HTMLCanvasElement.cpp [plain text]
#include "config.h"
#include "HTMLCanvasElement.h"
#include "CanvasGradient.h"
#include "CanvasPattern.h"
#include "CanvasRenderingContext2D.h"
#include "CanvasStyle.h"
#include "Document.h"
#include "FrameView.h"
#include "GraphicsContext.h"
#include "HTMLNames.h"
#include "RenderHTMLCanvas.h"
#include <math.h>
namespace WebCore {
using namespace HTMLNames;
const int defaultWidth = 300;
const int defaultHeight = 150;
HTMLCanvasElement::HTMLCanvasElement(Document* doc)
: HTMLElement(canvasTag, doc)
, m_size(defaultWidth, defaultHeight)
, m_createdDrawingContext(false)
, m_data(0)
, m_drawingContext(0)
{
}
HTMLCanvasElement::~HTMLCanvasElement()
{
if (m_2DContext)
m_2DContext->detachCanvas();
fastFree(m_data);
delete m_drawingContext;
}
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)
{
RenderHTMLCanvas* r = new (arena) RenderHTMLCanvas(this);
r->setIntrinsicWidth(width());
r->setIntrinsicHeight(height());
return r;
}
void HTMLCanvasElement::setHeight(int value)
{
setAttribute(heightAttr, String::number(value));
}
void HTMLCanvasElement::setWidth(int value)
{
setAttribute(widthAttr, String::number(value));
}
CanvasRenderingContext* HTMLCanvasElement::getContext(const String& type)
{
if (type == "2d") {
if (!m_2DContext)
m_2DContext = new CanvasRenderingContext2D(this);
return m_2DContext.get();
}
return 0;
}
void HTMLCanvasElement::willDraw(const FloatRect&)
{
if (renderer())
renderer()->repaint();
}
void HTMLCanvasElement::reset()
{
bool ok;
int w = getAttribute(widthAttr).toInt(&ok);
if (!ok)
w = defaultWidth;
int h = getAttribute(heightAttr).toInt(&ok);
if (!ok)
h = defaultHeight;
m_size = IntSize(w, h);
RenderHTMLCanvas* r = static_cast<RenderHTMLCanvas*>(renderer());
if (r) {
r->setIntrinsicWidth(w);
r->setIntrinsicHeight(h);
r->repaint();
}
m_createdDrawingContext = false;
fastFree(m_data);
m_data = 0;
delete m_drawingContext;
m_drawingContext = 0;
}
void HTMLCanvasElement::paint(GraphicsContext* p, const IntRect& r)
{
if (p->paintingDisabled())
return;
#if __APPLE__
if (CGImageRef image = createPlatformImage()) {
CGContextDrawImage(p->platformContext(), p->roundToDevicePixels(r), image);
CGImageRelease(image);
}
#endif
}
void HTMLCanvasElement::createDrawingContext() const
{
ASSERT(!m_createdDrawingContext);
ASSERT(!m_data);
m_createdDrawingContext = true;
float unscaledWidth = width();
float unscaledHeight = height();
float scaleFactor = document()->view() ? document()->view()->scaleFactor() : 1.0f;
float wf = ceilf(unscaledWidth * scaleFactor);
float hf = ceilf(unscaledHeight * scaleFactor);
if (!(wf > 0 && wf < UINT_MAX && hf > 0 && hf < UINT_MAX))
return;
unsigned w = static_cast<unsigned>(wf);
unsigned h = static_cast<unsigned>(hf);
size_t bytesPerRow = w * 4;
if (bytesPerRow / 4 != w) return;
m_data = fastCalloc(h, bytesPerRow);
if (!m_data)
return;
#if __APPLE__
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef bitmapContext = CGBitmapContextCreate(m_data, w, h, 8, bytesPerRow, colorSpace, kCGImageAlphaPremultipliedLast);
CGContextScaleCTM(bitmapContext, w / unscaledWidth, h / unscaledHeight);
CGColorSpaceRelease(colorSpace);
m_drawingContext = new GraphicsContext(bitmapContext);
CGContextRelease(bitmapContext);
#endif
}
GraphicsContext* HTMLCanvasElement::drawingContext() const
{
if (!m_createdDrawingContext)
createDrawingContext();
return m_drawingContext;
}
#if __APPLE__
CGImageRef HTMLCanvasElement::createPlatformImage() const
{
GraphicsContext* context = drawingContext();
if (!context)
return 0;
CGContextFlush(context->platformContext());
return CGBitmapContextCreateImage(context->platformContext());
}
#endif
}