Hide Metal drawables from Kotlin runtime

compose/mpp/demo/src/uikitMain/kotlin/androidx/compose/mpp/demo/bugs/IosBugs.kt

@@ -38,5 +38,6 @@ val IosBugs = Screen.Selection(
     MeasureAndLayoutCrash,
     AnimationFreezeBug,
     ModalMemoryLeak,
-    ModalCrash
+    ModalCrash,
+    PopupStretching
 )

compose/mpp/demo/src/uikitMain/kotlin/androidx/compose/mpp/demo/bugs/PopupStretching.kt

@@ -0,0 +1,96 @@
+/*
+ * Copyright 2024 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package androidx.compose.mpp.demo.bugs
+
+import androidx.compose.foundation.background
+import androidx.compose.foundation.horizontalScroll
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.layout.size
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material.Text
+import androidx.compose.material3.Button
+import androidx.compose.mpp.demo.Screen
+import androidx.compose.runtime.Composable
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.interop.LocalUIViewController
+import androidx.compose.ui.unit.dp
+import androidx.compose.ui.window.ComposeUIViewController
+import platform.UIKit.UIModalPresentationFormSheet
+import platform.UIKit.UISheetPresentationControllerDetent
+import platform.UIKit.sheetPresentationController
+
+val PopupStretching = Screen.Example("Popup stretching") {
+    val viewController = LocalUIViewController.current
+
+    Button(onClick = {
+        val bottomSheetController = ComposeUIViewController {
+            VerticalScrollWithIndependentHorizontalRows()
+        }
+
+        bottomSheetController.modalPresentationStyle = UIModalPresentationFormSheet
+        bottomSheetController.sheetPresentationController?.setDetents(
+            listOf(
+                UISheetPresentationControllerDetent.mediumDetent(),
+                UISheetPresentationControllerDetent.largeDetent(),
+            )
+        )
+
+        viewController.presentViewController(bottomSheetController, animated = true, completion = {})
+    }) {
+        Text("Show popup")
+    }
+}
+
+
+@Composable
+fun VerticalScrollWithIndependentHorizontalRows() {
+    Column(
+        modifier =
+        Modifier.fillMaxSize().verticalScroll(rememberScrollState(), enabled = true),
+    ) {
+        repeat(10) { rowIndex ->
+            val horizontalScrollState = rememberScrollState()
+
+            Spacer(Modifier.height(30.dp).background(Color.DarkGray))
+            Row(
+                modifier =
+                Modifier
+                    .padding(start = 16.dp, end = 16.dp)
+                    .horizontalScroll(horizontalScrollState),
+            ) {
+                repeat(5) {
+                    Box(
+                        modifier =
+                        Modifier
+                            .size(100.dp)
+                            .background(Color.Gray),
+                    ) {
+                        Text("Item $it in row $rowIndex")
+                    }
+                }
+            }
+        }
+    }
+}

compose/ui/ui-uikit/src/uikitMain/objc/CMPUIKitUtils/CMPUIKitUtils.xcodeproj/project.pbxproj

@@ -20,6 +20,7 @@
 		EA70A7EC2B27106100300068 /* CMPAccessibilityContainer.m in Sources */ = {isa = PBXBuildFile; fileRef = EA70A7E92B27106100300068 /* CMPAccessibilityContainer.m */; };
 		EA82F4F92B86144E00465418 /* CMPOSLogger.m in Sources */ = {isa = PBXBuildFile; fileRef = EA82F4F82B86144E00465418 /* CMPOSLogger.m */; };
 		EA82F4FC2B86184F00465418 /* CMPOSLoggerInterval.m in Sources */ = {isa = PBXBuildFile; fileRef = EA82F4FB2B86184F00465418 /* CMPOSLoggerInterval.m */; };
+		EAB33E182C12E746002CFF44 /* CMPMetalDrawablesHandler.m in Sources */ = {isa = PBXBuildFile; fileRef = EAB33E172C12E746002CFF44 /* CMPMetalDrawablesHandler.m */; };
 		EABD912B2BC02B5F00455279 /* CMPInteropWrappingView.m in Sources */ = {isa = PBXBuildFile; fileRef = EABD912A2BC02B5F00455279 /* CMPInteropWrappingView.m */; };
 		EAC703E32B8C826E001ECDA6 /* CMPAccessibilityElement.m in Sources */ = {isa = PBXBuildFile; fileRef = EA70A7E82B27106100300068 /* CMPAccessibilityElement.m */; };
 		EAC703E42B8C826E001ECDA6 /* CMPViewController.m in Sources */ = {isa = PBXBuildFile; fileRef = 997DFCDD2B18D135000B56B5 /* CMPViewController.m */; };
@@ -82,6 +83,8 @@
 		EA82F4F82B86144E00465418 /* CMPOSLogger.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = CMPOSLogger.m; sourceTree = "<group>"; };
 		EA82F4FA2B86184F00465418 /* CMPOSLoggerInterval.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = CMPOSLoggerInterval.h; sourceTree = "<group>"; };
 		EA82F4FB2B86184F00465418 /* CMPOSLoggerInterval.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = CMPOSLoggerInterval.m; sourceTree = "<group>"; };
+		EAB33E162C12E746002CFF44 /* CMPMetalDrawablesHandler.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = CMPMetalDrawablesHandler.h; sourceTree = "<group>"; };
+		EAB33E172C12E746002CFF44 /* CMPMetalDrawablesHandler.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = CMPMetalDrawablesHandler.m; sourceTree = "<group>"; };
 		EABD91292BC02B5F00455279 /* CMPInteropWrappingView.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = CMPInteropWrappingView.h; sourceTree = "<group>"; };
 		EABD912A2BC02B5F00455279 /* CMPInteropWrappingView.m */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.objc; path = CMPInteropWrappingView.m; sourceTree = "<group>"; };
 		EAC703DF2B8C8154001ECDA6 /* CMPUIKitUtilsTestApp-Bridging-Header.h */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.h; path = "CMPUIKitUtilsTestApp-Bridging-Header.h"; sourceTree = "<group>"; };
@@ -134,6 +137,8 @@
 				99DCAB0D2BD00F5C002E6AC7 /* CMPTextLoupeSession.m */,
 				99D97A862BF73A9B0035552B /* CMPEditMenuView.h */,
 				99D97A872BF73A9B0035552B /* CMPEditMenuView.m */,
+				EAB33E162C12E746002CFF44 /* CMPMetalDrawablesHandler.h */,
+				EAB33E172C12E746002CFF44 /* CMPMetalDrawablesHandler.m */,
 			);
 			path = CMPUIKitUtils;
 			sourceTree = "<group>";
@@ -308,6 +313,7 @@
 			buildActionMask = 2147483647;
 			files = (
 				997DFCDE2B18D135000B56B5 /* CMPViewController.m in Sources */,
+				EAB33E182C12E746002CFF44 /* CMPMetalDrawablesHandler.m in Sources */,
 				99D97A882BF73A9B0035552B /* CMPEditMenuView.m in Sources */,
 				EABD912B2BC02B5F00455279 /* CMPInteropWrappingView.m in Sources */,
 				EA70A7EC2B27106100300068 /* CMPAccessibilityContainer.m in Sources */,

compose/ui/ui-uikit/src/uikitMain/objc/CMPUIKitUtils/CMPUIKitUtils/CMPMacros.h

@@ -18,3 +18,12 @@
 
 #define CMP_MUST_BE_OVERRIDED
 #define CMP_MUST_BE_OVERRIDED_INVARIANT_VIOLATION assert(false && "MUST_OVERRIDE");
+
+// Marker for indicating that raw pointer returned from a function is owned by the caller
+#define CMP_OWNED
+
+// Marker for indicating that raw pointer is consumed when passed as an argument
+#define CMP_CONSUMED
+
+// Marker for indicating that raw pointer is implied as borrowed when returned from a function or passed as an argument
+#define CMP_BORROWED

compose/ui/ui-uikit/src/uikitMain/objc/CMPUIKitUtils/CMPUIKitUtils/CMPMetalDrawablesHandler.h

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import <Foundation/Foundation.h>
+#import <QuartzCore/QuartzCore.h>
+#import <Metal/Metal.h>
+
+#import "CMPMacros.h"
+
+NS_ASSUME_NONNULL_BEGIN
+
+@interface CMPMetalDrawablesHandler : NSObject
+
+- (instancetype)initWithMetalLayer:(CAMetalLayer *)metalLayer;
+
+- (void * CMP_OWNED)nextDrawable;
+- (void)releaseDrawable:(void * CMP_CONSUMED)drawablePtr;
+- (void * CMP_BORROWED)drawableTexture:(void * CMP_BORROWED)drawablePtr;
+- (void)presentDrawable:(void * CMP_CONSUMED)drawablePtr;
+- (void)scheduleDrawablePresentation:(void * CMP_CONSUMED)drawablePtr onCommandBuffer:(id <MTLCommandBuffer>)commandBuffer;
+
+
+@end
+
+NS_ASSUME_NONNULL_END

compose/ui/ui-uikit/src/uikitMain/objc/CMPUIKitUtils/CMPUIKitUtils/CMPMetalDrawablesHandler.m

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2023 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#import "CMPMetalDrawablesHandler.h"
+
+@implementation CMPMetalDrawablesHandler {
+    CAMetalLayer *_metalLayer;
+}
+
+- (instancetype)initWithMetalLayer:(CAMetalLayer *)metalLayer {
+    self = [super init];
+    if (self) {
+        _metalLayer = metalLayer;
+    }
+    return self;
+}
+
+- (void * CMP_OWNED)nextDrawable {
+    id <CAMetalDrawable> drawable = [_metalLayer nextDrawable];
+
+    if (drawable) {
+        void *ptr = (__bridge_retained void *)drawable;
+        return ptr;
+    } else {
+        return NULL;
+    }
+}
+
+- (void)releaseDrawable:(void * CMP_CONSUMED)drawablePtr {
+    assert(drawablePtr != NULL);
+
+    id <CAMetalDrawable> drawable __unused = (__bridge_transfer id <CAMetalDrawable>)drawablePtr;
+    // drawable will be released by ARC
+}
+
+- (void * CMP_BORROWED)drawableTexture:(void * CMP_BORROWED)drawablePtr {
+    assert(drawablePtr != NULL);
+
+    id <CAMetalDrawable> drawable = (__bridge id <CAMetalDrawable>)drawablePtr;
+    id <MTLTexture> texture = drawable.texture;    
+    void *texturePtr = (__bridge void *)texture;
+    return texturePtr;
+}
+
+- (void)presentDrawable:(void * CMP_CONSUMED)drawablePtr {
+    assert(drawablePtr != NULL);
+
+    id <CAMetalDrawable> drawable = (__bridge_transfer id <CAMetalDrawable>)drawablePtr;
+    [drawable present];
+}
+
+- (void)scheduleDrawablePresentation:(void * CMP_CONSUMED)drawablePtr onCommandBuffer:(id <MTLCommandBuffer>)commandBuffer {
+    assert(drawablePtr != NULL);
+
+    id <CAMetalDrawable> drawable = (__bridge_transfer id <CAMetalDrawable>)drawablePtr;
+    [commandBuffer presentDrawable:drawable];
+}
+
+@end

compose/ui/ui-uikit/src/uikitMain/objc/CMPUIKitUtils/CMPUIKitUtils/CMPUIKitUtils.h

@@ -27,3 +27,4 @@ FOUNDATION_EXPORT const unsigned char CMPUIKitUtilsVersionString[];
 #import "CMPAccessibilityContainer.h"
 #import "CMPOSLogger.h"
 #import "CMPTextLoupeSession.h"
+#import "CMPMetalDrawablesHandler.h"

compose/ui/ui/src/uikitMain/kotlin/androidx/compose/ui/window/MetalRedrawer.uikit.kt

@@ -20,6 +20,7 @@ import androidx.compose.ui.interop.UIKitInteropState
 import androidx.compose.ui.interop.UIKitInteropTransaction
 import androidx.compose.ui.interop.doLocked
 import androidx.compose.ui.interop.isNotEmpty
+import androidx.compose.ui.uikit.utils.CMPMetalDrawablesHandler
 import androidx.compose.ui.util.fastForEach
 import androidx.compose.ui.util.trace
 import kotlin.math.roundToInt
@@ -145,6 +146,7 @@ internal class MetalRedrawer(
     private val metalLayer: CAMetalLayer,
     private val callbacks: MetalRedrawerCallbacks
 ) {
+    private val metalDrawableHandler = CMPMetalDrawablesHandler(metalLayer)
     // Workaround for KN compiler bug
     // Type mismatch: inferred type is objcnames.protocols.MTLDeviceProtocol but platform.Metal.MTLDeviceProtocol was expected
     @Suppress("USELESS_CAST")
@@ -316,7 +318,7 @@ internal class MetalRedrawer(
             }
 
             val metalDrawable = trace("MetalRedrawer:draw:nextDrawable") {
-                metalLayer.nextDrawable()
+                metalDrawableHandler.nextDrawable()
             }
 
             if (metalDrawable == null) {
@@ -328,7 +330,7 @@ internal class MetalRedrawer(
             }
 
             val renderTarget =
-                BackendRenderTarget.makeMetal(width, height, metalDrawable.texture.objcPtr())
+                BackendRenderTarget.makeMetal(width, height, metalDrawableHandler.drawableTexture(metalDrawable).rawValue)
 
             val surface = Surface.makeFromBackendRenderTarget(
                 context,
@@ -344,6 +346,7 @@ internal class MetalRedrawer(
                 // Logger.warn { "'Surface.makeFromBackendRenderTarget' returned null. Skipping the frame." }
                 picture.close()
                 renderTarget.close()
+                metalDrawableHandler.releaseDrawable(metalDrawable)
                 dispatch_semaphore_signal(inflightSemaphore)
                 return@autoreleasepool
             }
@@ -372,7 +375,9 @@ internal class MetalRedrawer(
                     commandBuffer.label = "Present"
 
                     if (!presentsWithTransaction) {
-                        commandBuffer.presentDrawable(metalDrawable)
+                        // scheduleDrawablePresentation consumes metalDrawable
+                        // don't use metalDrawable after this call
+                        metalDrawableHandler.scheduleDrawablePresentation(metalDrawable, commandBuffer)
                     }
 
                     commandBuffer.addCompletedHandler {
@@ -388,7 +393,9 @@ internal class MetalRedrawer(
                             commandBuffer.waitUntilScheduled()
                         }
 
-                        metalDrawable.present()
+                        // presentDrawable consumes metalDrawable
+                        // don't use metalDrawable after this call
+                        metalDrawableHandler.presentDrawable(metalDrawable)
 
                         interopTransaction.actions.fastForEach {
                             it.invoke()