Optimize BaseGraphics when removed from stage. And adds View.onAncestorChanged

korge/src/commonMain/kotlin/korlibs/korge/internal/KorgeInternal.kt

@@ -3,3 +3,6 @@ package korlibs.korge.internal
 /** A mechanism to annotate Korge internal properties and methods that were left open in KorGE 1.0 so they can be marked as internal in KorGE 2.0 */
 @RequiresOptIn(level = RequiresOptIn.Level.WARNING)
 annotation class KorgeInternal
+
+//object KorgeInternalApi
+

korge/src/commonMain/kotlin/korlibs/korge/ui/UIView.kt

@@ -54,7 +54,8 @@ open class UIView(
         parent?.onChildChangedSize(this)
 	}
 
-    override fun onParentChanged() {
+    override fun onAncestorChanged() {
+        super.onAncestorChanged()
         updateState()
     }
 

korge/src/commonMain/kotlin/korlibs/korge/view/BaseGraphics.kt

@@ -51,14 +51,38 @@ abstract class BaseGraphics(
         invalidateLocalBounds()
     }
 
-    @OptIn(KorgeExperimental::class)
-    override fun renderInternal(ctx: RenderContext) {
+    override fun onAncestorChanged() {
+        super.onAncestorChanged()
+        if (parent == null || stage == null) {
+            if (bitmap.base != Bitmaps.transparent.bmp) {
+                //println("REMOVED FROM STAGE! $bitmap")
+                bitmapsToRemove.add(bitmap.base)
+            }
+            clearBitmaps(onParentChanged = true)
+        }
+    }
+
+    private fun clearBitmaps(onParentChanged: Boolean = false) {
+        if (bitmapsToRemove.isEmpty()) return
+
+        if (onParentChanged) {
+            //println("clearBitmaps! onParentChanged=$onParentChanged : $bitmapsToRemove")
+        }
+
         bitmapsToRemove.fastForEach {
             if (it != Bitmaps.transparent.bmp) {
-                ctx.agBitmapTextureManager.removeBitmap(it, "BaseGraphics")
+                _ctx?.agBitmapTextureManager?.removeBitmap(it, "BaseGraphics")
             }
         }
         bitmapsToRemove.clear()
+    }
+
+    private var _ctx: RenderContext? = null
+
+    @OptIn(KorgeExperimental::class)
+    override fun renderInternal(ctx: RenderContext) {
+        _ctx = ctx
+        clearBitmaps(onParentChanged = false)
 
         if (redrawIfRequired()) {
             //ctx.coroutineContext.launchUnscoped { this.bitmap.bmpBase.writeTo(localVfs("/tmp/image.png"), PNG) }

korge/src/commonMain/kotlin/korlibs/korge/view/Container.kt

@@ -146,6 +146,13 @@ open class Container(
     open fun onChildChangedSize(view: View) {
     }
 
+    override fun onAncestorChanged() {
+        super.onAncestorChanged()
+        forEachChild {
+            //it.apply { KorgeInternalApi._onAncestorChanged() }
+            it._onAncestorChanged()
+        }
+    }
     /**
      * Retrieves the index of a given child [View].
      */

korge/src/commonMain/kotlin/korlibs/korge/view/View.kt

@@ -768,6 +768,15 @@ abstract class View internal constructor(
     }
 
     protected open fun onParentChanged() {
+        onAncestorChanged()
+    }
+
+    //fun KorgeInternalApi._onAncestorChanged() {
+    internal fun _onAncestorChanged() {
+        onAncestorChanged()
+    }
+
+    protected open fun onAncestorChanged() {
     }
 
     override fun invalidateRender() {