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/*
* Copyright (C) 2010 Google Inc. All rights reserved.
* Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. 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 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 "CanvasSurface.h"
#include "AffineTransform.h"
#include "ExceptionCode.h"
#include "FloatRect.h"
#include "GraphicsContext.h"
#include "HTMLCanvasElement.h"
#include "ImageBuffer.h"
#include "MIMETypeRegistry.h"
namespace WebCore {
// These values come from the WhatWG spec.
const int CanvasSurface::DefaultWidth = 300;
const int CanvasSurface::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 CanvasSurface::MaxCanvasArea = 32768 * 8192; // Maximum canvas area in CSS pixels
CanvasSurface::CanvasSurface(float pageScaleFactor)
: m_size(DefaultWidth, DefaultHeight)
#if PLATFORM(ANDROID)
/* In Android we capture the drawing into a displayList, and then replay
* that list at various scale factors (sometimes zoomed out, other times
* zoomed in for "normal" reading, yet other times at arbitrary zoom values
* based on the user's choice). In all of these cases, we do not re-record
* the displayList, hence it is usually harmful to perform any pre-rounding,
* since we just don't know the actual drawing resolution at record time.
*/
// TODO - may be better to move the ifdef to the call site of this
// constructor
, m_pageScaleFactor(1.0f)
#else
, m_pageScaleFactor(pageScaleFactor)
#endif
, m_originClean(true)
, m_hasCreatedImageBuffer(false)
{
}
CanvasSurface::~CanvasSurface()
{
}
void CanvasSurface::setSurfaceSize(const IntSize& size)
{
m_size = size;
m_hasCreatedImageBuffer = false;
m_imageBuffer.clear();
}
String CanvasSurface::toDataURL(const String& mimeType, const double* quality, ExceptionCode& ec)
{
if (!m_originClean) {
ec = SECURITY_ERR;
return String();
}
if (m_size.isEmpty() || !buffer())
return String("data:,");
String lowercaseMimeType = mimeType.lower();
// FIXME: Make isSupportedImageMIMETypeForEncoding threadsafe (to allow this method to be used on a worker thread).
if (mimeType.isNull() || !MIMETypeRegistry::isSupportedImageMIMETypeForEncoding(lowercaseMimeType))
return buffer()->toDataURL("image/png");
return buffer()->toDataURL(lowercaseMimeType, quality);
}
void CanvasSurface::willDraw(const FloatRect&)
{
if (m_imageBuffer)
m_imageBuffer->clearImage();
}
IntRect CanvasSurface::convertLogicalToDevice(const FloatRect& logicalRect) const
{
return IntRect(convertLogicalToDevice(logicalRect.location()), convertLogicalToDevice(logicalRect.size()));
}
IntSize CanvasSurface::convertLogicalToDevice(const FloatSize& logicalSize) const
{
float wf = ceilf(logicalSize.width() * m_pageScaleFactor);
float hf = ceilf(logicalSize.height() * m_pageScaleFactor);
if (!(wf >= 1 && hf >= 1 && wf * hf <= MaxCanvasArea))
return IntSize();
return IntSize(static_cast<unsigned>(wf), static_cast<unsigned>(hf));
}
IntPoint CanvasSurface::convertLogicalToDevice(const FloatPoint& logicalPos) const
{
float xf = logicalPos.x() * m_pageScaleFactor;
float yf = logicalPos.y() * m_pageScaleFactor;
return IntPoint(static_cast<unsigned>(xf), static_cast<unsigned>(yf));
}
void CanvasSurface::createImageBuffer() const
{
ASSERT(!m_imageBuffer);
m_hasCreatedImageBuffer = 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 0, 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* CanvasSurface::drawingContext() const
{
return buffer() ? m_imageBuffer->context() : 0;
}
ImageBuffer* CanvasSurface::buffer() const
{
if (!m_hasCreatedImageBuffer)
createImageBuffer();
return m_imageBuffer.get();
}
AffineTransform CanvasSurface::baseTransform() const
{
ASSERT(m_hasCreatedImageBuffer);
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;
}
// FIXME: Everything below here relies on CanvasSurface really being
// a HTMLCanvasElement.
const SecurityOrigin& CanvasSurface::securityOrigin() const
{
return *(static_cast<const HTMLCanvasElement*>(this)->document()->securityOrigin());
}
RenderBox* CanvasSurface::renderBox() const
{
return static_cast<const HTMLCanvasElement*>(this)->renderBox();
}
RenderStyle* CanvasSurface::computedStyle()
{
return static_cast<HTMLCanvasElement*>(this)->computedStyle();
}
CSSStyleSelector* CanvasSurface::styleSelector()
{
return static_cast<HTMLCanvasElement*>(this)->document()->styleSelector();
}
} // namespace WebCore
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