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/*
* Copyright (C) 2004, 2006, 2007 Apple Inc. All rights reserved.
* Copyright (C) 2007 Alp Toker <alp@atoker.com>
*
* 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 APPLE COMPUTER, INC. ``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 APPLE COMPUTER, INC. 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 "config.h"
#include "HTMLCanvasElement.h"
#include "CanvasGradient.h"
#include "CanvasPattern.h"
#include "CanvasRenderingContext2D.h"
#include "CanvasStyle.h"
#include "Chrome.h"
#include "Document.h"
#include "ExceptionCode.h"
#include "Frame.h"
#include "GraphicsContext.h"
#include "HTMLNames.h"
#include "ImageBuffer.h"
#include "MIMETypeRegistry.h"
#include "MappedAttribute.h"
#include "Page.h"
#include "RenderHTMLCanvas.h"
#include "Settings.h"
#include <math.h>
#include <stdio.h>
namespace WebCore {
using namespace HTMLNames;
// These values come from the WhatWG spec.
static const int defaultWidth = 300;
static const int defaultHeight = 150;
// Firefox limits width/height to 32767 pixels, but slows down dramatically before it
// reaches that limit. We limit by area instead, giving us larger maximum dimensions,
// in exchange for a smaller maximum canvas size.
const float HTMLCanvasElement::MaxCanvasArea = 32768 * 8192; // Maximum canvas area in CSS pixels
HTMLCanvasElement::HTMLCanvasElement(const QualifiedName& tagName, Document* doc)
: HTMLElement(tagName, doc)
, m_size(defaultWidth, defaultHeight)
, m_observer(0)
, m_originClean(true)
, m_ignoreReset(false)
, m_createdImageBuffer(false)
{
ASSERT(hasTagName(canvasTag));
}
HTMLCanvasElement::~HTMLCanvasElement()
{
if (m_observer)
m_observer->canvasDestroyed(this);
}
#if ENABLE(DASHBOARD_SUPPORT)
HTMLTagStatus HTMLCanvasElement::endTagRequirement() const
{
Settings* settings = document()->settings();
if (settings && settings->usesDashboardBackwardCompatibilityMode())
return TagStatusForbidden;
return HTMLElement::endTagRequirement();
}
int HTMLCanvasElement::tagPriority() const
{
Settings* settings = document()->settings();
if (settings && settings->usesDashboardBackwardCompatibilityMode())
return 0;
return HTMLElement::tagPriority();
}
#endif
void HTMLCanvasElement::parseMappedAttribute(MappedAttribute* attr)
{
const QualifiedName& attrName = attr->name();
if (attrName == widthAttr || attrName == heightAttr)
reset();
HTMLElement::parseMappedAttribute(attr);
}
RenderObject* HTMLCanvasElement::createRenderer(RenderArena* arena, RenderStyle* style)
{
Settings* settings = document()->settings();
if (settings && settings->isJavaScriptEnabled()) {
m_rendererIsCanvas = true;
return new (arena) RenderHTMLCanvas(this);
}
m_rendererIsCanvas = false;
return HTMLElement::createRenderer(arena, style);
}
void HTMLCanvasElement::setHeight(int value)
{
setAttribute(heightAttr, String::number(value));
}
void HTMLCanvasElement::setWidth(int value)
{
setAttribute(widthAttr, String::number(value));
}
String HTMLCanvasElement::toDataURL(const String& mimeType, ExceptionCode& ec)
{
if (!m_originClean) {
ec = SECURITY_ERR;
return String();
}
if (m_size.isEmpty())
return String("data:,");
if (mimeType.isNull() || !MIMETypeRegistry::isSupportedImageMIMETypeForEncoding(mimeType))
return buffer()->toDataURL("image/png");
return buffer()->toDataURL(mimeType);
}
CanvasRenderingContext* HTMLCanvasElement::getContext(const String& type)
{
if (type == "2d") {
if (!m_2DContext)
m_2DContext.set(new CanvasRenderingContext2D(this));
return m_2DContext.get();
}
return 0;
}
void HTMLCanvasElement::willDraw(const FloatRect& rect)
{
m_imageBuffer->clearImage();
if (RenderBox* ro = renderBox()) {
FloatRect destRect = ro->contentBoxRect();
FloatRect r = mapRect(rect, FloatRect(0, 0, m_size.width(), m_size.height()), destRect);
r.intersect(destRect);
if (m_dirtyRect.contains(r))
return;
m_dirtyRect.unite(r);
ro->repaintRectangle(enclosingIntRect(m_dirtyRect));
}
if (m_observer)
m_observer->canvasChanged(this, rect);
}
void HTMLCanvasElement::reset()
{
if (m_ignoreReset)
return;
bool ok;
int w = getAttribute(widthAttr).toInt(&ok);
if (!ok)
w = defaultWidth;
int h = getAttribute(heightAttr).toInt(&ok);
if (!ok)
h = defaultHeight;
IntSize oldSize = m_size;
m_size = IntSize(w, h);
bool hadImageBuffer = m_createdImageBuffer;
m_createdImageBuffer = false;
m_imageBuffer.clear();
if (m_2DContext)
m_2DContext->reset();
if (RenderObject* ro = renderer())
if (m_rendererIsCanvas) {
if (oldSize != m_size)
static_cast<RenderHTMLCanvas*>(ro)->canvasSizeChanged();
if (hadImageBuffer)
ro->repaint();
}
if (m_observer)
m_observer->canvasResized(this);
}
void HTMLCanvasElement::paint(GraphicsContext* context, const IntRect& r)
{
// Clear the dirty rect
m_dirtyRect = FloatRect();
if (context->paintingDisabled())
return;
if (m_imageBuffer) {
Image* image = m_imageBuffer->image();
if (image)
context->drawImage(image, r);
}
}
IntRect HTMLCanvasElement::convertLogicalToDevice(const FloatRect& logicalRect) const
{
return IntRect(convertLogicalToDevice(logicalRect.location()), convertLogicalToDevice(logicalRect.size()));
}
IntSize HTMLCanvasElement::convertLogicalToDevice(const FloatSize& logicalSize) const
{
float pageScaleFactor = document()->frame() ? document()->frame()->page()->chrome()->scaleFactor() : 1.0f;
float wf = ceilf(logicalSize.width() * pageScaleFactor);
float hf = ceilf(logicalSize.height() * pageScaleFactor);
if (!(wf >= 1 && hf >= 1 && wf * hf <= MaxCanvasArea))
return IntSize();
return IntSize(static_cast<unsigned>(wf), static_cast<unsigned>(hf));
}
IntPoint HTMLCanvasElement::convertLogicalToDevice(const FloatPoint& logicalPos) const
{
float pageScaleFactor = document()->frame() ? document()->frame()->page()->chrome()->scaleFactor() : 1.0f;
float xf = logicalPos.x() * pageScaleFactor;
float yf = logicalPos.y() * pageScaleFactor;
return IntPoint(static_cast<unsigned>(xf), static_cast<unsigned>(yf));
}
void HTMLCanvasElement::createImageBuffer() const
{
ASSERT(!m_imageBuffer);
m_createdImageBuffer = true;
FloatSize unscaledSize(width(), height());
IntSize size = convertLogicalToDevice(unscaledSize);
if (!size.width() || !size.height())
return;
m_imageBuffer = ImageBuffer::create(size, false);
// The convertLogicalToDevice MaxCanvasArea check should prevent common cases
// where ImageBuffer::create() returns NULL, however we could still be low on memory.
if (!m_imageBuffer)
return;
m_imageBuffer->context()->scale(FloatSize(size.width() / unscaledSize.width(), size.height() / unscaledSize.height()));
m_imageBuffer->context()->setShadowsIgnoreTransforms(true);
}
GraphicsContext* HTMLCanvasElement::drawingContext() const
{
return buffer() ? m_imageBuffer->context() : 0;
}
ImageBuffer* HTMLCanvasElement::buffer() const
{
if (!m_createdImageBuffer)
createImageBuffer();
return m_imageBuffer.get();
}
TransformationMatrix HTMLCanvasElement::baseTransform() const
{
ASSERT(m_createdImageBuffer);
FloatSize unscaledSize(width(), height());
IntSize size = convertLogicalToDevice(unscaledSize);
TransformationMatrix transform;
if (size.width() && size.height())
transform.scaleNonUniform(size.width() / unscaledSize.width(), size.height() / unscaledSize.height());
transform.multiply(m_imageBuffer->baseTransform());
return transform;
}
}