Universal and mostly automated dispose logic (#292)

samples/SkiaMultiplatformSample/src/commonMain/kotlin/org/jetbrains/skiko/sample/Clocks.kt

@@ -19,7 +19,7 @@ class Clocks: SkikoView {
     private val fontCollection = FontCollection()
         .setDefaultFontManager(FontMgr.default)
 
-    override fun onRender(canvas: Canvas, width: Int, height: Int, currentTimestamp: Long) {
+    override fun onRender(canvas: Canvas, width: Int, height: Int, nanoTime: Long) {
         val watchFill = Paint().apply { color = 0xFFFFFFFF.toInt() }
         val watchStroke = Paint().apply {
                color = 0xFF000000.toInt()
@@ -50,7 +50,7 @@ class Clocks: SkikoView {
                     )
                     angle += (2.0 * PI / 12.0).toFloat()
                 }
-                val time = (currentTimestamp / 1E6) % 60000 +
+                val time = (nanoTime / 1E6) % 60000 +
                         (x.toFloat() / width * 5000).toLong() +
                         (y.toFloat() / width * 5000).toLong()
 

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

@@ -12,6 +12,8 @@ expect open class SkiaLayer {
 
     // Actual type of attach container is platform-specific.
     fun attachTo(container: Any)
+    fun detach()
+
     fun needRedraw()
 }
 

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

@@ -6,6 +6,7 @@ import org.jetbrains.skia.PictureRecorder
 import org.jetbrains.skia.Rect
 import org.jetbrains.skiko.context.MetalContextHandler
 import org.jetbrains.skiko.redrawer.MetalRedrawer
+import platform.Foundation.NSNotificationCenter
 import platform.Foundation.NSSelectorFromString
 import platform.UIKit.*
 import platform.darwin.NSObject
@@ -22,7 +23,7 @@ actual open class SkiaLayer(
         set(value) { throw UnsupportedOperationException() }
 
     actual val contentScale: Float
-        get() = view.contentScaleFactor.toFloat()
+        get() = view!!.contentScaleFactor?.toFloat()
 
     actual var fullscreen: Boolean
         get() = true
@@ -37,16 +38,16 @@ actual open class SkiaLayer(
     }
 
     val width: Float
-       get() = view.frame.useContents {
+       get() = view!!.frame.useContents {
            return@useContents size.width.toFloat()
        }
 
     val height: Float
-        get() = view.frame.useContents {
+        get() = view!!.frame.useContents {
             return@useContents size.height.toFloat()
         }
 
-    lateinit var view: UIView
+    internal var view: UIView? = null
     // We need to keep reference to controller as Objective-C will only keep weak reference here.
     lateinit private var controller: NSObject
     actual fun attachTo(container: Any) {
@@ -54,7 +55,8 @@ actual open class SkiaLayer(
     }
     fun attachTo(view: UIView) {
         this.view = view
-
+        contextHandler = MetalContextHandler(this)
+        pictureRecorder = PictureRecorder()
         // See https://developer.apple.com/documentation/uikit/touches_presses_and_gestures/using_responders_and_the_responder_chain_to_handle_events?language=objc
         controller = object : NSObject() {
             @ObjCAction
@@ -76,33 +78,48 @@ actual open class SkiaLayer(
         }
         // We have ':' in selector to take care of function argument.
         view.addGestureRecognizer(UITapGestureRecognizer(controller, NSSelectorFromString("onTap:")))
+        // TODO: maybe add observer for view.viewDidDisappear() to detach us?
         redrawer = MetalRedrawer(this, properties)
         redrawer?.redrawImmediately()
     }
 
+    private var isDisposed = false
+    actual fun detach() {
+        if (!isDisposed) {
+            redrawer?.dispose()
+            redrawer = null
+            contextHandler?.dispose()
+            contextHandler = null
+            picture?.instance?.close()
+            picture = null
+            pictureRecorder?.close()
+            pictureRecorder = null
+            isDisposed = true
+        }
+    }
     actual var skikoView: SkikoView? = null
 
     internal var redrawer: MetalRedrawer? = null
     private var picture: PictureHolder? = null
-    private val pictureRecorder = PictureRecorder()
-    private val contextHandler = MetalContextHandler(this)
+    private var pictureRecorder: PictureRecorder? = null
+    private var contextHandler: MetalContextHandler? = null
 
     fun update(nanoTime: Long) {
-        val (w, h) = view.frame.useContents {
+        val (w, h) = view!!.frame.useContents {
             size.width to size.height
         }
         val pictureWidth = (w.toFloat() * contentScale).coerceAtLeast(0.0F)
         val pictureHeight = (h.toFloat() * contentScale).coerceAtLeast(0.0F)
 
         val bounds = Rect.makeWH(pictureWidth, pictureHeight)
-        val canvas = pictureRecorder.beginRecording(bounds)
+        val canvas = pictureRecorder!!.beginRecording(bounds)
         skikoView?.onRender(canvas, pictureWidth.toInt(), pictureHeight.toInt(), nanoTime)
-        val picture = pictureRecorder.finishRecordingAsPicture()
+        val picture = pictureRecorder!!.finishRecordingAsPicture()
         this.picture = PictureHolder(picture, pictureWidth.toInt(), pictureHeight.toInt())
     }
 
     fun draw() {
-        contextHandler.apply {
+        contextHandler?.apply {
             if (!initContext()) {
                 error("initContext() failure")
             }

skiko/src/iosMain/kotlin/org/jetbrains/skiko/SkikoViewController.kt

@@ -33,17 +33,23 @@ class SkikoViewController : UIViewController {
         this.appFactory = appFactory
     }
 
+    private lateinit var skikoLayer: SkiaLayer
     override fun viewDidLoad() {
         super.viewDidLoad()
 
         val (width, height) = UIScreen.mainScreen.bounds.useContents {
             this.size.width to this.size.height
         }
-        val layer = SkiaLayer().apply {
+        skikoLayer = SkiaLayer().apply {
             skikoView = appFactory(this)
         }
         view.contentScaleFactor = UIScreen.mainScreen.scale
         view.setFrame(CGRectMake(0.0, 0.0, width, height))
-        layer.attachTo(this.view)
+        skikoLayer.attachTo(this.view)
+    }
+
+    // viewDidUnload() is deprecated and not called.
+    override fun viewDidDisappear(animated: Boolean) {
+        skikoLayer.detach()
     }
 }

skiko/src/iosMain/kotlin/org/jetbrains/skiko/context/MetalContextHandler.kt

@@ -38,7 +38,7 @@ internal class MetalContextHandler(layer: SkiaLayer) : ContextHandler(layer) {
     override fun initCanvas() {
         disposeCanvas()
         val scale = layer.contentScale
-        val (w, h) = layer.view.frame.useContents {
+        val (w, h) = layer.view!!.frame.useContents {
             (size.width * scale).toInt().coerceAtLeast(0) to (size.height * scale).toInt().coerceAtLeast(0)
         }
 

skiko/src/iosMain/kotlin/org/jetbrains/skiko/redrawer/MetalRedrawer.ios.kt

@@ -55,10 +55,11 @@ internal class MetalRedrawer(
 
     override fun syncSize() {
         metalLayer.contentsScale = layer.contentScale.toDouble()
-        val (w, h) = layer.view.frame.useContents {
+        val osView = layer.view!!
+        val (w, h) = osView.frame.useContents {
             size.width to size.height
         }
-        metalLayer.frame = layer.view.frame
+        metalLayer.frame = osView.frame
         metalLayer.init(layer, device)
         metalLayer.drawableSize = CGSizeMake(w * metalLayer.contentsScale, h * metalLayer.contentsScale)
     }
@@ -120,8 +121,10 @@ class MetalLayer : CAMetalLayer {
                 CGColorCreate(CGColorSpaceCreateDeviceRGB(), it.addressOf(0))
         }
         this.opaque = true
-        this.frame = skiaLayer.view.frame
-        skiaLayer.view.layer.addSublayer(this)
+        skiaLayer.view?.let {
+            this.frame = it.frame
+            it.layer.addSublayer(this)
+        }
     }
 
     fun draw()  {

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

@@ -48,10 +48,14 @@ actual open class SkiaLayer(properties: SkiaLayerProperties = makeDefaultSkiaLay
     }
 
     actual fun attachTo(container: Any) {
-        attachTo(container as HTMLCanvasElement)
+        attachTo(container as HTMLCanvasElement, false)
     }
 
-    fun attachTo(htmlCanvas: HTMLCanvasElement) {
+    actual fun detach() {
+        // TODO: when switch to the frame dispatcher - stop it here.
+    }
+
+    fun attachTo(htmlCanvas: HTMLCanvasElement, autoDetach: Boolean = true) {
         state = object: CanvasRenderer(htmlCanvas) {
             override fun drawFrame(currentTimestamp: Double) {
                 // currentTimestamp is in milliseconds.

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/SkiaLayer.jvm.kt

@@ -84,6 +84,15 @@ actual open class SkiaLayer internal constructor(
         }
     }
 
+    override fun removeNotify() {
+        dispose()
+        super.removeNotify()
+    }
+
+    actual fun detach() {
+        dispose()
+    }
+
     private var isInited = false
     private var isRendering = false
 
@@ -256,9 +265,8 @@ actual open class SkiaLayer internal constructor(
 
     open fun dispose() {
         check(isEventDispatchThread()) { "Method should be called from AWT event dispatch thread" }
-        check(!isDisposed) { "SkiaLayer is disposed" }
 
-        if (isInited) {
+        if (isInited && !isDisposed) {
             redrawer?.dispose()  // we should dispose redrawer first (to cancel `draw` in rendering thread)
             contextHandler?.dispose()
             picture?.instance?.close()
@@ -508,6 +516,16 @@ actual open class SkiaLayer internal constructor(
     }
 }
 
+fun SkiaLayer.disableTitleBar() {
+    backedLayer.useDrawingSurfacePlatformInfo {
+        platformOperations.disableTitleBar(it)
+    }
+}
+
+fun orderEmojiAndSymbolsPopup() {
+    platformOperations.orderEmojiAndSymbolsPopup()
+}
+
 // InputEvent is abstract, so we wrap to match modality.
 actual class SkikoPlatformInputEvent(val wrapped: InputEvent)
 actual typealias SkikoPlatformKeyboardEvent = KeyEvent

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/SkiaWindow.kt

-package org.jetbrains.skiko
-
-import javax.swing.JFrame
-
-@Deprecated("Will be removed soon")
-open class SkiaWindow(
-    properties: SkiaLayerProperties = makeDefaultSkiaLayerProperties(),
-    layerFactory: () -> SkiaLayer = { SkiaLayer(properties) }
-) : JFrame() {
-    val layer = layerFactory()
-
-    init {
-        contentPane.add(layer)
-    }
-
-    override fun dispose() {
-        layer.dispose()
-        super.dispose()
-    }
-
-    fun disableTitleBar() {
-        layer.backedLayer.useDrawingSurfacePlatformInfo {
-            platformOperations.disableTitleBar(it)
-        }
-    }
-}
-
-fun SkiaLayer.disableTitleBar() {
-    backedLayer.useDrawingSurfacePlatformInfo {
-        platformOperations.disableTitleBar(it)
-    }
-}
-
-fun orderEmojiAndSymbolsPopup() {
-    platformOperations.orderEmojiAndSymbolsPopup()
-}
\ No newline at end of file

skiko/src/jvmTest/kotlin/org/jetbrains/skiko/SkiaWindowTest.kt

@@ -27,6 +27,22 @@ import javax.swing.WindowConstants
 import kotlin.random.Random
 import kotlin.test.assertTrue
 
+internal open class SkiaWindow(
+    properties: SkiaLayerProperties = makeDefaultSkiaLayerProperties(),
+    layerFactory: () -> SkiaLayer = { SkiaLayer(properties) }
+) : JFrame() {
+    val layer = layerFactory()
+
+    init {
+        contentPane.add(layer)
+    }
+
+    override fun dispose() {
+        layer.dispose()
+        super.dispose()
+    }
+}
+
 @Suppress("BlockingMethodInNonBlockingContext", "SameParameterValue")
 class SkiaWindowTest {
     private val fontCollection = FontCollection()

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

@@ -18,6 +18,9 @@ actual open class SkiaLayer(properties: SkiaLayerProperties)  {
     actual fun attachTo(container: Any) {
         TODO("unimplemented")
     }
+    actual fun detach() {
+        TODO("unimplemented")
+    }
     actual var skikoView: SkikoView? = null
 }
 

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

 package org.jetbrains.skiko
 
+import kotlinx.cinterop.ObjCAction
 import kotlinx.cinterop.useContents
 import org.jetbrains.skiko.context.*
 import org.jetbrains.skia.*
 import org.jetbrains.skiko.redrawer.Redrawer
 import platform.AppKit.*
 import platform.Foundation.NSMakeRect
+import platform.Foundation.NSNotificationCenter
+import platform.Foundation.NSSelectorFromString
+import platform.Foundation.addObserver
+import platform.darwin.NSObject
 
 actual open class SkiaLayer(
     private val properties: SkiaLayerProperties = makeDefaultSkiaLayerProperties()
@@ -76,12 +81,9 @@ actual open class SkiaLayer(
                 updateTrackingAreas()
             }
             override fun updateTrackingAreas() {
-                bounds.useContents {
-                    println("update tracking areas to ${this.size.width} ${this.size.height}")
-                }
                 trackingArea?.let { removeTrackingArea(it) }
                 trackingArea = NSTrackingArea(rect = bounds,
-                    options = NSMouseMoved or NSTrackingActiveAlways, // NSTrackingActiveInActiveApp,
+                    options = NSMouseMoved or NSTrackingActiveInActiveApp,
                     owner = nsView, userInfo = null)
                 nsView.addTrackingArea(trackingArea!!)
             }
@@ -107,13 +109,23 @@ actual open class SkiaLayer(
             override fun keyUp(event: NSEvent) {
                 skikoView?.onKeyboardEvent(eventToKeyboard(event, SkikoKeyboardEventKind.UP))
             }
+
+            @ObjCAction
+            open fun onWindowClose(arg: NSObject?) {
+                detach()
+                val center = NSNotificationCenter.defaultCenter()
+                center.removeObserver(nsView)
+            }
         }
+        val center = NSNotificationCenter.defaultCenter()
+        center.addObserver(nsView, NSSelectorFromString("onWindowClose:"),
+            NSWindowWillCloseNotification!!, window)
         window.contentView!!.addSubview(nsView)
         redrawer = createNativeRedrawer(this, GraphicsApi.OPENGL, properties)
         redrawer?.redrawImmediately()
     }
 
-    fun disposeLayer() {
+    actual fun detach() {
         redrawer?.dispose()
         redrawer = null
         initedCanvas = false

skiko/src/macosMain/kotlin/org/jetbrains/skiko/redrawer/OpenGLRedrawer.macos.kt

@@ -18,10 +18,6 @@ internal class MacOsOpenGLRedrawer(
     private val layer: SkiaLayer,
     private val properties: SkiaLayerProperties
 ) : Redrawer {
-    init {
-        println("create MacOsOpenGLRedrawer")
-    }
-
     private val drawLayer = MacosGLLayer(layer, setNeedsDisplayOnBoundsChange = true)
 
     override fun dispose() {