LibWeb: Factor out canvas rendering options algorihtms

Factor out canvas parsing algorihtm for CanvasRenderingContext2DSettings
from JS::Value. This was only used in one place but needs to be usable
from other places too in the future.
This commit is contained in:
Totto16 2025-06-18 02:51:52 +02:00 committed by Andrew Kaster
commit 193ab3757b
Notes: github-actions[bot] 2025-06-30 15:47:50 +00:00
5 changed files with 68 additions and 51 deletions

View file

@ -342,6 +342,7 @@ set(SOURCES
HTML/BrowsingContextGroup.cpp
HTML/Canvas/CanvasDrawImage.cpp
HTML/Canvas/CanvasPath.cpp
HTML/Canvas/CanvasSettings.cpp
HTML/Canvas/CanvasState.cpp
HTML/Canvas/SerializeBitmap.cpp
HTML/CanvasGradient.cpp

View file

@ -0,0 +1,56 @@
/*
* Copyright (c) 2025, Ladybird contributors
* Copyright (c) 2025, Jelle Raaijmakers <jelle@ladybird.org>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/FlyString.h>
#include <LibJS/Runtime/VM.h>
#include <LibWeb/HTML/Canvas/CanvasSettings.h>
// https://html.spec.whatwg.org/multipage/canvas.html#canvasrenderingcontext2dsettings
JS::ThrowCompletionOr<Web::HTML::CanvasRenderingContext2DSettings> Web::HTML::CanvasRenderingContext2DSettings::from_js_value(JS::VM& vm, JS::Value value)
{
if (!value.is_nullish() && !value.is_object())
return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "CanvasRenderingContext2DSettings");
CanvasRenderingContext2DSettings settings;
if (value.is_nullish())
return settings;
auto& value_object = value.as_object();
JS::Value alpha = TRY(value_object.get("alpha"_fly_string));
settings.alpha = alpha.is_undefined() ? true : alpha.to_boolean();
JS::Value desynchronized = TRY(value_object.get("desynchronized"_fly_string));
settings.desynchronized = desynchronized.is_undefined() ? false : desynchronized.to_boolean();
JS::Value color_space = TRY(value_object.get("colorSpace"_fly_string));
if (!color_space.is_undefined()) {
auto color_space_string = TRY(color_space.to_string(vm));
if (color_space_string == "srgb"sv)
settings.color_space = Bindings::PredefinedColorSpace::Srgb;
else if (color_space_string == "display-p3"sv)
settings.color_space = Bindings::PredefinedColorSpace::DisplayP3;
else
return vm.throw_completion<JS::TypeError>(JS::ErrorType::InvalidEnumerationValue, color_space_string, "colorSpace");
}
JS::Value color_type = TRY(value_object.get("colorType"_fly_string));
if (!color_type.is_undefined()) {
auto color_type_string = TRY(color_type.to_string(vm));
if (color_type_string == "unorm8"sv)
settings.color_type = Bindings::CanvasColorType::Unorm8;
else if (color_type_string == "float16"sv)
settings.color_type = Bindings::CanvasColorType::Float16;
else
return vm.throw_completion<JS::TypeError>(JS::ErrorType::InvalidEnumerationValue, color_type_string, "colorType");
}
JS::Value will_read_frequently = TRY(value_object.get("willReadFrequently"_fly_string));
settings.will_read_frequently = will_read_frequently.is_undefined() ? false : will_read_frequently.to_boolean();
return settings;
}

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@ -6,14 +6,22 @@
#pragma once
#include <LibJS/Forward.h>
// FIXME: this needs to be shared inside the idl, this is not that easily fixable, so until that we are just using the definition of ImageDataPrototype and CanvasRenderingContext2DPrototype, and assert that it's the same in all duplicate declarations
#include <LibWeb/Bindings/CanvasRenderingContext2DPrototype.h>
#include <LibWeb/Bindings/ImageDataPrototype.h>
namespace Web::HTML {
struct CanvasRenderingContext2DSettings {
bool alpha { true };
bool desynchronized { false };
Bindings::PredefinedColorSpace color_space { Bindings::PredefinedColorSpace::Srgb };
Bindings::CanvasColorType color_type { Bindings::CanvasColorType::Unorm8 };
Web::Bindings::PredefinedColorSpace color_space { Web::Bindings::PredefinedColorSpace::Srgb };
Web::Bindings::CanvasColorType color_type { Web::Bindings::CanvasColorType::Unorm8 };
bool will_read_frequently { false };
[[nodiscard]] static JS::ThrowCompletionOr<CanvasRenderingContext2DSettings> from_js_value(JS::VM&, JS::Value);
};
// https://html.spec.whatwg.org/multipage/canvas.html#canvassettings

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@ -37,7 +37,7 @@ GC_DEFINE_ALLOCATOR(CanvasRenderingContext2D);
JS::ThrowCompletionOr<GC::Ref<CanvasRenderingContext2D>> CanvasRenderingContext2D::create(JS::Realm& realm, HTMLCanvasElement& element, JS::Value options)
{
auto context_attributes = TRY(context_attributes_from_options(realm.vm(), options));
auto context_attributes = TRY(CanvasRenderingContext2DSettings::from_js_value(realm.vm(), options));
return realm.create<CanvasRenderingContext2D>(realm, element, context_attributes);
}
@ -64,52 +64,6 @@ void CanvasRenderingContext2D::visit_edges(Cell::Visitor& visitor)
visitor.visit(m_element);
}
// https://html.spec.whatwg.org/multipage/canvas.html#canvasrenderingcontext2dsettings
JS::ThrowCompletionOr<CanvasRenderingContext2DSettings> CanvasRenderingContext2D::context_attributes_from_options(JS::VM& vm, JS::Value value)
{
if (!value.is_nullish() && !value.is_object())
return vm.throw_completion<JS::TypeError>(JS::ErrorType::NotAnObjectOfType, "CanvasRenderingContext2DSettings");
CanvasRenderingContext2DSettings settings;
if (value.is_nullish())
return settings;
auto& value_object = value.as_object();
JS::Value alpha = TRY(value_object.get("alpha"_fly_string));
settings.alpha = alpha.is_undefined() ? true : alpha.to_boolean();
JS::Value desynchronized = TRY(value_object.get("desynchronized"_fly_string));
settings.desynchronized = desynchronized.is_undefined() ? false : desynchronized.to_boolean();
JS::Value color_space = TRY(value_object.get("colorSpace"_fly_string));
if (!color_space.is_undefined()) {
auto color_space_string = TRY(color_space.to_string(vm));
if (color_space_string == "srgb"sv)
settings.color_space = Bindings::PredefinedColorSpace::Srgb;
else if (color_space_string == "display-p3"sv)
settings.color_space = Bindings::PredefinedColorSpace::DisplayP3;
else
return vm.throw_completion<JS::TypeError>(JS::ErrorType::InvalidEnumerationValue, color_space_string, "colorSpace");
}
JS::Value color_type = TRY(value_object.get("colorType"_fly_string));
if (!color_type.is_undefined()) {
auto color_type_string = TRY(color_type.to_string(vm));
if (color_type_string == "unorm8"sv)
settings.color_type = Bindings::CanvasColorType::Unorm8;
else if (color_type_string == "float16"sv)
settings.color_type = Bindings::CanvasColorType::Float16;
else
return vm.throw_completion<JS::TypeError>(JS::ErrorType::InvalidEnumerationValue, color_type_string, "colorType");
}
JS::Value will_read_frequently = TRY(value_object.get("willReadFrequently"_fly_string));
settings.will_read_frequently = will_read_frequently.is_undefined() ? false : will_read_frequently.to_boolean();
return settings;
}
HTMLCanvasElement& CanvasRenderingContext2D::canvas_element()
{
return *m_element;

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@ -134,8 +134,6 @@ private:
virtual void initialize(JS::Realm&) override;
virtual void visit_edges(Cell::Visitor&) override;
static JS::ThrowCompletionOr<CanvasRenderingContext2DSettings> context_attributes_from_options(JS::VM&, JS::Value);
virtual Gfx::Painter* painter_for_canvas_state() override { return painter(); }
virtual Gfx::Path& path_for_canvas_state() override { return path(); }