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f8dd3e14ba
Resolved style is a spec concept that refers to the weird mix of computed style and used style reflected by getComputedStyle(). The purpose of this class is to produce the *computed* style for a given element, so let's call it StyleComputer.
98 lines
2.6 KiB
C++
98 lines
2.6 KiB
C++
/*
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* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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*
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* SPDX-License-Identifier: BSD-2-Clause
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*/
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#include <AK/Base64.h>
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#include <AK/Checked.h>
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#include <LibGfx/Bitmap.h>
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#include <LibGfx/PNGWriter.h>
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#include <LibWeb/CSS/StyleComputer.h>
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#include <LibWeb/DOM/Document.h>
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#include <LibWeb/HTML/CanvasRenderingContext2D.h>
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#include <LibWeb/HTML/HTMLCanvasElement.h>
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#include <LibWeb/Layout/CanvasBox.h>
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namespace Web::HTML {
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static constexpr auto max_canvas_area = 16384 * 16384;
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HTMLCanvasElement::HTMLCanvasElement(DOM::Document& document, QualifiedName qualified_name)
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: HTMLElement(document, move(qualified_name))
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{
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}
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HTMLCanvasElement::~HTMLCanvasElement()
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{
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}
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unsigned HTMLCanvasElement::width() const
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{
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return attribute(HTML::AttributeNames::width).to_uint().value_or(300);
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}
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unsigned HTMLCanvasElement::height() const
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{
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return attribute(HTML::AttributeNames::height).to_uint().value_or(150);
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}
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RefPtr<Layout::Node> HTMLCanvasElement::create_layout_node()
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{
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auto style = document().style_computer().compute_style(*this);
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if (style->display() == CSS::Display::None)
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return nullptr;
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return adopt_ref(*new Layout::CanvasBox(document(), *this, move(style)));
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}
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CanvasRenderingContext2D* HTMLCanvasElement::get_context(String type)
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{
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if (type != "2d")
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return nullptr;
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if (!m_context)
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m_context = CanvasRenderingContext2D::create(*this);
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return m_context;
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}
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static Gfx::IntSize bitmap_size_for_canvas(const HTMLCanvasElement& canvas)
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{
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auto width = canvas.width();
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auto height = canvas.height();
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Checked<size_t> area = width;
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area *= height;
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if (area.has_overflow()) {
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dbgln("Refusing to create {}x{} canvas (overflow)", width, height);
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return {};
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}
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if (area.value() > max_canvas_area) {
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dbgln("Refusing to create {}x{} canvas (exceeds maximum size)", width, height);
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return {};
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}
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return Gfx::IntSize(width, height);
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}
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bool HTMLCanvasElement::create_bitmap()
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{
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auto size = bitmap_size_for_canvas(*this);
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if (size.is_empty()) {
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m_bitmap = nullptr;
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return false;
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}
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if (!m_bitmap || m_bitmap->size() != size)
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m_bitmap = Gfx::Bitmap::try_create(Gfx::BitmapFormat::BGRA8888, size);
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return m_bitmap;
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}
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String HTMLCanvasElement::to_data_url(const String& type, [[maybe_unused]] Optional<double> quality) const
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{
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if (!m_bitmap)
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return {};
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if (type != "image/png")
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return {};
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auto encoded_bitmap = Gfx::PNGWriter::encode(*m_bitmap);
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return AK::URL::create_with_data(type, encode_base64(encoded_bitmap), true).to_string();
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}
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}
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