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/*
* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <AK/Checked.h>
#include <LibGfx/Bitmap.h>
#include <LibWeb/CSS/StyleResolver.h>
#include <LibWeb/DOM/CanvasRenderingContext2D.h>
#include <LibWeb/DOM/Document.h>
#include <LibWeb/DOM/HTMLCanvasElement.h>
#include <LibWeb/Layout/LayoutCanvas.h>
namespace Web {
static constexpr auto max_canvas_area = 16384 * 16384;
HTMLCanvasElement::HTMLCanvasElement(Document& document, const FlyString& tag_name)
: HTMLElement(document, tag_name)
{
}
HTMLCanvasElement::~HTMLCanvasElement()
{
}
unsigned HTMLCanvasElement::width() const
{
return attribute(HTML::AttributeNames::width).to_uint().value_or(300);
}
unsigned HTMLCanvasElement::height() const
{
return attribute(HTML::AttributeNames::height).to_uint().value_or(150);
}
RefPtr<LayoutNode> HTMLCanvasElement::create_layout_node(const StyleProperties* parent_style)
{
auto style = document().style_resolver().resolve_style(*this, parent_style);
if (style->display() == CSS::Display::None)
return nullptr;
return adopt(*new LayoutCanvas(document(), *this, move(style)));
}
CanvasRenderingContext2D* HTMLCanvasElement::get_context(String type)
{
ASSERT(type == "2d");
if (!m_context)
m_context = CanvasRenderingContext2D::create(*this);
return m_context;
}
static Gfx::IntSize bitmap_size_for_canvas(const HTMLCanvasElement& canvas)
{
auto width = canvas.width();
auto height = canvas.height();
Checked<size_t> area = width;
area *= height;
if (area.has_overflow()) {
dbg() << "Refusing to create " << width << "x" << height << " canvas (overflow)";
return {};
}
if (area.value() > max_canvas_area) {
dbg() << "Refusing to create " << width << "x" << height << " canvas (exceeds maximum size)";
return {};
}
return Gfx::IntSize(width, height);
}
bool HTMLCanvasElement::create_bitmap()
{
auto size = bitmap_size_for_canvas(*this);
if (size.is_empty()) {
m_bitmap = nullptr;
return false;
}
if (!m_bitmap || m_bitmap->size() != size)
m_bitmap = Gfx::Bitmap::create(Gfx::BitmapFormat::RGBA32, size);
return m_bitmap;
}
}
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