ladybird/Libraries/LibWeb/HTML/OffscreenCanvas.h
Tim Ledbetter 5413716802 LibWeb: Don't crash when setting offscreen canvas size to 0
Previously, this would crash because `Gfx::Bitmap` can't have a zero
size.
2025-07-04 16:10:38 +01:00

90 lines
3.2 KiB
C++

/*
* Copyright (c) 2025, Ladybird contributors
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#pragma once
#include <LibGfx/Bitmap.h>
#include <LibWeb/Bindings/PlatformObject.h>
#include <LibWeb/Bindings/Transferable.h>
#include <LibWeb/DOM/EventTarget.h>
#include <LibWeb/Forward.h>
#include <LibWeb/WebIDL/Types.h>
namespace Web::HTML {
// https://html.spec.whatwg.org/multipage/canvas.html#offscreenrenderingcontext
// NOTE: This is the Variant created by the IDL wrapper generator, and needs to be updated accordingly.
using OffscreenRenderingContext = Variant<GC::Root<OffscreenCanvasRenderingContext2D>, GC::Root<WebGL::WebGLRenderingContext>, GC::Root<WebGL::WebGL2RenderingContext>, Empty>;
// https://html.spec.whatwg.org/multipage/canvas.html#imageencodeoptions
struct ImageEncodeOptions {
FlyString type { "image/png"_fly_string };
Optional<double> quality;
};
// https://html.spec.whatwg.org/multipage/canvas.html#offscreencanvas
class OffscreenCanvas : public DOM::EventTarget
, public Web::Bindings::Transferable {
WEB_PLATFORM_OBJECT(OffscreenCanvas, DOM::EventTarget);
GC_DECLARE_ALLOCATOR(OffscreenCanvas);
public:
static GC::Ref<OffscreenCanvas> create(JS::Realm&, WebIDL::UnsignedLong width, WebIDL::UnsignedLong height);
static WebIDL::ExceptionOr<GC::Ref<OffscreenCanvas>> construct_impl(
JS::Realm&,
WebIDL::UnsignedLong width,
WebIDL::UnsignedLong height);
virtual ~OffscreenCanvas() override;
// ^Web::Bindings::Transferable
virtual WebIDL::ExceptionOr<void> transfer_steps(HTML::TransferDataHolder&) override;
virtual WebIDL::ExceptionOr<void> transfer_receiving_steps(HTML::TransferDataHolder&) override;
virtual HTML::TransferType primary_interface() const override;
WebIDL::UnsignedLong width() const;
WebIDL::UnsignedLong height() const;
RefPtr<Gfx::Bitmap> bitmap() const;
WebIDL::ExceptionOr<void> set_width(WebIDL::UnsignedLong);
WebIDL::ExceptionOr<void> set_height(WebIDL::UnsignedLong);
Gfx::IntSize bitmap_size_for_canvas() const;
JS::ThrowCompletionOr<OffscreenRenderingContext> get_context(Bindings::OffscreenRenderingContextId contextId, JS::Value options);
WebIDL::ExceptionOr<GC::Ref<ImageBitmap>> transfer_to_image_bitmap();
GC::Ref<WebIDL::Promise> convert_to_blob(Optional<ImageEncodeOptions> options);
void set_oncontextlost(GC::Ptr<WebIDL::CallbackType>);
GC::Ptr<WebIDL::CallbackType> oncontextlost();
void set_oncontextrestored(GC::Ptr<WebIDL::CallbackType>);
GC::Ptr<WebIDL::CallbackType> oncontextrestored();
private:
OffscreenCanvas(JS::Realm&, RefPtr<Gfx::Bitmap> bitmap);
virtual void initialize(JS::Realm&) override;
virtual void visit_edges(Cell::Visitor&) override;
enum class HasOrCreatedContext {
No,
Yes,
};
JS::ThrowCompletionOr<HasOrCreatedContext> create_2d_context(JS::Value options);
void reset_context_to_default_state();
void set_new_bitmap_size(Gfx::IntSize new_size);
Variant<GC::Ref<HTML::OffscreenCanvasRenderingContext2D>, GC::Ref<WebGL::WebGLRenderingContext>, GC::Ref<WebGL::WebGL2RenderingContext>, Empty> m_context;
RefPtr<Gfx::Bitmap> m_bitmap;
};
}