/* | |
* 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 "CanvasContextAttributes.h" | |
#include "CanvasGradient.h" | |
#include "CanvasPattern.h" | |
#include "CanvasRenderingContext2D.h" | |
#if ENABLE(3D_CANVAS) | |
#include "WebGLContextAttributes.h" | |
#include "WebGLRenderingContext.h" | |
#endif | |
#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) | |
{ | |
Frame* frame = document()->frame(); | |
if (frame && frame->script()->canExecuteScripts(NotAboutToExecuteScript)) { | |
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() || !buffer()) | |
return String("data:,"); | |
String lowercaseMimeType = mimeType.lower(); | |
if (mimeType.isNull() || !MIMETypeRegistry::isSupportedImageMIMETypeForEncoding(lowercaseMimeType)) | |
return buffer()->toDataURL("image/png"); | |
return buffer()->toDataURL(lowercaseMimeType); | |
} | |
CanvasRenderingContext* HTMLCanvasElement::getContext(const String& type, CanvasContextAttributes* attrs) | |
{ | |
// A Canvas can either be "2D" or "webgl" but never both. If you request a 2D canvas and the existing | |
// context is already 2D, just return that. If the existing context is WebGL, then destroy it | |
// before creating a new 2D context. Vice versa when requesting a WebGL canvas. Requesting a | |
// context with any other type string will destroy any existing context. | |
// FIXME - The code depends on the context not going away once created, to prevent JS from | |
// seeing a dangling pointer. So for now we will disallow the context from being changed | |
// once it is created. | |
if (type == "2d") { | |
if (m_context && !m_context->is2d()) | |
return 0; | |
if (!m_context) | |
m_context = new CanvasRenderingContext2D(this); | |
return m_context.get(); | |
} | |
#if ENABLE(3D_CANVAS) | |
Settings* settings = document()->settings(); | |
if (settings && settings->webGLEnabled() && settings->acceleratedCompositingEnabled()) { | |
// Accept the legacy "webkit-3d" name as well as the provisional "experimental-webgl" name. | |
// Once ratified, we will also accept "webgl" as the context name. | |
if ((type == "webkit-3d") || | |
(type == "experimental-webgl")) { | |
if (m_context && !m_context->is3d()) | |
return 0; | |
if (!m_context) { | |
m_context = WebGLRenderingContext::create(this, static_cast<WebGLContextAttributes*>(attrs)); | |
if (m_context) { | |
// Need to make sure a RenderLayer and compositing layer get created for the Canvas | |
setNeedsStyleRecalc(SyntheticStyleChange); | |
} | |
} | |
return m_context.get(); | |
} | |
} | |
#else | |
UNUSED_PARAM(attrs); | |
#endif | |
return 0; | |
} | |
void HTMLCanvasElement::willDraw(const FloatRect& rect) | |
{ | |
if (m_imageBuffer) | |
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); | |
#if ENABLE(3D_CANVAS) | |
if (m_context && m_context->is3d()) | |
static_cast<WebGLRenderingContext*>(m_context.get())->reshape(width(), height()); | |
#endif | |
bool hadImageBuffer = m_createdImageBuffer; | |
m_createdImageBuffer = false; | |
m_imageBuffer.clear(); | |
if (m_context && m_context->is2d()) | |
static_cast<CanvasRenderingContext2D*>(m_context.get())->reset(); | |
if (RenderObject* renderer = this->renderer()) { | |
if (m_rendererIsCanvas) { | |
if (oldSize != m_size) | |
toRenderHTMLCanvas(renderer)->canvasSizeChanged(); | |
if (hadImageBuffer) | |
renderer->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 ENABLE(3D_CANVAS) | |
WebGLRenderingContext* context3D = 0; | |
if (m_context && m_context->is3d()) { | |
context3D = static_cast<WebGLRenderingContext*>(m_context.get()); | |
context3D->beginPaint(); | |
} | |
#endif | |
if (m_imageBuffer) { | |
Image* image = m_imageBuffer->image(); | |
if (image) | |
context->drawImage(image, DeviceColorSpace, r); | |
} | |
#if ENABLE(3D_CANVAS) | |
if (context3D) | |
context3D->endPaint(); | |
#endif | |
} | |
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); | |
// 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(); | |
} | |
AffineTransform HTMLCanvasElement::baseTransform() const | |
{ | |
ASSERT(m_createdImageBuffer); | |
FloatSize unscaledSize(width(), height()); | |
IntSize size = convertLogicalToDevice(unscaledSize); | |
AffineTransform transform; | |
if (size.width() && size.height()) | |
transform.scaleNonUniform(size.width() / unscaledSize.width(), size.height() / unscaledSize.height()); | |
transform.multiply(m_imageBuffer->baseTransform()); | |
return transform; | |
} | |
#if ENABLE(3D_CANVAS) | |
bool HTMLCanvasElement::is3D() const | |
{ | |
return m_context && m_context->is3d(); | |
} | |
#endif | |
} |