Don't draw if window is invisible (JFrame.isVisible = false) (#149)

Partially fix https://github.com/JetBrains/skiko/issues/137

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

@@ -30,13 +30,13 @@ open class SkiaLayer(
         ContentScale,
     }
 
-    internal val backedLayer : HardwareLayer
+    internal val backedLayer: HardwareLayer
 
     val canvas: java.awt.Canvas
         get() = backedLayer
 
     init {
-        setOpaque(false)
+        isOpaque = false
         layout = null
         backedLayer = object : HardwareLayer() {
             override fun paint(g: Graphics) {
@@ -54,9 +54,12 @@ open class SkiaLayer(
                 return this@SkiaLayer.inputMethodRequests
             }
         }
-        add(backedLayer)
         @Suppress("LeakingThis")
+        add(backedLayer)
         backedLayer.addHierarchyListener {
+            if (it.changeFlags and HierarchyEvent.SHOWING_CHANGED.toLong() != 0L) {
+                checkShowing()
+            }
             if (it.changeFlags and HierarchyEvent.DISPLAYABILITY_CHANGED.toLong() != 0L) {
                 checkInit()
             }
@@ -69,10 +72,24 @@ open class SkiaLayer(
     private fun checkInit() {
         if (!isInited && isDisplayable) {
             backedLayer.defineContentScale()
+            checkShowing()
             init()
         }
     }
 
+    private fun checkShowing() {
+        isShowingCached = super.isShowing()
+        if (isShowing) {
+            repaint()
+        }
+    }
+
+    private var isShowingCached = false
+
+    override fun isShowing(): Boolean {
+        return isShowingCached
+    }
+
     val contentScale: Float
         get() = backedLayer.contentScale
 
@@ -84,7 +101,9 @@ open class SkiaLayer(
 
     var fullscreen: Boolean
         get() = backedLayer.fullscreen
-        set(value) { backedLayer.fullscreen = value }
+        set(value) {
+            backedLayer.fullscreen = value
+        }
 
     var renderer: SkiaRenderer? = null
     val clipComponents = mutableListOf<ClipRectangle>()
@@ -117,7 +136,7 @@ open class SkiaLayer(
         do {
             thrown = false
             try {
-	            renderApi = fallbackRenderApiQueue.removeAt(0)
+                renderApi = fallbackRenderApiQueue.removeAt(0)
                 contextHandler?.dispose()
                 redrawer?.dispose()
                 contextHandler = createContextHandler(this, renderApi)
@@ -137,10 +156,10 @@ open class SkiaLayer(
     }
 
     private val stateHandlers =
-            mutableMapOf<PropertyKind, MutableList<(SkiaLayer) -> Unit>>()
+        mutableMapOf<PropertyKind, MutableList<(SkiaLayer) -> Unit>>()
 
     fun onStateChanged(kind: PropertyKind, handler: (SkiaLayer) -> Unit) {
-        stateHandlers.getOrPut( kind, { mutableListOf() }) += handler
+        stateHandlers.getOrPut(kind, { mutableListOf() }) += handler
     }
 
     private fun notifyChange(kind: PropertyKind) {
@@ -386,5 +405,5 @@ open class SkiaLayer(
             rounded = value.toFloat()
         }
         return rounded.toInt()
-    } 
+    }
 }

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

@@ -17,8 +17,10 @@ internal class AngleRedrawer(
     private var device: Long = 0
 
     private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
-        update(System.nanoTime())
-        draw()
+        if (layer.isShowing) {
+            update(System.nanoTime())
+            draw()
+        }
     }
 
     override fun dispose() {

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

@@ -25,8 +25,10 @@ internal class Direct3DRedrawer(
     }
 
     private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
-        update(System.nanoTime())
-        draw()
+        if (layer.isShowing) {
+            update(System.nanoTime())
+            draw()
+        }
     }
 
     override fun dispose() = synchronized(drawLock) {

skiko/src/jvmMain/kotlin/org/jetbrains/skiko/redrawer/LinuxOpenGLRedrawer.kt

@@ -83,11 +83,14 @@ internal class LinuxOpenGLRedrawer(
     companion object {
         private val toRedraw = mutableSetOf<LinuxOpenGLRedrawer>()
         private val toRedrawCopy = mutableSetOf<LinuxOpenGLRedrawer>()
-        private val toRedrawAlive = toRedrawCopy.asSequence().filterNot(LinuxOpenGLRedrawer::isDisposed)
+        private val toRedrawVisible = toRedrawCopy
+            .asSequence()
+            .filterNot(LinuxOpenGLRedrawer::isDisposed)
+            .filter { it.layer.isShowing }
 
         private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
             // we should wait for the window with the maximum frame limit to avoid bottleneck when there is a window on a slower monitor
-            toRedrawAlive.maxByOrNull { it.frameLimit }?.limitFramesIfNeeded()
+            toRedrawVisible.maxByOrNull { it.frameLimit }?.limitFramesIfNeeded()
 
             toRedrawCopy.clear()
             toRedrawCopy.addAll(toRedraw)
@@ -95,7 +98,7 @@ internal class LinuxOpenGLRedrawer(
 
             val nanoTime = System.nanoTime()
 
-            for (redrawer in toRedrawAlive) {
+            for (redrawer in toRedrawVisible) {
                 try {
                     redrawer.update(nanoTime)
                 } catch (e: CancellationException) {
@@ -103,9 +106,9 @@ internal class LinuxOpenGLRedrawer(
                 }
             }
 
-            val drawingSurfaces = toRedrawAlive.associateWith { lockLinuxDrawingSurface(it.layer.backedLayer) }
+            val drawingSurfaces = toRedrawVisible.associateWith { lockLinuxDrawingSurface(it.layer.backedLayer) }
             try {
-                toRedrawAlive.forEach { redrawer ->
+                toRedrawVisible.forEach { redrawer ->
                     drawingSurfaces[redrawer]!!.makeCurrent(redrawer.context)
                     redrawer.draw()
                 }
@@ -113,11 +116,11 @@ internal class LinuxOpenGLRedrawer(
                 // TODO(demin) it seems now vsync doesn't work as expected with two windows (we have fps = refreshRate / windowCount)
                 //  perhaps we should create frameDispatcher for each display.
                 //  Don't know what happened, but on 620547a commit everything was okay. maybe something changed in the code, maybe my system changed
-                toRedrawAlive.forEach { redrawer ->
+                toRedrawVisible.forEach { redrawer ->
                     drawingSurfaces[redrawer]!!.swapBuffers()
                 }
 
-                toRedrawAlive.forEach { redrawer ->
+                toRedrawVisible.forEach { redrawer ->
                     drawingSurfaces[redrawer]!!.makeCurrent(redrawer.context)
                     OpenGLApi.instance.glFinish()
                 }

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

@@ -9,7 +9,6 @@ import org.jetbrains.skia.DirectContext
 import org.jetbrains.skiko.*
 import javax.swing.SwingUtilities.convertPoint
 import javax.swing.SwingUtilities.getRootPane
-import kotlin.time.ExperimentalTime
 
 internal class MetalRedrawer(
     private val layer: SkiaLayer,
@@ -32,8 +31,10 @@ internal class MetalRedrawer(
     }
 
     private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
-        update(System.nanoTime())
-        draw()
+        if (layer.isShowing) {
+            update(System.nanoTime())
+            draw()
+        }
     }
 
     override fun dispose() = synchronized(drawLock) {

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

@@ -19,9 +19,11 @@ internal class SoftwareRedrawer(
             frameLimiter.awaitNextFrame()
         }
 
-        layer.update(System.nanoTime())
-        if (layer.prepareDrawContext()) {
-            layer.draw()
+        if (layer.isShowing) {
+            layer.update(System.nanoTime())
+            if (layer.prepareDrawContext()) {
+                layer.draw()
+            }
         }
     }
 

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

@@ -65,7 +65,10 @@ internal class WindowsOpenGLRedrawer(
     companion object {
         private val toRedraw = mutableSetOf<WindowsOpenGLRedrawer>()
         private val toRedrawCopy = mutableSetOf<WindowsOpenGLRedrawer>()
-        private val toRedrawAlive = toRedrawCopy.asSequence().filterNot(WindowsOpenGLRedrawer::isDisposed)
+        private val toRedrawVisible = toRedrawCopy
+            .asSequence()
+            .filterNot(WindowsOpenGLRedrawer::isDisposed)
+            .filter { it.layer.isShowing }
 
         private val frameDispatcher = FrameDispatcher(Dispatchers.Swing) {
             toRedrawCopy.clear()
@@ -74,7 +77,7 @@ internal class WindowsOpenGLRedrawer(
 
             val nanoTime = System.nanoTime()
 
-            for (redrawer in toRedrawAlive) {
+            for (redrawer in toRedrawVisible) {
                 try {
                     redrawer.update(nanoTime)
                 } catch (e: CancellationException) {
@@ -82,21 +85,21 @@ internal class WindowsOpenGLRedrawer(
                 }
             }
 
-            for (redrawer in toRedrawAlive) {
+            for (redrawer in toRedrawVisible) {
                 redrawer.makeCurrent()
                 redrawer.draw()
             }
 
-            for (redrawer in toRedrawAlive) {
+            for (redrawer in toRedrawVisible) {
                 redrawer.swapBuffers()
             }
 
-            for (redrawer in toRedrawAlive) {
+            for (redrawer in toRedrawVisible) {
                 redrawer.makeCurrent()
                 OpenGLApi.instance.glFinish()
             }
 
-            val isVsyncEnabled = toRedrawAlive.all { it.properties.isVsyncEnabled }
+            val isVsyncEnabled = toRedrawVisible.all { it.properties.isVsyncEnabled }
             if (isVsyncEnabled) {
                 withContext(Dispatchers.IO) {
                     dwmFlush() // wait for vsync