Hide the Metal layer when the SkiaLayer becomes hidden. (#677)

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

@@ -163,7 +163,11 @@ actual open class SkiaLayer internal constructor(
     private var isRendering = false
 
     private fun checkShowing() {
+        val wasShowing = isShowingCached
         isShowingCached = super.isShowing()
+        if (wasShowing != isShowing) {
+            redrawer?.setVisible(isShowing)
+        }
         if (isShowing) {
             redrawer?.syncSize()
             repaint()

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

@@ -136,6 +136,10 @@ internal class MetalRedrawer(
         )
     }
 
+    override fun setVisible(isVisible: Boolean) {
+        setLayerVisible(device, isVisible)
+    }
+
     fun makeContext() = DirectContext(
         makeMetalContext(device)
     )
@@ -153,6 +157,7 @@ internal class MetalRedrawer(
     private external fun disposeDevice(device: Long)
     private external fun finishFrame(device: Long)
     private external fun resizeLayers(device: Long, x: Int, y: Int, width: Int, height: Int)
+    private external fun setLayerVisible(device: Long, isVisible: Boolean)
     private external fun setContentScale(device: Long, contentScale: Float)
     private external fun setVSyncEnabled(device: Long, enabled: Boolean)
     private external fun isOccluded(window: Long): Boolean

skiko/src/awtMain/objectiveC/macos/MetalRedrawer.mm

@@ -251,6 +251,23 @@ JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_resizeLay
     }
 }
 
+JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_setLayerVisible(
+    JNIEnv *env, jobject redrawer, jlong devicePtr, jboolean isVisible)
+{
+    @autoreleasepool {
+        MetalDevice *device = (__bridge MetalDevice *) (void *) devicePtr;
+        BOOL hidden = !isVisible;
+        if (!device || !device.layer || device.layer.hidden == hidden) {
+            return;
+        }
+        [CATransaction begin];
+        [CATransaction setValue:(id)kCFBooleanTrue forKey:kCATransactionDisableActions];
+        device.layer.hidden = hidden;
+        [CATransaction commit];
+        [CATransaction flush];
+    }
+}
+
 JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_setContentScale(JNIEnv *env, jobject obj, jlong devicePtr, jfloat contentScale)
 {
     @autoreleasepool {

skiko/src/awtTest/kotlin/org/jetbrains/skiko/SkiaLayerTest.kt

@@ -534,6 +534,35 @@ class SkiaLayerTest {
         } finally {
             window.dispose()
         }
+    }
+
+    @Test
+    fun `hiding parent stops drawing layer`() = uiTest {
+        val window = UiTestWindow()
+        try {
+            window.setLocation(200, 200)
+            window.setSize(400, 200)
+            window.defaultCloseOperation = WindowConstants.DISPOSE_ON_CLOSE
+            val app = RectRenderer(window.layer, 200, 100, Color.RED)
+            window.layer.skikoView = app
+            window.isUndecorated = true
+            window.isVisible = true
+
+            // Force the layered pane to draw itself with a specific color so that the test doesn't depend on the
+            // default window background, which could be different on different platforms.
+            window.layeredPane.background = Color.BLUE
+            window.layeredPane.isOpaque = true
+
+            delay(1000)
+            screenshots.assert(window.bounds, "visible_parent")
+
+            window.contentPane.isVisible = false
+
+            delay(1000)
+            screenshots.assert(window.bounds, "hidden_parent")
+        } finally {
+            window.close()
+        }
 
     }
 

skiko/src/commonMain/kotlin/org/jetbrains/skiko/redrawer/Redrawer.kt

@@ -5,5 +5,6 @@ internal interface Redrawer {
     fun needRedraw()
     fun redrawImmediately()
     fun syncSize() = Unit
+    fun setVisible(isVisible: Boolean) = Unit
     val renderInfo: String
 }

skiko/src/jvmMain/cpp/common/stubs.cc

@@ -132,6 +132,12 @@ JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_resizeLay
     skikoUnimplemented("Java_org_jetbrains_skiko_redrawer_MetalRedrawer_resizeLayers");
 }
 
+JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_setLayerVisible(
+    JNIEnv *env, jobject redrawer, jlong devicePtr, jboolean isVisible)
+{
+    skikoUnimplemented("Java_org_jetbrains_skiko_redrawer_MetalRedrawer_setLayerVisible");
+}
+
 JNIEXPORT void JNICALL Java_org_jetbrains_skiko_redrawer_MetalRedrawer_setContentScale(JNIEnv *env, jobject obj, jlong devicePtr, jfloat contentScale)
 {
     skikoUnimplemented("Java_org_jetbrains_skiko_redrawer_MetalRedrawer_setContentScale");