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24e2c402f5
The display list is an immutable data structure, so once it's created, rasterization can be moved to a separate thread. This allows more room for performing other tasks between processing HTML rendering tasks. This change makes PaintingSurface, ImmutableBitmap, and GlyphRun atomic ref-counted, as they are shared between the main and rendering threads by being included in the display list.
98 lines
4.8 KiB
C++
98 lines
4.8 KiB
C++
/*
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* Copyright (c) 2022-2024, Tim Flynn <trflynn89@ladybird.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <LibGfx/Bitmap.h>
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#include <LibWeb/DOM/Document.h>
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#include <LibWeb/DOM/ElementFactory.h>
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#include <LibWeb/HTML/BrowsingContext.h>
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#include <LibWeb/HTML/HTMLCanvasElement.h>
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#include <LibWeb/HTML/TagNames.h>
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#include <LibWeb/HTML/TraversableNavigable.h>
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#include <LibWeb/Namespace.h>
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#include <LibWeb/Page/Page.h>
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#include <LibWeb/Painting/BackingStore.h>
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#include <LibWeb/WebDriver/Screenshot.h>
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namespace Web::WebDriver {
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// https://w3c.github.io/webdriver/#dfn-draw-a-bounding-box-from-the-framebuffer
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ErrorOr<GC::Ref<HTML::HTMLCanvasElement>, WebDriver::Error> draw_bounding_box_from_the_framebuffer(HTML::BrowsingContext& browsing_context, DOM::Element& element, Gfx::IntRect rect)
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{
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// 1. If either the initial viewport's width or height is 0 CSS pixels, return error with error code unable to capture screen.
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auto viewport_rect = browsing_context.top_level_traversable()->viewport_rect();
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if (viewport_rect.is_empty())
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return Error::from_code(ErrorCode::UnableToCaptureScreen, "Viewport is empty"sv);
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auto viewport_device_rect = browsing_context.page().enclosing_device_rect(viewport_rect).to_type<int>();
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// 2. Let paint width be the initial viewport's width – min(rectangle x coordinate, rectangle x coordinate + rectangle width dimension).
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auto paint_width = viewport_device_rect.width() - min(rect.x(), rect.x() + rect.width());
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// 3. Let paint height be the initial viewport's height – min(rectangle y coordinate, rectangle y coordinate + rectangle height dimension).
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auto paint_height = viewport_device_rect.height() - min(rect.y(), rect.y() + rect.height());
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// 4. Let canvas be a new canvas element, and set its width and height to paint width and paint height, respectively.
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auto canvas_element = DOM::create_element(element.document(), HTML::TagNames::canvas, Namespace::HTML).release_value_but_fixme_should_propagate_errors();
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auto& canvas = as<HTML::HTMLCanvasElement>(*canvas_element);
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// FIXME: Handle DevicePixelRatio in HiDPI mode.
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MUST(canvas.set_width(paint_width));
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MUST(canvas.set_height(paint_height));
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// FIXME: 5. Let context, a canvas context mode, be the result of invoking the 2D context creation algorithm given canvas as the target.
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canvas.create_2d_context();
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canvas.allocate_painting_surface_if_needed();
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if (!canvas.surface())
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return Error::from_code(ErrorCode::UnableToCaptureScreen, "Failed to allocate painting surface"sv);
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// 6. Complete implementation specific steps equivalent to drawing the region of the framebuffer specified by the following coordinates onto context:
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// - X coordinate: rectangle x coordinate
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// - Y coordinate: rectangle y coordinate
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// - Width: paint width
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// - Height: paint height
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Gfx::IntRect paint_rect { rect.x(), rect.y(), paint_width, paint_height };
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auto bitmap = MUST(Gfx::Bitmap::create(Gfx::BitmapFormat::BGRA8888, Gfx::AlphaType::Premultiplied, canvas.surface()->size()));
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auto backing_store = Web::Painting::BitmapBackingStore(bitmap);
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IGNORE_USE_IN_ESCAPING_LAMBDA bool did_paint = false;
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browsing_context.page().client().start_display_list_rendering(paint_rect.to_type<Web::DevicePixels>(), backing_store, {}, [&did_paint] {
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did_paint = true;
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});
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HTML::main_thread_event_loop().spin_until(GC::create_function(HTML::main_thread_event_loop().heap(), [&] {
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return did_paint;
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}));
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canvas.surface()->write_from_bitmap(*bitmap);
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// 7. Return success with canvas.
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return canvas;
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}
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// https://w3c.github.io/webdriver/#dfn-encoding-a-canvas-as-base64
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Response encode_canvas_element(HTML::HTMLCanvasElement& canvas)
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{
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// FIXME: 1. If the canvas element’s bitmap’s origin-clean flag is set to false, return error with error code unable to capture screen.
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// 2. If the canvas element’s bitmap has no pixels (i.e. either its horizontal dimension or vertical dimension is zero) then return error with error code unable to capture screen.
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if (canvas.surface()->size().is_empty())
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return Error::from_code(ErrorCode::UnableToCaptureScreen, "Captured screenshot is empty"sv);
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// 3. Let file be a serialization of the canvas element’s bitmap as a file, using "image/png" as an argument.
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// 4. Let data url be a data: URL representing file. [RFC2397]
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auto data_url = canvas.to_data_url("image/png"sv, JS::js_undefined());
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// 5. Let index be the index of "," in data url.
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auto index = data_url.find_byte_offset(',');
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VERIFY(index.has_value());
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// 6. Let encoded string be a substring of data url using (index + 1) as the start argument.
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auto encoded_string = MUST(data_url.substring_from_byte_offset(*index + 1));
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// 7. Return success with data encoded string.
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return JsonValue { move(encoded_string) };
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}
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}
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