flutter::ImageGeneratorRegistry Class Reference

Keeps a priority-ordered registry of image generator builders to be used when decoding images. This object must be created, accessed, and collected on the UI thread (typically the engine or its runtime controller). More...

#include <image_generator_registry.h>

Public Member Functions
	ImageGeneratorRegistry ()
	~ImageGeneratorRegistry ()
void	AddFactory (ImageGeneratorFactory factory, int32_t priority)
	Install a new factory for image generators.
std::shared_ptr< ImageGenerator >	CreateCompatibleGenerator (const sk_sp< SkData > &buffer)
	Walks the list of image generator builders in descending priority order until a compatible ImageGenerator is able to be built. This method is safe to perform on the UI thread, as checking for ImageGenerator compatibility is expected to be a lightweight operation. The returned ImageGenerator can then be used to fully decode the image on e.g. the IO thread.
fml::WeakPtr< ImageGeneratorRegistry >	GetWeakPtr () const

Detailed Description

Keeps a priority-ordered registry of image generator builders to be used when decoding images. This object must be created, accessed, and collected on the UI thread (typically the engine or its runtime controller).

Definition at line 28 of file image_generator_registry.h.

Constructor & Destructor Documentation

ImageGeneratorRegistry()

flutter::ImageGeneratorRegistry::ImageGeneratorRegistry

(

)

Definition at line 21 of file image_generator_registry.cc.

                                               : weak_factory_(this) {
  AddFactory(
      [](sk_sp<SkData> buffer) {
        return APNGImageGenerator::MakeFromData(std::move(buffer));
      },
      0);
 
  AddFactory(
      [](sk_sp<SkData> buffer) {
        return BuiltinSkiaCodecImageGenerator::MakeFromData(std::move(buffer));
      },
      0);
 
  // todo(bdero): https://github.com/flutter/flutter/issues/82603
#ifdef FML_OS_MACOSX
  AddFactory(
      [](sk_sp<SkData> buffer) {
        auto generator =
            SkImageGeneratorCG::MakeFromEncodedCG(std::move(buffer));
        return BuiltinSkiaImageGenerator::MakeFromGenerator(
            std::move(generator));
      },
      0);
#elif FML_OS_WIN
  AddFactory(
      [](sk_sp<SkData> buffer) {
        auto generator = SkImageGeneratorWIC::MakeFromEncodedWIC(buffer);
        return BuiltinSkiaImageGenerator::MakeFromGenerator(
            std::move(generator));
      },
      0);
#endif
}

~ImageGeneratorRegistry()

flutter::ImageGeneratorRegistry::~ImageGeneratorRegistry ( )

default

Member Function Documentation

AddFactory()

void flutter::ImageGeneratorRegistry::AddFactory	(	ImageGeneratorFactory	factory,
		int32_t	priority
	)

Install a new factory for image generators.

Parameters

[in]	factory	Callback that produces ImageGenerators for compatible input data.
[in]	priority	The priority used to determine the order in which factories are tried. Higher values mean higher priority. The built-in Skia decoders are installed at priority 0, and so a priority > 0 takes precedent over the builtin decoders. When multiple decoders are added with the same priority, those which are added earlier take precedent.

See also

CreateCompatibleGenerator

Definition at line 57 of file image_generator_registry.cc.

                                                          {
  image_generator_factories_.insert({std::move(factory), priority, ++nonce_});
}

CreateCompatibleGenerator()

std::shared_ptr< ImageGenerator > flutter::ImageGeneratorRegistry::CreateCompatibleGenerator

(

const sk_sp< SkData > &

buffer

)

Walks the list of image generator builders in descending priority order until a compatible ImageGenerator is able to be built. This method is safe to perform on the UI thread, as checking for ImageGenerator compatibility is expected to be a lightweight operation. The returned ImageGenerator can then be used to fully decode the image on e.g. the IO thread.

Parameters

[in]

buffer

The raw encoded image data.

Returns

An ImageGenerator that is compatible with the input buffer. If no compatible ImageGenerator type was found, then std::shared_ptr<ImageGenerator>(nullptr) is returned.

See also

ImageGenerator

Definition at line 63 of file image_generator_registry.cc.

                                                                             {
  if (!image_generator_factories_.size()) {
    FML_LOG(WARNING)
        << "There are currently no image decoders installed. If you're writing "
           "your own platform embedding, you can register new image decoders "
           "via `ImageGeneratorRegistry::AddFactory` on the "
           "`ImageGeneratorRegistry` provided by the engine. Otherwise, please "
           "file a bug on https://github.com/flutter/flutter/issues.";
  }
 
  for (auto& factory : image_generator_factories_) {
    std::shared_ptr<ImageGenerator> result = factory.callback(buffer);
    if (result) {
      return result;
    }
  }
  return nullptr;
}

GetWeakPtr()

fml::WeakPtr< ImageGeneratorRegistry > flutter::ImageGeneratorRegistry::GetWeakPtr

(

)

const

Definition at line 82 of file image_generator_registry.cc.

          {
  return weak_factory_.GetWeakPtr();
}

---

The documentation for this class was generated from the following files:

• lib/ui/painting/image_generator_registry.h
• lib/ui/painting/image_generator_registry.cc