Google Git
Sign in
android / platform / external / chromium_org / third_party / WebKit / 81c961c / . / Source / core / html / canvas / CanvasRenderingContext2D.cpp
blob: ccca4ddd03fc0da373af9092d78ca687cfec0e49 [file] [log] [blame]
/*
* Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
* Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
* Copyright (C) 2007 Alp Toker <alp@atoker.com>
* Copyright (C) 2008 Eric Seidel <eric@webkit.org>
* Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
* Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
* Copyright (C) 2012, 2013 Intel Corporation. All rights reserved.
* Copyright (C) 2013 Adobe Systems Incorporated. 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 "core/html/canvas/CanvasRenderingContext2D.h"
#include "bindings/v8/ExceptionMessages.h"
#include "bindings/v8/ExceptionState.h"
#include "bindings/v8/ExceptionStatePlaceholder.h"
#include "core/CSSPropertyNames.h"
#include "core/accessibility/AXObjectCache.h"
#include "core/css/CSSFontSelector.h"
#include "core/css/parser/BisonCSSParser.h"
#include "core/css/StylePropertySet.h"
#include "core/css/resolver/StyleResolver.h"
#include "core/dom/ExceptionCode.h"
#include "core/fetch/ImageResource.h"
#include "core/frame/ImageBitmap.h"
#include "core/html/HTMLCanvasElement.h"
#include "core/html/HTMLImageElement.h"
#include "core/html/HTMLMediaElement.h"
#include "core/html/HTMLVideoElement.h"
#include "core/html/ImageData.h"
#include "core/html/TextMetrics.h"
#include "core/html/canvas/CanvasGradient.h"
#include "core/html/canvas/CanvasPattern.h"
#include "core/html/canvas/CanvasStyle.h"
#include "core/html/canvas/Path2D.h"
#include "core/rendering/RenderImage.h"
#include "core/rendering/RenderLayer.h"
#include "core/rendering/RenderTheme.h"
#include "platform/fonts/FontCache.h"
#include "platform/geometry/FloatQuad.h"
#include "platform/graphics/DrawLooperBuilder.h"
#include "platform/graphics/GraphicsContextStateSaver.h"
#include "platform/text/TextRun.h"
#include "wtf/CheckedArithmetic.h"
#include "wtf/MathExtras.h"
#include "wtf/OwnPtr.h"
#include "wtf/Uint8ClampedArray.h"
#include "wtf/text/StringBuilder.h"
namespace WebCore {
static const int defaultFontSize = 10;
static const char defaultFontFamily[] = "sans-serif";
static const char defaultFont[] = "10px sans-serif";
static const double TryRestoreContextInterval = 0.5;
static const unsigned MaxTryRestoreContextAttempts = 4;
static bool contextLostRestoredEventsEnabled()
{
return RuntimeEnabledFeatures::experimentalCanvasFeaturesEnabled();
}
CanvasRenderingContext2D::CanvasRenderingContext2D(HTMLCanvasElement* canvas, const Canvas2DContextAttributes* attrs, bool usesCSSCompatibilityParseMode)
: CanvasRenderingContext(canvas)
, m_usesCSSCompatibilityParseMode(usesCSSCompatibilityParseMode)
, m_hasAlpha(!attrs || attrs->alpha())
, m_isContextLost(false)
, m_contextRestorable(true)
, m_storageMode(!attrs ? PersistentStorage : attrs->parsedStorage())
, m_tryRestoreContextAttemptCount(0)
, m_dispatchContextLostEventTimer(this, &CanvasRenderingContext2D::dispatchContextLostEvent)
, m_dispatchContextRestoredEventTimer(this, &CanvasRenderingContext2D::dispatchContextRestoredEvent)
, m_tryRestoreContextEventTimer(this, &CanvasRenderingContext2D::tryRestoreContextEvent)
{
m_stateStack.append(adoptPtrWillBeNoop(new State()));
ScriptWrappable::init(this);
}
void CanvasRenderingContext2D::unwindStateStack()
{
if (size_t stackSize = m_stateStack.size()) {
if (GraphicsContext* context = canvas()->existingDrawingContext()) {
while (--stackSize)
context->restore();
}
}
}
CanvasRenderingContext2D::~CanvasRenderingContext2D()
{
}
void CanvasRenderingContext2D::validateStateStack()
{
#if ASSERT_ENABLED
GraphicsContext* context = canvas()->existingDrawingContext();
if (context && !context->contextDisabled())
ASSERT(context->saveCount() == m_stateStack.size());
#endif
}
bool CanvasRenderingContext2D::isAccelerated() const
{
if (!canvas()->hasImageBuffer())
return false;
GraphicsContext* context = drawingContext();
return context && context->isAccelerated();
}
bool CanvasRenderingContext2D::isContextLost() const
{
return m_isContextLost;
}
void CanvasRenderingContext2D::loseContext()
{
if (m_isContextLost)
return;
m_isContextLost = true;
m_dispatchContextLostEventTimer.startOneShot(0, FROM_HERE);
}
void CanvasRenderingContext2D::restoreContext()
{
if (!m_contextRestorable)
return;
// This code path is for restoring from an eviction
// Restoring from surface failure is handled internally
ASSERT(m_isContextLost && !canvas()->hasImageBuffer());
if (canvas()->buffer()) {
if (contextLostRestoredEventsEnabled()) {
m_dispatchContextRestoredEventTimer.startOneShot(0, FROM_HERE);
} else {
// legacy synchronous context restoration.
reset();
m_isContextLost = false;
}
}
}
void CanvasRenderingContext2D::trace(Visitor* visitor)
{
#if ENABLE(OILPAN)
visitor->trace(m_stateStack);
visitor->trace(m_fetchedFonts);
#endif
CanvasRenderingContext::trace(visitor);
}
void CanvasRenderingContext2D::dispatchContextLostEvent(Timer<CanvasRenderingContext2D>*)
{
if (contextLostRestoredEventsEnabled()) {
RefPtrWillBeRawPtr<Event> event = Event::createCancelable(EventTypeNames::contextlost);
canvas()->dispatchEvent(event);
if (event->defaultPrevented()) {
m_contextRestorable = false;
}
}
// If an image buffer is present, it means the context was not lost due to
// an eviction, but rather due to a surface failure (gpu context lost?)
if (m_contextRestorable && canvas()->hasImageBuffer()) {
m_tryRestoreContextAttemptCount = 0;
m_tryRestoreContextEventTimer.startRepeating(TryRestoreContextInterval, FROM_HERE);
}
}
void CanvasRenderingContext2D::tryRestoreContextEvent(Timer<CanvasRenderingContext2D>* timer)
{
if (!m_isContextLost) {
// Canvas was already restored (possibly thanks to a resize), so stop trying.
m_tryRestoreContextEventTimer.stop();
return;
}
if (canvas()->hasImageBuffer() && canvas()->buffer()->restoreSurface()) {
m_tryRestoreContextEventTimer.stop();
dispatchContextRestoredEvent(0);
}
if (++m_tryRestoreContextAttemptCount > MaxTryRestoreContextAttempts)
canvas()->discardImageBuffer();
if (!canvas()->hasImageBuffer()) {
// final attempt: allocate a brand new image buffer instead of restoring
timer->stop();
if (canvas()->buffer())
dispatchContextRestoredEvent(0);
}
}
void CanvasRenderingContext2D::dispatchContextRestoredEvent(Timer<CanvasRenderingContext2D>*)
{
if (!m_isContextLost)
return;
reset();
m_isContextLost = false;
if (contextLostRestoredEventsEnabled()) {
RefPtrWillBeRawPtr<Event> event(Event::create(EventTypeNames::contextrestored));
canvas()->dispatchEvent(event);
}
}
void CanvasRenderingContext2D::reset()
{
validateStateStack();
unwindStateStack();
m_stateStack.resize(1);
m_stateStack.first() = adoptPtrWillBeNoop(new State());
m_path.clear();
validateStateStack();
}
// Important: Several of these properties are also stored in GraphicsContext's
// StrokeData. The default values that StrokeData uses may not the same values
// that the canvas 2d spec specifies. Make sure to sync the initial state of the
// GraphicsContext in HTMLCanvasElement::createImageBuffer()!
CanvasRenderingContext2D::State::State()
: m_unrealizedSaveCount(0)
, m_strokeStyle(CanvasStyle::createFromRGBA(Color::black))
, m_fillStyle(CanvasStyle::createFromRGBA(Color::black))
, m_lineWidth(1)
, m_lineCap(ButtCap)
, m_lineJoin(MiterJoin)
, m_miterLimit(10)
, m_shadowBlur(0)
, m_shadowColor(Color::transparent)
, m_globalAlpha(1)
, m_globalComposite(CompositeSourceOver)
, m_globalBlend(blink::WebBlendModeNormal)
, m_invertibleCTM(true)
, m_lineDashOffset(0)
, m_imageSmoothingEnabled(true)
, m_textAlign(StartTextAlign)
, m_textBaseline(AlphabeticTextBaseline)
, m_unparsedFont(defaultFont)
, m_realizedFont(false)
{
}
CanvasRenderingContext2D::State::State(const State& other)
: CSSFontSelectorClient()
, m_unrealizedSaveCount(other.m_unrealizedSaveCount)
, m_unparsedStrokeColor(other.m_unparsedStrokeColor)
, m_unparsedFillColor(other.m_unparsedFillColor)
, m_strokeStyle(other.m_strokeStyle)
, m_fillStyle(other.m_fillStyle)
, m_lineWidth(other.m_lineWidth)
, m_lineCap(other.m_lineCap)
, m_lineJoin(other.m_lineJoin)
, m_miterLimit(other.m_miterLimit)
, m_shadowOffset(other.m_shadowOffset)
, m_shadowBlur(other.m_shadowBlur)
, m_shadowColor(other.m_shadowColor)
, m_globalAlpha(other.m_globalAlpha)
, m_globalComposite(other.m_globalComposite)
, m_globalBlend(other.m_globalBlend)
, m_transform(other.m_transform)
, m_invertibleCTM(other.m_invertibleCTM)
, m_lineDashOffset(other.m_lineDashOffset)
, m_imageSmoothingEnabled(other.m_imageSmoothingEnabled)
, m_textAlign(other.m_textAlign)
, m_textBaseline(other.m_textBaseline)
, m_unparsedFont(other.m_unparsedFont)
, m_font(other.m_font)
, m_realizedFont(other.m_realizedFont)
{
if (m_realizedFont)
static_cast<CSSFontSelector*>(m_font.fontSelector())->registerForInvalidationCallbacks(this);
}
CanvasRenderingContext2D::State& CanvasRenderingContext2D::State::operator=(const State& other)
{
if (this == &other)
return *this;
#if !ENABLE(OILPAN)
if (m_realizedFont)
static_cast<CSSFontSelector*>(m_font.fontSelector())->unregisterForInvalidationCallbacks(this);
#endif
m_unrealizedSaveCount = other.m_unrealizedSaveCount;
m_unparsedStrokeColor = other.m_unparsedStrokeColor;
m_unparsedFillColor = other.m_unparsedFillColor;
m_strokeStyle = other.m_strokeStyle;
m_fillStyle = other.m_fillStyle;
m_lineWidth = other.m_lineWidth;
m_lineCap = other.m_lineCap;
m_lineJoin = other.m_lineJoin;
m_miterLimit = other.m_miterLimit;
m_shadowOffset = other.m_shadowOffset;
m_shadowBlur = other.m_shadowBlur;
m_shadowColor = other.m_shadowColor;
m_globalAlpha = other.m_globalAlpha;
m_globalComposite = other.m_globalComposite;
m_globalBlend = other.m_globalBlend;
m_transform = other.m_transform;
m_invertibleCTM = other.m_invertibleCTM;
m_imageSmoothingEnabled = other.m_imageSmoothingEnabled;
m_textAlign = other.m_textAlign;
m_textBaseline = other.m_textBaseline;
m_unparsedFont = other.m_unparsedFont;
m_font = other.m_font;
m_realizedFont = other.m_realizedFont;
if (m_realizedFont)
static_cast<CSSFontSelector*>(m_font.fontSelector())->registerForInvalidationCallbacks(this);
return *this;
}
CanvasRenderingContext2D::State::~State()
{
#if !ENABLE(OILPAN)
if (m_realizedFont)
static_cast<CSSFontSelector*>(m_font.fontSelector())->unregisterForInvalidationCallbacks(this);
#endif
}
void CanvasRenderingContext2D::State::fontsNeedUpdate(CSSFontSelector* fontSelector)
{
ASSERT_ARG(fontSelector, fontSelector == m_font.fontSelector());
ASSERT(m_realizedFont);
m_font.update(fontSelector);
}
void CanvasRenderingContext2D::realizeSaves()
{
validateStateStack();
if (state().m_unrealizedSaveCount) {
ASSERT(m_stateStack.size() >= 1);
// Reduce the current state's unrealized count by one now,
// to reflect the fact we are saving one state.
m_stateStack.last()->m_unrealizedSaveCount--;
m_stateStack.append(adoptPtrWillBeNoop(new State(state())));
// Set the new state's unrealized count to 0, because it has no outstanding saves.
// We need to do this explicitly because the copy constructor and operator= used
// by the Vector operations copy the unrealized count from the previous state (in
// turn necessary to support correct resizing and unwinding of the stack).
m_stateStack.last()->m_unrealizedSaveCount = 0;
GraphicsContext* context = drawingContext();
if (context)
context->save();
validateStateStack();
}
}
void CanvasRenderingContext2D::restore()
{
validateStateStack();
if (state().m_unrealizedSaveCount) {
// We never realized the save, so just record that it was unnecessary.
--m_stateStack.last()->m_unrealizedSaveCount;
return;
}
ASSERT(m_stateStack.size() >= 1);
if (m_stateStack.size() <= 1)
return;
m_path.transform(state().m_transform);
m_stateStack.removeLast();
m_path.transform(state().m_transform.inverse());
GraphicsContext* c = drawingContext();
if (c)
c->restore();
validateStateStack();
}
CanvasStyle* CanvasRenderingContext2D::strokeStyle() const
{
return state().m_strokeStyle.get();
}
void CanvasRenderingContext2D::setStrokeStyle(PassRefPtr<CanvasStyle> prpStyle)
{
RefPtr<CanvasStyle> style = prpStyle;
if (!style)
return;
if (state().m_strokeStyle && state().m_strokeStyle->isEquivalentColor(*style))
return;
if (style->isCurrentColor()) {
if (style->hasOverrideAlpha())
style = CanvasStyle::createFromRGBA(colorWithOverrideAlpha(currentColor(canvas()), style->overrideAlpha()));
else
style = CanvasStyle::createFromRGBA(currentColor(canvas()));
} else if (canvas()->originClean() && style->canvasPattern() && !style->canvasPattern()->originClean()) {
canvas()->setOriginTainted();
}
realizeSaves();
modifiableState().m_strokeStyle = style.release();
GraphicsContext* c = drawingContext();
if (!c)
return;
state().m_strokeStyle->applyStrokeColor(c);
modifiableState().m_unparsedStrokeColor = String();
}
CanvasStyle* CanvasRenderingContext2D::fillStyle() const
{
return state().m_fillStyle.get();
}
void CanvasRenderingContext2D::setFillStyle(PassRefPtr<CanvasStyle> prpStyle)
{
RefPtr<CanvasStyle> style = prpStyle;
if (!style)
return;
if (state().m_fillStyle && state().m_fillStyle->isEquivalentColor(*style))
return;
if (style->isCurrentColor()) {
if (style->hasOverrideAlpha())
style = CanvasStyle::createFromRGBA(colorWithOverrideAlpha(currentColor(canvas()), style->overrideAlpha()));
else
style = CanvasStyle::createFromRGBA(currentColor(canvas()));
} else if (canvas()->originClean() && style->canvasPattern() && !style->canvasPattern()->originClean()) {
canvas()->setOriginTainted();
}
realizeSaves();
modifiableState().m_fillStyle = style.release();
GraphicsContext* c = drawingContext();
if (!c)
return;
state().m_fillStyle->applyFillColor(c);
modifiableState().m_unparsedFillColor = String();
}
float CanvasRenderingContext2D::lineWidth() const
{
return state().m_lineWidth;
}
void CanvasRenderingContext2D::setLineWidth(float width)
{
if (!(std::isfinite(width) && width > 0))
return;
if (state().m_lineWidth == width)
return;
realizeSaves();
modifiableState().m_lineWidth = width;
GraphicsContext* c = drawingContext();
if (!c)
return;
c->setStrokeThickness(width);
}
String CanvasRenderingContext2D::lineCap() const
{
return lineCapName(state().m_lineCap);
}
void CanvasRenderingContext2D::setLineCap(const String& s)
{
LineCap cap;
if (!parseLineCap(s, cap))
return;
if (state().m_lineCap == cap)
return;
realizeSaves();
modifiableState().m_lineCap = cap;
GraphicsContext* c = drawingContext();
if (!c)
return;
c->setLineCap(cap);
}
String CanvasRenderingContext2D::lineJoin() const
{
return lineJoinName(state().m_lineJoin);
}
void CanvasRenderingContext2D::setLineJoin(const String& s)
{
LineJoin join;
if (!parseLineJoin(s, join))
return;
if (state().m_lineJoin == join)
return;
realizeSaves();
modifiableState().m_lineJoin = join;
GraphicsContext* c = drawingContext();
if (!c)
return;
c->setLineJoin(join);
}
float CanvasRenderingContext2D::miterLimit() const
{
return state().m_miterLimit;
}
void CanvasRenderingContext2D::setMiterLimit(float limit)
{
if (!(std::isfinite(limit) && limit > 0))
return;
if (state().m_miterLimit == limit)
return;
realizeSaves();
modifiableState().m_miterLimit = limit;
GraphicsContext* c = drawingContext();
if (!c)
return;
c->setMiterLimit(limit);
}
float CanvasRenderingContext2D::shadowOffsetX() const
{
return state().m_shadowOffset.width();
}
void CanvasRenderingContext2D::setShadowOffsetX(float x)
{
if (!std::isfinite(x))
return;
if (state().m_shadowOffset.width() == x)
return;
realizeSaves();
modifiableState().m_shadowOffset.setWidth(x);
applyShadow();
}
float CanvasRenderingContext2D::shadowOffsetY() const
{
return state().m_shadowOffset.height();
}
void CanvasRenderingContext2D::setShadowOffsetY(float y)
{
if (!std::isfinite(y))
return;
if (state().m_shadowOffset.height() == y)
return;
realizeSaves();
modifiableState().m_shadowOffset.setHeight(y);
applyShadow();
}
float CanvasRenderingContext2D::shadowBlur() const
{
return state().m_shadowBlur;
}
void CanvasRenderingContext2D::setShadowBlur(float blur)
{
if (!(std::isfinite(blur) && blur >= 0))
return;
if (state().m_shadowBlur == blur)
return;
realizeSaves();
modifiableState().m_shadowBlur = blur;
applyShadow();
}
String CanvasRenderingContext2D::shadowColor() const
{
return Color(state().m_shadowColor).serialized();
}
void CanvasRenderingContext2D::setShadowColor(const String& color)
{
RGBA32 rgba;
if (!parseColorOrCurrentColor(rgba, color, canvas()))
return;
if (state().m_shadowColor == rgba)
return;
realizeSaves();
modifiableState().m_shadowColor = rgba;
applyShadow();
}
const Vector<float>& CanvasRenderingContext2D::getLineDash() const
{
return state().m_lineDash;
}
static bool lineDashSequenceIsValid(const Vector<float>& dash)
{
for (size_t i = 0; i < dash.size(); i++) {
if (!std::isfinite(dash[i]) || dash[i] < 0)
return false;
}
return true;
}
void CanvasRenderingContext2D::setLineDash(const Vector<float>& dash)
{
if (!lineDashSequenceIsValid(dash))
return;
realizeSaves();
modifiableState().m_lineDash = dash;
// Spec requires the concatenation of two copies the dash list when the
// number of elements is odd
if (dash.size() % 2)
modifiableState().m_lineDash.appendVector(dash);
applyLineDash();
}
float CanvasRenderingContext2D::lineDashOffset() const
{
return state().m_lineDashOffset;
}
void CanvasRenderingContext2D::setLineDashOffset(float offset)
{
if (!std::isfinite(offset) || state().m_lineDashOffset == offset)
return;
realizeSaves();
modifiableState().m_lineDashOffset = offset;
applyLineDash();
}
void CanvasRenderingContext2D::applyLineDash() const
{
GraphicsContext* c = drawingContext();
if (!c)
return;
DashArray convertedLineDash(state().m_lineDash.size());
for (size_t i = 0; i < state().m_lineDash.size(); ++i)
convertedLineDash[i] = static_cast<DashArrayElement>(state().m_lineDash[i]);
c->setLineDash(convertedLineDash, state().m_lineDashOffset);
}
float CanvasRenderingContext2D::globalAlpha() const
{
return state().m_globalAlpha;
}
void CanvasRenderingContext2D::setGlobalAlpha(float alpha)
{
if (!(alpha >= 0 && alpha <= 1))
return;
if (state().m_globalAlpha == alpha)
return;
realizeSaves();
modifiableState().m_globalAlpha = alpha;
GraphicsContext* c = drawingContext();
if (!c)
return;
c->setAlphaAsFloat(alpha);
}
String CanvasRenderingContext2D::globalCompositeOperation() const
{
return compositeOperatorName(state().m_globalComposite, state().m_globalBlend);
}
void CanvasRenderingContext2D::setGlobalCompositeOperation(const String& operation)
{
CompositeOperator op = CompositeSourceOver;
blink::WebBlendMode blendMode = blink::WebBlendModeNormal;
if (!parseCompositeAndBlendOperator(operation, op, blendMode))
return;
if ((state().m_globalComposite == op) && (state().m_globalBlend == blendMode))
return;
realizeSaves();
modifiableState().m_globalComposite = op;
modifiableState().m_globalBlend = blendMode;
GraphicsContext* c = drawingContext();
if (!c)
return;
c->setCompositeOperation(op, blendMode);
}
void CanvasRenderingContext2D::setCurrentTransform(PassRefPtr<SVGMatrixTearOff> passMatrixTearOff)
{
RefPtr<SVGMatrixTearOff> matrixTearOff = passMatrixTearOff;
const AffineTransform& transform = matrixTearOff->value();
setTransform(transform.a(), transform.b(), transform.c(), transform.d(), transform.e(), transform.f());
}
void CanvasRenderingContext2D::scale(float sx, float sy)
{
GraphicsContext* c = drawingContext();
if (!c)
return;
if (!state().m_invertibleCTM)
return;
if (!std::isfinite(sx) | !std::isfinite(sy))
return;
AffineTransform newTransform = state().m_transform;
newTransform.scaleNonUniform(sx, sy);
if (state().m_transform == newTransform)
return;
realizeSaves();
if (!newTransform.isInvertible()) {
modifiableState().m_invertibleCTM = false;
return;
}
modifiableState().m_transform = newTransform;
c->scale(sx, sy);
m_path.transform(AffineTransform().scaleNonUniform(1.0 / sx, 1.0 / sy));
}
void CanvasRenderingContext2D::rotate(float angleInRadians)
{
GraphicsContext* c = drawingContext();
if (!c)
return;
if (!state().m_invertibleCTM)
return;
if (!std::isfinite(angleInRadians))
return;
AffineTransform newTransform = state().m_transform;
newTransform.rotateRadians(angleInRadians);
if (state().m_transform == newTransform)
return;
realizeSaves();
if (!newTransform.isInvertible()) {
modifiableState().m_invertibleCTM = false;
return;
}
modifiableState().m_transform = newTransform;
c->rotate(angleInRadians);
m_path.transform(AffineTransform().rotateRadians(-angleInRadians));
}
void CanvasRenderingContext2D::translate(float tx, float ty)
{
GraphicsContext* c = drawingContext();
if (!c)
return;
if (!state().m_invertibleCTM)
return;
if (!std::isfinite(tx) | !std::isfinite(ty))
return;
AffineTransform newTransform = state().m_transform;
newTransform.translate(tx, ty);
if (state().m_transform == newTransform)
return;
realizeSaves();
if (!newTransform.isInvertible()) {
modifiableState().m_invertibleCTM = false;
return;
}
modifiableState().m_transform = newTransform;
c->translate(tx, ty);
m_path.transform(AffineTransform().translate(-tx, -ty));
}
void CanvasRenderingContext2D::transform(float m11, float m12, float m21, float m22, float dx, float dy)
{
GraphicsContext* c = drawingContext();
if (!c)
return;
if (!state().m_invertibleCTM)
return;
if (!std::isfinite(m11) | !std::isfinite(m21) | !std::isfinite(dx) | !std::isfinite(m12) | !std::isfinite(m22) | !std::isfinite(dy))
return;
AffineTransform transform(m11, m12, m21, m22, dx, dy);
AffineTransform newTransform = state().m_transform * transform;
if (state().m_transform == newTransform)
return;
realizeSaves();
modifiableState().m_transform = newTransform;
if (!newTransform.isInvertible()) {
modifiableState().m_invertibleCTM = false;
return;
}
c->concatCTM(transform);
m_path.transform(transform.inverse());
}
void CanvasRenderingContext2D::resetTransform()
{
GraphicsContext* c = drawingContext();
if (!c)
return;
AffineTransform ctm = state().m_transform;
bool invertibleCTM = state().m_invertibleCTM;
// It is possible that CTM is identity while CTM is not invertible.
// When CTM becomes non-invertible, realizeSaves() can make CTM identity.
if (ctm.isIdentity() && invertibleCTM)
return;
realizeSaves();
// resetTransform() resolves the non-invertible CTM state.
modifiableState().m_transform.makeIdentity();
modifiableState().m_invertibleCTM = true;
c->setCTM(canvas()->baseTransform());
if (invertibleCTM)
m_path.transform(ctm);
// When else, do nothing because all transform methods didn't update m_path when CTM became non-invertible.
// It means that resetTransform() restores m_path just before CTM became non-invertible.
}
void CanvasRenderingContext2D::setTransform(float m11, float m12, float m21, float m22, float dx, float dy)
{
GraphicsContext* c = drawingContext();
if (!c)
return;
if (!std::isfinite(m11) | !std::isfinite(m21) | !std::isfinite(dx) | !std::isfinite(m12) | !std::isfinite(m22) | !std::isfinite(dy))
return;
resetTransform();
transform(m11, m12, m21, m22, dx, dy);
}
void CanvasRenderingContext2D::setStrokeColor(const String& color)
{
if (color == state().m_unparsedStrokeColor)
return;
realizeSaves();
setStrokeStyle(CanvasStyle::createFromString(color));
modifiableState().m_unparsedStrokeColor = color;
}
void CanvasRenderingContext2D::setStrokeColor(float grayLevel)
{
if (state().m_strokeStyle && state().m_strokeStyle->isEquivalentRGBA(grayLevel, grayLevel, grayLevel, 1.0f))
return;
setStrokeStyle(CanvasStyle::createFromGrayLevelWithAlpha(grayLevel, 1.0f));
}
void CanvasRenderingContext2D::setStrokeColor(const String& color, float alpha)
{
setStrokeStyle(CanvasStyle::createFromStringWithOverrideAlpha(color, alpha));
}
void CanvasRenderingContext2D::setStrokeColor(float grayLevel, float alpha)
{
if (state().m_strokeStyle && state().m_strokeStyle->isEquivalentRGBA(grayLevel, grayLevel, grayLevel, alpha))
return;
setStrokeStyle(CanvasStyle::createFromGrayLevelWithAlpha(grayLevel, alpha));
}
void CanvasRenderingContext2D::setStrokeColor(float r, float g, float b, float a)
{
if (state().m_strokeStyle && state().m_strokeStyle->isEquivalentRGBA(r, g, b, a))
return;
setStrokeStyle(CanvasStyle::createFromRGBAChannels(r, g, b, a));
}
void CanvasRenderingContext2D::setStrokeColor(float c, float m, float y, float k, float a)
{
if (state().m_strokeStyle && state().m_strokeStyle->isEquivalentCMYKA(c, m, y, k, a))
return;
setStrokeStyle(CanvasStyle::createFromCMYKAChannels(c, m, y, k, a));
}
void CanvasRenderingContext2D::setFillColor(const String& color)
{
if (color == state().m_unparsedFillColor)
return;
realizeSaves();
setFillStyle(CanvasStyle::createFromString(color));
modifiableState().m_unparsedFillColor = color;
}
void CanvasRenderingContext2D::setFillColor(float grayLevel)
{
if (state().m_fillStyle && state().m_fillStyle->isEquivalentRGBA(grayLevel, grayLevel, grayLevel, 1.0f))
return;
setFillStyle(CanvasStyle::createFromGrayLevelWithAlpha(grayLevel, 1.0f));
}
void CanvasRenderingContext2D::setFillColor(const String& color, float alpha)
{
setFillStyle(CanvasStyle::createFromStringWithOverrideAlpha(color, alpha));
}
void CanvasRenderingContext2D::setFillColor(float grayLevel, float alpha)
{
if (state().m_fillStyle && state().m_fillStyle->isEquivalentRGBA(grayLevel, grayLevel, grayLevel, alpha))
return;
setFillStyle(CanvasStyle::createFromGrayLevelWithAlpha(grayLevel, alpha));
}
void CanvasRenderingContext2D::setFillColor(float r, float g, float b, float a)
{
if (state().m_fillStyle && state().m_fillStyle->isEquivalentRGBA(r, g, b, a))
return;
setFillStyle(CanvasStyle::createFromRGBAChannels(r, g, b, a));
}
void CanvasRenderingContext2D::setFillColor(float c, float m, float y, float k, float a)
{
if (state().m_fillStyle && state().m_fillStyle->isEquivalentCMYKA(c, m, y, k, a))
return;
setFillStyle(CanvasStyle::createFromCMYKAChannels(c, m, y, k, a));
}
void CanvasRenderingContext2D::beginPath()
{
m_path.clear();
}
static bool validateRectForCanvas(float& x, float& y, float& width, float& height)
{
if (!std::isfinite(x) | !std::isfinite(y) | !std::isfinite(width) | !std::isfinite(height))
return false;
if (!width && !height)
return false;
if (width < 0) {
width = -width;
x -= width;
}
if (height < 0) {
height = -height;
y -= height;
}
return true;
}
static bool isFullCanvasCompositeMode(CompositeOperator op)
{
// See 4.8.11.1.3 Compositing
// CompositeSourceAtop and CompositeDestinationOut are not listed here as the platforms already
// implement the specification's behavior.
return op == CompositeSourceIn || op == CompositeSourceOut || op == CompositeDestinationIn || op == CompositeDestinationAtop;
}
static WindRule parseWinding(const String& windingRuleString)
{
if (windingRuleString == "nonzero")
return RULE_NONZERO;
if (windingRuleString == "evenodd")
return RULE_EVENODD;
ASSERT_NOT_REACHED();
return RULE_EVENODD;
}
void CanvasRenderingContext2D::fillInternal(const Path& path, const String& windingRuleString)
{
if (path.isEmpty()) {
return;
}
GraphicsContext* c = drawingContext();
if (!c) {
return;
}
if (!state().m_invertibleCTM) {
return;
}
FloatRect clipBounds;
if (!c->getTransformedClipBounds(&clipBounds)) {
return;
}
// If gradient size is zero, then paint nothing.
Gradient* gradient = c->fillGradient();
if (gradient && gradient->isZeroSize()) {
return;
}
WindRule windRule = c->fillRule();
c->setFillRule(parseWinding(windingRuleString));
if (isFullCanvasCompositeMode(state().m_globalComposite)) {
fullCanvasCompositedFill(path);
didDraw(clipBounds);
} else if (state().m_globalComposite == CompositeCopy) {
clearCanvas();
c->fillPath(path);
didDraw(clipBounds);
} else {
FloatRect dirtyRect;
if (computeDirtyRect(path.boundingRect(), clipBounds, &dirtyRect)) {
c->fillPath(path);
didDraw(dirtyRect);
}
}
c->setFillRule(windRule);
}
void CanvasRenderingContext2D::fill(const String& windingRuleString)
{
fillInternal(m_path, windingRuleString);
}
void CanvasRenderingContext2D::fill(Path2D* domPath, const String& windingRuleString)
{
fillInternal(domPath->path(), windingRuleString);
}
void CanvasRenderingContext2D::strokeInternal(const Path& path)
{
if (path.isEmpty()) {
return;
}
GraphicsContext* c = drawingContext();
if (!c) {
return;
}
if (!state().m_invertibleCTM) {
return;
}
FloatRect clipBounds;
if (!c->getTransformedClipBounds(&clipBounds))
return;
// If gradient size is zero, then paint nothing.
Gradient* gradient = c->strokeGradient();
if (gradient && gradient->isZeroSize()) {
return;
}
if (isFullCanvasCompositeMode(state().m_globalComposite)) {
fullCanvasCompositedStroke(path);
didDraw(clipBounds);
} else if (state().m_globalComposite == CompositeCopy) {
clearCanvas();
c->strokePath(path);
didDraw(clipBounds);
} else {
FloatRect bounds = path.boundingRect();
inflateStrokeRect(bounds);
FloatRect dirtyRect;
if (computeDirtyRect(bounds, clipBounds, &dirtyRect)) {
c->strokePath(path);
didDraw(dirtyRect);
}
}
}
void CanvasRenderingContext2D::stroke()
{
strokeInternal(m_path);
}
void CanvasRenderingContext2D::stroke(Path2D* domPath)
{
strokeInternal(domPath->path());
}
void CanvasRenderingContext2D::clipInternal(const Path& path, const String& windingRuleString)
{
GraphicsContext* c = drawingContext();
if (!c) {
return;
}
if (!state().m_invertibleCTM) {
return;
}
realizeSaves();
c->canvasClip(path, parseWinding(windingRuleString));
}
void CanvasRenderingContext2D::clip(const String& windingRuleString)
{
clipInternal(m_path, windingRuleString);
}
void CanvasRenderingContext2D::clip(Path2D* domPath, const String& windingRuleString)
{
clipInternal(domPath->path(), windingRuleString);
}
bool CanvasRenderingContext2D::isPointInPath(const float x, const float y, const String& windingRuleString)
{
return isPointInPathInternal(m_path, x, y, windingRuleString);
}
bool CanvasRenderingContext2D::isPointInPath(Path2D* domPath, const float x, const float y, const String& windingRuleString)
{
return isPointInPathInternal(domPath->path(), x, y, windingRuleString);
}
bool CanvasRenderingContext2D::isPointInPathInternal(const Path& path, const float x, const float y, const String& windingRuleString)
{
GraphicsContext* c = drawingContext();
if (!c)
return false;
if (!state().m_invertibleCTM)
return false;
FloatPoint point(x, y);
AffineTransform ctm = state().m_transform;
FloatPoint transformedPoint = ctm.inverse().mapPoint(point);
if (!std::isfinite(transformedPoint.x()) || !std::isfinite(transformedPoint.y()))
return false;
return path.contains(transformedPoint, parseWinding(windingRuleString));
}
bool CanvasRenderingContext2D::isPointInStroke(const float x, const float y)
{
return isPointInStrokeInternal(m_path, x, y);
}
bool CanvasRenderingContext2D::isPointInStroke(Path2D* domPath, const float x, const float y)
{
return isPointInStrokeInternal(domPath->path(), x, y);
}
bool CanvasRenderingContext2D::isPointInStrokeInternal(const Path& path, const float x, const float y)
{
GraphicsContext* c = drawingContext();
if (!c)
return false;
if (!state().m_invertibleCTM)
return false;
FloatPoint point(x, y);
AffineTransform ctm = state().m_transform;
FloatPoint transformedPoint = ctm.inverse().mapPoint(point);
if (!std::isfinite(transformedPoint.x()) || !std::isfinite(transformedPoint.y()))
return false;
StrokeData strokeData;
strokeData.setThickness(lineWidth());
strokeData.setLineCap(getLineCap());
strokeData.setLineJoin(getLineJoin());
strokeData.setMiterLimit(miterLimit());
strokeData.setLineDash(getLineDash(), lineDashOffset());
return path.strokeContains(transformedPoint, strokeData);
}
void CanvasRenderingContext2D::scrollPathIntoView()
{
scrollPathIntoViewInternal(m_path);
}
void CanvasRenderingContext2D::scrollPathIntoView(Path2D* path2d)
{
scrollPathIntoViewInternal(path2d->path());
}
void CanvasRenderingContext2D::scrollPathIntoViewInternal(const Path& path)
{
if (!state().m_invertibleCTM || path.isEmpty())
return;
canvas()->document().updateLayoutIgnorePendingStylesheets();
// Apply transformation and get the bounding rect
Path transformedPath = path;
transformedPath.transform(state().m_transform);
FloatRect boundingRect = transformedPath.boundingRect();
// Offset by the canvas rect (We should take border and padding into account).
RenderBoxModelObject* rbmo = canvas()->renderBoxModelObject();
IntRect canvasRect = canvas()->renderer()->absoluteBoundingBoxRect();
canvasRect.move(rbmo->borderLeft() + rbmo->paddingLeft(),
rbmo->borderTop() + rbmo->paddingTop());
LayoutRect pathRect = enclosingLayoutRect(boundingRect);
pathRect.moveBy(canvasRect.location());
if (canvas()->renderer()) {
canvas()->renderer()->scrollRectToVisible(
pathRect, ScrollAlignment::alignCenterAlways, ScrollAlignment::alignTopAlways);
}
// TODO: should implement "inform the user" that the caret and/or
// selection the specified rectangle of the canvas. See http://crbug.com/357987
}
void CanvasRenderingContext2D::clearRect(float x, float y, float width, float height)
{
if (!validateRectForCanvas(x, y, width, height))
return;
GraphicsContext* context = drawingContext();
if (!context)
return;
if (!state().m_invertibleCTM)
return;
FloatRect rect(x, y, width, height);
FloatRect dirtyRect;
if (!computeDirtyRect(rect, &dirtyRect))
return;
bool saved = false;
if (shouldDrawShadows()) {
context->save();
saved = true;
context->clearShadow();
}
if (state().m_globalAlpha != 1) {
if (!saved) {
context->save();
saved = true;
}
context->setAlphaAsFloat(1);
}
if (state().m_globalComposite != CompositeSourceOver) {
if (!saved) {
context->save();
saved = true;
}
context->setCompositeOperation(CompositeSourceOver);
}
context->clearRect(rect);
if (saved)
context->restore();
validateStateStack();
didDraw(dirtyRect);
}
void CanvasRenderingContext2D::fillRect(float x, float y, float width, float height)
{
if (!validateRectForCanvas(x, y, width, height))
return;
GraphicsContext* c = drawingContext();
if (!c)
return;
if (!state().m_invertibleCTM)
return;
FloatRect clipBounds;
if (!c->getTransformedClipBounds(&clipBounds))
return;
// from the HTML5 Canvas spec:
// If x0 = x1 and y0 = y1, then the linear gradient must paint nothing
// If x0 = x1 and y0 = y1 and r0 = r1, then the radial gradient must paint nothing
Gradient* gradient = c->fillGradient();
if (gradient && gradient->isZeroSize())
return;
FloatRect rect(x, y, width, height);
if (rectContainsTransformedRect(rect, clipBounds)) {
c->fillRect(rect);
didDraw(clipBounds);
} else if (isFullCanvasCompositeMode(state().m_globalComposite)) {
fullCanvasCompositedFill(rect);
didDraw(clipBounds);
} else if (state().m_globalComposite == CompositeCopy) {
clearCanvas();
c->fillRect(rect);
didDraw(clipBounds);
} else {
FloatRect dirtyRect;
if (computeDirtyRect(rect, clipBounds, &dirtyRect)) {
c->fillRect(rect);
didDraw(dirtyRect);
}
}
}
void CanvasRenderingContext2D::strokeRect(float x, float y, float width, float height)
{
if (!validateRectForCanvas(x, y, width, height))
return;
if (!(state().m_lineWidth >= 0))
return;
GraphicsContext* c = drawingContext();
if (!c)
return;
if (!state().m_invertibleCTM)
return;
FloatRect clipBounds;
if (!c->getTransformedClipBounds(&clipBounds))
return;
// If gradient size is zero, then paint nothing.
Gradient* gradient = c->strokeGradient();
if (gradient && gradient->isZeroSize())
return;
FloatRect rect(x, y, width, height);
if (isFullCanvasCompositeMode(state().m_globalComposite)) {
fullCanvasCompositedStroke(rect);
didDraw(clipBounds);
} else if (state().m_globalComposite == CompositeCopy) {
clearCanvas();
c->strokeRect(rect);
didDraw(clipBounds);
} else {
FloatRect boundingRect = rect;
boundingRect.inflate(state().m_lineWidth / 2);
FloatRect dirtyRect;
if (computeDirtyRect(boundingRect, clipBounds, &dirtyRect)) {
c->strokeRect(rect);
didDraw(dirtyRect);
}
}
}
void CanvasRenderingContext2D::setShadow(float width, float height, float blur)
{
setShadow(FloatSize(width, height), blur, Color::transparent);
}
void CanvasRenderingContext2D::setShadow(float width, float height, float blur, const String& color)
{
RGBA32 rgba;
if (!parseColorOrCurrentColor(rgba, color, canvas()))
return;
setShadow(FloatSize(width, height), blur, rgba);
}
void CanvasRenderingContext2D::setShadow(float width, float height, float blur, float grayLevel)
{
setShadow(FloatSize(width, height), blur, makeRGBA32FromFloats(grayLevel, grayLevel, grayLevel, 1));
}
void CanvasRenderingContext2D::setShadow(float width, float height, float blur, const String& color, float alpha)
{
RGBA32 rgba;
if (!parseColorOrCurrentColor(rgba, color, canvas()))
return;
setShadow(FloatSize(width, height), blur, colorWithOverrideAlpha(rgba, alpha));
}
void CanvasRenderingContext2D::setShadow(float width, float height, float blur, float grayLevel, float alpha)
{
setShadow(FloatSize(width, height), blur, makeRGBA32FromFloats(grayLevel, grayLevel, grayLevel, alpha));
}
void CanvasRenderingContext2D::setShadow(float width, float height, float blur, float r, float g, float b, float a)
{
setShadow(FloatSize(width, height), blur, makeRGBA32FromFloats(r, g, b, a));
}
void CanvasRenderingContext2D::setShadow(float width, float height, float blur, float c, float m, float y, float k, float a)
{
setShadow(FloatSize(width, height), blur, makeRGBAFromCMYKA(c, m, y, k, a));
}
void CanvasRenderingContext2D::clearShadow()
{
setShadow(FloatSize(), 0, Color::transparent);
}
void CanvasRenderingContext2D::setShadow(const FloatSize& offset, float blur, RGBA32 color)
{
if (state().m_shadowOffset == offset && state().m_shadowBlur == blur && state().m_shadowColor == color)
return;
bool wasDrawingShadows = shouldDrawShadows();
realizeSaves();
modifiableState().m_shadowOffset = offset;
modifiableState().m_shadowBlur = blur;
modifiableState().m_shadowColor = color;
if (!wasDrawingShadows && !shouldDrawShadows())
return;
applyShadow();
}
void CanvasRenderingContext2D::applyShadow()
{
GraphicsContext* c = drawingContext();
if (!c)
return;
if (shouldDrawShadows()) {
c->setShadow(state().m_shadowOffset, state().m_shadowBlur, state().m_shadowColor,
DrawLooperBuilder::ShadowIgnoresTransforms);
} else {
c->clearShadow();
}
}
bool CanvasRenderingContext2D::shouldDrawShadows() const
{
return alphaChannel(state().m_shadowColor) && (state().m_shadowBlur || !state().m_shadowOffset.isZero());
}
static inline FloatRect normalizeRect(const FloatRect& rect)
{
return FloatRect(std::min(rect.x(), rect.maxX()),
std::min(rect.y(), rect.maxY()),
std::max(rect.width(), -rect.width()),
std::max(rect.height(), -rect.height()));
}
static inline void clipRectsToImageRect(const FloatRect& imageRect, FloatRect* srcRect, FloatRect* dstRect)
{
if (imageRect.contains(*srcRect))
return;
// Compute the src to dst transform
FloatSize scale(dstRect->size().width() / srcRect->size().width(), dstRect->size().height() / srcRect->size().height());
FloatPoint scaledSrcLocation = srcRect->location();
scaledSrcLocation.scale(scale.width(), scale.height());
FloatSize offset = dstRect->location() - scaledSrcLocation;
srcRect->intersect(imageRect);
// To clip the destination rectangle in the same proportion, transform the clipped src rect
*dstRect = *srcRect;
dstRect->scale(scale.width(), scale.height());
dstRect->move(offset);
}
void CanvasRenderingContext2D::drawImage(CanvasImageSource* imageSource, float x, float y, ExceptionState& exceptionState)
{
FloatSize destRectSize = imageSource->defaultDestinationSize();
drawImage(imageSource, x, y, destRectSize.width(), destRectSize.height(), exceptionState);
}
void CanvasRenderingContext2D::drawImage(CanvasImageSource* imageSource,
float x, float y, float width, float height, ExceptionState& exceptionState)
{
FloatSize sourceRectSize = imageSource->sourceSize();
drawImage(imageSource, 0, 0, sourceRectSize.width(), sourceRectSize.height(), x, y, width, height, exceptionState);
}
void CanvasRenderingContext2D::drawImage(CanvasImageSource* imageSource,
float sx, float sy, float sw, float sh,
float dx, float dy, float dw, float dh, ExceptionState& exceptionState)
{
GraphicsContext* c = drawingContext(); // Do not exit yet if !c because we may need to throw exceptions first
CompositeOperator op = c ? c->compositeOperation() : CompositeSourceOver;
blink::WebBlendMode blendMode = c ? c->blendModeOperation() : blink::WebBlendModeNormal;
drawImageInternal(imageSource, sx, sy, sw, sh, dx, dy, dw, dh, exceptionState, op, blendMode);
}
void CanvasRenderingContext2D::drawImageInternal(CanvasImageSource* imageSource,
float sx, float sy, float sw, float sh,
float dx, float dy, float dw, float dh, ExceptionState& exceptionState,
CompositeOperator op, blink::WebBlendMode blendMode)
{
RefPtr<Image> image;
SourceImageStatus sourceImageStatus;
if (!imageSource->isVideoElement()) {
SourceImageMode mode = canvas() == imageSource ? CopySourceImageIfVolatile : DontCopySourceImage; // Thunking for ==
image = imageSource->getSourceImageForCanvas(mode, &sourceImageStatus);
if (sourceImageStatus == UndecodableSourceImageStatus)
exceptionState.throwDOMException(InvalidStateError, "The HTMLImageElement provided is in the 'broken' state.");
if (!image || !image->width() || !image->height())
return;
}
GraphicsContext* c = drawingContext();
if (!c)
return;
if (!state().m_invertibleCTM)
return;
if (!std::isfinite(dx) || !std::isfinite(dy) || !std::isfinite(dw) || !std::isfinite(dh)
|| !std::isfinite(sx) || !std::isfinite(sy) || !std::isfinite(sw) || !std::isfinite(sh)
|| !dw || !dh || !sw || !sh)
return;
FloatRect clipBounds;
if (!c->getTransformedClipBounds(&clipBounds))
return;
FloatRect srcRect = normalizeRect(FloatRect(sx, sy, sw, sh));
FloatRect dstRect = normalizeRect(FloatRect(dx, dy, dw, dh));
clipRectsToImageRect(FloatRect(FloatPoint(), imageSource->sourceSize()), &srcRect, &dstRect);
imageSource->adjustDrawRects(&srcRect, &dstRect);
if (srcRect.isEmpty())
return;
FloatRect dirtyRect = clipBounds;
if (imageSource->isVideoElement()) {
drawVideo(static_cast<HTMLVideoElement*>(imageSource), srcRect, dstRect);
computeDirtyRect(dstRect, clipBounds, &dirtyRect);
} else {
if (rectContainsTransformedRect(dstRect, clipBounds)) {
c->drawImage(image.get(), dstRect, srcRect, op, blendMode);
} else if (isFullCanvasCompositeMode(op)) {
fullCanvasCompositedDrawImage(image.get(), dstRect, srcRect, op);
} else if (op == CompositeCopy) {
clearCanvas();
c->drawImage(image.get(), dstRect, srcRect, op, blendMode);
} else {
FloatRect dirtyRect;
computeDirtyRect(dstRect, clipBounds, &dirtyRect);
c->drawImage(image.get(), dstRect, srcRect, op, blendMode);
}
if (sourceImageStatus == ExternalSourceImageStatus && isAccelerated() && canvas()->buffer())
canvas()->buffer()->flush();
}
if (canvas()->originClean() && wouldTaintOrigin(imageSource))
canvas()->setOriginTainted();
didDraw(dirtyRect);
}
void CanvasRenderingContext2D::drawVideo(HTMLVideoElement* video, FloatRect srcRect, FloatRect dstRect)
{
GraphicsContext* c = drawingContext();
GraphicsContextStateSaver stateSaver(*c);
c->clip(dstRect);
c->translate(dstRect.x(), dstRect.y());
c->scale(dstRect.width() / srcRect.width(), dstRect.height() / srcRect.height());
c->translate(-srcRect.x(), -srcRect.y());
video->paintCurrentFrameInContext(c, IntRect(IntPoint(), IntSize(video->videoWidth(), video->videoHeight())));
stateSaver.restore();
validateStateStack();
}
void CanvasRenderingContext2D::drawImageFromRect(HTMLImageElement* image,
float sx, float sy, float sw, float sh,
float dx, float dy, float dw, float dh,
const String& compositeOperation)
{
if (!image)
return;
CompositeOperator op;
blink::WebBlendMode blendOp = blink::WebBlendModeNormal;
if (!parseCompositeAndBlendOperator(compositeOperation, op, blendOp) || blendOp != blink::WebBlendModeNormal)
op = CompositeSourceOver;
drawImageInternal(image, sx, sy, sw, sh, dx, dy, dw, dh, IGNORE_EXCEPTION, op, blendOp);
}
void CanvasRenderingContext2D::setAlpha(float alpha)
{
setGlobalAlpha(alpha);
}
void CanvasRenderingContext2D::setCompositeOperation(const String& operation)
{
setGlobalCompositeOperation(operation);
}
void CanvasRenderingContext2D::clearCanvas()
{
FloatRect canvasRect(0, 0, canvas()->width(), canvas()->height());
GraphicsContext* c = drawingContext();
if (!c)
return;
c->save();
c->setCTM(canvas()->baseTransform());
c->clearRect(canvasRect);
c->restore();
}
bool CanvasRenderingContext2D::rectContainsTransformedRect(const FloatRect& rect, const FloatRect& transformedRect) const
{
FloatQuad quad(rect);
FloatQuad transformedQuad(transformedRect);
return state().m_transform.mapQuad(quad).containsQuad(transformedQuad);
}
static void drawImageToContext(Image* image, GraphicsContext* context, const FloatRect& dest, const FloatRect& src, CompositeOperator op)
{
context->drawImage(image, dest, src, op);
}
template<class T> void CanvasRenderingContext2D::fullCanvasCompositedDrawImage(T* image, const FloatRect& dest, const FloatRect& src, CompositeOperator op)
{
ASSERT(isFullCanvasCompositeMode(op));
GraphicsContext* c = drawingContext();
c->beginLayer(1, op);
drawImageToContext(image, c, dest, src, CompositeSourceOver);
c->endLayer();
}
static void fillPrimitive(const FloatRect& rect, GraphicsContext* context)
{
context->fillRect(rect);
}
static void fillPrimitive(const Path& path, GraphicsContext* context)
{
context->fillPath(path);
}
template<class T> void CanvasRenderingContext2D::fullCanvasCompositedFill(const T& area)
{
ASSERT(isFullCanvasCompositeMode(state().m_globalComposite));
GraphicsContext* c = drawingContext();
ASSERT(c);
c->beginLayer(1, state().m_globalComposite);
CompositeOperator previousOperator = c->compositeOperation();
c->setCompositeOperation(CompositeSourceOver);
fillPrimitive(area, c);
c->setCompositeOperation(previousOperator);
c->endLayer();
}
static void strokePrimitive(const FloatRect& rect, GraphicsContext* context)
{
context->strokeRect(rect);
}
static void strokePrimitive(const Path& path, GraphicsContext* context)
{
context->strokePath(path);
}
template<class T> void CanvasRenderingContext2D::fullCanvasCompositedStroke(const T& area)
{
ASSERT(isFullCanvasCompositeMode(state().m_globalComposite));
GraphicsContext* c = drawingContext();
ASSERT(c);
c->beginLayer(1, state().m_globalComposite);
CompositeOperator previousOperator = c->compositeOperation();
c->setCompositeOperation(CompositeSourceOver);
strokePrimitive(area, c);
c->setCompositeOperation(previousOperator);
c->endLayer();
}
PassRefPtr<CanvasGradient> CanvasRenderingContext2D::createLinearGradient(float x0, float y0, float x1, float y1)
{
RefPtr<CanvasGradient> gradient = CanvasGradient::create(FloatPoint(x0, y0), FloatPoint(x1, y1));
return gradient.release();
}
PassRefPtr<CanvasGradient> CanvasRenderingContext2D::createRadialGradient(float x0, float y0, float r0, float x1, float y1, float r1, ExceptionState& exceptionState)
{
if (r0 < 0 || r1 < 0) {
exceptionState.throwDOMException(IndexSizeError, String::format("The %s provided is less than 0.", r0 < 0 ? "r0" : "r1"));
return nullptr;
}
RefPtr<CanvasGradient> gradient = CanvasGradient::create(FloatPoint(x0, y0), r0, FloatPoint(x1, y1), r1);
return gradient.release();
}
PassRefPtr<CanvasPattern> CanvasRenderingContext2D::createPattern(CanvasImageSource* imageSource,
const String& repetitionType, ExceptionState& exceptionState)
{
bool repeatX, repeatY;
CanvasPattern::parseRepetitionType(repetitionType, repeatX, repeatY, exceptionState);
if (exceptionState.hadException())
return nullptr;
SourceImageStatus status;
RefPtr<Image> imageForRendering = imageSource->getSourceImageForCanvas(CopySourceImageIfVolatile, &status);
switch (status) {
case NormalSourceImageStatus:
break;
case ZeroSizeCanvasSourceImageStatus:
exceptionState.throwDOMException(InvalidStateError, String::format("The canvas %s is 0.", imageSource->sourceSize().width() ? "height" : "width"));
return nullptr;
case UndecodableSourceImageStatus:
exceptionState.throwDOMException(InvalidStateError, "Source image is in the 'broken' state.");
return nullptr;
case InvalidSourceImageStatus:
imageForRendering = Image::nullImage();
break;
case IncompleteSourceImageStatus:
return nullptr;
default:
case ExternalSourceImageStatus: // should not happen when mode is CopySourceImageIfVolatile
ASSERT_NOT_REACHED();
return nullptr;
}
ASSERT(imageForRendering);
bool originClean = !wouldTaintOrigin(imageSource);
return CanvasPattern::create(imageForRendering.release(), repeatX, repeatY, originClean);
}
bool CanvasRenderingContext2D::computeDirtyRect(const FloatRect& localRect, FloatRect* dirtyRect)
{
FloatRect clipBounds;
if (!drawingContext()->getTransformedClipBounds(&clipBounds))
return false;
return computeDirtyRect(localRect, clipBounds, dirtyRect);
}
bool CanvasRenderingContext2D::computeDirtyRect(const FloatRect& localRect, const FloatRect& transformedClipBounds, FloatRect* dirtyRect)
{
FloatRect canvasRect = state().m_transform.mapRect(localRect);
if (alphaChannel(state().m_shadowColor)) {
FloatRect shadowRect(canvasRect);
shadowRect.move(state().m_shadowOffset);
shadowRect.inflate(state().m_shadowBlur);
canvasRect.unite(shadowRect);
}
canvasRect.intersect(transformedClipBounds);
if (canvasRect.isEmpty())
return false;
if (dirtyRect)
*dirtyRect = canvasRect;
return true;
}
void CanvasRenderingContext2D::didDraw(const FloatRect& dirtyRect)
{
if (dirtyRect.isEmpty())
return;
// If we are drawing to hardware and we have a composited layer, just call contentChanged().
if (isAccelerated()) {
RenderBox* renderBox = canvas()->renderBox();
if (renderBox && renderBox->hasAcceleratedCompositing()) {
renderBox->contentChanged(CanvasPixelsChanged);
canvas()->clearCopiedImage();
canvas()->notifyObserversCanvasChanged(dirtyRect);
return;
}
}
canvas()->didDraw(dirtyRect);
}
GraphicsContext* CanvasRenderingContext2D::drawingContext() const
{
if (isContextLost())
return 0;
return canvas()->drawingContext();
}
static PassRefPtrWillBeRawPtr<ImageData> createEmptyImageData(const IntSize& size)
{
if (RefPtrWillBeRawPtr<ImageData> data = ImageData::create(size)) {
data->data()->zeroFill();
return data.release();
}
return nullptr;
}
PassRefPtrWillBeRawPtr<ImageData> CanvasRenderingContext2D::createImageData(PassRefPtrWillBeRawPtr<ImageData> imageData) const
{
return createEmptyImageData(imageData->size());
}
PassRefPtrWillBeRawPtr<ImageData> CanvasRenderingContext2D::createImageData(float sw, float sh, ExceptionState& exceptionState) const
{
if (!sw || !sh) {
exceptionState.throwDOMException(IndexSizeError, String::format("The source %s is 0.", sw ? "height" : "width"));
return nullptr;
}
FloatSize logicalSize(fabs(sw), fabs(sh));
if (!logicalSize.isExpressibleAsIntSize())
return nullptr;
IntSize size = expandedIntSize(logicalSize);
if (size.width() < 1)
size.setWidth(1);
if (size.height() < 1)
size.setHeight(1);
return createEmptyImageData(size);
}
PassRefPtrWillBeRawPtr<ImageData> CanvasRenderingContext2D::getImageData(float sx, float sy, float sw, float sh, ExceptionState& exceptionState) const
{
if (!canvas()->originClean())
exceptionState.throwSecurityError("The canvas has been tainted by cross-origin data.");
else if (!sw || !sh)
exceptionState.throwDOMException(IndexSizeError, String::format("The source %s is 0.", sw ? "height" : "width"));
if (exceptionState.hadException())
return nullptr;
if (sw < 0) {
sx += sw;
sw = -sw;
}
if (sh < 0) {
sy += sh;
sh = -sh;
}
FloatRect logicalRect(sx, sy, sw, sh);
if (logicalRect.width() < 1)
logicalRect.setWidth(1);
if (logicalRect.height() < 1)
logicalRect.setHeight(1);
if (!logicalRect.isExpressibleAsIntRect())
return nullptr;
IntRect imageDataRect = enclosingIntRect(logicalRect);
ImageBuffer* buffer = canvas()->buffer();
if (!buffer || isContextLost())
return createEmptyImageData(imageDataRect.size());
RefPtr<Uint8ClampedArray> byteArray = buffer->getUnmultipliedImageData(imageDataRect);
if (!byteArray)
return nullptr;
return ImageData::create(imageDataRect.size(), byteArray.release());
}
void CanvasRenderingContext2D::putImageData(ImageData* data, float dx, float dy)
{
putImageData(data, dx, dy, 0, 0, data->width(), data->height());
}
void CanvasRenderingContext2D::putImageData(ImageData* data, float dx, float dy, float dirtyX, float dirtyY, float dirtyWidth, float dirtyHeight)
{
ImageBuffer* buffer = canvas()->buffer();
if (!buffer)
return;
if (dirtyWidth < 0) {
dirtyX += dirtyWidth;
dirtyWidth = -dirtyWidth;
}
if (dirtyHeight < 0) {
dirtyY += dirtyHeight;
dirtyHeight = -dirtyHeight;
}
FloatRect clipRect(dirtyX, dirtyY, dirtyWidth, dirtyHeight);
clipRect.intersect(IntRect(0, 0, data->width(), data->height()));
IntSize destOffset(static_cast<int>(dx), static_cast<int>(dy));
IntRect destRect = enclosingIntRect(clipRect);
destRect.move(destOffset);
destRect.intersect(IntRect(IntPoint(), buffer->size()));
if (destRect.isEmpty())
return;
IntRect sourceRect(destRect);
sourceRect.move(-destOffset);
buffer->putByteArray(Unmultiplied, data->data(), IntSize(data->width(), data->height()), sourceRect, IntPoint(destOffset));
didDraw(destRect);
}
String CanvasRenderingContext2D::font() const
{
if (!state().m_realizedFont)
return defaultFont;
StringBuilder serializedFont;
const FontDescription& fontDescription = state().m_font.fontDescription();
if (fontDescription.style() == FontStyleItalic)
serializedFont.appendLiteral("italic ");
if (fontDescription.weight() == FontWeightBold)
serializedFont.appendLiteral("bold ");
if (fontDescription.variant() == FontVariantSmallCaps)
serializedFont.appendLiteral("small-caps ");
serializedFont.appendNumber(fontDescription.computedPixelSize());
serializedFont.appendLiteral("px");
const FontFamily& firstFontFamily = fontDescription.family();
for (const FontFamily* fontFamily = &firstFontFamily; fontFamily; fontFamily = fontFamily->next()) {
if (fontFamily != &firstFontFamily)
serializedFont.append(',');
// FIXME: We should append family directly to serializedFont rather than building a temporary string.
String family = fontFamily->family();
if (family.startsWith("-webkit-"))
family = family.substring(8);
if (family.contains(' '))
family = "\"" + family + "\"";
serializedFont.append(' ');
serializedFont.append(family);
}
return serializedFont.toString();
}
void CanvasRenderingContext2D::setFont(const String& newFont)
{
// The style resolution required for rendering text is not available in frame-less documents.
if (!canvas()->document().frame())
return;
MutableStylePropertyMap::iterator i = m_fetchedFonts.find(newFont);
RefPtrWillBeRawPtr<MutableStylePropertySet> parsedStyle = i != m_fetchedFonts.end() ? i->value : nullptr;
if (!parsedStyle) {
parsedStyle = MutableStylePropertySet::create();
CSSParserMode mode = m_usesCSSCompatibilityParseMode ? HTMLQuirksMode : HTMLStandardMode;
BisonCSSParser::parseValue(parsedStyle.get(), CSSPropertyFont, newFont, true, mode, 0);
m_fetchedFonts.add(newFont, parsedStyle);
}
if (parsedStyle->isEmpty())
return;
String fontValue = parsedStyle->getPropertyValue(CSSPropertyFont);
// According to http://lists.w3.org/Archives/Public/public-html/2009Jul/0947.html,
// the "inherit" and "initial" values must be ignored.
if (fontValue == "inherit" || fontValue == "initial")
return;
// The parse succeeded.
String newFontSafeCopy(newFont); // Create a string copy since newFont can be deleted inside realizeSaves.
realizeSaves();
modifiableState().m_unparsedFont = newFontSafeCopy;
// Map the <canvas> font into the text style. If the font uses keywords like larger/smaller, these will work
// relative to the canvas.
RefPtr<RenderStyle> newStyle = RenderStyle::create();
if (RenderStyle* computedStyle = canvas()->computedStyle()) {
FontDescription elementFontDescription(computedStyle->fontDescription());
// Reset the computed size to avoid inheriting the zoom factor from the <canvas> element.
elementFontDescription.setComputedSize(elementFontDescription.specifiedSize());
newStyle->setFontDescription(elementFontDescription);
} else {
FontFamily fontFamily;
fontFamily.setFamily(defaultFontFamily);
FontDescription defaultFontDescription;
defaultFontDescription.setFamily(fontFamily);
defaultFontDescription.setSpecifiedSize(defaultFontSize);
defaultFontDescription.setComputedSize(defaultFontSize);
newStyle->setFontDescription(defaultFontDescription);
}
newStyle->font().update(newStyle->font().fontSelector());
// Now map the font property longhands into the style.
CSSPropertyValue properties[] = {
CSSPropertyValue(CSSPropertyFontFamily, *parsedStyle),
CSSPropertyValue(CSSPropertyFontStyle, *parsedStyle),
CSSPropertyValue(CSSPropertyFontVariant, *parsedStyle),
CSSPropertyValue(CSSPropertyFontWeight, *parsedStyle),
CSSPropertyValue(CSSPropertyFontSize, *parsedStyle),
CSSPropertyValue(CSSPropertyLineHeight, *parsedStyle),
};
StyleResolver& styleResolver = canvas()->document().ensureStyleResolver();
styleResolver.applyPropertiesToStyle(properties, WTF_ARRAY_LENGTH(properties), newStyle.get());
#if !ENABLE(OILPAN)
if (state().m_realizedFont)
static_cast<CSSFontSelector*>(state().m_font.fontSelector())->unregisterForInvalidationCallbacks(&modifiableState());
#endif
modifiableState().m_font = newStyle->font();
modifiableState().m_font.update(canvas()->document().styleEngine()->fontSelector());
modifiableState().m_realizedFont = true;
canvas()->document().styleEngine()->fontSelector()->registerForInvalidationCallbacks(&modifiableState());
}
String CanvasRenderingContext2D::textAlign() const
{
return textAlignName(state().m_textAlign);
}
void CanvasRenderingContext2D::setTextAlign(const String& s)
{
TextAlign align;
if (!parseTextAlign(s, align))
return;
if (state().m_textAlign == align)
return;
realizeSaves();
modifiableState().m_textAlign = align;
}
String CanvasRenderingContext2D::textBaseline() const
{
return textBaselineName(state().m_textBaseline);
}
void CanvasRenderingContext2D::setTextBaseline(const String& s)
{
TextBaseline baseline;
if (!parseTextBaseline(s, baseline))
return;
if (state().m_textBaseline == baseline)
return;
realizeSaves();
modifiableState().m_textBaseline = baseline;
}
void CanvasRenderingContext2D::fillText(const String& text, float x, float y)
{
drawTextInternal(text, x, y, true);
}
void CanvasRenderingContext2D::fillText(const String& text, float x, float y, float maxWidth)
{
drawTextInternal(text, x, y, true, maxWidth, true);
}
void CanvasRenderingContext2D::strokeText(const String& text, float x, float y)
{
drawTextInternal(text, x, y, false);
}
void CanvasRenderingContext2D::strokeText(const String& text, float x, float y, float maxWidth)
{
drawTextInternal(text, x, y, false, maxWidth, true);
}
static inline bool isSpaceCharacter(UChar c)
{
// According to specification all space characters should be replaced with 0x0020 space character.
// http://www.whatwg.org/specs/web-apps/current-work/multipage/the-canvas-element.html#text-preparation-algorithm
// The space characters according to specification are : U+0020, U+0009, U+000A, U+000C, and U+000D.
// http://www.whatwg.org/specs/web-apps/current-work/multipage/common-microsyntaxes.html#space-character
// This function returns true for 0x000B also, so that this is backward compatible.
// Otherwise, the test LayoutTests/canvas/philip/tests/2d.text.draw.space.collapse.space.html will fail
return c == 0x0009 || c == 0x000A || c == 0x000B || c == 0x000C || c == 0x000D;
}
static String normalizeSpaces(const String& text)
{
unsigned textLength = text.length();
Vector<UChar> charVector(textLength);
for (unsigned i = 0; i < textLength; i++) {
if (isSpaceCharacter(text[i]))
charVector[i] = ' ';
else
charVector[i] = text[i];
}
return String(charVector);
}
PassRefPtr<TextMetrics> CanvasRenderingContext2D::measureText(const String& text)
{
RefPtr<TextMetrics> metrics = TextMetrics::create();
// The style resolution required for rendering text is not available in frame-less documents.
if (!canvas()->document().frame())
return metrics.release();
FontCachePurgePreventer fontCachePurgePreventer;
canvas()->document().updateRenderTreeIfNeeded();
const Font& font = accessFont();
String normalizedText = normalizeSpaces(text);
const TextRun textRun(normalizedText);
FloatRect textBounds = font.selectionRectForText(textRun, FloatPoint(), font.fontDescription().computedSize(), 0, -1, true);
// x direction
metrics->setWidth(font.width(textRun));
metrics->setActualBoundingBoxLeft(-textBounds.x());
metrics->setActualBoundingBoxRight(textBounds.maxX());
// y direction
const FontMetrics& fontMetrics = font.fontMetrics();
const float ascent = fontMetrics.floatAscent();
const float descent = fontMetrics.floatDescent();
const float baselineY = getFontBaseline(fontMetrics);
metrics->setFontBoundingBoxAscent(ascent - baselineY);
metrics->setFontBoundingBoxDescent(descent + baselineY);
metrics->setActualBoundingBoxAscent(-textBounds.y() - baselineY);
metrics->setActualBoundingBoxDescent(textBounds.maxY() + baselineY);
// Note : top/bottom and ascend/descend are currently the same, so there's no difference
// between the EM box's top and bottom and the font's ascend and descend
metrics->setEmHeightAscent(0);
metrics->setEmHeightDescent(0);
metrics->setHangingBaseline(-0.8f * ascent + baselineY);
metrics->setAlphabeticBaseline(baselineY);
metrics->setIdeographicBaseline(descent + baselineY);
return metrics.release();
}
void CanvasRenderingContext2D::drawTextInternal(const String& text, float x, float y, bool fill, float maxWidth, bool useMaxWidth)
{
// The style resolution required for rendering text is not available in frame-less documents.
if (!canvas()->document().frame())
return;
// accessFont needs the style to be up to date, but updating style can cause script to run,
// (e.g. due to autofocus) which can free the GraphicsContext, so update style before grabbing
// the GraphicsContext.
canvas()->document().updateRenderTreeIfNeeded();
GraphicsContext* c = drawingContext();
if (!c)
return;
if (!state().m_invertibleCTM)
return;
if (!std::isfinite(x) | !std::isfinite(y))
return;
if (useMaxWidth && (!std::isfinite(maxWidth) || maxWidth <= 0))
return;
// If gradient size is zero, then paint nothing.
Gradient* gradient = c->strokeGradient();
if (!fill && gradient && gradient->isZeroSize())
return;
gradient = c->fillGradient();
if (fill && gradient && gradient->isZeroSize())
return;
FontCachePurgePreventer fontCachePurgePreventer;
const Font& font = accessFont();
const FontMetrics& fontMetrics = font.fontMetrics();
String normalizedText = normalizeSpaces(text);
// FIXME: Need to turn off font smoothing.
RenderStyle* computedStyle = canvas()->computedStyle();
TextDirection direction = computedStyle ? computedStyle->direction() : LTR;
bool isRTL = direction == RTL;
bool override = computedStyle ? isOverride(computedStyle->unicodeBidi()) : false;
TextRun textRun(normalizedText, 0, 0, TextRun::AllowTrailingExpansion, direction, override, true, TextRun::NoRounding);
// Draw the item text at the correct point.
FloatPoint location(x, y + getFontBaseline(fontMetrics));
float fontWidth = font.width(TextRun(normalizedText, 0, 0, TextRun::AllowTrailingExpansion, direction, override));
useMaxWidth = (useMaxWidth && maxWidth < fontWidth);
float width = useMaxWidth ? maxWidth : fontWidth;
TextAlign align = state().m_textAlign;
if (align == StartTextAlign)
align = isRTL ? RightTextAlign : LeftTextAlign;
else if (align == EndTextAlign)
align = isRTL ? LeftTextAlign : RightTextAlign;
switch (align) {
case CenterTextAlign:
location.setX(location.x() - width / 2);
break;
case RightTextAlign:
location.setX(location.x() - width);
break;
default:
break;
}
// The slop built in to this mask rect matches the heuristic used in FontCGWin.cpp for GDI text.
TextRunPaintInfo textRunPaintInfo(textRun);
textRunPaintInfo.bounds = FloatRect(location.x() - fontMetrics.height() / 2,
location.y() - fontMetrics.ascent() - fontMetrics.lineGap(),
width + fontMetrics.height(),
fontMetrics.lineSpacing());
if (!fill)
inflateStrokeRect(textRunPaintInfo.bounds);
c->setTextDrawingMode(fill ? TextModeFill : TextModeStroke);
GraphicsContextStateSaver stateSaver(*c);
if (useMaxWidth) {
c->translate(location.x(), location.y());
// We draw when fontWidth is 0 so compositing operations (eg, a "copy" op) still work.
c->scale((fontWidth > 0 ? (width / fontWidth) : 0), 1);
location = FloatPoint();
}
FloatRect clipBounds;
if (!c->getTransformedClipBounds(&clipBounds)) {
return;
}
if (isFullCanvasCompositeMode(state().m_globalComposite)) {
c->beginLayer(1, state().m_globalComposite);
CompositeOperator previousOperator = c->compositeOperation();
c->setCompositeOperation(CompositeSourceOver);
c->drawBidiText(font, textRunPaintInfo, location, Font::UseFallbackIfFontNotReady);
c->setCompositeOperation(previousOperator);
c->endLayer();
didDraw(clipBounds);
} else if (state().m_globalComposite == CompositeCopy) {
clearCanvas();
c->drawBidiText(font, textRunPaintInfo, location, Font::UseFallbackIfFontNotReady);
didDraw(clipBounds);
} else {
FloatRect dirtyRect;
if (computeDirtyRect(textRunPaintInfo.bounds, clipBounds, &dirtyRect)) {
c->drawBidiText(font, textRunPaintInfo, location, Font::UseFallbackIfFontNotReady);
didDraw(dirtyRect);
}
}
}
void CanvasRenderingContext2D::inflateStrokeRect(FloatRect& rect) const
{
// Fast approximation of the stroke's bounding rect.
// This yields a slightly oversized rect but is very fast
// compared to Path::strokeBoundingRect().
static const float root2 = sqrtf(2);
float delta = state().m_lineWidth / 2;
if (state().m_lineJoin == MiterJoin)
delta *= state().m_miterLimit;
else if (state().m_lineCap == SquareCap)
delta *= root2;
rect.inflate(delta);
}
const Font& CanvasRenderingContext2D::accessFont()
{
// This needs style to be up to date, but can't assert so because drawTextInternal
// can invalidate style before this is called (e.g. drawingContext invalidates style).
if (!state().m_realizedFont)
setFont(state().m_unparsedFont);
return state().m_font;
}
int CanvasRenderingContext2D::getFontBaseline(const FontMetrics& fontMetrics) const
{
switch (state().m_textBaseline) {
case TopTextBaseline:
return fontMetrics.ascent();
case HangingTextBaseline:
// According to http://wiki.apache.org/xmlgraphics-fop/LineLayout/AlignmentHandling
// "FOP (Formatting Objects Processor) puts the hanging baseline at 80% of the ascender height"
return (fontMetrics.ascent() * 4) / 5;
case BottomTextBaseline:
case IdeographicTextBaseline:
return -fontMetrics.descent();
case MiddleTextBaseline:
return -fontMetrics.descent() + fontMetrics.height() / 2;
case AlphabeticTextBaseline:
default:
// Do nothing.
break;
}
return 0;
}
blink::WebLayer* CanvasRenderingContext2D::platformLayer() const
{
return canvas()->buffer() ? canvas()->buffer()->platformLayer() : 0;
}
bool CanvasRenderingContext2D::imageSmoothingEnabled() const
{
return state().m_imageSmoothingEnabled;
}
void CanvasRenderingContext2D::setImageSmoothingEnabled(bool enabled)
{
if (enabled == state().m_imageSmoothingEnabled)
return;
realizeSaves();
modifiableState().m_imageSmoothingEnabled = enabled;
GraphicsContext* c = drawingContext();
if (c)
c->setImageInterpolationQuality(enabled ? CanvasDefaultInterpolationQuality : InterpolationNone);
}
PassRefPtr<Canvas2DContextAttributes> CanvasRenderingContext2D::getContextAttributes() const
{
RefPtr<Canvas2DContextAttributes> attributes = Canvas2DContextAttributes::create();
attributes->setAlpha(m_hasAlpha);
return attributes.release();
}
void CanvasRenderingContext2D::drawFocusIfNeeded(Element* element)
{
drawFocusIfNeededInternal(m_path, element);
}
void CanvasRenderingContext2D::drawFocusIfNeeded(Path2D* path2d, Element* element)
{
drawFocusIfNeededInternal(path2d->path(), element);
}
void CanvasRenderingContext2D::drawFocusIfNeededInternal(const Path& path, Element* element)
{
if (!focusRingCallIsValid(path, element))
return;
// Note: we need to check document->focusedElement() rather than just calling
// element->focused(), because element->focused() isn't updated until after
// focus events fire.
if (element->document().focusedElement() == element)
drawFocusRing(path);
}
bool CanvasRenderingContext2D::focusRingCallIsValid(const Path& path, Element* element)
{
ASSERT(element);
if (!state().m_invertibleCTM)
return false;
if (path.isEmpty())
return false;
if (!element->isDescendantOf(canvas()))
return false;
return true;
}
void CanvasRenderingContext2D::drawFocusRing(const Path& path)
{
GraphicsContext* c = drawingContext();
if (!c)
return;
// These should match the style defined in html.css.
Color focusRingColor = RenderTheme::theme().focusRingColor();
const int focusRingWidth = 5;
const int focusRingOutline = 0;
// We need to add focusRingWidth to dirtyRect.
StrokeData strokeData;
strokeData.setThickness(focusRingWidth);
FloatRect dirtyRect;
if (!computeDirtyRect(path.strokeBoundingRect(strokeData), &dirtyRect))
return;
c->save();
c->setAlphaAsFloat(1.0);
c->clearShadow();
c->setCompositeOperation(CompositeSourceOver, blink::WebBlendModeNormal);
c->drawFocusRing(path, focusRingWidth, focusRingOutline, focusRingColor);
c->restore();
validateStateStack();
didDraw(dirtyRect);
}
} // namespace WebCore