a37c29e353
This patch adds HTMLCanvasElement along with a LayoutCanvas object.
The DOM and layout parts are very similar to <img> elements.
The <canvas> element holds a Gfx::Bitmap which is sized according to
the "width" and "height" attributes on the element.
Calling .getContext("2d") on a <canvas> element gives you a context
object that draws into the underlying Gfx::Bitmap of the <canvas>.
The context weakly points to the <canvas> which allows it to outlive
the canvas element if needed.
This is really quite cool. :^)
92 lines
3.1 KiB
C++
92 lines
3.1 KiB
C++
/*
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* Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice, this
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* list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
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* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
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* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#include <LibGfx/Bitmap.h>
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#include <LibWeb/CSS/StyleResolver.h>
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#include <LibWeb/DOM/CanvasRenderingContext2D.h>
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#include <LibWeb/DOM/Document.h>
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#include <LibWeb/DOM/HTMLCanvasElement.h>
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#include <LibWeb/Layout/LayoutCanvas.h>
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namespace Web {
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HTMLCanvasElement::HTMLCanvasElement(Document& document, const String& tag_name)
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: HTMLElement(document, tag_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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int HTMLCanvasElement::preferred_width() const
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{
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bool ok = false;
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int width = attribute("width").to_int(ok);
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if (ok)
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return width;
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return 300;
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}
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int HTMLCanvasElement::preferred_height() const
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{
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bool ok = false;
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int height = attribute("height").to_int(ok);
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if (ok)
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return height;
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return 300;
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}
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RefPtr<LayoutNode> HTMLCanvasElement::create_layout_node(const StyleProperties* parent_style) const
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{
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auto style = document().style_resolver().resolve_style(*this, parent_style);
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auto display = style->string_or_fallback(CSS::PropertyID::Display, "inline");
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if (display == "none")
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return nullptr;
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return adopt(*new LayoutCanvas(*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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ASSERT(type.to_lowercase() == "2d");
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dbg() << "get_context with m_context=" << m_context.ptr();
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if (!m_context)
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m_context = CanvasRenderingContext2D::create(*this);
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dbg() << "get_context returning m_context=" << m_context.ptr();
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return m_context;
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}
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Gfx::Bitmap& HTMLCanvasElement::ensure_bitmap()
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{
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if (!m_bitmap || m_bitmap->size() != Gfx::Size(preferred_width(), preferred_height())) {
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m_bitmap = Gfx::Bitmap::create(Gfx::BitmapFormat::RGBA32, { preferred_width(), preferred_height() });
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}
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return *m_bitmap;
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}
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}
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