repositories {
         mavenCentral()
         gradlePluginPortal()
-        maven {
-            url = uri("https://dl.bintray.com/kotlin/kotlin-eap")
-        }
+        google()
     }
     
 }

samples/SkiaMultiplatformSample/src/androidMain/kotlin/org/jetbrains/skiko/sample/App.android.kt

+//

skiko/build.gradle.kts

@@ -202,12 +202,7 @@ val Project.supportWasm: Boolean
     get() = findProperty("skiko.wasm.enabled") == "true" || isInIdea
 
 val Project.supportAndroid: Boolean
-    get() = findProperty("skiko.android.enabled") == "true"
-
-val skikoAwtJar by project.tasks.registering(Jar::class) {
-    archiveBaseName.set("skiko-awt")
-    from(kotlin.jvm("awt").compilations["main"].output.allOutputs)
-}
+    get() = findProperty("skiko.android.enabled") == "true" // || isInIdea
 
 kotlin {
     jvm("awt") {
@@ -218,11 +213,14 @@ kotlin {
     }
 
     if (supportAndroid) {
-        // todo: use android target
         jvm("android") {
             compilations.all {
                 kotlinOptions.jvmTarget = "11"
             }
+            // We need an additional attribute to distinguish between JVM variants.
+            attributes {
+                attributes.attribute(Attribute.of("ui", String::class.java), "android")
+            }
             // TODO: seems incorrect.
             generateVersion(OS.Android, Arch.Arm64)
         }
@@ -230,7 +228,7 @@ kotlin {
 
     if (supportWasm) {
         js(IR) {
-            browser() {
+            browser {
                 testTask {
                     dependsOn("linkWasm")
                     useKarma {
@@ -265,19 +263,11 @@ kotlin {
             }
         }
 
-        /*
-        val androidMain by getting {
-            dependencies {
-
-            }
-        } */
-
         val jvmMain by creating {
             dependsOn(commonMain)
             dependencies {
                 implementation(kotlin("stdlib"))
                 implementation("org.jetbrains.kotlinx:kotlinx-coroutines-core-jvm:$coroutinesVersion")
-                implementation("org.jetbrains.kotlinx:kotlinx-coroutines-swing:$coroutinesVersion")
             }
         }
 
@@ -609,17 +599,25 @@ fun skiaStaticLibraries(skiaDir: String, targetString: String): List<String> {
 
 val allJvmRuntimeJars = mutableMapOf<Pair<OS, Arch>, TaskProvider<Jar>>()
 
-val skikoJvmRuntimeJar = createSkikoJvmJarTask(hostOs, hostArch)
+val skikoAwtJar by project.tasks.registering(Jar::class) {
+    archiveBaseName.set("skiko-awt")
+    from(kotlin.jvm("awt").compilations["main"].output.allOutputs)
+}
+val skikoJvmRuntimeJar = createSkikoJvmJarTask(hostOs, hostArch, skikoAwtJar)
 val skikoRuntimeDirForTests = skikoRuntimeDirForTestsTask(hostOs, hostArch, skikoJvmRuntimeJar)
 
 if (supportAndroid) {
     val os = OS.Android
+    val skikoAndroidJar by project.tasks.registering(Jar::class) {
+        archiveBaseName.set("skiko-android")
+        from(kotlin.jvm("android").compilations["main"].output.allOutputs)
+    }
     for (arch in arrayOf(Arch.X64, Arch.Arm64)) {
-        createSkikoJvmJarTask(os, arch)
+        createSkikoJvmJarTask(os, arch, skikoAndroidJar)
     }
 }
 
-fun createSkikoJvmJarTask(os: OS, arch: Arch): TaskProvider<Jar> {
+fun createSkikoJvmJarTask(os: OS, arch: Arch, commonJar: TaskProvider<Jar>): TaskProvider<Jar> {
     val skiaBindingsDir = registerOrGetSkiaDirProvider(os, arch)
     val compileBindings = createCompileJvmBindingsTask(os, arch, skiaBindingsDir)
     val objcCompile = if (os == OS.MacOS) createObjcCompileTask(os, arch, skiaBindingsDir) else null
@@ -651,7 +649,7 @@ fun createSkikoJvmJarTask(os: OS, arch: Arch): TaskProvider<Jar> {
         nativeFiles.add(nativeLib2)
         nativeFiles.add(createChecksums2.map { it.outputs.files.singleFile })
     }
-    val skikoJvmRuntimeJar = skikoJvmRuntimeJarTask(os, arch, skikoAwtJar, nativeFiles)
+    val skikoJvmRuntimeJar = skikoJvmRuntimeJarTask(os, arch, commonJar, nativeFiles)
     allJvmRuntimeJars[os to arch] = skikoJvmRuntimeJar
     return skikoJvmRuntimeJar
 }

skiko/src/androidMain/kotlin/org/jetbrains/skiko/Actuals.android.kt

+package org.jetbrains.skiko
+
+import org.jetbrains.skiko.redrawer.Redrawer
+
+actual fun setSystemLookAndFeel(): Unit = TODO()
+
+internal class AndroidOpenGLRedrawer(
+    private val layer: SkiaLayer,
+    private val properties: SkiaLayerProperties
+) : Redrawer {
+    override fun dispose() = TODO()
+    override fun needRedraw() = TODO()
+    override fun redrawImmediately() = TODO()
+
+    override val renderInfo: String get() = "Android renderer"
+}
+
+internal actual fun makeDefaultRenderFactory(): RenderFactory {
+    return object : RenderFactory {
+        override fun createRedrawer(
+            layer: SkiaLayer,
+            renderApi: GraphicsApi,
+            properties: SkiaLayerProperties
+        ): Redrawer = when (hostOs) {
+            OS.Android -> AndroidOpenGLRedrawer(layer, properties)
+            else -> throw IllegalArgumentException("Must not happen")
+        }
+    }
+}

skiko/src/androidMain/kotlin/org/jetbrains/skiko/SkiaLayer.android.kt

+package org.jetbrains.skiko
+
+import android.view.KeyEvent
+import android.view.MotionEvent
+import org.jetbrains.skia.Canvas
+import org.jetbrains.skiko.redrawer.Redrawer
+
+actual typealias SkikoGesturePlatformEvent = MotionEvent
+actual typealias SkikoPlatformPointerEvent = MotionEvent
+// TODO: most likely wrong.
+actual typealias SkikoPlatformInputEvent = Any
+actual typealias SkikoTouchPlatformEvent = Any
+actual typealias SkikoPlatformKeyboardEvent = KeyEvent
+
+actual open class SkiaLayer {
+    actual var renderApi: GraphicsApi = GraphicsApi.OPENGL
+    actual val contentScale: Float
+        get() = 1.0f
+
+    actual var fullscreen: Boolean
+        get() = false
+        set(value) {
+            if (value) throw IllegalArgumentException("fullscreen unsupported")
+        }
+
+    actual var transparency: Boolean
+        get() = false
+        set(value) {
+            if (value) throw IllegalArgumentException("transparency unsupported")
+        }
+
+
+    actual var skikoView: SkikoView? = null
+
+    actual fun attachTo(container: Any) {
+        TODO("Implement attachTo()")
+    }
+
+    actual fun detach() {
+    }
+
+    actual fun needRedraw() {
+        TODO("Implement needRedraw()")
+    }
+
+    internal var redrawer: Redrawer? = null
+
+    var width: Int = 0
+    var height: Int = 0
+
+    internal actual fun draw(canvas: Canvas): Unit = TODO()
+}
\ No newline at end of file

skiko/src/androidMain/kotlin/org/jetbrains/skiko/SkikoKey.android.kt

+package org.jetbrains.skiko
+
+import android.view.KeyEvent.*
+
+// See https://developer.android.com/reference/android/view/KeyEvent
+actual enum class SkikoKey(val value: Int) {
+    KEY_UNKNOWN(KEYCODE_UNKNOWN),
+    KEY_A(KEYCODE_A),
+    KEY_S(KEYCODE_S),
+    KEY_D(KEYCODE_D),
+    KEY_F(KEYCODE_F),
+    KEY_H(KEYCODE_H),
+    KEY_G(KEYCODE_G),
+    KEY_Z(KEYCODE_Z),
+    KEY_X(KEYCODE_X),
+    KEY_C(KEYCODE_C),
+    KEY_V(KEYCODE_V),
+    KEY_B(KEYCODE_B),
+    KEY_Q(KEYCODE_Q),
+    KEY_W(KEYCODE_W),
+    KEY_E(KEYCODE_E),
+    KEY_R(KEYCODE_R),
+    KEY_Y(KEYCODE_Y),
+    KEY_T(KEYCODE_T),
+    KEY_U(KEYCODE_U),
+    KEY_I(KEYCODE_I),
+    KEY_P(KEYCODE_P),
+    KEY_L(KEYCODE_L),
+    KEY_J(KEYCODE_J),
+    KEY_K(KEYCODE_K),
+    KEY_N(KEYCODE_N),
+    KEY_M(KEYCODE_M),
+    KEY_O(KEYCODE_O),
+    KEY_1(KEYCODE_1),
+    KEY_2(KEYCODE_2),
+    KEY_3(KEYCODE_3),
+    KEY_4(KEYCODE_4),
+    KEY_5(KEYCODE_5),
+    KEY_6(KEYCODE_6),
+    KEY_7(KEYCODE_7),
+    KEY_8(KEYCODE_8),
+    KEY_9(KEYCODE_9),
+    KEY_0(KEYCODE_0),
+    KEY_CLOSE_BRACKET(KEYCODE_RIGHT_BRACKET),
+    KEY_OPEN_BRACKET(KEYCODE_LEFT_BRACKET),
+    KEY_QUOTE(KEYCODE_UNKNOWN),
+    KEY_SEMICOLON(KEYCODE_SEMICOLON),
+    KEY_SLASH(KEYCODE_SLASH),
+    KEY_COMMA(KEYCODE_COMMA),
+    KEY_BACKSLASH(KEYCODE_BACKSLASH),
+    KEY_PERIOD(KEYCODE_PERIOD),
+    KEY_BACK_QUOTE(KEYCODE_UNKNOWN),
+    KEY_EQUALS(KEYCODE_EQUALS),
+    KEY_MINUS(KEYCODE_MINUS),
+    KEY_ENTER(KEYCODE_ENTER),
+    KEY_ESCAPE(KEYCODE_ESCAPE),
+    KEY_TAB(KEYCODE_TAB),
+    KEY_BACKSPACE(KEYCODE_DEL),
+    KEY_SPACE(KEYCODE_SPACE),
+    KEY_CAPSLOCK(KEYCODE_CAPS_LOCK),
+    KEY_LEFT_META(KEYCODE_META_LEFT),
+    KEY_LEFT_SHIFT(KEYCODE_SHIFT_LEFT),
+    KEY_LEFT_ALT(KEYCODE_ALT_LEFT),
+    KEY_LEFT_CONTROL(KEYCODE_CTRL_LEFT),
+    KEY_RIGHT_META(KEYCODE_META_RIGHT),
+    KEY_RIGHT_SHIFT(KEYCODE_SHIFT_RIGHT),
+    KEY_RIGHT_ALT(KEYCODE_ALT_RIGHT),
+    KEY_RIGHT_CONTROL(KEYCODE_CTRL_RIGHT),
+    KEY_MENU(KEYCODE_UNKNOWN),
+    KEY_UP(KEYCODE_SYSTEM_NAVIGATION_UP),
+    KEY_DOWN(KEYCODE_SYSTEM_NAVIGATION_DOWN),
+    KEY_LEFT(KEYCODE_SYSTEM_NAVIGATION_LEFT),
+    KEY_RIGHT(KEYCODE_SYSTEM_NAVIGATION_RIGHT),
+    KEY_F1(KEYCODE_F1),
+    KEY_F2(KEYCODE_F2),
+    KEY_F3(KEYCODE_F3),
+    KEY_F4(KEYCODE_F4),
+    KEY_F5(KEYCODE_F5),
+    KEY_F6(KEYCODE_F6),
+    KEY_F7(KEYCODE_F7),
+    KEY_F8(KEYCODE_F8),
+    KEY_F9(KEYCODE_F9),
+    KEY_F10(KEYCODE_F10),
+    KEY_F11(KEYCODE_F11),
+    KEY_F12(KEYCODE_F12),
+    KEY_PRINTSCEEN(KEYCODE_UNKNOWN),
+    KEY_SCROLL_LOCK(KEYCODE_UNKNOWN),
+    KEY_PAUSE(KEYCODE_UNKNOWN),
+    KEY_INSERT(KEYCODE_INSERT),
+    KEY_HOME(KEYCODE_HOME),
+    KEY_PGUP(KEYCODE_PAGE_UP),
+    KEY_DELETE(KEYCODE_FORWARD_DEL),
+    KEY_END(KEYCODE_MOVE_END),
+    KEY_PGDOWN(KEYCODE_PAGE_DOWN),
+    KEY_NUM_LOCK(KEYCODE_UNKNOWN),
+    KEY_NUMPAD_0(KEYCODE_NUMPAD_0),
+    KEY_NUMPAD_1(KEYCODE_NUMPAD_1),
+    KEY_NUMPAD_2(KEYCODE_NUMPAD_2),
+    KEY_NUMPAD_3(KEYCODE_NUMPAD_3),
+    KEY_NUMPAD_4(KEYCODE_NUMPAD_4),
+    KEY_NUMPAD_5(KEYCODE_NUMPAD_5),
+    KEY_NUMPAD_6(KEYCODE_NUMPAD_6),
+    KEY_NUMPAD_7(KEYCODE_NUMPAD_7),
+    KEY_NUMPAD_8(KEYCODE_NUMPAD_8),
+    KEY_NUMPAD_9(KEYCODE_NUMPAD_9),
+    KEY_NUMPAD_ENTER(KEYCODE_NUMPAD_ENTER),
+    KEY_NUMPAD_ADD(KEYCODE_NUMPAD_ADD),
+    KEY_NUMPAD_SUBTRACT(KEYCODE_NUMPAD_SUBTRACT),
+    KEY_NUMPAD_MULTIPLY(KEYCODE_NUMPAD_MULTIPLY),
+    KEY_NUMPAD_DIVIDE(KEYCODE_NUMPAD_DIVIDE),
+    KEY_NUMPAD_DECIMAL(KEYCODE_UNKNOWN);
+}
\ No newline at end of file

skiko/src/awtMain/kotlin/org/jetbrains/skiko/SkiaLayer.awt.kt

@@ -466,7 +466,7 @@ actual open class SkiaLayer internal constructor(
         }
     }
 
-    internal fun draw(canvas: Canvas) {
+    actual internal fun draw(canvas: Canvas) {
         check(!isDisposed) { "SkiaLayer is disposed" }
         lockPicture {
             canvas.drawPicture(it.instance)

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/context/Direct3DContextHandler.kt → skiko/src/awtMain/kotlin/org/jetbrains/skiko/context/Direct3DContextHandler.kt

 package org.jetbrains.skiko.context
 
 import org.jetbrains.skia.Surface
-import org.jetbrains.skia.impl.Native
 import org.jetbrains.skia.impl.getPtr
 import org.jetbrains.skiko.SkiaLayer
 import org.jetbrains.skiko.redrawer.Direct3DRedrawer

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/context/DirectSoftwareContextHandler.kt → skiko/src/awtMain/kotlin/org/jetbrains/skiko/context/DirectSoftwareContextHandler.kt

 package org.jetbrains.skiko.context
 
-import org.jetbrains.skia.Surface
-import org.jetbrains.skia.impl.Native
 import org.jetbrains.skia.impl.getPtr
 import org.jetbrains.skiko.SkiaLayer
 import org.jetbrains.skiko.redrawer.AbstractDirectSoftwareRedrawer

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/context/SoftwareContextHandler.kt → skiko/src/awtMain/kotlin/org/jetbrains/skiko/context/SoftwareContextHandler.kt

@@ -4,7 +4,6 @@ import org.jetbrains.skia.Bitmap
 import org.jetbrains.skia.Canvas
 import org.jetbrains.skia.ColorAlphaType
 import org.jetbrains.skia.ImageInfo
-import org.jetbrains.skia.Picture
 import org.jetbrains.skiko.SkiaLayer
 import org.jetbrains.skiko.hostOs
 import org.jetbrains.skiko.OS

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/AngleRedrawer.kt → skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/AngleRedrawer.kt

 package org.jetbrains.skiko.redrawer
 
-import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.swing.Swing
 import org.jetbrains.skia.BackendRenderTarget
 import org.jetbrains.skia.DirectContext
 import org.jetbrains.skiko.FrameDispatcher
 import org.jetbrains.skiko.SkiaLayer
 import org.jetbrains.skiko.SkiaLayerProperties
 import org.jetbrains.skiko.context.AngleContextHandler
-import org.jetbrains.skiko.context.DirectSoftwareContextHandler
 
 internal class AngleRedrawer(
     private val layer: SkiaLayer,

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/Direct3DRedrawer.kt → skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/Direct3DRedrawer.kt

 package org.jetbrains.skiko.redrawer
 
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.swing.Swing
 import kotlinx.coroutines.withContext
 import org.jetbrains.skia.DirectContext
 import org.jetbrains.skia.Surface
 import org.jetbrains.skiko.*
-import org.jetbrains.skiko.context.AngleContextHandler
 import org.jetbrains.skiko.context.Direct3DContextHandler
 
 internal class Direct3DRedrawer(

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/Actuals.awt.kt → skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/MainUIDispatcher.awt.kt

@@ -4,5 +4,5 @@ import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.MainCoroutineDispatcher
 import kotlinx.coroutines.swing.Swing
 
-actual val MainUIDispatcher: MainCoroutineDispatcher
+val MainUIDispatcher: MainCoroutineDispatcher
     get() = Dispatchers.Swing

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/MetalRedrawer.kt

@@ -3,7 +3,6 @@ package org.jetbrains.skiko.redrawer
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
-import kotlinx.coroutines.swing.Swing
 import kotlinx.coroutines.withContext
 import org.jetbrains.skia.BackendRenderTarget
 import org.jetbrains.skia.DirectContext
@@ -34,7 +33,7 @@ internal class MetalRedrawer(
         setVSyncEnabled(device, properties.isVsyncEnabled)
     }
 
-    private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
+    private val frameDispatcher = FrameDispatcher(MainUIDispatcher) {
         if (layer.isShowing) {
             update(System.nanoTime())
             draw()

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/SoftwareRedrawer.kt → skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/SoftwareRedrawer.kt

@@ -7,8 +7,6 @@ import org.jetbrains.skiko.SkiaLayer
 import org.jetbrains.skiko.SkiaLayerProperties
 import org.jetbrains.skiko.context.SoftwareContextHandler
 
-expect val MainUIDispatcher: MainCoroutineDispatcher
-
 internal class SoftwareRedrawer(
     private val layer: SkiaLayer,
     private val properties: SkiaLayerProperties

skiko/src/awtMain/kotlin/org/jetbrains/skiko/redrawer/WindowsOpenGLRedrawer.kt

@@ -2,7 +2,6 @@ package org.jetbrains.skiko.redrawer
 
 import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.swing.Swing
 import kotlinx.coroutines.withContext
 import org.jetbrains.skiko.*
 import org.jetbrains.skiko.context.OpenGLContextHandler
@@ -79,7 +78,7 @@ internal class WindowsOpenGLRedrawer(
             .filterNot(WindowsOpenGLRedrawer::isDisposed)
             .filter { it.layer.isShowing }
 
-        private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
+        private val frameDispatcher = FrameDispatcher(MainUIDispatcher) {
             toRedrawCopy.addAll(toRedraw)
             toRedraw.clear()
 

skiko/src/commonMain/kotlin/org/jetbrains/skiko/Events.kt

 package org.jetbrains.skiko
 
+import kotlin.jvm.JvmInline
+
 // Clicked mouse buttons bitmask.
-inline class SkikoMouseButtons(val value: Int) {
+@JvmInline
+value class SkikoMouseButtons(val value: Int) {
     companion object {
         val NONE = SkikoMouseButtons(0)
         val LEFT = SkikoMouseButtons(1)
@@ -55,7 +58,8 @@ inline class SkikoMouseButtons(val value: Int) {
     }
 }
 
-inline class SkikoInputModifiers(val value: Int) {
+@JvmInline
+value class SkikoInputModifiers(val value: Int) {
     companion object {
         val EMPTY = SkikoInputModifiers(0)
         val META = SkikoInputModifiers(1)

skiko/src/commonMain/kotlin/org/jetbrains/skiko/SkiaLayer.kt

 package org.jetbrains.skiko
 
+import org.jetbrains.skia.Canvas
 import org.jetbrains.skia.Picture
 
 expect open class SkiaLayer {
@@ -15,6 +16,8 @@ expect open class SkiaLayer {
     fun detach()
 
     fun needRedraw()
+
+    internal fun draw(canvas: Canvas)
 }
 
 

skiko/src/iosMain/kotlin/org/jetbrains/skiko/SkiaLayer.ios.kt

@@ -172,7 +172,7 @@ actual open class SkiaLayer {
     internal var redrawer: MetalRedrawer? = null
     private var contextHandler: MetalContextHandler? = null
 
-    internal fun draw(canvas: Canvas) {
+    internal actual fun draw(canvas: Canvas) {
         check(!isDisposed) { "SkiaLayer is disposed" }
         val (w, h) = view!!.frame.useContents {
             size.width to size.height

skiko/src/jsMain/kotlin/org/jetbrains/skiko/SkiaLayer.js.kt

 package org.jetbrains.skiko
 
 import kotlinx.browser.window
+import org.jetbrains.skia.Canvas
 import org.w3c.dom.HTMLCanvasElement
 import org.w3c.dom.events.InputEvent
 import org.w3c.dom.events.KeyboardEvent
@@ -101,6 +102,10 @@ actual open class SkiaLayer {
         window.matchMedia("(resolution: ${contentScale}dppx)").addEventListener("change", { setOnChangeScaleNotifier() }, true)
         onContentScaleChanged?.invoke(contentScale)
     }
+
+    internal actual fun draw(canvas: Canvas) {
+        skikoView?.onRender(canvas, state!!.width, state!!.height, currentNanoTime())
+    }
 }
 
 var onContentScaleChanged: ((Float) -> Unit)? = null

skiko/src/linuxMain/kotlin/org/jetbrains/skiko/SkiaLayer.linux.kt

 package org.jetbrains.skiko
 
+import org.jetbrains.skia.Canvas
+
 actual open class SkiaLayer  {
     actual var renderApi: GraphicsApi
         get() = TODO("Not yet implemented")
@@ -21,6 +23,11 @@ actual open class SkiaLayer  {
     actual fun detach() {
         TODO("unimplemented")
     }
+
+    internal actual fun draw(canvas: Canvas) {
+        TODO("unimplemented")
+    }
+
     actual var skikoView: SkikoView? = null
 }
 

skiko/src/macosMain/kotlin/org/jetbrains/skiko/SkiaLayer.macos.kt

@@ -25,7 +25,7 @@ import platform.Foundation.addObserver
 import platform.darwin.NSObject
 import platform.CoreGraphics.CGRectMake
 
-actual open class SkiaLayer() {
+actual open class SkiaLayer {
     fun isShowing(): Boolean {
         return true
     }
@@ -226,7 +226,7 @@ actual open class SkiaLayer() {
         this.picture = PictureHolder(picture, pictureWidth.toInt(), pictureHeight.toInt())
     }
 
-    internal fun draw(canvas: Canvas) {
+    internal actual fun draw(canvas: Canvas) {
         picture?.also {
             canvas.drawPicture(it.instance)
         }