ladybird/Userland/Libraries/LibGfx/PortableImageMapLoader.h
MacDue 6cf8eeb7a4 LibGfx: Return bool not ErrorOr<bool> from ImageDecoderPlugin::sniff()
Nobody made use of the ErrorOr return value and it just added more
chance of confusion, since it was not clear if failing to sniff an
image should return an error or false. The answer was false, if you
returned Error you'd crash the ImageDecoder.
2023-02-26 19:43:17 +01:00

194 lines
4.9 KiB
C++

/*
* Copyright (c) 2020, Hüseyin ASLITÜRK <asliturk@hotmail.com>
* Copyright (c) 2022, the SerenityOS developers.
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <AK/RefPtr.h>
#include <AK/StringView.h>
#include <AK/Types.h>
#include <LibGfx/Bitmap.h>
#include <LibGfx/PortableImageLoaderCommon.h>
namespace Gfx {
template<class TFormatDetails>
struct PortableImageMapLoadingContext {
using FormatDetails = TFormatDetails;
enum class Type {
Unknown,
ASCII,
RAWBITS
};
enum class State {
NotDecoded = 0,
Error,
MagicNumber,
Width,
Height,
Maxval,
Bitmap,
Decoded
};
Type type { Type::Unknown };
State state { State::NotDecoded };
u8 const* data { nullptr };
size_t data_size { 0 };
size_t width { 0 };
size_t height { 0 };
FormatDetails format_details {};
RefPtr<Gfx::Bitmap> bitmap;
};
template<typename TContext>
class PortableImageDecoderPlugin final : public ImageDecoderPlugin {
public:
static bool sniff(ReadonlyBytes);
static ErrorOr<NonnullOwnPtr<ImageDecoderPlugin>> create(ReadonlyBytes);
PortableImageDecoderPlugin(u8 const*, size_t);
virtual ~PortableImageDecoderPlugin() override = default;
virtual IntSize size() override;
virtual void set_volatile() override;
[[nodiscard]] virtual bool set_nonvolatile(bool& was_purged) override;
virtual bool initialize() override;
virtual bool is_animated() override;
virtual size_t loop_count() override;
virtual size_t frame_count() override;
virtual ErrorOr<ImageFrameDescriptor> frame(size_t index) override;
virtual ErrorOr<Optional<ReadonlyBytes>> icc_data() override;
private:
OwnPtr<TContext> m_context;
};
template<typename TContext>
PortableImageDecoderPlugin<TContext>::PortableImageDecoderPlugin(u8 const* data, size_t size)
{
m_context = make<TContext>();
m_context->data = data;
m_context->data_size = size;
}
template<typename TContext>
IntSize PortableImageDecoderPlugin<TContext>::size()
{
if (m_context->state == TContext::State::Error)
return {};
if (m_context->state < TContext::State::Decoded) {
bool success = decode(*m_context);
if (!success)
return {};
}
return { m_context->width, m_context->height };
}
template<typename TContext>
void PortableImageDecoderPlugin<TContext>::set_volatile()
{
if (m_context->bitmap)
m_context->bitmap->set_volatile();
}
template<typename TContext>
bool PortableImageDecoderPlugin<TContext>::set_nonvolatile(bool& was_purged)
{
if (!m_context->bitmap)
return false;
return m_context->bitmap->set_nonvolatile(was_purged);
}
template<typename TContext>
bool PortableImageDecoderPlugin<TContext>::initialize()
{
using Context = TContext;
if (m_context->data_size < 2)
return false;
if (m_context->data[0] == 'P' && m_context->data[1] == Context::FormatDetails::ascii_magic_number)
return true;
if (m_context->data[0] == 'P' && m_context->data[1] == Context::FormatDetails::binary_magic_number)
return true;
return false;
}
template<typename TContext>
ErrorOr<NonnullOwnPtr<ImageDecoderPlugin>> PortableImageDecoderPlugin<TContext>::create(ReadonlyBytes data)
{
return adopt_nonnull_own_or_enomem(new (nothrow) PortableImageDecoderPlugin<TContext>(data.data(), data.size()));
}
template<typename TContext>
bool PortableImageDecoderPlugin<TContext>::sniff(ReadonlyBytes data)
{
using Context = TContext;
if (data.size() < 2)
return false;
if (data.data()[0] == 'P' && data.data()[1] == Context::FormatDetails::ascii_magic_number)
return true;
if (data.data()[0] == 'P' && data.data()[1] == Context::FormatDetails::binary_magic_number)
return true;
return false;
}
template<typename TContext>
bool PortableImageDecoderPlugin<TContext>::is_animated()
{
return false;
}
template<typename TContext>
size_t PortableImageDecoderPlugin<TContext>::loop_count()
{
return 0;
}
template<typename TContext>
size_t PortableImageDecoderPlugin<TContext>::frame_count()
{
return 1;
}
template<typename TContext>
ErrorOr<ImageFrameDescriptor> PortableImageDecoderPlugin<TContext>::frame(size_t index)
{
if (index > 0)
return Error::from_string_literal("PortableImageDecoderPlugin: Invalid frame index");
if (m_context->state == TContext::State::Error)
return Error::from_string_literal("PortableImageDecoderPlugin: Decoding failed");
if (m_context->state < TContext::State::Decoded) {
bool success = decode(*m_context);
if (!success)
return Error::from_string_literal("PortableImageDecoderPlugin: Decoding failed");
}
VERIFY(m_context->bitmap);
return ImageFrameDescriptor { m_context->bitmap, 0 };
}
template<typename TContext>
ErrorOr<Optional<ReadonlyBytes>> PortableImageDecoderPlugin<TContext>::icc_data()
{
return OptionalNone {};
}
}