Add native Android image decoder supported by API 28+ (flutter#26746)

ci/licenses_golden/licenses_flutter

@@ -759,6 +759,8 @@ FILE: ../../../flutter/shell/platform/android/android_environment_gl.h
 FILE: ../../../flutter/shell/platform/android/android_exports.lst
 FILE: ../../../flutter/shell/platform/android/android_external_texture_gl.cc
 FILE: ../../../flutter/shell/platform/android/android_external_texture_gl.h
+FILE: ../../../flutter/shell/platform/android/android_image_generator.cc
+FILE: ../../../flutter/shell/platform/android/android_image_generator.h
 FILE: ../../../flutter/shell/platform/android/android_shell_holder.cc
 FILE: ../../../flutter/shell/platform/android/android_shell_holder.h
 FILE: ../../../flutter/shell/platform/android/android_surface_gl.cc

fml/platform/android/jni_util.cc

@@ -173,6 +173,17 @@ bool ClearException(JNIEnv* env) {
   return true;
 }
 
+bool CheckException(JNIEnv* env) {
+  if (!HasException(env))
+    return true;
+
+  jthrowable exception = env->ExceptionOccurred();
+  env->ExceptionClear();
+  FML_LOG(ERROR) << fml::jni::GetJavaExceptionInfo(env, exception);
+  env->DeleteLocalRef(exception);
+  return false;
+}
+
 std::string GetJavaExceptionInfo(JNIEnv* env, jthrowable java_throwable) {
   ScopedJavaLocalRef<jclass> throwable_clazz(
       env, env->FindClass("java/lang/Throwable"));

fml/platform/android/jni_util.h

@@ -42,6 +42,7 @@ bool HasException(JNIEnv* env);
 
 bool ClearException(JNIEnv* env);
 
+bool CheckException(JNIEnv* env);
 std::string GetJavaExceptionInfo(JNIEnv* env, jthrowable java_throwable);
 
 }  // namespace jni

lib/ui/painting/image_decoder_unittests.cc

@@ -149,7 +149,7 @@ class UnknownImageGenerator : public ImageGenerator {
  public:
   UnknownImageGenerator() : info_(SkImageInfo::MakeUnknown()){};
   ~UnknownImageGenerator() = default;
-  const SkImageInfo& GetInfo() const { return info_; }
+  const SkImageInfo& GetInfo() { return info_; }
 
   unsigned int GetFrameCount() const { return 1; }
 
@@ -159,15 +159,15 @@ class UnknownImageGenerator : public ImageGenerator {
     return {std::nullopt, 0, SkCodecAnimation::DisposalMethod::kKeep};
   }
 
-  SkISize GetScaledDimensions(float scale) const {
+  SkISize GetScaledDimensions(float scale) {
     return SkISize::Make(info_.width(), info_.height());
   }
 
   bool GetPixels(const SkImageInfo& info,
                  void* pixels,
                  size_t row_bytes,
                  unsigned int frame_index,
-                 std::optional<unsigned int> prior_frame) const {
+                 std::optional<unsigned int> prior_frame) {
     return false;
   };
 
@@ -236,7 +236,7 @@ TEST_F(ImageDecoderFixtureTest, ValidImageResultsInSuccess) {
     ASSERT_GE(data->size(), 0u);
 
     ImageGeneratorRegistry registry;
-    std::unique_ptr<ImageGenerator> generator =
+    std::shared_ptr<ImageGenerator> generator =
         registry.CreateCompatibleGenerator(data);
     ASSERT_TRUE(generator);
 
@@ -293,7 +293,7 @@ TEST_F(ImageDecoderFixtureTest, ExifDataIsRespectedOnDecode) {
     ASSERT_GE(data->size(), 0u);
 
     ImageGeneratorRegistry registry;
-    std::unique_ptr<ImageGenerator> generator =
+    std::shared_ptr<ImageGenerator> generator =
         registry.CreateCompatibleGenerator(data);
     ASSERT_TRUE(generator);
 
@@ -352,7 +352,7 @@ TEST_F(ImageDecoderFixtureTest, CanDecodeWithoutAGPUContext) {
     ASSERT_GE(data->size(), 0u);
 
     ImageGeneratorRegistry registry;
-    std::unique_ptr<ImageGenerator> generator =
+    std::shared_ptr<ImageGenerator> generator =
         registry.CreateCompatibleGenerator(data);
     ASSERT_TRUE(generator);
 
@@ -427,7 +427,7 @@ TEST_F(ImageDecoderFixtureTest, CanDecodeWithResizes) {
       ASSERT_GE(data->size(), 0u);
 
       ImageGeneratorRegistry registry;
-      std::unique_ptr<ImageGenerator> generator =
+      std::shared_ptr<ImageGenerator> generator =
           registry.CreateCompatibleGenerator(data);
       ASSERT_TRUE(generator);
 
@@ -593,7 +593,7 @@ TEST(ImageDecoderTest, VerifySimpleDecoding) {
   ASSERT_EQ(SkISize::Make(600, 200), image->dimensions());
 
   ImageGeneratorRegistry registry;
-  std::unique_ptr<ImageGenerator> generator =
+  std::shared_ptr<ImageGenerator> generator =
       registry.CreateCompatibleGenerator(data);
   ASSERT_TRUE(generator);
 
@@ -610,7 +610,7 @@ TEST(ImageDecoderTest, VerifySubpixelDecodingPreservesExifOrientation) {
   auto data = OpenFixtureAsSkData("Horizontal.jpg");
 
   ImageGeneratorRegistry registry;
-  std::unique_ptr<ImageGenerator> generator =
+  std::shared_ptr<ImageGenerator> generator =
       registry.CreateCompatibleGenerator(data);
   ASSERT_TRUE(generator);
   auto descriptor =
@@ -662,7 +662,7 @@ TEST_F(ImageDecoderFixtureTest,
   ASSERT_TRUE(gif_mapping);
 
   ImageGeneratorRegistry registry;
-  std::unique_ptr<ImageGenerator> gif_generator =
+  std::shared_ptr<ImageGenerator> gif_generator =
       registry.CreateCompatibleGenerator(gif_mapping);
   ASSERT_TRUE(gif_generator);
 

lib/ui/painting/image_descriptor.cc

@@ -47,7 +47,7 @@ ImageDescriptor::ImageDescriptor(sk_sp<SkData> buffer,
       row_bytes_(row_bytes) {}
 
 ImageDescriptor::ImageDescriptor(sk_sp<SkData> buffer,
-                                 std::unique_ptr<ImageGenerator> generator)
+                                 std::shared_ptr<ImageGenerator> generator)
     : buffer_(std::move(buffer)),
       generator_(std::move(generator)),
       image_info_(CreateImageInfo()),
@@ -83,7 +83,7 @@ void ImageDescriptor::initEncoded(Dart_NativeArguments args) {
     return;
   }
 
-  std::unique_ptr<ImageGenerator> generator =
+  auto generator =
       registry->CreateCompatibleGenerator(immutable_buffer->data());
 
   if (!generator) {
@@ -140,20 +140,7 @@ void ImageDescriptor::instantiateCodec(Dart_Handle codec_handle,
 }
 
 sk_sp<SkImage> ImageDescriptor::image() const {
-  SkBitmap bitmap;
-  if (!bitmap.tryAllocPixels(image_info_)) {
-    FML_DLOG(ERROR) << "Failed to allocate memory for bitmap of size "
-                    << image_info_.computeMinByteSize() << "B";
-    return nullptr;
-  }
-
-  const auto& pixmap = bitmap.pixmap();
-  if (!get_pixels(pixmap)) {
-    FML_DLOG(ERROR) << "Failed to get pixels for image.";
-    return nullptr;
-  }
-  bitmap.setImmutable();
-  return SkImage::MakeFromBitmap(bitmap);
+  return generator_->GetImage();
 }
 
 bool ImageDescriptor::get_pixels(const SkPixmap& pixmap) const {

lib/ui/painting/image_descriptor.h

@@ -123,7 +123,7 @@ class ImageDescriptor : public RefCountedDartWrappable<ImageDescriptor> {
                   const SkImageInfo& image_info,
                   std::optional<size_t> row_bytes);
   ImageDescriptor(sk_sp<SkData> buffer,
-                  std::unique_ptr<ImageGenerator> generator);
+                  std::shared_ptr<ImageGenerator> generator);
 
   sk_sp<SkData> buffer_;
   std::shared_ptr<ImageGenerator> generator_;

lib/ui/painting/image_generator.cc

@@ -4,17 +4,38 @@
 
 #include "flutter/lib/ui/painting/image_generator.h"
 
+#include "flutter/fml/logging.h"
+
 namespace flutter {
 
 ImageGenerator::~ImageGenerator() = default;
 
+sk_sp<SkImage> ImageGenerator::GetImage() {
+  SkImageInfo info = GetInfo();
+
+  SkBitmap bitmap;
+  if (!bitmap.tryAllocPixels(info)) {
+    FML_DLOG(ERROR) << "Failed to allocate memory for bitmap of size "
+                    << info.computeMinByteSize() << "B";
+    return nullptr;
+  }
+
+  const auto& pixmap = bitmap.pixmap();
+  if (!GetPixels(pixmap.info(), pixmap.writable_addr(), pixmap.rowBytes())) {
+    FML_DLOG(ERROR) << "Failed to get pixels for image.";
+    return nullptr;
+  }
+  bitmap.setImmutable();
+  return SkImage::MakeFromBitmap(bitmap);
+}
+
 BuiltinSkiaImageGenerator::~BuiltinSkiaImageGenerator() = default;
 
 BuiltinSkiaImageGenerator::BuiltinSkiaImageGenerator(
     std::unique_ptr<SkImageGenerator> generator)
     : generator_(std::move(generator)) {}
 
-const SkImageInfo& BuiltinSkiaImageGenerator::GetInfo() const {
+const SkImageInfo& BuiltinSkiaImageGenerator::GetInfo() {
   return generator_->getInfo();
 }
 
@@ -33,8 +54,7 @@ const ImageGenerator::FrameInfo BuiltinSkiaImageGenerator::GetFrameInfo(
           .disposal_method = SkCodecAnimation::DisposalMethod::kKeep};
 }
 
-SkISize BuiltinSkiaImageGenerator::GetScaledDimensions(
-    float desired_scale) const {
+SkISize BuiltinSkiaImageGenerator::GetScaledDimensions(float desired_scale) {
   return generator_->getInfo().dimensions();
 }
 
@@ -43,12 +63,10 @@ bool BuiltinSkiaImageGenerator::GetPixels(
     void* pixels,
     size_t row_bytes,
     unsigned int frame_index,
-    std::optional<unsigned int> prior_frame) const {
+    std::optional<unsigned int> prior_frame) {
   return generator_->getPixels(info, pixels, row_bytes);
 }
 
-BuiltinSkiaCodecImageGenerator::~BuiltinSkiaCodecImageGenerator() = default;
-
 std::unique_ptr<ImageGenerator> BuiltinSkiaImageGenerator::MakeFromGenerator(
     std::unique_ptr<SkImageGenerator> generator) {
   if (!generator) {
@@ -57,6 +75,8 @@ std::unique_ptr<ImageGenerator> BuiltinSkiaImageGenerator::MakeFromGenerator(
   return std::make_unique<BuiltinSkiaImageGenerator>(std::move(generator));
 }
 
+BuiltinSkiaCodecImageGenerator::~BuiltinSkiaCodecImageGenerator() = default;
+
 BuiltinSkiaCodecImageGenerator::BuiltinSkiaCodecImageGenerator(
     std::unique_ptr<SkCodec> codec)
     : codec_generator_(static_cast<SkCodecImageGenerator*>(
@@ -67,7 +87,7 @@ BuiltinSkiaCodecImageGenerator::BuiltinSkiaCodecImageGenerator(
     : codec_generator_(static_cast<SkCodecImageGenerator*>(
           SkCodecImageGenerator::MakeFromEncodedCodec(buffer).release())) {}
 
-const SkImageInfo& BuiltinSkiaCodecImageGenerator::GetInfo() const {
+const SkImageInfo& BuiltinSkiaCodecImageGenerator::GetInfo() {
   return codec_generator_->getInfo();
 }
 
@@ -93,7 +113,7 @@ const ImageGenerator::FrameInfo BuiltinSkiaCodecImageGenerator::GetFrameInfo(
 }
 
 SkISize BuiltinSkiaCodecImageGenerator::GetScaledDimensions(
-    float desired_scale) const {
+    float desired_scale) {
   return codec_generator_->getScaledDimensions(desired_scale);
 }
 
@@ -102,7 +122,7 @@ bool BuiltinSkiaCodecImageGenerator::GetPixels(
     void* pixels,
     size_t row_bytes,
     unsigned int frame_index,
-    std::optional<unsigned int> prior_frame) const {
+    std::optional<unsigned int> prior_frame) {
   SkCodec::Options options;
   options.fFrameIndex = frame_index;
   if (prior_frame.has_value()) {

lib/ui/painting/image_generator.h

@@ -48,7 +48,7 @@ class ImageGenerator {
   /// @note    This method is executed on the UI thread and used for layout
   ///          purposes by the framework, and so this method should not perform
   ///          long synchronous tasks.
-  virtual const SkImageInfo& GetInfo() const = 0;
+  virtual const SkImageInfo& GetInfo() = 0;
 
   /// @brief   Get the number of frames that the encoded image stores. This
   ///          method is always expected to be called before `GetFrameInfo`, as
@@ -87,9 +87,11 @@ class ImageGenerator {
   /// @note       This method is called prior to `GetPixels` in order to query
   ///             for supported sizes.
   /// @see        `GetPixels`
-  virtual SkISize GetScaledDimensions(float scale) const = 0;
+  virtual SkISize GetScaledDimensions(float scale) = 0;
 
-  /// @brief      Decode the image into a given buffer.
+  /// @brief      Decode the image into a given buffer. This method is currently
+  ///             always used for sub-pixel image decoding. For full-sized still
+  ///             images, `GetImage` is always attempted first.
   /// @param[in]  info         The desired size and color info of the decoded
   ///                          image to be returned. The implementation of
   ///                          `GetScaledDimensions` determines which sizes are
@@ -119,7 +121,12 @@ class ImageGenerator {
       void* pixels,
       size_t row_bytes,
       unsigned int frame_index = 0,
-      std::optional<unsigned int> prior_frame = std::nullopt) const = 0;
+      std::optional<unsigned int> prior_frame = std::nullopt) = 0;
+
+  /// @brief   Creates an `SkImage` based on the current `ImageInfo` of this
+  ///          `ImageGenerator`.
+  /// @return  A new `SkImage` containing the decoded image data.
+  sk_sp<SkImage> GetImage();
 };
 
 class BuiltinSkiaImageGenerator : public ImageGenerator {
@@ -129,7 +136,7 @@ class BuiltinSkiaImageGenerator : public ImageGenerator {
   BuiltinSkiaImageGenerator(std::unique_ptr<SkImageGenerator> generator);
 
   // |ImageGenerator|
-  const SkImageInfo& GetInfo() const override;
+  const SkImageInfo& GetInfo() override;
 
   // |ImageGenerator|
   unsigned int GetFrameCount() const override;
@@ -142,15 +149,15 @@ class BuiltinSkiaImageGenerator : public ImageGenerator {
       unsigned int frame_index) const override;
 
   // |ImageGenerator|
-  SkISize GetScaledDimensions(float desired_scale) const override;
+  SkISize GetScaledDimensions(float desired_scale) override;
 
   // |ImageGenerator|
   bool GetPixels(
       const SkImageInfo& info,
       void* pixels,
       size_t row_bytes,
       unsigned int frame_index = 0,
-      std::optional<unsigned int> prior_frame = std::nullopt) const override;
+      std::optional<unsigned int> prior_frame = std::nullopt) override;
 
   static std::unique_ptr<ImageGenerator> MakeFromGenerator(
       std::unique_ptr<SkImageGenerator> generator);
@@ -169,7 +176,7 @@ class BuiltinSkiaCodecImageGenerator : public ImageGenerator {
   BuiltinSkiaCodecImageGenerator(sk_sp<SkData> buffer);
 
   // |ImageGenerator|
-  const SkImageInfo& GetInfo() const override;
+  const SkImageInfo& GetInfo() override;
 
   // |ImageGenerator|
   unsigned int GetFrameCount() const override;
@@ -182,15 +189,15 @@ class BuiltinSkiaCodecImageGenerator : public ImageGenerator {
       unsigned int frame_index) const override;
 
   // |ImageGenerator|
-  SkISize GetScaledDimensions(float desired_scale) const override;
+  SkISize GetScaledDimensions(float desired_scale) override;
 
   // |ImageGenerator|
   bool GetPixels(
       const SkImageInfo& info,
       void* pixels,
       size_t row_bytes,
       unsigned int frame_index = 0,
-      std::optional<unsigned int> prior_frame = std::nullopt) const override;
+      std::optional<unsigned int> prior_frame = std::nullopt) override;
 
   static std::unique_ptr<ImageGenerator> MakeFromData(sk_sp<SkData> data);
 

lib/ui/painting/image_generator_registry.cc

@@ -52,7 +52,7 @@ void ImageGeneratorRegistry::AddFactory(ImageGeneratorFactory factory,
       {factory, priority, fml::tracing::TraceNonce()});
 }
 
-std::unique_ptr<ImageGenerator>
+std::shared_ptr<ImageGenerator>
 ImageGeneratorRegistry::CreateCompatibleGenerator(sk_sp<SkData> buffer) {
   if (!image_generator_factories_.size()) {
     FML_LOG(WARNING)
@@ -64,7 +64,7 @@ ImageGeneratorRegistry::CreateCompatibleGenerator(sk_sp<SkData> buffer) {
   }
 
   for (auto& factory : image_generator_factories_) {
-    std::unique_ptr<ImageGenerator> result = factory.callback(buffer);
+    std::shared_ptr<ImageGenerator> result = factory.callback(buffer);
     if (result) {
       return result;
     }