[macOS] Consolidate external texture classes

Previously, external textures were modelled in the macOS embedder by a
top-level FlutterMacOSExternalTexture protocol with a single textureID
getter, and two implementations: FlutterExternalTextureGL and
FlutterExternalTextureMetal.

With the removal of OpenGL support from the macOS embedder, the only
remaining external texture implementation is Metal. This patch squashes
this set of types into a single FlutterExternalTexture class.

Issue: flutter/flutter#108304
Issue: flutter/flutter#114445

ci/licenses_golden/licenses_flutter

@@ -2629,16 +2629,15 @@ FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEngin
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEngineTestUtils.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEngineTestUtils.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterEngine_Internal.h
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureMetal.h
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureMetal.mm
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTexture.h
+FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTexture.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterIOSurfaceHolder.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterIOSurfaceHolder.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterKeyPrimaryResponder.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterKeyboardManager.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterKeyboardManager.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterKeyboardManagerUnittests.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterKeyboardViewDelegate.h
-FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMacOSExternalTexture.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMenuPlugin.h
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMenuPlugin.mm
 FILE: ../../../flutter/shell/platform/darwin/macos/framework/Source/FlutterMenuPluginTest.mm

shell/platform/darwin/macos/BUILD.gn

@@ -69,16 +69,14 @@ source_set("flutter_framework_source") {
     "framework/Source/FlutterEmbedderKeyResponder.mm",
     "framework/Source/FlutterEngine.mm",
     "framework/Source/FlutterEngine_Internal.h",
-    "framework/Source/FlutterExternalTextureMetal.h",
-    "framework/Source/FlutterExternalTextureMetal.mm",
+    "framework/Source/FlutterExternalTexture.h",
+    "framework/Source/FlutterExternalTexture.mm",
     "framework/Source/FlutterIOSurfaceHolder.h",
     "framework/Source/FlutterIOSurfaceHolder.mm",
     "framework/Source/FlutterKeyPrimaryResponder.h",
     "framework/Source/FlutterKeyboardManager.h",
     "framework/Source/FlutterKeyboardManager.mm",
     "framework/Source/FlutterKeyboardViewDelegate.h",
-    "framework/Source/FlutterMacOSExternalTexture.h",
-    "framework/Source/FlutterMacOSExternalTexture.h",
     "framework/Source/FlutterMenuPlugin.h",
     "framework/Source/FlutterMenuPlugin.mm",
     "framework/Source/FlutterMenuPlugin_Internal.h",

shell/platform/darwin/macos/framework/Source/FlutterEmbedderExternalTextureUnittests.mm

@@ -10,7 +10,7 @@
 
 #import "flutter/shell/platform/darwin/graphics/FlutterDarwinContextMetalSkia.h"
 #import "flutter/shell/platform/darwin/graphics/FlutterDarwinExternalTextureMetal.h"
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureMetal.h"
+#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTexture.h"
 #include "flutter/shell/platform/embedder/embedder.h"
 #include "flutter/shell/platform/embedder/embedder_external_texture_metal.h"
 #import "flutter/testing/testing.h"
@@ -140,9 +140,9 @@ - (CVPixelBufferRef)pixelBuffer {
       [[TestExternalTexture alloc] initWidth:width
                                       height:height
                              pixelFormatType:kCVPixelFormatType_32BGRA];
-  FlutterExternalTextureMetal* textureHolder =
-      [[FlutterExternalTextureMetal alloc] initWithFlutterTexture:testExternalTexture
-                                               darwinMetalContext:darwinContextMetal];
+  FlutterExternalTexture* textureHolder =
+      [[FlutterExternalTexture alloc] initWithFlutterTexture:testExternalTexture
+                                          darwinMetalContext:darwinContextMetal];
 
   // Callback to resolve the texture.
   EmbedderExternalTextureMetal::ExternalTextureCallback callback = [&](int64_t texture_id, size_t w,
@@ -192,9 +192,9 @@ - (CVPixelBufferRef)pixelBuffer {
       [[TestExternalTexture alloc] initWidth:width
                                       height:height
                              pixelFormatType:kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange];
-  FlutterExternalTextureMetal* textureHolder =
-      [[FlutterExternalTextureMetal alloc] initWithFlutterTexture:testExternalTexture
-                                               darwinMetalContext:darwinContextMetal];
+  FlutterExternalTexture* textureHolder =
+      [[FlutterExternalTexture alloc] initWithFlutterTexture:testExternalTexture
+                                          darwinMetalContext:darwinContextMetal];
 
   // Callback to resolve the texture.
   EmbedderExternalTextureMetal::ExternalTextureCallback callback = [&](int64_t texture_id, size_t w,
@@ -246,9 +246,9 @@ - (CVPixelBufferRef)pixelBuffer {
       [[TestExternalTexture alloc] initWidth:width
                                       height:height
                              pixelFormatType:kCVPixelFormatType_420YpCbCr8BiPlanarFullRange];
-  FlutterExternalTextureMetal* textureHolder =
-      [[FlutterExternalTextureMetal alloc] initWithFlutterTexture:testExternalTexture
-                                               darwinMetalContext:darwinContextMetal];
+  FlutterExternalTexture* textureHolder =
+      [[FlutterExternalTexture alloc] initWithFlutterTexture:testExternalTexture
+                                          darwinMetalContext:darwinContextMetal];
 
   // Callback to resolve the texture.
   EmbedderExternalTextureMetal::ExternalTextureCallback callback = [&](int64_t texture_id, size_t w,

shell/platform/darwin/macos/framework/Source/FlutterExternalTextureMetal.h → shell/platform/darwin/macos/framework/Source/FlutterExternalTexture.h

@@ -5,20 +5,26 @@
 #import <Foundation/Foundation.h>
 
 #import "flutter/shell/platform/darwin/graphics/FlutterDarwinContextMetalSkia.h"
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterMacOSExternalTexture.h"
+#include "flutter/shell/platform/embedder/embedder.h"
 
 /**
+ * Embedding side texture wrappers for Metal external textures.
  * Used to bridge FlutterTexture object and handle the texture copy request the
  * Flutter engine.
  */
-@interface FlutterExternalTextureMetal : NSObject <FlutterMacOSExternalTexture>
+@interface FlutterExternalTexture : NSObject
 
 /**
  * Initializes a texture adapter with |texture|.
  */
 - (nonnull instancetype)initWithFlutterTexture:(nonnull id<FlutterTexture>)texture
                             darwinMetalContext:(nonnull FlutterDarwinContextMetalSkia*)context;
 
+/**
+ * Returns the ID for the FlutterExternalTexture instance.
+ */
+- (int64_t)textureID;
+
 /**
  * Accepts texture buffer copy request from the Flutter engine.
  * When the user side marks the textureID as available, the Flutter engine will

shell/platform/darwin/macos/framework/Source/FlutterExternalTextureMetal.mm → shell/platform/darwin/macos/framework/Source/FlutterExternalTexture.mm

@@ -2,11 +2,11 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureMetal.h"
+#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTexture.h"
 
 #include "flutter/fml/platform/darwin/cf_utils.h"
 
-@implementation FlutterExternalTextureMetal {
+@implementation FlutterExternalTexture {
   FlutterDarwinContextMetalSkia* _darwinMetalContext;
 
   int64_t _textureID;

shell/platform/darwin/macos/framework/Source/FlutterRenderer.mm

@@ -5,7 +5,7 @@
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterRenderer.h"
 
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterEngine_Internal.h"
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTextureMetal.h"
+#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTexture.h"
 #import "flutter/shell/platform/darwin/macos/framework/Source/FlutterView.h"
 #include "flutter/shell/platform/embedder/embedder.h"
 
@@ -111,15 +111,13 @@ - (void)presentWithoutContent {
 
 - (BOOL)populateTextureWithIdentifier:(int64_t)textureID
                          metalTexture:(FlutterMetalExternalTexture*)textureOut {
-  id<FlutterMacOSExternalTexture> texture = [self getTextureWithID:textureID];
-  FlutterExternalTextureMetal* metalTexture =
-      reinterpret_cast<FlutterExternalTextureMetal*>(texture);
-  return [metalTexture populateTexture:textureOut];
+  FlutterExternalTexture* texture = [self getTextureWithID:textureID];
+  return [texture populateTexture:textureOut];
 }
 
-- (id<FlutterMacOSExternalTexture>)onRegisterTexture:(id<FlutterTexture>)texture {
-  return [[FlutterExternalTextureMetal alloc] initWithFlutterTexture:texture
-                                                  darwinMetalContext:_darwinMetalContext];
+- (FlutterExternalTexture*)onRegisterTexture:(id<FlutterTexture>)texture {
+  return [[FlutterExternalTexture alloc] initWithFlutterTexture:texture
+                                             darwinMetalContext:_darwinMetalContext];
 }
 
 @end

shell/platform/darwin/macos/framework/Source/FlutterTextureRegistrar.h

@@ -5,7 +5,7 @@
 #import <Cocoa/Cocoa.h>
 
 #import "flutter/shell/platform/darwin/macos/framework/Headers/FlutterEngine.h"
-#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterMacOSExternalTexture.h"
+#import "flutter/shell/platform/darwin/macos/framework/Source/FlutterExternalTexture.h"
 
 /*
  * Delegate methods for FlutterTextureRegistrar.
@@ -15,7 +15,7 @@
 /*
  * Called by the FlutterTextureRegistrar when a texture is registered.
  */
-- (nonnull id<FlutterMacOSExternalTexture>)onRegisterTexture:(nonnull id<FlutterTexture>)texture;
+- (nonnull FlutterExternalTexture*)onRegisterTexture:(nonnull id<FlutterTexture>)texture;
 
 @end
 
@@ -43,6 +43,6 @@
 /*
  * Returns the registered texture with the provided `textureID`.
  */
-- (nullable id<FlutterMacOSExternalTexture>)getTextureWithID:(int64_t)textureID;
+- (nullable FlutterExternalTexture*)getTextureWithID:(int64_t)textureID;
 
 @end

shell/platform/darwin/macos/framework/Source/FlutterTextureRegistrar.mm

@@ -11,8 +11,8 @@ @implementation FlutterTextureRegistrar {
 
   __weak FlutterEngine* _flutterEngine;
 
-  // A mapping of textureID to internal FlutterExternalTextureGL adapter.
-  NSMutableDictionary<NSNumber*, id<FlutterMacOSExternalTexture>>* _textures;
+  // A mapping of textureID to internal FlutterExternalTexture wrapper.
+  NSMutableDictionary<NSNumber*, FlutterExternalTexture*>* _textures;
 }
 
 - (instancetype)initWithDelegate:(id<FlutterTextureRegistrarDelegate>)delegate
@@ -26,7 +26,7 @@ - (instancetype)initWithDelegate:(id<FlutterTextureRegistrarDelegate>)delegate
 }
 
 - (int64_t)registerTexture:(id<FlutterTexture>)texture {
-  id<FlutterMacOSExternalTexture> externalTexture = [_delegate onRegisterTexture:texture];
+  FlutterExternalTexture* externalTexture = [_delegate onRegisterTexture:texture];
   int64_t textureID = [externalTexture textureID];
   BOOL success = [_flutterEngine registerTextureWithID:textureID];
   if (success) {
@@ -54,7 +54,7 @@ - (void)unregisterTexture:(int64_t)textureID {
   }
 }
 
-- (id<FlutterMacOSExternalTexture>)getTextureWithID:(int64_t)textureID {
+- (FlutterExternalTexture*)getTextureWithID:(int64_t)textureID {
   return _textures[@(textureID)];
 }